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Drag Racing Discussions => Front Engine Dragsters => Topic started by: lake_harley on December 23, 2019, 03:57:52 PM

Title: Potential FED Build
Post by: lake_harley on December 23, 2019, 03:57:52 PM
My first post here on the FED forum will serve 2 purposes.....

First, a brief intro. I'm 67 years young and have been around cars and motorcycles most of my adult life. I did a little bit of drag racing when I was in my late teens, got more interested in hot rods and a few British sports cars, eventually came back to dirt circle track racing with a street stock and a UMP modified, and have recently been smitten with hot rods again; specifically a T roadster and a '31 Model A coupe. But....there's been a hankering in the back of my mind for a FED ever since I bought my first Hot Rod magazine at age 12 in 1964 that had a very in-depth article on Don Gartlit's dragster. All of that brings me to today....considering ground-up building a mild (short by today's standards) FED for bracket racing at a local 1/8th mile track.

So, with that, the second part is asking some questions that I have in my mind going into a possible build.

I'm currently thinking a car with a 125" to 132" wheelbase to mimic the look of what a lower class dragster would have been when I was in my teens in the 60's and into the early 70's. I currently have a mild 350 SBC as well as a mild 327 SBC in my shop. Either might be in the 275-300 HP range on a dyno....I'd hope. I also have two Powerglides, one from a running, driving car that was being resto-modded, and another as a core.

I'm torn between building with chrome moly tubing vs DOM. I'm a competent fabricator and welder, having had a steel fabrication business for about 15 years prior to "mostly" retiring. I know a chrome moly car will be about 50 to 60# lighter, but there's a trade off on cost (slight, really) and having to TIG everything. I do TIG weld, and pretty nicely if I say so myself.

Budget would be a consideration, not that I couldn't spend a fair amount on the car, but realistically it will probably only be raced 6-8 times a year at the local 1/8th mile track at Sikeston MO.

I've seen some discussion about solid mounted front axles vs torsion suspended front ends and wondered if it would be a HUGE mistake to keep the front end simple and just go solid?

I'd likely go with a 9" Ford, that I could narrow the housing and have axles re-splined, or I already have a couple 8" Fords that would likely be plenty strong for a 300 HP, light car. With the 8" Ford rearend, I'd have to buy short aftermarket axles, likely from Moser. Some reading I've done has talked about setting up a "tight" rearend by shimming the spiders really tight rather than using a posi or running a spool. Is that a viable option?

I'm also wondering about smaller things, one example for now.....foot brake the car or run a trans brake? Current thinking is foot brake would just keep the car a bit simpler.

I would likely buy the appropriate SFI construction guildlines that apply to FED's, and although my car wouldn't likely be fast enough (thinking maybe low to mid 7's in the 1/8 Mi.) to need to be certified I might choose to build per guidelines to make the car: A) safe, and B) more re-sellable someday after I've had some fun.

Quite honestly, I don't have strong desire to even drive the car, but always have taken pleasure from the build itself, and would enjoy just seeing the car compete. Heck, I built an airplane that a friend test-piloted a couple times but I've never flown it, and I'm happy enough that I reached my goal of building an airplane. ;D

So, I'll wrap it up at that for now. I'd appreciate input and opinions about some of the questions I have currently. I'm sure there will be more.

I appreciate being approved for the forum and look forward to being an active part of it.

Lynn
Title: Re: Potential FED Build
Post by: crider on December 23, 2019, 05:32:01 PM
Welcome aboard, these cars are a blast to drive. Here's my personal take on it, I would build the chassis from molly and to the sfi spec, just for the sake of being able to sell it later on down the road. If it were for sale the first question 90% of potential buys will ask is, is the chassis certified. It will be a hard sell for very little money if it won't pass. As for the rear end, I would stick with a 9" for several reasons, number one being parts availability. It's also easy to make the anti rotation mount and to mount up a cover for the trans coupler. As for the question of trans brake or not, in my area at least they don't allow center steer cars in the foot brake classes, so that is something to consider. I'm sure some guys with more knowledge than me will chime in soon. And most of all have fun and enjoy the build
Title: Re: Potential FED Build
Post by: lake_harley on December 23, 2019, 06:14:02 PM
Thanks, crider.  I openly admit to being out of touch, so thanks for the info on center steer cars (dragster?altered/funny car?) not being allowed to compete in foot brake classes. I take it that pretty much mandates a trans brake, or is a hand/handle operated brake allowed? I'm guessing not?

Lynn
Title: Re: Potential FED Build
Post by: jeff/21 on December 23, 2019, 07:42:52 PM
Hi!
I don' know if it's still the same but it use to be that dragsters with a 120"wheel base or less had to have suspension, ours 130" no suspension
i've found that short cars wide front axle makes car stable even on temp strips set-up at airports or streets
 9" ford all kinds of parts
powerglide use a input shaft made to use a turbo 350 torque greater choice used and off the shelf
build it to SFI specs

best of luck and Merry Christmas
Title: Re: Potential FED Build
Post by: THE FRENCHTOWN FLYER on December 24, 2019, 06:28:00 AM
My opinion:

132" or greater

327 for the purists. With the right converter you won't miss the extra 23 ci of a 350 and the 327 will rev higher.

4130 chassis to SFI cert specs.

I like torsion F.E. (The first time you stand it up in the air on the line you'll appreciate it.)

9" w/ spool

Hand AND foot brake levers. Foot allows 2 hands on the wheel; hand allows precision staging.

trans brake; you can always disconnect it.

I know I probably just added another grand or two to the build but it will be fun to drive, more competitive, and have a higher resale value so you will recoup some of the up-front investment.

Good luck and Merry Christmas.
Title: Re: Potential FED Build
Post by: denverflatheader on December 24, 2019, 08:37:34 AM
Lynn - maybe you already have them, if not, I would acquire the actual front and rear wheels and tires you plan to run.  It will help you setup your chassis clearances exactly.  The 327 is one of my favorite engines of all times.  When placing the engine and pg, look at your oil pan ground clearance, it might end up below the lower chassis tubes.  The more clearance helps easier loading on trailer.  Alan
Title: Re: Potential FED Build
Post by: lake_harley on December 24, 2019, 09:40:20 AM
Frenchtown Flyer.....thanks for the recommendations. They all seem like sound ideas and good reason behind them. One exception I might make and that is a friend might have a 8 3/4" rearend for cheap, or even free. Says he has some taller gears too, maybe even something 5.00+ that would likely work out OK on the 1/8 Mi.. Free or cheap might be hard to pass up. If that falls through though, I'd definitely plan on a 9" Ford.

denverflatheader....Another good suggestion. I will definitely have wheels and tires that I want to use to properly space everything before narrowing a rearend housing and to determine chassis ride height.

Given the ~300-ish HP I expect to run, what size tire would be at least a good starting point? Something along the line of a 29-9 X 15 Hoosier on a 8" (or maybe 10") wheel even close to being able to hook up without dragging along a tire that's larger than needed for the HP?

Lynn
Title: Re: Potential FED Build
Post by: wideopen231 on December 24, 2019, 09:58:51 AM
My opinion and at 2 cent maybe over priced. molly chassis is pretty much no brainier. Lighter,stronger and will resale. As for wheel base i would build longest you can(shop and or trailer limits).Not saying you would need 200 plus but 175 or so might make for easier job getting tuned out. I know you said you figure 300 hp,but that always seems to grow. As for 327. Probably my favorite sbc,maybe heard 10,000 stories from dad about the ones he raced when I was born is part to blame.

Rearend hands down 9".Strong,easier to find parts and fairly cheap. Transmission definitely glide,agian tons of aftermarket stuff and at 300 hp it would be cheap build.


As for building.Souns like no problem for you.Heck I built mine from ground up and if I was better I would be half a__ fabricator. Jump in and enjoy.
Title: Re: Potential FED Build
Post by: THE FRENCHTOWN FLYER on December 24, 2019, 12:08:09 PM
One additional recommendation I learned from a pro builder vis-a-vis chassis setup. Use four inches for ground clearance, not the minimum allowed three inches. It won't mean doodily-squat in terms of performance but it will make loading / unloading from the trailer much easier.
Title: Re: Potential FED Build
Post by: lake_harley on December 24, 2019, 12:32:54 PM
4" ground clearance....check. Please don't let that be your last recommendation though. ;)

Lynn
Title: Re: Potential FED Build
Post by: wideopen231 on December 24, 2019, 03:06:21 PM
4" ground clearance....check. Please don't let that be your last recommendation though. ;)

Lynn
Agree .Ask How I know this?
Title: Re: Potential FED Build
Post by: crider on December 24, 2019, 03:39:03 PM
I agree, you'll be glad for any and all extra ground clearance you can get
Title: Re: Potential FED Build
Post by: denverflatheader on December 24, 2019, 04:22:36 PM
Here’s an excellent online racing calculator which helps decision making.  For tire diameter answer, you input proposed rear gear ratio, anticipated engine rpm and mph at stripe.  This calculator is user friendly and lightning fast with answers.

http://www.wallaceracing.com/Calculators.htm

I had a 1970s dragster with an 8-3/4 Mopar (489) rear with Mark Williams axles and spool and had no issues with it.  It would work fine for your project.
Title: Re: Potential FED Build
Post by: jeff/21 on December 24, 2019, 04:35:41 PM
we ran 10x30 on 10" rims  with sbc flat top pistons,  flat tappet cam, vortec heads 1 carb on gas hooked up really well.
free isn't always the best 8 3/4"are a fair rear end but are harder to get parts for and will take away from the resale value/ are you going to run drum or disc brakes we went cheap disc from a small ford truck
 chev impala calipers with circle track mounting brackets  heavy but they worked well after the first season things changed weight removal bigger motor bigger tires more upgrades in the trans alky injection more work but a faster car
plan around your budget and add 30% little things add-up
Title: Re: Potential FED Build
Post by: THE FRENCHTOWN FLYER on December 24, 2019, 06:14:40 PM
Please don't let that be your last recommendation though. ;)

Lynn
Getting back to the three inch ground clearance - dragsters and altereds are allowed to have body overhang of 30" ahead of the front axle.

Not in line with your vision of period correct? OK, but if you do it right that front nosepiece - or wing - or bumper - or whatever can be made to deflect downward so as to trip the finish line lights two feet ahead of the front tire, effectively making your lane 1318 feet, allowing your car to trip the clocks two feet before it arrives there.

Like my RPU
or altered
Title: Re: Potential FED Build
Post by: lake_harley on December 24, 2019, 07:14:24 PM
Here’s an excellent online racing calculator which helps decision making.  For tire diameter answer, you input proposed rear gear ratio, anticipated engine rpm and mph at stripe.  This calculator is user friendly and lightning fast with answers.

http://www.wallaceracing.com/Calculators.htm

I had a 1970s dragster with an 8-3/4 Mopar (489) rear with Mark Williams axles and spool and had no issues with it.  It would work fine for your project.

That calculator website is interesting. It might keep me entertained for days.  :D  I just hope it doesn't get my hopes up too much since my "theoretical" FED calculates as being quicker than I might hope.

Lynn
Title: Re: Potential FED Build
Post by: THE FRENCHTOWN FLYER on December 25, 2019, 06:02:24 AM
LOL slowing it down is a lot easier than speeding it up. And cheaper

I built my RPU with 2.47:1 Bonneville gears in the rear, with a 4.56 waiting in the wings. It never got changed to the 456s. Its fast enough. And with the 1-2 shift spaced way out I can dial that puppy within a gnatsass by altering my shift RPM.
Title: Re: Potential FED Build
Post by: Paul New on December 25, 2019, 06:30:03 PM
I agree with the 4” ground clearance!  My first dragster I built had the 3” minimum it was difficult.  Buy the SFI specs 2.6A is good to 7.50 and you can build with mild steel tubing 2.4C is 6.0-7.49.  Of you decide you want to run a torsion front axle I have a brand new Mark Williams torsion bar and a wide front axle 44” king pin C-C if you may be interested

https://sfifoundation.com/drag-racing-chassis/
Title: Re: Potential FED Build
Post by: jeff/21 on December 26, 2019, 08:25:03 AM

what ever you do make sure you can fit in the car with all your safety equipment on This year I had a chance to do something that was on my bucket list that was to drive a sprint car took the car out to run laps behind the shop street clothes just a helmet and arm restraints  everything felt good, next day we went to the race I got dressed Sfi 15 suit could barely fit in the car couldn't fit the steering wheel on didn't have time to re position steering or lower the seat!
All this to say You have to be comfortable!
Title: Re: Potential FED Build
Post by: dreracecar on December 26, 2019, 12:35:35 PM
Most people will tell you to use the Ford 9"--- except me.
 Chrysler 8 3/4 is a good choice for what YOU plan to do, They offer more room for your legs, good gear sets are available, less exspensive than a Ford build, Not that it really matters but a Ford eats up a touch more HP because the pinion is lower. Don't go with a diff, spools are plenty cheap these days for them and available in the popular spline counts. With todays tracks and tires they will handle 800HP easily
 Chrome Moly is so much eaiser to work with them DOM mild steel  and the cost difference is a couple bucks, Places like Aircraft Spruce sells Moly at a reasonable price and will/can sell only the amount needed without cutting charges (as in ordering 2 -6' pieces instead of a 12"). Proper planning and the material can be shipped in short runs instead of freight shipping a 20' length.
 Front torsion will add another $400+ to the build and not really needed because current rear tires do most of the work and a solid front end is fine, A piece of 1 3/4" X 120wall and the split front axle will slide in or you can split the 1 3/4 and clamp the full axle in place
Title: Re: Potential FED Build
Post by: lake_harley on December 26, 2019, 04:22:06 PM
Thanks again to everyone for input and suggestions. There are obviously differing opinions like front suspension/no front suspension, 9" Ford/8 3/4" Chrysler, DOM/4130. I'm looking forward to getting started and hope the project cars I have that need to sell first find new owners soon. I'm taking all the suggestions seriously and hope that I make some wise choices as I develop a build plan.

I did call the main steel supplier I used for my fabrication business today and got quotes on 3 of the sizes of tube I would need. Based on a rough estimate on the footage I would need of different sizes, it appears DOM would run about $150 to $200 less than 4130. I can pick up 4130 from Wicks Aircraft who is only about 1 1/2 Hr. from where I live. Not really a huge price difference.

Thanks.
 
Lynn
Title: Re: Potential FED Build
Post by: Paul New on December 26, 2019, 04:40:51 PM
I agree with Bruce an 8 3/4 would be perfect and way more comfortable to have your legs go over.
Title: Re: Potential FED Build
Post by: wideopen231 on December 26, 2019, 06:13:46 PM
Main reason I would not consider anything but molly. Stronger with half the weight . Also added safety,its not always how fast you go it other car too. Minor cost increase in the big picture. At some point selling it will be in picture.

You have said motor will be mild combo,why have extra weight?
Title: Re: Potential FED Build
Post by: jeff/21 on December 27, 2019, 11:41:17 AM
a friend has a gremlin with 8 3/4" powered by a 454 only break stock axles when he gets wheel hop(10x30slicks)
9" do eat more power as for housings they come in all shape and sizes from big, truck and fabbed ones to smaller early models and some aftermarket with small round backs
Title: Re: Potential FED Build
Post by: afaulk on December 27, 2019, 07:31:45 PM
Thanks again to everyone for input and suggestions. There are obviously differing opinions like front suspension/no front suspension, 9" Ford/8 3/4" Chrysler, DOM/4130. I'm looking forward to getting started and hope the project cars I have that need to sell first find new owners soon. I'm taking all the suggestions seriously and hope that I make some wise choices as I develop a build plan.           If you have a good deal on the Mopar rear end, get it. I had one with a spool and 35 spline axles. At 4.80s in the eighth it was no problem. Chromoly tubing and a good set of plans to work off, you'll have a car you can sell when the time comes. Longer is better if you decide to add more power later. Good luck and have fun.

I did call the main steel supplier I used for my fabrication business today and got quotes on 3 of the sizes of tube I would need. Based on a rough estimate on the footage I would need of different sizes, it appears DOM would run about $150 to $200 less than 4130. I can pick up 4130 from Wicks Aircraft who is only about 1 1/2 Hr. from where I live. Not really a huge price difference.

Thanks.
 
Lynn
Title: Re: Potential FED Build
Post by: rooman on December 28, 2019, 05:26:09 AM
Apart from the other reasons noted above, the biggest advantage in using 4130 is that by using .058 wall for the main frame rails you can slip fit decreasing diameter tubes to step the rails down from 1.5" at the shoulder hoop to 1.375" in the engine bay and then 1.25" for the front of the frame.

Roo
Title: Re: Potential FED Build
Post by: lake_harley on December 28, 2019, 07:15:53 AM
Thanks again for the additional input and suggestions. I can understand that 4130 construction is preferred for many reasons, including the convenient telescoping tube ability. I haven't decided to go 4130 or DOM just yet, but if building with .120" wall DOM, can transitions from one diameter tubing to another (1 1/2" to 1 3/8" for instance) be done with a butt joint and a stepped sleeve that has at least .120" wall at the smallest end? That sleeve would end up being 1 1/4" at the big end and 1 1/8 at the small end OD, with a 7/8" ID all the way through. I do intend to order the SFI book and that will likely clear up many/most of my questions, but for now I'm just considering options.

Thanks.

Lynn
Title: Re: Potential FED Build
Post by: dreracecar on December 28, 2019, 09:19:37 AM
Why are you making more work for yourself???  Even doing things for myself --my time is not free
Title: Re: Potential FED Build
Post by: wideopen231 on December 28, 2019, 10:12:29 AM
^^^ agree. Its so much more simpler with molly.

 Piece of advise.Design around what you think is extreme you will want for car and build towards that chassis wise,then put in combo you want and you will have room to grow if you want latter. Speed is a drug and the more you get the more you will want,to a point. Myself I have never found that point.LOL Just its easier to do once then do and have to redo for another step.
Title: Re: Potential FED Build
Post by: lake_harley on December 28, 2019, 06:16:25 PM
OK....I concede (as I hang my head in shame), 4130 is the best way to go for numerous reasons and I should quit trying to take shortcuts or pinching pennies. I do wonder about my bender and dies being up to doing a nice job on .058" 4130. I have to pull out my bender and check, but I believe the 1.5" die I have is for 5.5" centerline radius bends. I don't know if it is too tight (no inside mandrel) to bend without kinks or ripples. I guess the only way I'll know is to get some tube and try it out.

The bender I have is a JD2, and if I recall from conversation with dreracecar on another website (the HAMB) that it isn't exactly the preferred bender to use anyway. I guess I'll just have to get some 4130 of a couple sizes and do some test bends to answer that uncertainty for myself. I do recall from previous use that my 1 3/4", 6.5" centerline radius die created an unacceptable, rippled inside radius on 16 Ga. HREW tube. I don't recall ever bending anything under .083" with the 1.5" die, but I fear the tighter radius on it will have the same problem when bending 4130. 

I know I keep saying it, but I do appreciate the suggestions and advice from everyone.

Lynn
Title: Re: Potential FED Build
Post by: fuel749 on December 29, 2019, 06:49:32 AM
OK....I concede (as I hang my head in shame), 4130 is the best way to go for numerous reasons and I should quit trying to take shortcuts or pinching pennies. I do wonder about my bender and dies being up to doing a nice job on .058" 4130. I have to pull out my bender and check, but I believe the 1.5" die I have is for 5.5" centerline radius bends. I don't know if it is too tight (no inside mandrel) to bend without kinks or ripples. I guess the only way I'll know is to get some tube and try it out.

The bender I have is a JD2, and if I recall from conversation with dreracecar on another website (the HAMB) that it isn't exactly the preferred bender to use anyway. I guess I'll just have to get some 4130 of a couple sizes and do some test bends to answer that uncertainty for myself. I do recall from previous use that my 1 3/4", 6.5" centerline radius die created an unacceptable, rippled inside radius on 16 Ga. HREW tube. I don't recall ever bending anything under .083" with the 1.5" die, but I fear the tighter radius on it will have the same problem when bending 4130. 

I know I keep saying it, but I do appreciate the suggestions and advice from everyone.

Lynn

Your JD2 will be just fine with the right die set.
Title: Re: Potential FED Build
Post by: masracingtd1167 on December 29, 2019, 09:22:49 AM
I have another suggestion ! Why not look into a chassis kit ! It would come with all of the major bends you need and you build it the way you want it ! As far as the rear end an 8 3/4 mopar rear would be just fine for what you are doing and they still make a lot of good parts for them ! Stay away from an open rear and use a spool ! Use a nice small tire ! For something like you are running a 9 inch tire would be good ! Just do it and don't let your age get in the way ! I just tuned 69 this year and have no plans on stopping !
Title: Re: Potential FED Build
Post by: rooman on December 30, 2019, 04:35:01 AM
I have a Pro Tools bender which is just a clone of the JD2 and it sometimes has problems with 1.5" x .058" with a 6" CLR die. I either use .065" and splice it to the .058" with the sleeve in the front cage hoop area or I go to Force's shop and bend it on their $100K mandrel bender (which obviously is not an option for you  ;D)

Roo
Title: Re: Potential FED Build
Post by: lake_harley on December 30, 2019, 06:34:30 AM
I made a call yesterday to a friend of mine who builds dirt circle track modifieds and has a Mittler Bros. bender. It's the type that has a shoe to support the tube on the outer radius of the bend as it's drawn around the die. So, I believe I have tube bending covered.

Now, if my projects would just sell! I have a "barn find" '48 Ford coupe that I've lost interest in. The other is a fiberglass '33 Willys. The Willys is a "stretch" version by Dennis Taylor. I bought it as a body and bare chassis. It now has a Moser 9" and triangulated 4-link and Mustang II front suspension under it, so it's in bare "roller" state. It's a blank canvas now and could either go the direction of street rod or drag race. My phone number and e-mail are below if someone is interested. I do have photos that I could send via text or e-mail. Location is Southeast Missouri.

Lynn Winter
(573) 788-2574
winter62@att.net 
Title: Re: Potential FED Build
Post by: dreracecar on December 30, 2019, 08:21:12 AM
You will not get any good bends with 16ga mils steel tubing without a mandrel to support the ID at the start of the bend. To start any bend, the tubing has to crush first and mild that thin never recovers. Lots of people use the JD bender, , I prefer the Hossfeld as It produces a better bend for me.
Title: Re: Potential FED Build
Post by: lake_harley on December 31, 2019, 08:22:51 AM
I've done some searches for FED plans/blueprints and have found S&W, Mark Williams, and Neil&Parks. I also saw plans on Facebook and I believe e-bay but I'm apprehensive if they are properly designed to certify under SFI 2.6.

All of the plans are based on ~200" wheelbase which is a lot longer than I want. I've talked with someone at Mark Williams and S&W to pose the question about shortening the wheelbase. Both agreed that the plans can indeed be modified as I have in mind but it would stiffen the chassis (as I expected) but didn't see that as a problem for my intended purpose.

S&W plans consist of multiple sheets and it sounds like they go into more construction detail than the Mark Williams plans so I went ahead and ordered the S&W plans.

I'm really getting stoked about this project and hope the new year brings buyers for the project cars I have for sale so I can get started building!

 
Lynn
Title: Re: Potential FED Build
Post by: lake_harley on January 03, 2020, 12:50:15 PM
I received the S&W FED plans today. I am really pleased with the detail that the drawings cover! There are 4 or 5 24" X 34" sheets that cover overall layout with multiple views, as well as cross-sectional views at various "stations" on the chassis. In addition to the large sheets the plans included a material list and additional 8 1/2" X 11" sheets that detail key tubing sections which indicate lengths between bends and bend angles for tubes such as the shoulder hoop, lower rear tube, etc..

Studying the plans will keep me entertained and occupied for some time. I find that studying the plans for something like this (I built an airplane from plans) helps me to get a good mental picture of how things will go together and that eventually makes building easier.

Lynn
Title: Re: Potential FED Build
Post by: lake_harley on January 09, 2020, 11:08:15 AM
A question has been running through my mind for a few days now, since I've been considering engine placement. I'm still open to either a 9" ford or 8 3/4" Mopar rearend and wondered if there's any significant difference in the pinion length between the two? Specifically, I'm wondering the difference in distance from the axle centerline to the forward end of the pinion for the two rearend designs. I'd like to keep everything as "close coupled" as possible and even an inch or two difference might sway my choice. I have a 9" here to measure but does anyone have a 8 3/4 Mopar to measure axle centerline to front of pinion threads distance?

Thanks, in advance.

Lynn
Title: Re: Potential FED Build
Post by: wideopen231 on January 09, 2020, 11:38:25 AM
IMO setting motor way back is wrong approach if that what you are looking at with above statement. My observation has been that doing so just results in adding bunch of weight to front end later to make car drive able. May be worng its just waht I have seen on few others.
Title: Re: Potential FED Build
Post by: lake_harley on January 09, 2020, 02:41:53 PM
Thanks for the post. With a long-shaft Powerglide I have and would plan to run, a 9" Ford would put the back of the engine about 39" to 40" forward of the axle centerline. I will add that I'm only expecting 275-300 HP with a mild 350 or 327 carbureted SBC (I already have both running, complete engines). Would you consider the 39-40" too close? I'll also mention that my desire is a pretty short (125-140" wheelbase) car that would be reminiscent of lower class & HP dragsters of the late 60's and early 70's. Trying to relive my youth, I guess.

Lynn
Title: Re: Potential FED Build
Post by: crider on January 09, 2020, 03:13:13 PM
My car is 178" wb, and I have a full length glide coupled straight into a 9". Irun a BBC and by the Et's I'm guessing right around 600hp. It has taken me quite a few runs to get the car dialed in to a point where it will run straight and be consistent, so I would say you should be fine at the power level you are wanting. Just set the wheelie bar low at first and see and it goes
Title: Re: Potential FED Build
Post by: lake_harley on January 09, 2020, 07:39:20 PM
In my calculations on axle centerline to back of engine dimension of 39-40", I added 3" of gap for the coupler length between the transmission output and roughly the front of the pinion threads. Is that about correct for a short coupler?

Lynn
Title: Re: Potential FED Build
Post by: Rat on January 09, 2020, 08:39:53 PM
Hi Lynn, Happy New Year and Welcome to the site.
We are using an 8 3/4 Chrysler, full length glide and coupler, the engine plate is 44" front the diff center line.
As you are finding out there are so many different combinations of FED. As other have stated build to suit your situation (shed/trailer etc) but safe and resaleable. With your horsepower target you can get away with a shorter/lighter chassis but be ready for some wheels up action. Enjoy the journey and the ride. 8)
Title: Re: Potential FED Build
Post by: AF150 on January 10, 2020, 09:20:52 AM
Just a few thoughts...
If you put the engine out about 44" (back of block to rear axle centerline) with a full length powerglide,you can use a Mark Williams collapsible coupler. Makes transmission or third member removal possible without moving the engine. You will need an alignment bar for the rear end you pick.
Fab a fixture to hold housing square on your table with axle center about 15" above ground level.Then slide the block to the desired location and set the engine angle. Basically, you build the rest of the car around this arrangement.

I wouldn't recommend building less than 150" and 175" would be better. Most cars in the mid 60s were that long and it will handle better with any power plant.

MB
Title: Re: Potential FED Build
Post by: lake_harley on January 10, 2020, 02:30:10 PM
Fab a fixture to hold housing square on your table with axle center about 15" above ground level.Then slide the block to the desired location and set the engine angle. Basically, you build the rest of the car around this arrangement.


Thanks. I've found, read and learned from photos of several FED builds and plan to do exactly as you describe with an alignment bar through the engine and into the third member. I plan to build a jig rigid enough to move around in my shop without it twisting, bending and sagging. I've seen jigs with just a single beam and arms coming off to locate items and tubes, but I'm leaning toward a double square tube jig just slightly narrower than my chassis, with crossmembers tack welded and/or clamped into place to locate and support things.

Also.....RAT   I appreciate your reply and input. I'll take all of the info and suggestions I can. I realize some of the opinions might conflict, but I'll try to make good decisions based on everyone's input.

Lynn
Title: Re: Potential FED Build
Post by: 225digger on January 10, 2020, 02:51:28 PM
if you did not come across glenns personal site, check out the build of his digger by rooman   some pretty good pics on there... also take note to his chassis table

https://www.lever-family-racing.com/lever-family-racing-home/family-vehicles/2010-front-engine-dragster/2010-front-engine-dragster-week-2010-02-06
Title: Re: Potential FED Build
Post by: Rat on January 10, 2020, 11:35:43 PM
Hi Lynn, One of my favorite sayings is "The only stupid question is the one not asked". I also learned a long time ago what works for one does not work for another. I may not work for you but never dismiss their idea it may come in handy later with another combo. Listen to everyone one and make up your own mind from the info gathered. When it works/doesn't work it was your decision. This forum is a great resource for differing ideas and information. Ultimately have fun. Cheers Rat.  :D
Title: Re: Potential FED Build
Post by: Curly1 on January 11, 2020, 04:05:26 AM
I have learned a lot with my 225" front engine dragster and few if any are the same. Part of the reason for that is the length of the frame, how it is braced in front and the flex of it. Tire choice, tire pressure may not work on two different ones that appear very similar.
Most of the Rear Engine Four link dragsters have become pretty generic and others can get you a close set up on them. There is NOTHING Generic about a front engine dragster, they are like women and have multiple personalities. Some of those are not pretty and hard to tame.

My dragster is working good now but it was a fight and she did not give in easily. When I throw more horsepower at it we may be in for another fight.......
Title: Re: Potential FED Build
Post by: Don Munyon on January 12, 2020, 05:06:09 PM
First time on the forum. Anyhow my spare 8 3/4 chuck measures 11 5/16 from axle center to the end of the pinion thread, hope that will help. My dragster is 145 inch wb with the motor out 31 inches, the motor center line dumps down about 7 degrees. I believe it to be a mid 60's dragster but it was a bare bones used chassis when I bought it. It now has a 8 3/4 rear end, shorty glide, hand brake and the driver sits low in the seat. I have had over 40 years of fun with this car at the local strip
Title: Re: Potential FED Build
Post by: lake_harley on January 12, 2020, 07:42:04 PM
Don....Thank you for your post. I appreciate the measurement on the 8 3/4" rearend pinion length. Your car certainly speaks to what I hope to build and I thank you for the photo of it!

I saw the car's performance figures listed under your user name and as I suspected it's much quicker than the carbureted mild SBC car that I envision.

Lynn
Title: Re: Potential FED Build
Post by: lake_harley on January 15, 2020, 03:26:23 PM
Don I tried sending a PM to you and wonder if you received it. I can't find anything in my "sent" box, but maybe I forgot to save a copy there?

I had a number of questions specific to your car and thought contacting you directly might be better.

Lynn
Title: Re: Potential FED Build
Post by: lake_harley on January 17, 2020, 05:29:57 PM
I'm still in the "potential build" stage on a FED, but just in case this actually moves forward I bought a 8 3/4" Mopar rearend housing with axles and brakes today. It came out of a A100 "Little Red Wagon" sort of truck and although I didn't measure the brakes it appears they are 10" X 2.5". I settled on a Mopar as opposed to a 9" Ford for the simple reason the axles can be cut/re-splined quite a bit cheaper than buying a set of aftermarket axles. To do the same with a 9" I'd have to find something with 31 spline axles and everybody seems to really be proud of them. Seems that someone also mentioned that the Mopar rearend is slightly less bulky in size to give a bit more room in the cockpit. I can handle narrowing the Mopar housing myself when that time comes.

A friend mentioned he had a 3rd member that I can get at a really reasonable price. I believe it's a 741 housing, but I'm not positive. I'll probably pick that up too thinking even if it's a 741 it would hold up to my projected 300-ish HP SBC.

Another thing I've been watching for on Facebook Marketplace and Craigslist is a used pair of slicks and wheels of appropriate sizes for mock-up purposes. There seem to be a lot of used and abused 10.5 X 15 slicks out there but wonderif I'd really need that wide of a tire to hook up only 300 HP in a FED? I'm thinking a relatively tall tire, perhaps about 29" tall? My un-educated gut feeling is that a 29 X 9 X 15 might get the job done with my projected HP and the car wouldn't be dragging the extra width and possibly weight down the track. I'm looking for input here, so fire away.

Anyway.... although a baby step it was the first step toward a FED build. Now if I could just sell my Willys to make room and free up capital.....

Lynn
Title: Re: Potential FED Build
Post by: THE FRENCHTOWN FLYER on January 18, 2020, 07:18:24 AM
I know a guy with an inline-powered altered who uses 9 x 29 slicks.
It runs 8.30s in the quarter.

He is the reason I'm downsizing from 12 x 31.5 tires next season.
Title: Re: Potential FED Build
Post by: dreracecar on January 18, 2020, 07:59:17 AM
You want either a 742 or 489 case, the 741 pinion is the weakest of the three
Title: Re: Potential FED Build
Post by: Don Munyon on January 19, 2020, 02:05:41 PM
Lynn
I did receive your email and took a few days to reply, hope you did get the answers to your questions. That being said, you mentioned that the 8 3/4 that you have has 10 x 2 1/2 brakes and respline the axles. Do you plan to use the drum brakes, if so I have a few suggestions if your interested. I'm saying that as a budget builder who had to make a lot of parts rather than buy them.
Title: Re: Potential FED Build
Post by: THE FRENCHTOWN FLYER on January 19, 2020, 02:58:38 PM
I remember that some dragster builders preferred drum brakes because they could be set to have zero drag, as opposed to some drag from disc pads at the hit. The reasoning was that they were good for one high speed stop before they faded - and one stop was all they needed.
Title: Re: Potential FED Build
Post by: lake_harley on January 19, 2020, 04:03:13 PM
Frenchtown Flyer.....One good stop before brake fade logic makes sense to me.

Don.....If you have suggestions regarding brakes, or anything else for that matter, please post them!

Lynn
Title: Re: Potential FED Build
Post by: Don Munyon on January 19, 2020, 07:43:58 PM
I don't remember having a problem with brake fade but I do use the chute most of the time. What I do remember was the first time at the track with this car. I couldn't stage or hold it in staging lights without it creeping which really got the starter POed at me. Anyhow (here is the tip) I changed the master cylinder to a smaller bore 3/4 or 7/8, put larger wheel cylinders from the front of a AMC and got rid of the metalic linings. After that no problems, I only changed to disc a few years ago to get rid of all that weight of the drums backing plates etc.
Title: Re: Potential FED Build
Post by: lake_harley on January 19, 2020, 08:35:10 PM
Thanks, Don, for the reminder on using a smaller MC to increase pressure to the brakes. Would about a 6:1 or 7:1 brake lever or pedal ratio be about right? I've used that pedal ratio on hot rods in the past.

Also, any particular model AMC and/or range of years that will fit the 8 3/4 rearend 10" drum backing plates without a lot of changes?

Lynn
Title: Re: Potential FED Build
Post by: dreracecar on January 20, 2020, 10:27:31 AM
Zero drag with the drumbrakes vs disc drag??? bunch of "Hooey" Disc brakes are lighter and lower reciprocal weight than heavy drums that take time and HP to get going. Call it like it is "Some people are not smart-just cheap"
Title: Re: Potential FED Build
Post by: Don Munyon on January 20, 2020, 04:38:30 PM
Wow! I didn,t see that one coming. Bye bye
Title: Re: Potential FED Build
Post by: Roger on January 20, 2020, 08:40:17 PM
Back in the 70’s I had 2 different FEDs that used drum brakes. One had an 8 3/4 with Chrysler drum brakes with semi-metallic linings that ran 140+ and one had an 8 3/4 with 1962 Pontiac Bonneville drum brakes with semi-metallic linings that ran 150+. Both cars had iron BBC in them and I never had an issue with brake fade or any other brake problems. At the speeds you’d be running with your engines and as long as all the brake components are in good condition, I’d use them. They may be heavier that discs? but they are every bit as effective. And it ain’t got nothing to do with being cheap but more to do with being wise with your funds.

Looking at the parts you have maybe put one of your engines in with a Powerglide, buy a 4000rpm stall convertor and feed it to the 8 ¾ rear with a stock open rear end with original gears. Both my earlier FEDs used stock open carriers with 4.10 gears and the faster car would pull the front end up 10” and carry it for 60 or 70 feet and ran perfectly straight. I put a 300hp 350 in my 1600# altered with a 2100 stall convertor (totally wrong) and ran 6.81 @ 103mph in the 1/8th. It was so consistent that I made money with the car! No reason you can’t do the same and have a good time doing it.
Title: Re: Potential FED Build
Post by: THE FRENCHTOWN FLYER on January 21, 2020, 05:54:47 AM
I put a 300hp 350 in my 1600# altered with a 2100 stall convertor (totally wrong) and ran 6.81 @ 103mph in the 1/8th. It was so consistent that I made money with the car! No reason you can’t do the same and have a good time doing it.

Sometimes "totally wrong" is absolutely perfectly right.

Case-In-Point: I use 2.47 (totally wrong) rear end gears in my home built RPU. I wanted a car so easy to drive even a trained monkey could win with it. Hooks in a mudslide.
Two track championships. Nine wins in twelve final rounds before I retired it after proving my point.
Pass the bananas.
Title: Re: Potential FED Build
Post by: dreracecar on January 21, 2020, 08:48:16 AM
Back in the 70’s I had 2 different FEDs that used drum brakes. One had an 8 3/4 with Chrysler drum brakes with semi-metallic linings that ran 140+ and one had an 8 3/4 with 1962 Pontiac Bonneville drum brakes with semi-metallic linings that ran 150+. Both cars had iron BBC in them and I never had an issue with brake fade or any other brake problems. At the speeds you’d be running with your engines and as long as all the brake components are in good condition, I’d use them. They may be heavier that discs? but they are every bit as effective. And it ain’t got nothing to do with being cheap but more to do with being wise with your funds.

Looking at the parts you have maybe put one of your engines in with a Powerglide, buy a 4000rpm stall convertor and feed it to the 8 ¾ rear with a stock open rear end with original gears. Both my earlier FEDs used stock open carriers with 4.10 gears and the faster car would pull the front end up 10” and carry it for 60 or 70 feet and ran perfectly straight. I put a 300hp 350 in my 1600# altered with a 2100 stall convertor (totally wrong) and ran 6.81 @ 103mph in the 1/8th. It was so consistent that I made money with the car! No reason you can’t do the same and have a good time doing it.

  News Flash--- the 70's was over 40 years ago, when you could buy quality USA/OEM parts and they sold good racing shoes for drum brakes, Just because the packaging says "Performance" does not make it so. Like it or not my opinion on safety will never change
Title: Re: Potential FED Build
Post by: Roger on January 21, 2020, 11:04:04 AM
Hold on there a moment partner, my reply was to your reply that stated “Disc brakes are lighter and lower reciprocal weight than heavy drums that take time and HP to get going” and "Some people are not smart-just cheap". Let me remind you of some words spoken in this forum: “its more like why spend the money for somthing that is not needed.” I agree with that statement as well as you. You wrote it! For the speeds he’ll run in the 1/8 mile I stand by my words as long as all the brake components are in good condition so why spend more money if not needed.

And it’s now you bring up safety??? Safety should never have been an after-thought. Your assumption that quality products must be made in the USA is a personal opinion at best, unless of course you have documentation of such in the area of drum brake components. I checked and there are still both regular and semi-metallic brake shoes available off the shelf and there are several companies that can reline your core shoes with the bonded or riveted linings of your choice. Rest assured, my opinion of doing things safely will never change as well. And this comes from an old guy that actually climbs in and races his car down the track.
Title: Re: Potential FED Build
Post by: dreracecar on January 22, 2020, 10:00:54 AM
I have a greater responsibility ,  I load my friend into a car that I built and maintain, I'm the last one to shake his hand and the last person he sees going into the beams, Its that trust that he has in me that I provided the best for him.

  Yes , I have said that certain things are not nessasary , but were all performance enhancers that would offer no clear advantage and make the cost of racing go up.  You cant garentee that a racer given the option of purchasing brake parts will source out the correct type and material and chose by cost alone, even if that means driving across town to save $2.00. That being said, Does the racer have to buy his disc brake setup from M/W or LAMB?  NO, as they are a bit pricey, A set of Willwood's or Strange can be had, saving the racer a chunk of change and are the exact same system using the same materials and construction and one can expect the same life and performance levels
Title: Re: Potential FED Build
Post by: crider on January 22, 2020, 03:53:30 PM
Will a set of drum brakes stop a lightweight car at the speed you'll be running? Probably will, but for the few hundred bucks a set of wilwoods cost, do you really want to take that chance? And after buying good shoes, hardware, wheel cylinders and drums, how much will you really save? I can say after just rebuilding stock Mopar brakes on my 69 road runner 8 3/4 rear, that doing drum brakes correctly isn't all that cheap. And after having to spin a funny car out to stop it several years back because of having old Hurst brakes on it, you really do not want to take chances with the braking system. If you do want to save a few bucks, shop around for a good used set of drag racing brakes. Just my 2 cents,
Title: Re: Potential FED Build
Post by: jeff/21 on January 22, 2020, 04:02:06 PM
i've used wilwood brakes on various projects, and on all my oval track cars with the proper sized master it's like having power brakes.