Messages

31

Spud Miller's Cave / Re: Bigger mag for more power?

« on: October 08, 2014, 12:58:19 PM »

The cam is an Isky rr-735.
Dur in 278°, dur out 286° @ .050".
Overlap is 111°
Do you think the cam is long enough to be able to skip the toluene?

32

Spud Miller's Cave / Re: Bigger mag for more power?

« on: October 08, 2014, 10:35:34 AM »

I might try some Fuel next season. Just to make sure the 7 sec run will be there.
I have stock main caps, alu rods, forged steel crank and forged pistons. Around 14:1 in CR. Stack injected sbc.
I have read in Spuds nitro notes that above 25% the stock main caps might crack.
So around 20% seams to be "safe".
BUT, will my SprintMag handle this? Lets say the SprintMag will be recharged and in perfect condition.
Or do I have to move up to a SuperMag?

33

Spud Miller's Cave / Bigger mag for more power?

« on: October 05, 2014, 11:12:19 AM »

I run a n/a alcohol injected 350" sbc in my FED. Best et so far is 8.41sec 159.5mph. Planing to do some upgrades this winter to be able to go faster. My goal is a 7 sec run, which might be hard...
I have a Mallory SprintMag I, which never have been recharged during the 4 years I have raced with it.doing about 10-20 passes each year.
Engine is running good and feels strong. Can I expect any power gains if I have the mag recharged?
Or should I get a bigger mag? SuperMag IV would be nice since they do not need to be recharged.
Will a bigger mag help me make more power? Or will it just increase the losses since it takes more power to drive?
What mag is the best for my application?

34

Front Engine Dragsters / Re: How to properly launch a FED?

« on: June 11, 2014, 07:56:19 AM »

Thanks!
How much pressure do you run i  them?

35

Front Engine Dragsters / Re: How to properly launch a FED?

« on: June 07, 2014, 01:19:04 AM »

A softer (lower rpm) launch will make it easier to climb the ring gear.  You want to launch at 600 - 400 rpm under the converters stall speed.  And yes, it raise slicks air pressure @ 5 psi. increments until you start slipping the tire.  You really need somebody watching the car to help with that, shorter wheelie bar contact with pavement, less than 4 wrinkles of the slick at launch movement.  Those wrinkles are important clues also, they need to be in the lower front of the tire, and not behind axle centerline.

I will try to launch 600 - 400 rpm bellow the converter stall speed next time I'm on the track.
In what range will a "normal" tire pressure be? I know it will depend on a lots of things, but it would be good to just have an idea. I have been running around 10-12PSI before. Wouldn't the tire pressure be very high if I increase with 5PSI a couple of times until I get some tire speed?

Take a look, remember I am a low  HP dragster only running 8.00

GlennLever, what is the size of your tires? How much pressure do you run in them?

36

Front Engine Dragsters / Re: How to properly launch a FED?

« on: June 03, 2014, 01:59:03 PM »

Or...
Am I doing it the hard way now... Is it better to just leave the wheelie bar as it is, since it probably is fairly right. Pick a fixed launch rpm and only experiment with the tire pressure until I get some tire speed at the launch and see if the problem is gone?

37

Front Engine Dragsters / Re: How to properly launch a FED?

« on: June 03, 2014, 01:06:16 PM »

My car has a torsion suspension at front, I will have to check for any "bump steer" effect when the axle unloads/loads.

I made some measurements on my wheelie bar today. It seams like it is about 2" off to the left. I guess it is to the right direction, to help unload the left wheel since the right one will be unloaded by the engine applying torque on the rear axle?
I will make the wheelie bar adjustable side ways asap. Is it a good idea to decrease the offset a bit since the car is pulling to the right?
One other thing I saw was that when the single wheelie bar is offset the wheelie bar wheel is no longer parallel to the car. Is this a problem? I have not seen any wheelie bars that is adjustable to compensate for this.

Tire speed is easy, start dropping tire pressure in 1/2# increments.  It'll eventually give you tire speed.  If i dead hook my tires on my 200" car, it'll drive the car in a random direction.

I do not really follow you on this one. Shouldn't I be adding pressure to eventually loose some traction with the harder tires and then get some tire speed?

How big is the window from starting to get tire speed to smoking the tires?

38

Front Engine Dragsters / Re: How to properly launch a FED?

« on: June 02, 2014, 01:07:48 PM »

Thanks for all the good and helpful answers!

I had a small impact with the track wall about a year ago, very narrow track. Then I built a chassis jig and straightened the chassis. After the repairs the wheelbase and the cross measurement of the wheelbase differed around 2mm, that's around 1/16". So I think that the chassis is as square as it can get.

I'm currently running about 1/4" - 1/2" of toe in. I know it is a bit much, but I thought I rather have to much then to little, the car would be more stable at high speed? Are there any down sides except the increased roll resistance?

I will try to get hold of some shoe polish to paint on the wheelie bar wheel. It is a very good idea.
How do I tell if the wheelie bar wheel is steering the car, or if the car is steering to the right for some other reason and the wheelie bar just follows?

I do not think that I'm steering the car to the right by mistake. I don't shift to 2nd until about 100-150 m out, so during the launch and the following seconds both hands are on the steering wheel.

I was just in my garage and I measured the roll out of the tires and I noticed that the left tire have changed allot since before the race previous weekend!
The tires are brand new and this weekend I put one burnout and one pass in them, both the pass and the burn out were actually quite gentle...
I have measured the roll out of the tires during 1-2 weeks in the garage, tires mounted to the rims, and they were within 1/8".
Now how ever has one of the tires expanded and the roll out differs a little more than 1"!! How is that even possible??
I have completely deflated the big tire and put about 21 PSI in the small one. I will try to inflate the small one even more and put it out in the sun for a while. Is it possible to get them back with in 1/8" again? Have some one heard of anything like this?
I do not think this sudden tire expansion completely explains the launch problem. Last 2-3 seasons I have had the same problem with my old set of tires.

My Race master tires have arrows on then so they are direction sensitive. Is it possible to swap them anyway? Or will the tires be damaged?

39

Front Engine Dragsters / Re: How to properly launch a FED?

« on: June 01, 2014, 10:25:04 PM »

The rear tires are brand new and are within 1/4".
I allready have a wheelie bar. It has a singel wheel. According to my measurements the wheelie bar wheel is of center with about 1". I'm not sure how this affects the launch but I will make i adjustable and center it.
I also have a hard time knowing if the wheelie bar hits the track or not.
What is a good starting point for wheelie bar height?
What is the best way to get a good amount of wheel speed with the setup I have now?

Skickat från min GT-I9505 via Tapatalk

40

Front Engine Dragsters / How to properly launch a FED?

« on: June 01, 2014, 11:30:49 AM »

What is the best way to launch a FED?
I have an FED, old 60s Jr Fuel, that I'm racing with just for fun. My problem is that the FED tends to pull to the right (most of the times) when I let it go from the transbrake. I have tried some different launch rpms and different tire pressues with out finding something that I think works good enough.
I have a long distance to the nearest dragway so I get perhaps 10-15 passes a year. So it takes time to figure it all out by my self. So if any of you have any ideas I would really appreciate it.
The FED has 150" WB.
350" SBC, alcy injected
PG with transbrake
Chrysler 8-3/4" - 4.11 rear ratio
M&H Racemaster 12" x 33" x 15"

Once I get up to speed the car is stable.

Am I perhaps launching it to "gentle" so that the slicks hock up to soon/hard? Can I get this problem then?

How do you launch your FEDs?

41

Matt Shaff's Engine Shop / Re: Piston ring end gap

« on: May 14, 2014, 08:17:21 AM »

I have emailed Total Seal with this question and got the following answer:
 
"Might not be a bad idea to increase the gaps .002-.003” just to be safe."

So that's what I will do and hopefully I don't have to worry about this again.

42

Matt Shaff's Engine Shop / Piston ring end gap

« on: May 11, 2014, 02:03:28 AM »

I'm just about to adjust the piston ring end gap of my new rings and a question came up..
I have and old FED with a 350" SBC. The engine is alcohol injected with a Enderle stack injection. The bore is 4.00" and it has forged Arias pistons.
The block is half filled with blockfiller and there is water in that part of the block that is left and in the heads. No water pump or radiator. E.g. not a normal working cooling system.
I have also had some plans on skipping the water which causes lots of extra work filling and draining.

I have got some new gapless top rings from Total Seal.
They recommend:
Top = 0.026"
2nd = 0.022"
But this is most likely for regular engines with a working cooling system that will keep the engine at a more constant temperature.

Will that fact that I run my engine with out a working cooling system affect the piston ring end gap?
Is it a good or bad idea to increase the end gap just to make sure the rings will not butt due to heat?
I have also read that the gap of the 2nd ring should be larger that the top ring gap. In this case the top ring is gapless so I suppose there will not be any pressure building up between the rings?

Are there any rule of thumb or best practices regarding the piston ring end gap on this type of engines?