FrontEngineDragsters.Org Forum
Technical => Matt Shaff's Engine Shop => Topic started by: George on March 18, 2013, 05:03:58 AM
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I am considering trying spark plug indexing . I have read several online articles and not sure it's worth the hassle. What's your opinion?
I have a 13.4 : 1 SBC ,355 CID, Dart 230 cast iron heads, Hilborn stack injection, alky, MSD 12LT mag. I have no interference problems with spark plug to piston. Running NGK 8,gapped at .018.
Thanks . George
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George:
If you have no interference problems now, I doubt that indexing would provide any improvement.
In the old days when we ran stock 461 castings on a small block, we had to index.
It was typical to angle mill those heads .125" to .150".
This brought the spark plug right to the deck. I found that if you indexed 180* from the normal - meaning you
pointed the ground strap up, the combustion chamber could "see" the spark plug.
I believe your Dart heads have the spark plug slightly higher than the old Chevy castings and you dont have to cut them so much.
By the number posted in your personal box, your little small block hauls ass!
Tell us more about your combo. Whats it run in the quarter mile?
Matt
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Here is something we found . I am not 100 percent shure this worked but I would like to share it with you guy's . I run injected alcohol with a tunnel ram manifold . When I started spraying it with Nitrous we would sometimes burn the side electrode off of a plug ! The funny part was that it would be different plugs every time . I always index my plugs but between 3 and 6 o clock was good enough or so we thought . Even with a safe tune up It would burn a plug but never the same cylender . Finally we tried indexing the plugs very carefully so the open part of the gap was facing toward the intake valve . From then on we never burned another side electrode . I guess the cool air and fuel would keep the electrode from burning . I would be interested to see what you guy's think about this.
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George:
If you have no interference problems now, I doubt that indexing would provide any improvement.
In the old days when we ran stock 461 castings on a small block, we had to index.
It was typical to angle mill those heads .125" to .150".
This brought the spark plug right to the deck. I found that if you indexed 180* from the normal - meaning you
pointed the ground strap up, the combustion chamber could "see" the spark plug.
I believe your Dart heads have the spark plug slightly higher than the old Chevy castings and you dont have to cut them so much.
By the number posted in your personal box, your little small block hauls ass!
Tell us more about your combo. Whats it run in the quarter mile?
Matt
Matt, It's been on the dyno making 640 hp. It's got Hilborn 327B 2 7/16", Waterman 400, 16As nozzles, usually start with an 80 bypass. Heads have been ported, no welding or putty. Scat std. weight crank and Callies rods. Ross pistons 13.4:1. It's been very reliable. It has only been on the 1/4 at Bowling Green Ky. That was the HHRR 2010. We were just figuring thing out and with the help of Scott Parks we got it to run 8.32 @ 155 mph. At that time we were running a Hoosier 12x29 tire. We soon changed to the Goodyear 2585 and went from 1.12-1.15 60' to 1.06-1.10 . We also bought a Race Air and got better with tuning.( Notice I didn't say good) Also improved the engine heads, compression and cam last year ( was 607hp). I would guess we could get it into the low 8s now?
The reason I am considering spark plug indexing is we tend to run best when it's rich and we are getting what I think is too much fuel in the oil, even with a vacuum pump. I'm thinking if I index toward the exhaust valve it might help. Don't know but I'm looking for others to share their tune ups?
Thank for your input. George.
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George it may not be too rich . How hot are you getting it? and how much dose the temp increase durring a run?
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George it may not be too rich . How hot are you getting it? and how much dose the temp increase durring a run?
I have a themocouple in just one cylinder and it will only give me the high temp. So after 1/8 mile run I see 1000-1100F. I have seen hotter temps BUT it may have been caused by alky burning in the upswept zoomie.
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George I have never had much luck using E.G.T's for tuning mine . Like you said fuel burning in the pipe can cause high readings even if it is too rich . We were getting milky oil and thought that we were too rich and went slower and still had milky oil! I wasn't paying much attention to engine temp we would warm the car in the pit's and tow it to the lanes . One day I looked at the temp guage at the end of a run and it was only 140 degree's ! We started driving the car to the lanes to build heat in the motor and it worked well for us . I try to stage at around 160 to170 degree's and at the end of the track it's around 180 and bingo no more milky oil . If you are going 1.06 at the sixty ft. that is really good and 5.08 at the 1/8 you can't be too far off on your tune up . Sound's like 7 second potential too me! If you have some time read some of the articles that Spud Miller has posted on this forum .Very interesting stuff ! Good luck with your racing this year . and post some pictures of your car !
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I may try bringing the car up to the staging lanes with the engine running. It's for sure the engine runs better with a good heat soak. I installed a heater in the oil pan and made thermocouples for both the transmission and engine oil. They are installed in the drain plug locations. Before we start the car , I try and get the oil warm and turn the engine over with the block mounted starter . I crank the engine wo/ ignition until the oil pressure comes up. I have helped with a car running a dry sump and I think that's the ticket for pre-warming the oil and getting it circulated without starting the engine.
Oh, do you run coolant in the engine? We do not.
Thanks for your input. George
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Great discussions guys!
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Thank's Ricardo This forum is a great place for us to share information with each other . Most of the other forum's like Bracket Talk and Yellow Bullet are not really geared for what we do . Racing a F.E.D. is much different than a R.E.D. After seeing what George is going on his 60ft's I am thinking about going back to those 12x31 Goodyear's if I can get a set.
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Checkout the Southwest Junior Fuel Forum. http://www.angelfire.com/tx/fuelcarfan/jrfuelers/results.html
There is a thread on the purchase of the Goodyears. Last set I bought used from Scott Parks. Too bad someone else doesn't make a lightweight grow tire.
Good racing. George
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Thank's Ricardo This forum is a great place for us to share information with each other . Most of the other forum's like Bracket Talk and Yellow Bullet are not really geared for what we do . Racing a F.E.D. is much different than a R.E.D. After seeing what George is going on his 60ft's I am thinking about going back to those 12x31 Goodyear's if I can get a set.
Thank you Bill and everybody else here for sharing precious knowledge with FED rookies like me.
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I will have to index the plugs on my deal because I'm shooting for a max compression piston dome. But I would index anyway. Why not? If you don't do it, the guy in the next lane will. All it costs is some time.
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I will have to index the plugs on my deal because I'm shooting for a max compression piston dome. But I would index anyway. Why not? If you don't do it, the guy in the next lane will. All it costs is some time.
It will take tapered washers for my deal or a lot of spark plugs. How is the plug indexed in relation to the intake valve? Injection ? Fuel ? Compression ?
What's it worth on the dyno and/or track?
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I'm shooting for the spark plugs having the open side of the gap somewhere between facing down towards the piston top and the intake valve. It's on a Kinsler 2.875" stack injector, methanol and CR will be around 16:1 (maybe). I have no knowledge on what indexing is worth on the dyno or track.
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Thanks for the insight. I don't see it worth the time or the money for my setup. George
I am going to work on getting more heat in the engine before a run.
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On the South West Junior Fuel Association website, Jon Hansen posted some interesting thoughts on engine temperature for Jr Fuel engines. The posting was a while back but you may want to go check that out. Sounds like you have a pretty honking 355 there George. What is your car weight?
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Our combination weight is close to 1500. That's with driver etc. We run an on board battery , full length Reid case. Aluminium 8 3/4 case and spool, drilled axles.
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I'm shooting for the spark plugs having the open side of the gap somewhere between facing down towards the piston top and the intake valve. It's on a Kinsler 2.875" stack injector, methanol and CR will be around 16:1 (maybe). I have no knowledge on what indexing is worth on the dyno or track.
[/q Chuck when you run comp everything matter's !Comp has to be my favorite class I have worked on Billy Griffin's comp team for 10 year's and really enjoy it . The time and effort that goes into these cars is unreal . These guy's deserve a lot more credit than they get .
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On the South West Junior Fuel Association website, Jon Hansen posted some interesting thoughts on engine temperature for Jr Fuel engines. The posting was a while back but you may want to go check that out. Sounds like you have a pretty honking 355 there George. What is your car weight?
I found the article (posted almost 2 years ago)
. Very interesting! Thanks. George
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Bill...I have zero Comp Eliminator racing experience at this time but I could not agree with you more. Those racers are the real scientists of Drag Racing. I got a taste of that hanging with the Parks and Brian Darcy a bit.
George..."two years"! Seems like I read it yesterday. Time flies.
This thread is getting way off topic.
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On the South West Junior Fuel Association website, Jon Hansen posted some interesting thoughts on engine temperature for Jr Fuel engines. The posting was a while back but you may want to go check that out. Sounds like you have a pretty honking 355 there George. What is your car weight?
I found the article (posted almost 2 years ago)
. Very interesting! Thanks. George
George - Could you please post the link?
Thanks
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Here is the post from the SWJFA forum.
Posted by Jon Hansen on April 28, 2011, 1:37 am
Some of you guys might have noticed, starting with the 1'st SWJFA event I attended, Evadale 08,I was taking engine temps with my infa-red temp gun as you guys were staging. Even holding back a few racers waiting/hoping the engine temp would get hotter.
Alky burners run better with more engine heat. I shoot for 180°to 200° head temp, just above the block as the car is moving into the staging lights. And advised those of you that were not getting anywhere close to those numbers to lean the BV [ and readjust the idle]. Bob McKray shoots for the same temps on his non-RR SBC, 7.20's running car.
Now the 180-200 temps are for water in the heads/blocks combo's. Dry blocks shoot for 150° to 160°
OK, here's "the rest of the story" or at least my 2 cents. 1'st the most important reason to run water, of course it keeps the engine temps more even, especialy in the middle cylinders of a SBC with the exhaust valves next to each other. Case in point if you have ever noticed black marks,streaks in the bore, that means it's been RED HOT there. Running water in the block helps support the cylinders, which helps better ring seal. Bob McKray sometimes gets hired to "tune" at a dyno test. One time he was hired, the customer was happy with the HP it was running, and he said " OK, now dump the water because we race dry" Next run-up it lost 20hp, can't be, so put the water back in, 20hp increase. Holy Crap, how can that be ? Well Bob and I figure the water supports/dampens the harmonics in the cylinder walls, and so you end-up with better ring seal = more power. Our theory was backed-up by Rick Watters, who builds most of the winning Comp elim motors [ he will be glad to build you a complete, top to bottom JrFuel motor for 60-70k], when I talked to him at this years Vegas National event, when he said running with-out water your cylinder walls ring like a bell with harmonics, no way you can get good ring seal with the cylinders vibrating.
As some of you may know, besides having a motor in Bud Hammer's Heritage JrFuel car, I've also had a motor in Dean Carter's B/ND for a couple of years, 2008, 2009, and I crew on his car at the West Coast NHRA Comp events. At 2011 Div 7 race in Vegas [I wasn't there] they cracked a head, either too hot or too much porting, so they couldn't run water. When I was taking engine temps at the Vegas National he was staging at over 200° dry, it ran pretty good with the last qualifing at 7.05, 188mph at 4500'DA. But when I checked the engine temp at the turn-off, it was 235° to 238° for that run. When I check under the valve cover I noticed a pushrod not where it should be, turned-out the # 3 cylinder exhaust valve was stuck in the guide. So they were done racing for the event.
So lesson learned, 235° is way too hot for a dry block, and I think too hot for water too.
Now you know the limits 200° for wet blocks and 170° for dry, and if you're looking for cheap 20hp and you're running dry, run water.
Yes, I know Parks doesn't run or believe in running water, mostly because they lost a round because of a water leak, and of course they consider the weight of the water, and some of their heads are soo large they can't run water.
OH ya we also put a blanket over the motor after we warm it up in the pits before we go to the staging lanes to keep the heat in the motor. Another thing is we plug in our freeze plug heaters [ one on each side], and oil pan heater when we warm-up the motor for the 1'st time of the day.
I know of some bracket racers that change their engine temps to run their index/dial-in. 10° makes a difference.
I hope this helps.
Jon
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Looks like my last post killed this thread. Dead!Dead! Dead! :(
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I don't think so George. Everybody is probably busy indexing plugs and playing with engine temperature! If you do decide to run your deal hotter, keep in mind that eventually you will probably need to adjust your fuel system to optimize.
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I don't think so George. Everybody is probably busy indexing plugs and playing with engine temperature! If you do decide to run your deal hotter, keep in mind that eventually you will probably need to adjust your fuel system to optimize.
Yea!
I am working on installing a freeze plug heater on each side. The design of coolant flow and return is a question as I don't want a pump and prefer an expansion tank with little or no overflow. Any proven designs out there for a SBC? Thanks.
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Sorry to be a little late on this , But I run a waterpump on my blown engine and have not had to touch my heads in over 12 years except for a valve replacment from zinging. A Riverrat waterpump is cam driven and goes between the front cover and your fuel pump.
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I run with SWJFA and our block is dry as a bone. Of course we tow the dragster around.
We use to run with water but decided to pull the plug about a year ago mostly for the weight but also for saftey.
When we had water it was just filling the block and not circulating. The water pump holes in the front of the motor were blocked off, the back two water holes on the hilborn manifold had plugs.
The two front water holes in the hilborn manifold were connected and tee'd into a vented catch can to let any steam out and catch any fluid. Worked really good but I'd have pull the rear plugs to fill with water often. Kind of a pain.