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Discussion Starter · #1 ·
I want to step up the program a little but I don't want to make many changes. The gears/converter/trans/heads/intake/CID are staying but I can other things to optimize the combo better. I would love to run mid/low 9s naturally aspirated and possibly still drive it on the street a little if possible. I have not put nitrous on it becaue of the cast pistons but I would like to try a small shot next year if possible.
The current combo is:

392CID-

-3.85" stroke Scat crank
-5.956" H-beam rods
-302 Keith Black KB116 Hypereutectic dome pistons
-PRo Topline 215s ported to 237CCs, angle milled 52.5CC chambers, 2.08/1.60 valves
-14.5:1 compression and .028" quench
-Solid Roller Isky 290/300 Adv, 256/266 @ .050", 108LSA/108ICL, .656/.656" lift
-Comp Cams Pacaloy Springs 235#s seat/635#s open
-Ported Super Victor intake
-9375 1050 Dominator
-1.72 Rockers
-C4 w/9" Converter currently 5800 stall
-4.30 Gears
-28/10.5/15S ET Drag Stiff Sidewall Slicks run at 18PSI on Centerline 15x8.5 rims
-Front wheels/tires: '89 GT Wheels with 235-60-15 tires
-Sunoco 112 Race gas (110 motor octane)
-3320#s W/Driver and 3150 W/O Driver (All steel and full stock interior) and 8pt Cage
-Totally Stock Suspension W/No Traction Aids (Soon to install Cal Tracs)
-7qts 10W30 Valvoline Oil in the 8qt Milodon Pan
-Front wheels/tires: '89 GT Wheels with 235-60-15 tires

Best ET uncapped:
1.34 60'
6.30 @ 109
9.81 @ 135

Best ET w/Exhaust:
1.34 60'
6.45 @105
10.21 @ 129

I did not have stud guirdles for my heads all year because I couldn't find any made for these heads but I now found a company that makes the guirdles so I will get a set. I may change the pistons to some forged pistons this winter but money is tight and I want to spend the money where it will give the most improvement to ETs and MPH. Thanks for any help, suggestions, and recomendations anybody might have.
 

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Well.... what is the converter doing?

I think you're probably ready to step up in the ring department and I'd suggest "Cam, Rocker Arms, Springs".... as Jay would put it.
And you might consider a Vacuum pump.
 

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If you want my opinion, I'd switch to a much lighter piston (Ross makes a good one) and run a thinner ring package. This will allow your engine to make more power and last Longer due to the lighter mass of the pistons and less drag due to the rings.

My humble opinion
Tom Cowle
 

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Discussion Starter · #4 ·
Chris Uratchko said:
Well.... what is the converter doing?

I think you're probably ready to step up in the ring department and I'd suggest "Cam, Rocker Arms, Springs".... as Jay would put it.
And you might consider a Vacuum pump.
The converter is 5800 flash stall with the current combo and it has worked flawlessly the whole year. Paint is burned off it but it still 60' and MPH the same pass after pass. I am thinking the converter will tighten up a little if I go with a bigger cam but I am willing to trade off a little 60' for some added upper RPM power so I don't spin so much out of the hole in the hot summer months from the greasy tracks.

I am using 5/64ths top and 2nd rings currently with Total Seal gapless 2nd rings on my current pistons. I will not use gapless again! Major blowby and oil being blown out of everywhere from day one but one I put 4 K&N breathers in my valve covers (and installed baffles inside the valve covers) to relieve the pressure and used a spring to hold down the oil dipstick, the front and rear main almost totally quit leaking and no more oil being blown out of the breathers. I was thinking regular conventional or C&A gapless TOP rings possibly unless there is a reason not to that I don't know of. I know I should use 1/16th rings for over 7000RPMs and I am considering getting a set of forged pistons for use with thinner rings.

What cam specs would be good? I currently shift at 7000RPM and 7500 at times but it ETs the same either way. I would like to shift at 7500-7800 and actually make MORE power up there and get better ETs from it unlike how it is now it doesn't improve ET or MPH up high. I think the compression might have been too much for the cam and the converter too loose for the cam which might be why I got all this low end power and nothing up top. Should I spread the LSA out to 110 or 112 and go a little larger on the duration like 260/260 or 260/265 @ .050. or am I going in the wrong direction? Lift I can take up to .750 gross lift or .720 net with the terrible geometry of these heads and using 1.72 rockers (rocker placement is too close to the valve). I don't really have room for a vacuum pump and I am still using a mechanical belt driven Edelbrock Victor water pump. How much power does an electric water pump free up? Is it worth the price?
Thanks Chris
 

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Discussion Starter · #5 ·
Do rings really use much power? I thought the thinner rings helped with ring seal eliminating flutter at high RPMs and only a little power to be gained with low tension rings?
I'm sure it's an extreme situation, but David Reher has made the claim that in a 1000 horsepower engine, 150 horsepower is consumed overcoming friction in the cylinder walls.....

The ring package is everything when it comes to the shortblock.... there are many things in the short block that can be masked, or overlooked and still have a decent engine, but when it comes to making the engine shine, the ring package is everything in my book...............
 

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Do rings really use much power? I thought the thinner rings helped with ring seal eliminating flutter at high RPMs and only a little power to be gained with low tension rings?
I'm sure it's an extreme situation, but David Reher has made the claim that in a 1000 horsepower engine, 150 horsepower is consumed overcoming friction in the cylinder walls.....

The ring package is everything when it comes to the shortblock.... there are many things in the short block that can be masked, or overlooked and still have a decent engine, but when it comes to making the engine shine, the ring package is everything in my book............... and most significantly in an n/a engine.
 

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89 coupe said:
Need to go faster, what should I change?
...jobs.... :smt005


Sorry... these things just pop in my head. Carry on. :oops:
 

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Discussion Starter · #9 ·
Keith Seymore said:
89 coupe said:
Need to go faster, what should I change?
...jobs.... :smt005


Sorry... these things just pop in my head. Carry on. :oops:
That is true, a different/better job would help with no doubt :wink:
 

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Discussion Starter · #10 ·
Chris Uratchko said:
Do rings really use much power? I thought the thinner rings helped with ring seal eliminating flutter at high RPMs and only a little power to be gained with low tension rings?
I'm sure it's an extreme situation, but David Reher has made the claim that in a 1000 horsepower engine, 150 horsepower is consumed overcoming friction in the cylinder walls.....

The ring package is everything when it comes to the shortblock.... there are many things in the short block that can be masked, or overlooked and still have a decent engine, but when it comes to making the engine shine, the ring package is everything in my book............... and most significantly in an n/a engine.
That is weird how your response somehow got on my post above as if I typed it in :shock:

Can a low tension ring package be used without a vacuum pump or will that cause ring seal problems? What about an electric vacuum pump, will that work and how much do they cost if they do work? I was considering Mahle pistons because of their price and reputation. Is 1/16 a decent ring size or should I definitely go narrower? I do drive this on the street so it will get some miles put on it. Maybe 15-20 hours of idling and putting along in August during the week at Woodward Dream Cruise by Detroit each year and full throttle jaunts here and there. Also a lot of local cruising and driving to/from the track. I want something somewhat durable and cost effective. Hellfire rings? I heard some good things about them but I have no experience with them. ??
 

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JE Has a nice ring package that they offer in some of their pistons... I can give you some data on the results in a couple weeks. They offer a 1.2/1.5/3mm. The 1.2 is a carbon steel ring with a moly face, the second ring is a napier, which I'm not overly fond of, and the oil ring is the vertical hastings type oil ring.

This could be a nice package for a part time street part time race engine.... I just put it in that kind of engine with no vacuum pump.

The no vacuum pump deal makes it sensitive to the oil ring tension.... Top ring tension I'd like to see the pistons gas ported if they are back cut in radial section. As for axial thickness.......... well that depends on your application... hose, no hose....
 

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Discussion Starter · #12 ·
Chris, do you sell this stuff?

If so, maybe I should give you a call?
 

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Well... I'm not really a big dealer that gets great prices... for the hard to get, custom stuff I will go out of my way to get, but if it's catalog stuff that you can get from Jegs or Summit I don't sell it.

If someone wants help ordering pistons, or ring package, or a custom crank, custom cam, custom cylinder head work, etc I will help with that.

Chris
 
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