Engine rebuild advice
Thread Starter
Race Director
Joined: Jun 2004
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From: WI
Engine rebuild advice
I'm rebuilding my engine and have been considering CID options.
Use of the engine is mostly road course racing. Would staying 355 be better for this use?
Going to 383 would only be $75 extra in clearance work cost plus $200 for a Scat 9000 crank. (#CS383P6)
Pistons, would using an inverted dome type (dish) be better for combustion efficiency? KB164 411/102g $300 a good choice?
Rods, SCAT #26000 - I-Beam, 4340, 12-Point ARP Cap Screw, 6.000 in. $200
Use of the engine is mostly road course racing. Would staying 355 be better for this use?
Going to 383 would only be $75 extra in clearance work cost plus $200 for a Scat 9000 crank. (#CS383P6)
Pistons, would using an inverted dome type (dish) be better for combustion efficiency? KB164 411/102g $300 a good choice?
Rods, SCAT #26000 - I-Beam, 4340, 12-Point ARP Cap Screw, 6.000 in. $200
Team Owner
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Le Mans Master
Joined: Feb 2000
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From: Kempner Texas
I suggest you do some research on other piston options. Flat tops give the best flame propagation.
The BB racing engines I use to build all had pistons with knuckles, but on re-builds it was easy to see how the flame travel had been impeded.
Jake
The BB racing engines I use to build all had pistons with knuckles, but on re-builds it was easy to see how the flame travel had been impeded.
Jake
Melting Slicks
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One of my friends is selling this one down here:
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Melting Slicks
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From: S.L.C. UT
For the little money it costs these days to do a 383, it almost seems like a 350 is a absolute engine, especially if you need a bore and buy pistons and your 350 crank needs to be turned. Then it really isn't much more money.
And the added torque EVERYWHERE is huge, especially in our heavy (By race car standards) cars, makes a world of difference.
And the added torque EVERYWHERE is huge, especially in our heavy (By race car standards) cars, makes a world of difference.
Drifting
Joined: Dec 2005
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From: NORTHEAST
383 hands down, We used dished pistons where the rules said flat top pistons no dome pistons allowed 11:01 compression rule and we saw on the average 11 horse on the dyno. And we did get cought as they called it an inverted dome and had to got to a flat top piston after that.
Think of the flame travel with an inverted dome.
Think of the flame travel with an inverted dome.
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Depends on what class you want to run in.
383 will probably put you in the same class as T1 C5z06
355 most groups keeps you in the same class unless you go overboard.
If I did a rebuild and didn't care what class I'd go 383/396
383 will probably put you in the same class as T1 C5z06
355 most groups keeps you in the same class unless you go overboard.
If I did a rebuild and didn't care what class I'd go 383/396
Burning Brakes
Joined: Feb 2000
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From: Parker, Colorado, USofA
So what ARE the common displacements now? When I built the 383 (crap, about 10 years ago), it was a trivial cost over a 350 as it was so commonly ordered....407 (409?) was the new hotness, but had issues with jacket cooling....I think.
So 355, 383, 396, 40X, how expensive are the other displacements?
So 355, 383, 396, 40X, how expensive are the other displacements?
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Going to a 383 is +8 points in NASA. Im pretty sure that will bump you to TTA. I thought you wanted to stay in TTB? Unless you still run street tires.
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Race Director
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From: WI
Yeah I was going through the points and TTA it would be. NASA isn't even having a Road America event this year. I don't know what I want to do there. I guess I'll just do HPDE events for this year. I'd like to do TT and not a W2W class.
Piston speed on a 383 is okay with lots of WOT time road racing?
Seems a shame to put the hot cam in the 383 from my 350.
Piston speed on a 383 is okay with lots of WOT time road racing?
Seems a shame to put the hot cam in the 383 from my 350.
Race Director
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From: Texas
Yeah I was going through the points and TTA it would be. NASA isn't even having a Road America event this year. I don't know what I want to do there. I guess I'll just do HPDE events for this year. I'd like to do TT and not a W2W class.
Piston speed on a 383 is okay with lots of WOT time road racing?
Seems a shame to put the hot cam in the 383 from my 350.
Piston speed on a 383 is okay with lots of WOT time road racing?
Seems a shame to put the hot cam in the 383 from my 350.
Lots of us running 383s. Mine is new so I can't speak to longetivity yet. However I know of several that have >20k miles on their builds.
Budget is also a factor. You'll want to put your money where you'll get the biggest payoff relative to your goals. That seems obvious but I think we're all guilty of overlooking the obvious on occasion.
For a roadrace engine, I would focus on the lightest rotating assembly you can afford. You'll be surprised at how much piston and rod weight varies.
Le Mans Master
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The LT4 HOTCam would give you disappointing results in my opinion.
Lots of us running 383s. Mine is new so I can't speak to longetivity yet. However I know of several that have >20k miles on their builds.
Budget is also a factor. You'll want to put your money where you'll get the biggest payoff relative to your goals. That seems obvious but I think we're all guilty of overlooking the obvious on occasion. For a roadrace engine, I would focus on the lightest rotating assembly you can afford. You'll be surprised at how much piston and rod weight varies.
Lots of us running 383s. Mine is new so I can't speak to longetivity yet. However I know of several that have >20k miles on their builds.
Budget is also a factor. You'll want to put your money where you'll get the biggest payoff relative to your goals. That seems obvious but I think we're all guilty of overlooking the obvious on occasion.
For a roadrace engine, I would focus on the lightest rotating assembly you can afford. You'll be surprised at how much piston and rod weight varies.
When I build my engine Im going as light as possible. NASA also doesnt give points for lightweight forged rotating assemblies. I am staying 355 though so its hard for me to find a 3.48 stroke 1 piece seal crank that is lighter than 50 lbs. Rods and pistons get LIGHT though. 
Le Mans Master
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The only thing I could find from Scat was their cast 9000 series or stock weight forged. All the lighter ones were for a two piece seal. If you have a link or part number please share!
Le Mans Master
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From: Akron Ohio
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Sorry to get off topic.
As for the cam, the HOTcam is better at higher RPM. With a 383 and a superram I would keep duration on the smaller side and go with more lift. Are you having your stock heads ported?
As for the cam, the HOTcam is better at higher RPM. With a 383 and a superram I would keep duration on the smaller side and go with more lift. Are you having your stock heads ported?