How much can be milled off the deck?
Thread Starter
Team Owner
Joined: Jul 2003
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How much can be milled off the deck?
The pistons Im looking at are Speed Pro Forged by Federal Mogul, they advertise a 0.022" deck clearance.
Im not sure how to ask this, but how much can be milled off the deck of an L98 before port alignment/seal, head clearance, etc come into play?
Looking to lightly bump static compression...
Pistons are +6.10cc
Im not sure how to ask this, but how much can be milled off the deck of an L98 before port alignment/seal, head clearance, etc come into play?
Looking to lightly bump static compression...
Pistons are +6.10cc
Race Director
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From: Texas
The pistons Im looking at are Speed Pro Forged by Federal Mogul, they advertise a 0.022" deck clearance.
Im not sure how to ask this, but how much can be milled off the deck of an L98 before port alignment/seal, head clearance, etc come into play?
Looking to lightly bump static compression...
Pistons are +6.10cc
Im not sure how to ask this, but how much can be milled off the deck of an L98 before port alignment/seal, head clearance, etc come into play?
Looking to lightly bump static compression...
Pistons are +6.10cc
Looks like the pistons you selected have a slight dome. If so, that will bump compression by itself. Also have to watch valve clearance.
Thread Starter
Team Owner
Joined: Jul 2003
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Typical is to mill so that the pistons are .010 in the hole. Some go to zero deck height. Stock pistons generally sit around .025 in the hole.
Looks like the pistons you selected have a slight dome. If so, that will bump compression by itself. Also have to watch valve clearance.
Looks like the pistons you selected have a slight dome. If so, that will bump compression by itself. Also have to watch valve clearance.
And this set:
http://www.summitracing.com/parts/TRW-8KL2491NF60/
With 2 reliefs, and +3.40
Anyone know a good way to figure compression ratio?
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From: Australia
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From: Overland Park Kansas
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http://www.popularhotrodding.com/eng...eze/index.html
The Speed-0-Motive article is good too, but I was surprised to find that it's been pieced out on the KB-Silvolite website. (And, I thought their engineers wrote it!) HA!
Seriously, there are two statements I feel should be qualified in the Speed-O-Motive article: The obvious one is where they suggest running lower thermostats to aid in the prevention of detonation. Since this forum is so smart, we ALL know it's going to take a bigger radiator/water pump to cool things down on 100-degree days. :-)
The other point is that dish pistons (in general) may not help quench as indicated. IMO, they forgot to qualify that statement. Notice early in the article quench is defined as the flat part of the piston that would contact the head at zero quench/clearance. With a true dish, it's face can be totally recessed -- meaning there'd be no real quench area. To follow the advice correctly, choosing a (dish) piston that's at least flat on the outside of the valve reliefs. An inverted dome would be a good example...or a stepped dish.
Last edited by GREGGPENN; Nov 11, 2009 at 01:30 PM.
Le Mans Master
Joined: Jul 2007
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From: Tampa Florida
Zero decking is not a problem....but piston choice (flat top, dished, domed, or multiple reliefs) can give you what your after with out the machine work. Just pick your parts and do the compression calculations for the all the parts working together as the others have suggested.
You can go the other way and shave the heads too.
You can go the other way and shave the heads too.
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Just a thought.
I know this doesnt answer your question...
If I were you, I wouldnt plan on bumping the compression too much over 10.0:1
why? because if you ever decide to supercharge it, you will be limited to how much boost you can run.
I know this doesnt answer your question...
If I were you, I wouldnt plan on bumping the compression too much over 10.0:1
why? because if you ever decide to supercharge it, you will be limited to how much boost you can run.
Thread Starter
Team Owner
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Figuring in the Pistons Ive got picked out, the heads, the head gasket, and the given boreXstroke size of a 350sbc...it gives me a compression ratio of 10.46:1
Should be a good strong runner on 93 octane.
Should be a good strong runner on 93 octane.
Safety Car
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From: Salem NH
If not, go for closer to 11:1.
All 10:1 does is make you wish you had boost, but know you can't run more than 5psi without detonation or reducing timing to around 20 degrees.
-- Joe
