question about PTW (piston to wall) clearance's

[brian97cobra]

I got my custom pistons from diamond. But this has to be a typo...

.0065 wall clearance???

my last set of diamond pistons were .0035

my cp's were .0045

they do have the double diamond coating if that makes a difference. but ive been told thats only like .002 difference.

 

[SlowSVT]

.0065 clearance?

Time to replace the pistons they are beyond their service limit. LOL You'll have piston slap right from the get-go!

My CP's call for .0045. I will set them at .0035.

 

[brian97cobra]

.0065 clearance?

Time to replace the pistons they are beyond their service limit. LOL You'll have piston slap right from the get-go!

My CP's call for .0045. I will set them at .0035.

yea my CP's were .0045 no slap at .0045.

diamond made no sense when i called.

they said that .0065 was before the coating on the pistons. but they say the coating is only like .0005-.0008. so even so how do they come up with the "install at this value"

total bs

either way im gonna run them as close to .004 as possible.

 

[SlowSVT]

yea my CP's were .0045 no slap at .0045.

diamond made no sense when i called.

they said that .0065 was before the coating on the pistons. but they say the coating is only like .0005-.0008. so even so how do they come up with the "install at this value"

total bs

either way im gonna run them as close to .004 as possible.

.004 sound more reasonable. The mfg probably assumes your running C16 @ 30 psi turning 8 sec 1/4's

If its Teflon coating that is usually used with tight PWC to minimize scuffing. I'm kinda luke warm on coating the skirts. The stuff can flake-off and may impede heat transfer to the cylinder walls.

 

[brian97cobra]

.004 sound more reasonable. The mfg probably assumes your running C16 @ 30 psi turning 8 sec 1/4's

If its Teflon coating that is usually used with tight PWC to minimize scuffing. I'm kinda luke warm on coating the skirts. The stuff can flake-off and may impede heat transfer to the cylinder walls.

The double diamond coating is hard anodized.

Idk my car made 1150-1200 fwhp before and is capable of running 8's at 25 psi with c16. That's what fuel I ran last time.

 

[SlowSVT]

The double diamond coating is hard anodized.

Idk my car made 1150-1200 fwhp before and is capable of running 8's at 25 psi with c16. That's what fuel I ran last time.

Anodize (aluminum oxide) is porous and not a very good conductor of heat (MMR red pistons are 100% anodized). Great anti-wear coating for the skirts but not much good everywhere else .............. IMO

1150-1200 hp on 25 psi running C16? That's risky!

Time for E85

 

[brian97cobra]

Anodize (aluminum oxide) is porous and not a very good conductor of heat (MMR red pistons are 100% anodized). Great anti-wear coating for the skirts but not much good everywhere else .............. IMO

1150-1200 hp on 25 psi running C16? That's risky!

Time for E85

e85 is only about 100-102 octane

e100 is around 106-108 octane

c16 is 116 octane

i dont see how that is risky


1150-1200 is fwhp. it put down just at 1000 rwhp and 891 rwtq.

 

[SlowSVT]

e85 is only about 100-102 octane

e100 is around 106-108 octane

c16 is 116 octane

i dont see how that is risky


1150-1200 is fwhp. it put down just at 1000 rwhp and 891 rwtq.

E85 has greater cooling capacity. Excessive heat has probably destroyed more Terminator engines than detonation. That's what I was getting at.

 

[brian97cobra]

E85 has greater cooling capacity. Excessive heat has probably destroyed more Terminator engines than detonation. That's what I was getting at.

yea during the combustion process when the e85 is burned the left over absorbs the heat and that i will agree with.

but i feel that a properly tuned car with the proper fuel will be just as safe.

 

[98 Saleen Cobra]

You'll be fine on C16.. if that's your choice of fuel

 

[SlowSVT]

yea during the combustion process when the e85 is burned the left over absorbs the heat and that i will agree with.

but i feel that a properly tuned car with the proper fuel will be just as safe.

The cooling effect of the intake charge of ethanol is much greater than gasoline which is one of it's main advantages. Your dousing the piston, valves and chamber with 40% more of a highly "evaporative" happy fuel which can make a huge difference at elevated power levels with regard to cooling. Pound per pound, compared to gasoline, E85 is pretty meek stuff (11000 btu's vs. 18000 btu's if I remember correctly) but your burning more or it.

I wasn't implying there is something wrong with C16. But I will say at those power levels E85 is an attractive option. The problem is finding a source for exotic fuels is like finding an oasis in the desert and not being able to stray too far from it. How much does it cost these days to fill the tank with C16?

Are the Diamond pistons 100% anodized?

 

[brian97cobra]

The cooling effect of the intake charge of ethanol is much greater than gasoline which is one of it's main advantages. Your dousing the piston, valves and chamber with 40% more of a highly "evaporative" happy fuel which can make a huge difference at elevated power levels with regard to cooling. Pound per pound, compared to gasoline, E85 is pretty meek stuff (11000 btu's vs. 18000 btu's if I remember correctly) but your burning more or it.

I wasn't implying there is something wrong with C16. But I will say at those power levels E85 is an attractive option. The problem is finding a source for exotic fuels is like finding an oasis in the desert and not being able to stray too far from it. How much does it cost these days to fill the tank with C16?

Are the Diamond pistons 100% anodized?

The pistons are fully coated top and bottom inside and all.

There are only 2 e85 gas stations within a 25 mile radius of my house.

Also at my power level I'd have to run id1600-id2000 injectors. I don't believe my id1000's will be able to spray enough fuel. Also my magnafuel 750 pump would probably handle it. But it would be close (just my opinion and what others have told me)

 

[04cobradude]

brian... FYI.. we made 945rwhp with Jeremy Haymore's car on 80lbs injectors and E85 on my dyno...

 

[brian97cobra]

brian... FYI.. we made 945rwhp with Jeremy Haymore's car on 80lbs injectors and E85 on my dyno...

Cool.

Good info well maybe I have the fuel system after all. Just need the tune for it.