Piston dome volume in CC's

[ΚĜΗΟŜΤ]

My biuld is getting near complete ( machine work and parts)

The pistons are in and they are Screaming Eagle part # 22868-00 forged 3 7/8 1550 pistons.

They say 10.5 comp ratio on them.

WHen we work out the numbers to achieve a 10 to 1 comp final ratio we will adjust the head CC's to accomplish this.

Was wondering if anyone knows what the small dome volume is in CC's of these pistons.

Thanks.

[jsachs1]

22868-00  =  8 cc.

22868-00A =  6 cc.
John

[ΚĜΗΟŜΤ]

Thank you!!                     

[L-]

Better put them on the rods, put the cylinders over them, bring them to top dead center  and see how that looks for your calculations with the gaskets you are going to use also.

L-

[ΚĜΗΟŜΤ]

I assume you are refering to setting deck hieght?

I am planning on doing that and adjusting (machining) cyclinder hieght for ZERO deck hieght and make total CC's for biuld at the heads.

I believe this is the plan.

Any suggestions to the contrary??

[rking1550]

bigboyz head porting has a calculator on their web page to figure this stuff out. they have the 10.5 pistons listed at 11.5 - 13 cc.  when calculating mine if I use the 11.5 cc  volume , it worked out to 11:1 static compression  it also worked out to exactly the ccp I got on the gage  206 . so I would say their numbers are right , at least in my case. if you have the pistons already you might want to check them  just to be sure , rather than taking a educated guess and having too much compression or to little if the numbers go the other way. just a suggestion. They guy who did my heads said I would end up with 10.6:1, which is not what I have, Always better to double check . and mine was with a 0 deck height.  good luck

[ΚĜΗΟŜΤ]

I also did some more google research,

the BigBoys calculator says 11.5 - 13 cc's, I would like to know why/how they got those numbers?

My google search showed 8 cc's when they were physically measured and reported.

Jsachs says 6-8 cc's and From what I have observed, He would know.

Any other opinions to the contrary?

[jsachs1]

   

[PanHeadRed]

Those calculators also have 95" gaskets listed as 3.95" in diameter.

[POORBOY]

Don't dout what John Sachs said

[mayor]

Any other opinions to the contrary?

here's a thread where PanHeadRed backs up John (w/pics):
http://harleytechtalk.com/htt/index.php/topic,1419.msg11700.html#msg11700

[L-]

Looks like you are on the right track.  Deck height has to be considered. One shouldn't just rely on published data since it can be measured.  There are some 11.0 builds out there that sure crank easier than my little ole 95 with 10.0:1 with HQ-0039 cams and travel limiters. ......

L-

[rking1550]

what about the
22870-00
and the
22869-00  pistons
is there much, if any difference in the cc's of the .005 and .010  pistons ?
 

[springer-]

the BigBoys calculator says 11.5 - 13 cc's, I would like to know why/how they got those numbers?

Reverse engineering at the time I was writing the calculator.  It also clearly states, "Values in RED are approximate.  Use actual measured values only"

Those calculators also have 95" gaskets listed as 3.95" in diameter.

That was based on Actual measured gaskets at the time I wrote the calculator.  It also clearly states, "Values in RED are approximate.  Use actual measured values only"

Can't stress enough Use actual measured values only"  .... Measure EVERYTHING.  It is the only way you get accurate results.  The calculator is based on common and widely used math formulas, no magic there.  As the saying goes, "garbage in equals garbage out".  You can not use someone elses numbers and expect it to be accurate.  Measure it!!!

[Tsani]

 

[PanHeadRed]

You can not use someone elses numbers and expect it to be accurate.  Measure it!!!



My point was, yours is not the only calculator with misinformation.

But while were on the subject your TDC values for the T/C Crane 290 are also incorrect.

[springer-]

But while were on the subject your TDC values for the T/C Crane 290 are also incorrect.

the crane numbers were from cranes website at the time.  do you have other numbers that you consider more accurate and can you tell me why they are more accurate?  please send me a pm.  btw, i spent days calling many of the cam manufactures and checking their specs vs what they had published.  many of them were wrong.  i am always open to correcting cam specs as i try to have the most accurate info for the cams.

thanks