350 engine build -compression question ?

hey there i have a std bore 4.000 350 with flat top pistons with 4 valve reliefs which i believe are -6cc and the heads im using are the 882's 194-150 , 76cc and are milled .030 , head gasket is 1003 fel-pro which is .041 thick what would be a estimated compression ratio ? the piston sheet said with 76cc heads and flatops would be 9:1 ?? the block has not been decked either !!

 

- 1cc per every .006" milled... So, your probably looking at around 9.5:1 would be a rough guesstimate.

 

yeah man thats what i was thinking too , nice to hear another persons input

 

Your welcome bud!!

 

If the pistons run to zero deck, you've 9.46:1. If they're 0.010" in, you've 9.26:1.

 

rightt on man thanks

 

no decking of the block is going to put the piston down in the hole.020to .025

pin height on the piston will add to this if rebuilder pistons were used

fel pro 1003 adds 9.1 cc to the head ......... 4.166 bore and .041 compressed

most 2 valve reliefs are at -5cc...i am not sure the 4 would be at- 6

4.0 bore
3.48 stroke
factory piston is gonna put it down in the hole roughly .020 if a cast rebuilder piston was used add another.020
fel pro 1003 9.1 cc
really should cc the heads to see what they are at...... .030 shave on 882's is quite a bit

doing the math quick you should be right aroound 8.5 -1 maybe 9-1 depending on the actual volume of the heads

if the valve reliefs are more and a rebuilder style piston was used it will be less

do you know the part number on the piston so we can get the pin height?

Fred

 

hey fred the pistons are mahule partnumber #5999110080303

 

If the blocks not decked i bet the pistons are at least .030 down in the jug ,you should check to get your quench right at .035 to.045..

 

Give me a hint Please? have a 16 comp whitout sparkplugs 350 400 crank 383.
flat top piston,afr heads,
16 a little to much ??????

 

nahh ur goin too need the angleplug conversion kit from summit to run that comp part number 3825633 lol......and u should run the .25 head gasket made from canadian hermaphrodite unicorn rare but not as rare as hens teeth

 

If you want to bump the comp a little more, you could do a .028 head gasket.

 

the heads have been torqued down but is still on the stand will these head gaskets still be good where they were just put on a few days ago ? the motor has not been run

 

A pair of 4V 305 cyl. heads with 57-58 cc chambers should bump the comp up to about 10.2:1 ..... Be prepared to run 93 octane fuel.

 

Those 305 heads are crap. They're really restrictive, even on a 305, they suck. You'll lose power even though they raise the C/R. They just don't have the flow to make the go.

 

or i could go with a set of 64cc and run a 0.015 gasket haha hmmmm