My 400m was dekked 0.25 and bored 0.30 with forged TRW 8.2:1 pitond and 0.80 shaved off the heads how much compression would this engine make ? with 272/272 cam 524 lift

 

Any number of compression calculators on the internet, but you really need to CC(measure) the combustion chamber volume.

 

Gonna need to mill intake on head so intake will fit. Also gonna need custom pushrods also. why did you cut so much off heads??? Seems like to much and possible head gskt issues sealing to block. If head gskt sealing to thin could allow the head gskt to move a little. Could of split the difference between head and block being decked. just curious on your thoughts. CC heads and go to www.wallisracing.com for calculators for figuring these things up for your application.

 

The engine was like this when i bought it i was told it was deked 0.25 and bored 0.30 over and the manifolds were all ported to match together and the smog stuff had been removed heads milled 2mm think that is just about 0.80 this motor runs realy strong

 

How far are the pistons in the hole ? Are they flat tops or dished ? If they are dished how many cc's? How many cc head gaskets are you using ?

 

Pistons are dished but i dont know the specks on how far in the hole they are or the gasket's

 

if you assume 12cc dish on the pistons, nominal for 8.2 pistons, and open chambered heads milled 0.080 inch, you will have 9.9-10:1 compression with a 0.041in compressed head gasket. to find the absolute static compression ratio you will need to know the chamber volume of the heads (as they measure). HTH

 

Okey i will try to get the info from the guy how built the engine ... someone told me that the compression ratio was just ower 10:1 but i thought it could not bee so much

 

and as wyo4x4 stated you'll need to mill the intake (angle too???)(which also means dedicated to these heads), to make up for the 0.080 inches taken from the head to line it all up again.

 

yes the mainifold is milled and on the head its a edelbrock 400 preformer all manifolds and heads have been mached together and ported the smog crap removed and block dekked 0.25 and bored 30 over .... im using a tappered 2" four hole spacer and 750 1411 edelbrock and dui hei diss with live wires

 

Have you checked piston to valve clearance ? Everything that has been done to it decreased it. imo .080 is too much off a head. It could leave you on the side of the road somewhere, someday. I never trade off durability for power in any street motor. Rather than trashing a good intake I would have milled the heads intake surface, I doubt it would need .020 off each head if even that.

 

I havent cheked the clearence but i wander how high lift cam i could use ... was thinking about crane roller 278/286

 

Can't know the second without the first. And there is a difference between duration and lift. I'm running a 284/284 duration, but lift is only .488@050. Cam grinds vary greatly.

 

Compress valvespring and see how much travel and then subtract atleast .060 for coil bind and this is the first things I would check. then do a rocker arm wear pattern on top of valve for pattern check. this will be the final thing to check and make sure your geometry will be decent and check the pushrods to not be touching or rubbing anything. Also check your rocker arm to not be hitting on valve retainer will cause valve guide wear and possible valve drop. A lot of things to check before. valve pattern check on valve tip is my biggest concern in your situation because so much has been machined. ASSUME NOTHING and check EVERYTHING!! Or you lose everything SCRAP IRON you go. IF positive stop rockers gonna have to grind out inside because of possible binding clearance. Rockers not really designed for high lifts with out checkin. Usually about .510 lift and things start to go bad with factory springs. The valvespring coils diameter is bigger dia. than the new springs usually being used these days but ASSUME NOTHING or SCRAP IRON. It can work but need to have your ducks all lined out and in a row. In my poor boy days we made stuff work and it can be done. Pushing the limits of reliability and valvetrain geometry was my biggest problems when getting into the .520 lifts on up with factory stuff. Newer springs and rocker arms and parts designed for application has saved me and made me less nervous. Only time I had problems was when I got lazy/hurry and had to make a muddbog and I made it sometimes I finished but at a expense.