304 standard deck height and safe max to shave off.

[tim_pato]

Default standard deck height for 304 heads and safe max to shave off.
Had a bit of a search on google and couldn't find A measurement, I've got a set of heads that have been tricked out some time in the past, Id like to have them shaved to up the compression a bit, but I'd like to make sure they haven't been ground already. And how much can you shave off them?

 

[Munz]

Need to measure the Combustion Chamber volume of the head and go from there

 

[ari666]

shaving heads is a **** way of upping compression btw.

you can get an idea if theyve been chopped by installing them and seeing how much clearance you have on your intake manifold bolt holes/valley. only a reaaaaly rough idea though.

 

[tim_pato]

Ha ha, flat tops are not in the budget atm. I'll see how much to get the shop to measure the cc? Standard is 63cc?

 

[mr j-man]

0 deck the block, cc the heads and then mill them.
Generally 0deck and flat tops will get around the 11.0:1 mark..

 

[tim_pato]

I'm only chasing 9.5 so if I get the heads and block shaved that should do it yeah?

 

[tim_pato]

Would the block height vary at all between motors and what how much would I need to get removed to take it to zero? Or is that something I should be asking the engine shop?

 

[ari666]

zero deck needs to be measured on the fully assembled engine. all bolts torqued to spec. each engine will be different.

if i recall, the dish in stock 304 pistons and CC of the chambers make 9.5:1 pretty hard to get

 

[mr j-man]

Id be taking the assembled short motor and the heads to the machine shop and have them perform your comp ratio requests.

Do u even know what compression u have right now?

 

[tim_pato]

Nah mate not a clue. I've gone with Hypatec flat tops now and I'll leave the block/heads alone.