i know i have dished pistons with releifs but the heads that came with to motor are world products stock replamements and do not specify in the part number what chamber size they are. i used a bore scope but do not have any numbers on the tops of the pistons so where do i go from here o and i bought the motor from a machine shop complete like this but it was over a 100 miles away and closed down. this motor has less the 3500 miles on it.

 

Unfortunately only the person who built the engine can tell you what is in it; anything else would be a guess

 

how would i go about buying heads and finding out what i have. can i just do a compresion test then go have the heads cc'd

 

Most dished SBC pistons are at least 10cc, so if you're looking at aluminum heads look for 64cc versions. This'll give you a driveable compression. I'm assuming the pistons are cast, and therefore you won't be adding boost or big doses of nitrous.

 

take your current heads off (You can also do this test by only removing 1 head) and go down to your local pharmacy and ask for the largest syringe minus the needle, they gave me one for free. You may want to reverse this process if you only have this car for a DD, while your out buy a set of head gaskets too.

While your heads are off use a dial indicator on the piston to tell when its at complete TDC then use a stright edge across which ever cylinder is at TDC and insert a feeler gauge between the piston and the straight edge. This will tell you your deck height.

Then level up your head on a work bench or something. Use a small piece of Plexiglass over the combustion chamber and begin filling with water. Make sure to add up all the CC's from the syringe until the head is full. That will give your combustion chamber size.

Use this calculator to estimate your compression ratio.
http://www.rbracing-rsr.com/compstaticcalc.html

If your 350 is stock the info/specs follow.
Bore = 4.000"
Stroke = 3.48"
Head gasket thickness = .040" for stock.
Deck height = which ever feeler gauge fit.
Piston top volume = more than 8.
Combustion chamber = CC's from syringe test.


FWIW---- you can use oil in the syringe and a piece of plexiglass small enough to cover the top of the piston and fill it with oil until its full. This will get you close to what the volume but wont be exact.

This process will give you the static compression ratio.

 

You really don't need that level of accuracy. A lot of work for nearly no reward. Very poor return on investment.

 

Do you have the part number?

 

yes but the part numbers do not specify what chamber i already called up world products

 

That's interesting. My World heads have the chamber size cast into them under the valve cover.

They also seem to list them by part number and chamber size. http://www.worldcastings.com/product...ron-heads.html

 

i called them lol. trust me look up the heads for some reason the stock replacement do not specify. under the driverside valve cover in the top left corner it says 2 in the top right it says r3 and in the center it says. world cast in the usa ego i-052 s/r

 

where else would the part numbers be on the head. do you think it would be only under one valve cover.

 

so they returned my email today. i was told if the heads are 2-3 years old their will be no way of determining the cc's without disasembly. and this only applys to s/r's