273 302 318 340 build

Just keep repeating..... "I need more CR.... I need more CR..." LOL

4spdragtop said

So more info on #2 318
Measured 3 holes. Average depth in hole was .0470" below deck.
Believe these are TRW pistons for 67-70 318. Advertised compression is 9.2 when used with 69cc heads and .039 thick gasket.
The guy sounds helpful/knowledgeable I hope to get a look at it this week.

Click to expand...

Well that would be better (I hope I AM wrong on this guy.) Clean/Scrape off a piston top and see if you find an Lxxxxy number on the top; the Lxxxx was standard TRW-ese. F in the 'y' position is for forged...I can't recall what the suffix was for cast.

Buuut, I compute 8.25 SCR with:
- 8 cc in 4 valve reliefs total
- .047 below the deck
- 64 cc head chambers with your 302 heads
If the 4 valve reliefs have only 4 cc's total displacement volume, then SCR is 8.6.

So much for 'advertised' compression... for 8 cc valve reliefs, it bumps up to 8.45 with the the .028 head gasket, and is 8.55 with the old .022 shim head gasket.

So you are in the low to mid 8's, it looks like...I wonder if his block was decked....