F440 HP piston question

Did all '70 440 HP motors have pistons with valve reliefs or just the six packs ?

6bbl only. 4bbl were flat top.

And 440+6 packs were supposed to have special cranks too. You can read about it here (Section 8 "Engine" of the Service Training Manual, Page 5, 2nd bullet):

http://www.e-bodies.org/resources/service-manuals-parts-catalogs-tsb/


"All 440 engines have same crankshaft, except 440-6 BBL, which has shot peened journal fillets. This is identified by surface texture of fillet and portions of counterweight."

69 440 six pack had the same part number in the parts book. From my experience of taking original motors apart of both years, the FORGING number on both cranks was 2208160 ( from my memory) I have found that same number in a couple of other motors, on 69-70 only. I believe they chose that forging to shot peen for the 6 pack motors. I bet that same shot peened crank found its way into a few non six pack motors as well.

Nice link, thanks Cody and all who replied.

Yep!

I thought heavy rod motors (70-72HP motors) had a tall compression height piston, IE, FM-2355 "sixpack" piston? As the "stock replacement" FM- 2266 piston is below deck quite a bit.

Reason I'm asking, friend is rebuilding his original motor in his super bird and though it had been rebuilt, it had cast pistons without valve reliefs and pentastars on the inside of the pistons.

Getting ready for assembly, he's got the 6-pack, 2355 pintons ready to be installed.

They do.

If it's not a 6pk motor it didn't have valve reliefs and was lower in the bore than the 6pk motors.

IIRC, blueprint specs for '70 are,
piston pin height, 2.06" 6bbl and 2.03" 4bbl
deck height, -.001" 6bbl and -.030" 4bbl