402LS1TA

I am ordering a 402 from SDPC tomorrow. SDPC says the deck height on this motor is Zero. I've also got a set of AFR 205 66cc heads to work with. According to the RSR compression calculator, with a .040 head gasket my static compression ratio works out to 10.3 to 1. If I were to have the heads milled .024" to 62cc chambers, the ratio would become 10.8 to 1. Which I like better. I've got my eye on a 238/244 .605/.612 114lsa cam.

So two questions follow.

1) Would the milling cause issues with piston / valve clearance? (aka would flycutting be necessary?)

2) Any idea what the gain of .5 compression points would net in HP?

I'm trying to figure out if it's really worth it. I definitely do NOT want to have to flycut the pistons at all.

02sierraz71_5.3

iTrader: (2)

1) clay the comb chamer to check p/v You could also call afr I think theyre valve angle is small shouldnt be an issue

2) I would guess maybe 5-10 rw

3)how about a slimmer gasket to up compression cheaply?

Bryan @ Speed Inc.

iTrader: (19)

if the pistons have valve reliefs in them, then that cam shouldn't be too big... especially since the duration is relatively mild and it's on a 114 lsa. but leaving the heads the way they are will keep the valves that much further from the piston.... keep that in mind. i'd stick w/ the 10.3 cr. it will make great power. if you wanted to up the cr from 10.3 then i'd do over 11:1 to make any real difference in power. but i'd stick w/ the 10.3. my .02

PREDATOR-Z

What is the size of your valve reliefs?