Rebuilding my locked up motor, have some questions? PICS INSIDE

[Chevlowrider]

Last summer I took my truck out for a cruise and it bogged and locked up tight on me. come to find out the oil pump went out and i lost oil pressure. so i put it in storage and forgot about it till this past weekend i finally got the motivation to work on it again. so i pushed it on the trailer and brought it home. A buddy and i pulled the motor and tore it apart to the bare block to check out the damage. I think i got lucky only the main and rod bearings got chewed up. none of the bearings spun, everything from the cam up doesnt show a bit of damage anywhere still looks like brand new. all the cylinders still look brand new with all the cross hatching still very visible.






The block and the crank are getting dropped off at the machine shop on thursday. the block is getting boiled and all the oil gallies cleaned and the crank is getting grinded and polished.

Now i have a question, my motos is a 5.3 bored .030" over, would it make any sense to go with 241 heads milled down .030" to make them about 60cc on this motor? My buddy has a set with about 40,xxx miles he just took off his GTO and said i could have them with all the valves, springs, rockers, push rods, everything for $100. and milling them would cost $35 per head.

[AFSP1211]

241's milled .03" = 62.3ish cc's. Advantage of the 241's over you 862's would be larger valves. I'd mill your 862's .01" to get those down to 59.7ish cc's. Milling too much of the block mating surface will cause the need for milling on the intake surface so everything lines up right. I've heard anything over .04" off the 241's will require this.

.07" milling from heads will reduce the bowl by about 1cc

[Chevlowrider]

where are you getting your numbers cause i thought 241 heads were 64cc heads and the rule of thumb was .007" = 1cc. so if i milled them down .030" that would = 4.285cc. so that would make those heads 59.7cc heads around there anyways. not trying to prove you wrong im just curious.

[AFSP1211]

I just milled a set of 241's and did quite a bit of searching before doin them. 243's are 64ish. You were correct about .007" for 1cc. My typo.

http://ls1tech.com/forums/generation...241-heads.html

http://www.theturboforums.com/smf/ls...swap-info-etc/

[Chevlowrider]

I just milled a set of 241's and did quite a bit of searching before doin them. 243's are 64ish. You were correct about .007" for 1cc. My typo.

http://ls1tech.com/forums/generation...241-heads.html

http://www.theturboforums.com/smf/ls...swap-info-etc/

What if I had the 241's milled .040" what would that do for me? And my 862's are garbage turns out the guy I had port and polish them didn't have a clue what he was doin and was just removing material.

[AFSP1211]

That puts you just under 61cc. Get some flat top pistons and mill the 241's .03". That should give you a high CR.

[Chevlowrider]

That puts you just under 61cc. Get some flat top pistons and mill the 241's .03". That should give you a high CR.

I've already got flat tops. So if I milled the heads .030" what compression ratio would that put me at?

[pl4yboy]

There are plenty of compression calculators online. Google "compression calculator" and put in your information.

[AFSP1211]

I'm runnin a 3.9" bore, stock stroke, .041 gasket, and 241's milled .03" and I'm going to be high 10.8-11:1

[Chevlowrider]

Yeah I used one of those and it said 10.67:1 and I didn't believe it was that high but if that's what u got it must be right.