Blew first LS headgasket today...
 

Well, i blew my first LS head gasket today, and only at a miserable 10 psi. Pulled the plugs after i had the car towed home, and #4 cylinder must of toasted...plug was nice and shiny new looking, and plenty of steam came out of the plug hole ::) I ordered up a fel-pro 9698pt MLS headgasket for tomorrow morning, and was just wondering when i torque the head bolts back down, should i torque them a hair more than what the service manual says? I know that the b18a1's had a service recall for re-torquing the heads, was also wondering if anyone new where i could find the info on this bulletin too. Just hoping that if i torque it a little more, this won't happen again any time soon :P

Re: Blew first LS headgasket today...
 

just get some ARP head bolts and problem solved ::)

make sure you unbolt the head uniformly

Re: Blew first LS headgasket today...
 

I constantly re-use honda headbolts without problems, ---- probably re-used my z6 ones on 4 different motors, but I always do a 5lb-ft overtorque just for a lil extra peace of mind.

Re: Blew first LS headgasket today...
 

Well, it doesn't really matter any more...pulled the head off to get ready for tomorrow, and the headgasket was fine. Unfortunately the cylinder wall wasn't...I have a huge split in the #4 sleeve that cracked both the inner and outer sleeves and is about 3 inches long. :'(

Re: Blew first LS headgasket today...
 

OUCH, that sucks. oh well, rebuild bigger and better!

Re: Blew first LS headgasket today...
 

I want to, just trying to find another block for a decent price. Almost debating going back to D-series...for all the time and money I dumped into this LS turbo setup, I could've built my d16z6 that i sold to handle way more than what I nuked this LS at.

Re: Blew first LS headgasket today...
 

LS blocks are cheap, im really supprised you cracked one at 10psi... dont give up just yet.

Re: Blew first LS headgasket today...
 

Seriously..


Was it tuned?

I'm assuming it wasnt.. or it wasnt tuned right.. If it was. what where your timing maps like?

Re: Blew first LS headgasket today...
 

haha, woulda have to had been like a basemap without bothering to use any of the ignition boost retard adjustment functions

Re: Blew first LS headgasket today...
 

Hey I have a spare block here, if you want we can work out a deal

Re: Blew first LS headgasket today...
 

I'm going to check out a motor this afternoon and see how it is, otherwise i think i'll take ya up on that block...and this time i can probably come and pick it up lol.It was running a vafc2 that was wbo2 tuned by my buddy, walbro 255lph pump, 450cc dsm's, and one of those crappy b&m fpr's turned up to 65psi. I think it had issues to begin with, timing was manually retarded completely and the vafc's richest setting dropped down to around -28 that still gave me a 10.5:1 afr. It was a mystery motor though...i know the kid who owned it before me beat the living ---- out of it, and for all i know it probably had 200,000 miles on it ::) There was no other reason it shoulda popped like it did...hell even my z6 i ran at 12 psi on the afc for longer than that and i never even had one issue with it.

Re: Blew first LS headgasket today...
 

why did it pop? cuz the vafc.... tuned or not

Re: Blew first LS headgasket today...
 

head studs r a must, head bolts pull the block toward the head, example rips the ------- threads right out of the block, plus the bolts loose tensil strenght, head studs pull the head onto the block, less bullshit and no worries.

Re: Blew first LS headgasket today...
 

I'm not denying that the vafc had something to do with it, but even if it did run lean it should never have cracked the sleeve, if anything torched out a piston and broke a rod. The rotating assembly is still fine, just the sleeve was shot.What would studs have to do with the sleeve? ??? Head studs are def. on the list for my new project though along with a few other goodies ;D

Re: Blew first LS headgasket today...
 

detonation from hella advanced timing? look at steavemodes old motor, 4 broken pistons lol and they were forged

Re: Blew first LS headgasket today...
 

yup afr's mean nothin with all that timin in the motor

Re: Blew first LS headgasket today...
 

Even with the dizzy fully retarded i don't think it would've advanced that far :l Manually retarding it all the way is alot of timing being taken out. I do know that a couple days before i started loosing boost for no apparent reason...everything was tight and clamped down good, but slowly started dropping a few pounds. I tried advancing it back a hair to see what would happen and it detonated pretty bad, so i dropped the dizzy back to where it was before. Still never got the psi back, but not that it really mattered after that anyway. I picked up a b16 block i think i'm gonna do up for boost, so this time around i want it chipped in TE and depending on what head i decide on, i might keep the vafc hooked up just to use a vtec head and try running it with a chipped pr4. Besides, LS heads flow like buttmud :X Isn't there another head that's non-vtec that flows almost the same as a b16 or b18 vtec head? I remember a thread on it going back a while...

Re: Blew first LS headgasket today...
 

Its the b20 head but it has 84mm chambers no go on 81mm pistons


Valve Job on a ls head does wonders

Re: Blew first LS headgasket today...
 

yes the P8R head has vtec valves in it but it has LS ports so it flows real close to a b16 head but with porting flows real well. it has 47cc chambers with an 84mm chamber bore. i have one so if anyone has any other questions hit me up

Re: Blew first LS headgasket today...
 

Well, i'm set up to do p&p jobs, maybe i'll spend a little time with the LS head and see what i can get it to flow on the flowbench. Even with a new set of valves and cams and a decent p&p job, my biggest concern is revving the motor up high...from what i've heard the LS heads are notorious for popping off rocker arms.

Re: Blew first LS headgasket today...
 

With a diy set up on port work dont expect the power range to shift much even with a set of larger cams

Re: Blew first LS headgasket today...
 

Well, i did alot of port work during my years at the race shop i used to work for. I had a good teacher when i first started learning, and even though my setup is considered DIY, it still serves it's purpose...even down to my homemade flowbench. On an average on d16z6 and a6 heads i used to pull an average of around 75cfm over stock with just a mild portmatch and polish. I'd be happy to get an LS head to average out around 225-250 cfm, but it's gonna take a little more than a mild p&p :P