rkreigh

building a stock crank 4.8 with manley rods and 3.82 bore

everyone recommends the ls9 but the bore size is too big

does all this "crevice volume" fill up with carbon or something?

like to see what you all recommend as alternatives

running ARP head studs, only looking to turn it up to around 7k and about 24 psi with a target of 900 rwhp on E85 or race gas

car is a tiix turbo car with the rpm 4l65e lvl 7 tranny rated for 800 at the tire

I'm going to "push that" just a bit on drag radials but the car is 95% street with just afew high 9's at the track to make sure it still can!

JoeNova

Lots run the LS9 gaskets on 5.3s and 4.8s. Yes, the gasket bore is a little large, but they seal just fine.

cullen

iTrader: (3)

I used the chevy performance headgaskets for LS1. part#12498544 . It is a MLS style gasket

tblentrprz

How many layer is the 8544? I've gotten conflicting info, 3 or 5 layer. Many Thanks

rkreigh

thanks for the tips, the ls9 gasket I know will work, I'd prefer to see if there is one that fits better, maybe an o ring inside the factory one?

Mike moran put in some special o rings that seated in a groove in both the head and the block, and as soon as they warmed up, they sealed really well under high boost

thought of a "race only" mod, have any of you all heard of doing this

TrendSetter

I also am not comfortable having so much crevice volume. I ended up reusing the stock 3 layer steel 4.8 gaskets when i did mine. some copper coat and they were good to go. been driving on them over a year and pushing 14-18psi on the street. I may start having problems once i get a good tire on the truck and it sees some real load, but it is just as likely to work fine.

turboventura

Im pretty sure felpro makes the correct size mls gasket.

stevieturbo

Why not just use the factory MLS gasket for that engine ?

OEM MLS gaskets are very good quality

SWRocket

JE have some gaskets http://www.jeproseal.com/domestic.html

What manley rods you use?

I found just JE pistons for the 4.8... (http://www.jepistons.com/Catalogs/SR...-5300-pro.aspx)

rkreigh

sounds like a plan

I'm planning on running around 25 or so PSI

thanks for the links! I'm going to run a lunati 4.0 forged crank, and looking for rods and pistons

one 4.8 stock crank engine is almost done for my old 68 vette,

it has Manley H beam rods, wiseco 3.82 pistons, and I'll be shopping for cams and timing chain soon now that the mod money is starting to flow

the other stroker 4.8 will be going into my TTiX Z06 tiger shark

looking to go to about 1k reliable hp at the tire as that's all the current drive train can handle on drag radials

tblentrprz

Curious. Why the 3.82 bore/4.0 stroke ratio?

redss82

Liljohn motorsport had custom gaskets made up a while back .051 thick 5 layer MLS gasket with a 3.910 cylinder bore that might fit what your looking for

LS1NOVA

iTrader: (12)

Liljohns gaskets are 3 layer.

Ls9's hold up the best, I've tried them all, 3 layer GM, fel pro, cometic.

stevieturbo

What ever happened the fancy FelPros with a thicker laser welded ring around the fire ring area that appeared at SEMA or PRI a few years ago ?

Never really heard much about them.

Cosworth offer the same design for Subarus and they work superbly.

rpturbo

iTrader: (47)

If your planning on running high boost, then just lock-wire or o-ring it, like you were basically saying Moran had done.

tblentrprz

Fel-Pro 26191PT MLS Laserweld technology head gasket for 4.8/5.3 Not sure if this is the gasket that a few have mentioned using at 20+ without pushing water or burn through. Sounds like a reasonable option on a small bore aluminum motor where the LS9 does not have enough cylinder wall to seal against.

http://www.felpro-only.com/laserweld-stopper-layer/

video detailing design http://link.brightcove.com/services/...=1634400479001

light reading material http://www.enginebuildermag.com/2012...-applications/

LS1NOVA

iTrader: (12)

I believe those were the ones I used but that was 28psi out a of PT88 on a 5.3 with milled 799's and repeated pulls on a roadcourse so it was probably out of the range for sealing anything very long. Maybe worth another shot now that it has TFS 220's. Tuning is 90% of it and my skills are limited in that department haha.