IMPATIENT 1

how much boost can we lay to a 5.3 alum block 08 longblock before they tend to push water with studs and gm headgaskets? we've gotta 08 5.3 and we'd like to put 18lbs to it with studs/gm gaskets, or are we gna have to oring the block?

Hank Peabody

iTrader: (2)

I'd like to know too. I think "skinnies" on here ran 16 with the stock L33 799 heads and GM headgaskets for an LS3 or something like that, and head studs, stock 10:1 CR. I could be remembering wrong, you might search on it. I was wondering if you put 317 heads on it giving more like 9:1 CR if you could get away with a little more turbo pressure since the cylinder pressure should be less. I guess the question is is 16psi at 10:1 CR the same cylinder pressure sas 20psi and 9:1 CR, or is that totally wrong thinking.

You would think 18psi should be totally safe though with studs, Ive run 16psi on a stock LQ4, stock bolts, stock gaskets, no problems. Or is the aluminum block a factor that lessens the amount you can run??

pwrtrip75

iTrader: (8)

Stock 5.3 shortblock with 317 heads & stock head bolts, I ran 15psi and a 50hp dry shot of N2O. On the standard one peice gasket. 3 years never had a problem.

I would think on a stock bottom end you'd push it to its HP limits before lifting the heads...my opinion... I could be wrong though.

Also the smaller bore = the more gasket surface area... not sure if that helps at all???

IMPATIENT 1

that's what i'm trying to find out. i know what the stock bottom ends will handle, but jus wondering how much boost will push coolant on a alum block 5.3 deal. we're doin these in dragboats, so its not like we'd ever see coolant pushed, we've got open cooling systems that feed from the lake and return to the lake. jus trying to find out if the alum blocks will withstand what the iron blocks do as far as sealing off combustion.

Grr

iTrader: (2)

If its stock bottom end, and your using steel gaskets and studs:

When the rods come out the side, thats about when it would start to push water. Which i would assume with a decent turbo would be about 20-22psi

IMPATIENT 1

lmao, does anybody here run or know of someone runnin a alum blocked 5.3 liter and how much boost are they see'n before pushing coolant is what i need to know i would ask the ls1 guys but the truck alum block is "supposed" to be stouter from what ive gathered.

Mike@Diablosport

iTrader: (2)

We made an easy 786 rwhp on a stock LS1 short block, if you need more than that, you should be considering a built bottom end anyhow

https://ls1tech.com/forums/dynamomet...light=786+rwhp

IMPATIENT 1

lol that's the kinda answer i was looking for! yes sir, not lookin for over 800 at the crank with it, but since its 10 to 1 alum 5.3 i suspect we'll be limited to around 16lbs tops before pushing, does that sound bout right?

Mike@Diablosport

iTrader: (2)

Not sure, we made that power with only 11.5 psi, thanks to a good set of heads and an 'all wrong' cam....

We'll be strapping down the same car after the new year looking for 1100+ with a new 6.0 bottom end with rods and pistons (yes, stock crank ), bigger heads (TFS 235s vs the AFR 205s), a new VA Speed Turbo cam vs the old TRak cam and a lot more boooost.

skinnies

iTrader: (33)

18lbs on the dyno it made 686rwhp, L33 5.3 with ls9 gaskets, arp head studs, gt2-3 cam, patriot springs, good pushrods. It's seen over 20lbs on the street and some LONG highway pulls, no coolant pushed yet. Ran the times in my sig off the footbrake and 18lbs.

IMPATIENT 1

awesome! so 800 at the crank is possible with a alum blocked 5.3 then! well i ordered the studs/pushrods/rodbolts, already had the gaskets.

slow67

iTrader: (2)

Quit asking if it will hold it or not, and get that 16'er on the water!!

IT_SS

iTrader: (5)

I want to have sex with that Vette by the way

Mike@Diablosport

iTrader: (2)

Have you seen the latest pics he has posted since its makeover?

Wait till he unveils his new hood....

IT_SS

iTrader: (5)

no I havent, I was drooling over it on ttf..... I want a white C5 now....

IMPATIENT 1

trying to bro, but having a hella badluck streak lately seems everytime i save up alil scratch to finish my 16ftr, something comes along and makes me spend it.

the alum 5.3 is goin into my uncle's 17ft earl tunnel, its the 1 that looks like a mini cheyenne.

canadoug

What internals did you run?

Old Buzzard

Another 10 yrs late to the party...

truckdoug

iTrader: (25)

this is timely tho. I'm building one of these

Pro Stock John

iTrader: (34)

One of the guys advising me made 30 psi and went 7.72. Not your average LS guy.

We been boosting mine 14-15 psi feels good. I plan to max it around 25.