Dubai_racing

hi

I have a project in mind that i want to ask you about and see if its gona work. I wanna work on the 8.1L L18 engine that of the Avalanche and make it a proper racing engine. As u know its a big engine and am looking HP's.
I know what to do to the block of the engine but am really abit lost in what to do for the heads. Am looking for +1500HP. is it going to work with this engine. Is there any ready made racing heads that will fit for this engine.

And does anyone know how much all of this is gona cost me.

gectek

iTrader: (2)

Horsepower is normally a funtion of RPM, and TQ is a function of displacement for the most part. You will get HP out of it, but maybe not as much as you think. They do not like to pull RPMs, kinda like a Diesel engine. They produce loads of TQ tho. That is why they were not used in cars, but big heavy vehicles.

The key to your build is valvetrain and getting it to pull RPMs. A very good cam, not an off shelf. I would def look to Comp Cams first because they make performance cams for them, but talk to them about a different setup for the turbos. The heads, I am unsure of, but it may be the only way is just to get them ported and as for the intake, that one is up in the air as well. Im sure there are companys that make intakes for them, i.e. sheetmetal, but am unsure of any cast intakes you could use.

slow67

iTrader: (2)

If I'm not mistaken, the 8.1L blocks are weak.

I would either call a sponsor, or someone that has lots of experience with high hp big blocks (like Steve Morris at New Era Racecraft).

gectek

iTrader: (2)

this is what i found just from a little searching
http://chevroletforum.com/forum/showthread.php?t=7474

WS6HUMMER

iTrader: (19)

They are also not related closely to the LS engines.

smokinHawk

iTrader: (48)

they more your better off getting a LSX block with a 4" crank, stonger, more aftermarket for it and will flow and make more power.
shipping is probably the same for both and by the time you build it to withstand 1500hp the lsx would be "cheaper"

gectek

iTrader: (2)

um really, even though this is LS1tech, could this thread at least go 20 posts before someone starts about the LSx anyway? IF he wants to work on that, why dont we try to let him know what is going on.

Why doesnt he just go TT on a skyline for that matter?

Honestly.

The 8.1L is more closely related to the big block than any other engine family. Although this was not the right place to put this thread, it an still get good information, although I do not believe this forum is the best place to discuss 8.1L performance at all. Maybe somehwere in the Big Block section, or another forum like the one i posted

andrew69_04

iTrader: (148)

raylar makes heads and cams for these 8.1's. only place i know of. there was a guy that turbo'd his 8.1 in his 01 silverado, look it up on youtube. ran pretty dam good.

gectek

iTrader: (2)

if you read the thread i posted, there is more info on the cams avail....comp makes them as well, and i just posted that.

http://www.compcams.com/technical/Ca...07/206-207.pdf

Silver_TransAm

iTrader: (2)

My dad has a twin rear mounted turbo 8.1l truck. All stock motor with just fuel upgrades. Truck ran a trap speed of 105mph on a conservative tune at 14psi. Truck weighs 7,000lbs and still pulls a travel trailer every other week.

Silver_TransAm

iTrader: (2)

This motor does not like anything higher than 5000rpms in stock config either.