GM L18 8.1 engine question
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GM L18 8.1 engine question Hello
I don't know if I'm at the right place to ask this question.
but here we go:
we are aiming to build a beast with a 427ci on a LS1 Fbody; but the other day we saw the Vortech 8.1 (496ci iron block) sitting in the garage, so I'm thinking if we rebuilt this motor with a decent setup we will have a 600+ rwhp N/A.
now my question, where can I find all the internal parts (piston, rods...etc) + heads?
(I know people will say go with LSX; I already have the block so why bother buying a new one).
I don't know if I'm at the right place to ask this question.
but here we go:
we are aiming to build a beast with a 427ci on a LS1 Fbody; but the other day we saw the Vortech 8.1 (496ci iron block) sitting in the garage, so I'm thinking if we rebuilt this motor with a decent setup we will have a 600+ rwhp N/A.
now my question, where can I find all the internal parts (piston, rods...etc) + heads?
(I know people will say go with LSX; I already have the block so why bother buying a new one).
Is it the Big Block with the cathedral port heads?
I think the crank and rods are the same as previous BBC's, but you might run into problems with the pistons if the heads are cathedral ports, and not like old BBC's with the good/bad ports.
Plus, I have no idea where you'd find an aftermarket manifold or get a tune either.
I think the crank and rods are the same as previous BBC's, but you might run into problems with the pistons if the heads are cathedral ports, and not like old BBC's with the good/bad ports.
Plus, I have no idea where you'd find an aftermarket manifold or get a tune either.
Did you try a search?There has been information about the 8.1L engines posted on here.They are used in boats and the marine industry has some hi-performance parts for them.I believe it won't be cheap though.Look up Raylarengine.com for some info.Hope this helps.
You should bother buying any LSX block over that BBC you currently have because:
-The car already has provisions for an LSX block. Do some research into dropping a big block into a 4th gen and you'll see the headache you'd be creating for yourself.
-That BBC has very little aftermarket compared to LSX motors, so you're automatically limiting your options when it comes to pretty much everything performance.
-The car already has provisions for an LSX block. Do some research into dropping a big block into a 4th gen and you'll see the headache you'd be creating for yourself.
-That BBC has very little aftermarket compared to LSX motors, so you're automatically limiting your options when it comes to pretty much everything performance.
This can be done and it will do just what you want but you will not save any money just because you already have the block, you'll have to spend more than you'll save to build this one right. I have this engine in my Silverado and have contemplated the same thing. The LS1 computer will run it with a retune as it uses the same sensor, fuel injection, and ignition set up. You will have to buy everything from Raylar Engine as they are the only aftermarket for this engine but they have everything you need for that HP level naturally aspirated. You'll have to use thier heads and intake at a minimum and build the whole engine from there. There is not any carbureted intake avalible anywhere. The three main things you'll need to swap it in are BBC headers, a compatible bell-housing transmission, and a BBC crossmember mount set-up. The exhaust ports, motor mounts, and bell-housing pattern are all standard BBC. It will make a ton of torque and power will be in a lower RPM range than the equivalent LS1 based 427 engine. You'll need a stronger rear axle also, the ten bolt may last ten minutes.
My 7,000 truck with Allison 5-speed auto holds it's own on the street, I win way more challenges than I loose in it.
For L18 specific discussion goto www.dieselplace.com and click on the "GM Gassers" subforum. There's a current thread there now with a lot of input by Ray of Raylar himself on building this engine for the street.
Vernon
My 7,000 truck with Allison 5-speed auto holds it's own on the street, I win way more challenges than I loose in it.
For L18 specific discussion goto www.dieselplace.com and click on the "GM Gassers" subforum. There's a current thread there now with a lot of input by Ray of Raylar himself on building this engine for the street.
Vernon
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Comp cams has cams for these engines. The heads really suck in stock form and the Mercury Marine ported versions are not much better. Raylar has a good set up and their heads were designed by a guy that knows what he is doing; but even then they were never meant to be a race head. The engines are popular with the off road guys; but I have not seen that many in cars. A standard BBC would probably be cheaper in the end and would make more power.
69myway, on here swapped on in a 69 corvette, its a troque monter, of course that's what they were built for. I don't think many of the old style big block bottom end pieces, swap out in to these motors
They are great for anyone wanting a plug and play low end grunt type engine. The lower ends are not where the problem is and creative people can adapt parts from one engine series to the other. Raylar has spent the money to develop the parts for the marine world that would be worth looking at if you are wanting more than just a low end machine. The factory head design is not worth putting to much effort into IMO. Darin Morgan did the development work for Raylar if I am not mistaken.
Last edited by Mr.L88; Feb 25, 2010 at 09:24 AM.
