Advanced Engineering Tech For the more hardcore LS1TECH residents

GM L18 8.1 engine question

Thread Tools
 
Search this Thread
 
Old 01-30-2010, 02:37 PM
  #1  
TECH Apprentice
Thread Starter
 
ELMiN8oR's Avatar
 
Join Date: Oct 2005
Location: Kuwait
Posts: 375
Likes: 0
Received 0 Likes on 0 Posts

Default 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).
Old 01-30-2010, 04:36 PM
  #2  
12 Second Club
iTrader: (10)
 
Black FormulaLs1's Avatar
 
Join Date: Jul 2004
Location: cape vincent NY
Posts: 2,089
Likes: 0
Received 1 Like on 1 Post

Default

i saw an 8.1L ls engine on ebay and was wondering the same damn thing....
Old 01-30-2010, 04:50 PM
  #3  
KCS
Moderator
iTrader: (20)
 
KCS's Avatar
 
Join Date: Mar 2005
Location: Conroe, TX
Posts: 8,853
Received 314 Likes on 212 Posts

Default

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.
Old 01-30-2010, 06:15 PM
  #4  
11 Second Club
iTrader: (2)
 
oldguy99Z's Avatar
 
Join Date: Dec 2005
Location: Lititz,Pa.
Posts: 128
Likes: 0
Received 0 Likes on 0 Posts

Default

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.
Old 01-30-2010, 09:40 PM
  #5  
TECH Fanatic
iTrader: (1)
 
3.4camaro's Avatar
 
Join Date: Aug 2005
Location: Galveston, TX
Posts: 1,203
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by ELMiN8oR
I already have the block so why bother buying a new one).
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.
Old 01-31-2010, 11:55 AM
  #6  
12 Second Club
iTrader: (10)
 
Black FormulaLs1's Avatar
 
Join Date: Jul 2004
Location: cape vincent NY
Posts: 2,089
Likes: 0
Received 1 Like on 1 Post

Default

i wonder how it would last on a monster shot of juice......
Old 01-31-2010, 04:50 PM
  #7  
TECH Regular
iTrader: (3)
 
Manic Mechanic's Avatar
 
Join Date: Jan 2005
Location: Magnolia, Texas
Posts: 464
Likes: 0
Received 0 Likes on 0 Posts

Default

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
Old 02-07-2010, 09:20 PM
  #8  
TECH Addict
iTrader: (8)
 
elias_799's Avatar
 
Join Date: Oct 2008
Location: toronto ontario canada
Posts: 2,047
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by Black FormulaLs1
i wonder how it would last on a monster shot of juice......
from what i heard, not very long at all
Old 02-23-2010, 06:22 PM
  #9  
Staging Lane
iTrader: (1)
 
Mr.L88's Avatar
 
Join Date: Dec 2004
Location: U.S.A.
Posts: 74
Likes: 0
Received 1 Like on 1 Post

Default

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.
Old 02-25-2010, 04:55 AM
  #10  
Banned
iTrader: (43)
 
poconojoe's Avatar
 
Join Date: Aug 2008
Location: Northeast PA
Posts: 1,066
Likes: 0
Received 2 Likes on 2 Posts
Default

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
Old 02-25-2010, 09:15 AM
  #11  
Staging Lane
iTrader: (1)
 
Mr.L88's Avatar
 
Join Date: Dec 2004
Location: U.S.A.
Posts: 74
Likes: 0
Received 1 Like on 1 Post

Default

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; 02-25-2010 at 09:24 AM.



Quick Reply: GM L18 8.1 engine question



All times are GMT -5. The time now is 12:07 PM.