jfman

iTrader: (6)

Anybody know a little about these motors ?

Are they big blocks ?

Can you use them in building a big block vintage chevy ?

mrdragster1970

I was told it's a 496-502 BBC, I heard GM sells them as crate motors, and they came in Pick ups. Just word of mouth, never saw anything in writing. I'm sure motor mounts are stock, so that should help. I know a few guys that drag race them, they like it.

GOaT Cheese

It is the latest big block, very little interchangeability between it and say the MK4/5 engines. It is not a 502, the 502 is the old school big block, the 8.1 is it's own engine. Displacement is I think around 496 inches. I could find out exactly if you like.

VORTECFCAR

iTrader: (2)

they are 496 cubes...

no interchangability I belive.

OKcruising

they are basically a big block, but with LSx features. 496 cubes, but nonexistent intercompatability with the older bbc's.

They are nice though, you get fuel injection. I love mine in my truck.

jfman

iTrader: (6)

What's the bolt pattern on the transmission mounting area ?

LSX bolt pattern or SBC/BBC bolt pattern ?


What about the mounts ? Are they lsx style mounts of BBC style mounts ?

OKcruising

Hmmm, try this thread, it may help.
if not, search over at thedieselplace.com

http://performancetrucks.net/forums/...0+motor+mounts

jfman

iTrader: (6)

Thanks finaly got some info !


installed the 8100 with no problems at all
every bolt in the motor is metric, M10x1.5 for most everything, bellhousing, motor mounts, etc, m8x1.0 for the exhaust an so on.

stock big block hedders bolted up to the motor, as well as stock motor mounts for my 1967 pickup. I mated it with a 1968 Turbo 400 transmission and the stock 8100 flex plate bolted up to it fine! i even used a starter for a 1980 small block chevy, $35.00 at autozone!!

everything is the same demensions inside the engine. my inital install the motor was stock, and this past two weeks i pulled the engine and Installed a ZZ502 camshaft (224/234@50, 544x527 lift)from gmpartsdirect.com, $160 shipped and converted to adjustable valve train with some arp studs and harland sharp rockers.

yes the firing order is different on a 8100, and yes the zz502 uses the classic firing order, no problems, my 8100 just runs on 1-8-4-3-6-5-7-2 now with no problems.

i'm using a wasted spark ignitino system instead of coil near plug, usinga 1990 lincoln towncar EDIS-8 ignition moule, and GM DIS coil packs. the EDIS-8 moule uses a 36 tooth wheel and a VR crank sensor. I moutned the 36 tooth wheel to the backside of my harmonic ballancer, and made a bracket that attached to the timing cover bolts. all timing and fuel are controled with a laptop running free software and everything is one in real time, no reprogramming..its on the fly.

OKcruising

I can't wait to see some numbers. Haven't heard of anyone going to a old school camshaft before on these engines.

hannes_slanec

Hello JFman, do you want to sell what you removed from the 8.1.
I have bought a 8.1 Vortec shortblock for my 68 Impala and want to get it complete. I would appreciate any performance hints.
Would be interested in Alu-heads, any idea?

Thanks and best regards

Hannes

jfman

iTrader: (6)

the info you see in red I got from another board. I dont own that motor.

ONEBADASSWS6

Interesting info.

The only thing I had heard about the 8100 was that it was a derivative of the old 7.4L 454ci Big Block from the mid 90's.

Apparently they adapted some of the LS technology to the old big block design??

Imagine if they took the big block and made a next generation, similar to what GM did with the Gen III small block?? Using the same design features, such as the structural oil pan, 6 bolt mains, high flowing heads, valve angles, combustion chamber design, ect?? It would probably be making 500HP, minimum, in stock form.