The 8.1L has been picking at my mind for over a year now. Especially the thought of it going in something older, 80's chevy SWB would be cool as hell.

Before the retards chime in, this isnt a small block, I dont plan on wrapping it to 8000 RPM. I'm not looking at building it in stock form. 9:1 compression isnt appealing. I already have a fun LS1 so dont bring in the "you could build a 408". I could build a SB1 if I wanted but thats not what I'm wanting.


What I want to know is info on after market support for this motor. Does anyone make a forged piston for this motor or H beams? Does anyone have specs on these parts? I'm having a hard time finding anything. Rod journal, rod leanght, stock compression height on pistons. All of it. The crank I've seen is nodular iron which I could probaly get away with leaving alone.

Block integrity? Has anyone pushed one of these motors ever? I've never seen it.


Next onto the heads. Are there any aftermarket aluminum heads? Any info on the stock heads? Porting etc.


I've driven these motors and I like them, they make a **** load of torque or would be fun as hell to build one since I've never even heard of anyone building one. Its a 496 so theres plenty of cubes to take advantage of.

No these motors werent made for performance but that doesnt me ****. Look at hondas, as much as I hate to say it I've seen some bad hondas. Any motor can be modified to produce power and with that much dipsplacement it makes it that much easier.


From what I've read a Th400 will bolt straight up to these and they except old school style BBC headers.

It would be alot of fun to have this motor in a fast truck. Tons of torque the power would be instant. With that many cubes I would build it for nitrous and fuel the HP with that, 350 range.

 

doesnt help ur thread, but my dads boat has twin 8.1's and they are great motors.

 

Can you say notch back torch and welder? That would be a fun ride !

 

http://www.raylarengine.com/cylinder_head.html

 

If aftermarket performance parts aren't here yet they are on their way and close.
I've researched this about a month ago. Didn't put much time into it but I got the info I needed.
I bought a 2003 8.1 swap over from a junkyard 75 miles from me, it came out of a wrecked truck with 32,000 miles, They ran it for me, I paid $2500, they pulled it and set it in the back of my truck. I set it in my garage with future plans for it when my current projects are at a stopping point.
I just got the idea to look on car-part.com and was suprised at the price so I crammed a bunch of info into my brain about mods and whats out there, I seen enough to know theres potential so I bought it.

 

I asked people about it a while back too and they said it wasnt a performance motor and as far as I've figure out you can make anything fast if you know what your doing.

I want throw a forged crank/rods/pistons aluminum heads 11:1 into a notch back with a 400 shot threw direct port. That would be one wicked *** fun street car. 1000 fly wheel horse in a 3000 lb car with that motor.


That website above is real interesting. I had not seen it until you posted it up. Good post

 

If you're going to do all that work why not build a 496 out of an old 454?
I do not understand why you need a factory 496 if you're going to change the whole rotating assembly and heads. I know you're not doing it for the factory SFI because you could get an aftermarket SFI set up to make 1000 hp easier than the factory stuff.

 

My plans for the 8.1 are to swap it in place of a TBI 454. The dually in my sig.
The stock 8.1 alone is a big power increase, plus I'll be able to tune it with HPTuners, and use some minor bolt on mods in the future.

 

Are heads interchangable on those motors? Do you have to clearance the 454 block for the stroker crank from a 496? I'd rather have a fresh block to work with. I havent been able to find anywhere that gives me the specs on the 8.1 to know whats interchangable in it. I can come across 8.1L for a fraction of $2500 thats why I'm considering it. Probaly the same price I could get a TBI 454 for. No I dont plan to use a factory intake but I would like to use factory computer and wiring harness. I would probaly use a sheetmetal intake or one like Raylar makes.

Are the U haul or van heads different (worth a damn?) than the 2500 truck heads. Are there different versions of this motor with more desirable parts?

 

Here's what little I know about the 8.1L:
The heads on the 8100 are NOT interchangeable with any other generation BBC. The only aftermarket heads/intake available are from Raylar, nobody else makes gen7 parts that I know of. There are no carb/distributor intakes available, so it's stock EFI or nothing. I hear (don't know for sure) that the block has provisions for a distributor, so you could have a custom intake fabbed to run a carb/dist. The stock throttlbody is a drive by wire, so you need the gas pedal assembly from the donor vehicle. It's a tall deck block, 4.25" bore x 4.37" stroke. Basically, nothing interchanges with the older engines although motor mounts, flywheel, and headers will bolt up if you use appropriate (metric) fasteners. All fasteners on this motor are metric. The firing order is different as well---I hear you can use an older style cam, but the pcm obviously needs the firing order altered.

Because the 8100 is no longer made, I don't see there ever being much of an aftermarket for this motor. If staying close to stock, tough motor for sure. To make big power, you'd probably be better off with a Gen6 or older.

 

I always thought it could be a good engine but do some home porting, cam regrinding maybe unless they make aftermarket cams for it. I'm thinking they do! Boost or nitrous would be needed to make up for added weight but that's my opinion. A low mantinence turbo with maybe 8psi to start....PT76'ish...ooo

 

Comp makes cams for this motor, Raylar makes intakes. These motors are used in lots of boats. I'm pretty sure the 496 used in boats is the same motor. From what it looks like on Raylar they are. And I beleive they are still in production.

There was one in a brand new U-haul I drove last weekend. I think it was an 07 GMC, it only had a few thousand miles on it.

 

I've got one at home. I wanted to put it in my 86 chevy truck. You know 6" lift 35" tires. Just to have extra torque to move it around with. You'd never be able to spin it very hard though, the bottom end just won't take it. If you ever drive one of the trucks that these engines came in GM has the factory shift points set at 4500. I have to say it, that's for a reason

I hate to sound like I'm comming off as being hard but if you are interested in this engine block because you are on a budget, then honestly......an engine of the magnitude that you are speaking of is a bit out of your league right now.

 

If you're wanting big block, save yourself all the hassle and make more power with an older block for a starting point.

 

I have some experience with the 8.1l. Yes the heads will not interchange. But so much other stuff will. Rod and main journals are the same. I used 6.700 long BBC rods in mine. I did have custom J/E pistons made. Exhaust manifolds are the same and it has prevision's for old style motor mounts.
If someone wanted to make a carbed intake for it. A distributor for a tall deck would drop right in.
I had Raylar's heads, 106 cam, and intake on my truck. On a ok tune it went 14.40 on the motor and 12.44@ 108mph on a 200hp shot in a 7000lbs truck.

 

Um stick with a 454 if you want to go that route
only one place sells parts for them raylar
I thought about putting one in my 04 silverado
Then after trying to find certain things etc. The cost wasnt worth it. I could build a 454 and buy a couple other things and still be less in the hole then tryin to use a 8.1. If you need more info just ask i did all the research over a year ago even had a motor ready to go

 

I saw a 8.1 on youtube that was turbo'd and sprayed. he was runnin i believe in the 11's. i think he had a bunch of crap put into it but i didnt pay much attention to it. get rid of the dam torque managment and that would help them out a bunch. i hate the doggyness off the line in my 8.1 3/4 ton.

 

http://www.youtube.com/watch?v=LlYRTQmvprk

here it is. pretty sweet

 

That would be me! LOL
Take a look at my avatar!

 

so what happened exactally?