Stupid Question Time

HanSolo0260 · March 11, 2004

I posted this on another board, but no help, so I'm taking a shot here. Not exactly truck related, but it is truck engine related, lol.

I want to swap a new 8.1 Vortec into my Firebird. I can pick one up with everything including computer and harness super cheap, with no defects and under 40k miles.

Really stupid question time, lol. Is this an entirely new motor or are there just minor changes compared to a 1st and 2nd gen BB? Other than the bore and stroke that makes it a 496, duh, lol. Is it just new ignition, heads and fuel/air delivery? The only place I'm finding performance parts is for trucks, so I'm actually assuming there are some major differences. But I wasn't too sure.

I've been looking all over and can't find any decent comparitive specs. Only half assed stuff. You must excuse my ignorance lol, I haven't kept myself up to date on new GM motors other than a 6.0 LQ9, lol.

The main reasons I'm trying to find out the major differences is so I know if I can swap out all of the brackets and only have the alternator and water pump running off of the crank. A/C and PS will be deleted of course. Maybe even use an electric W/P and eliminate that pully.

If external and properly sized internals are the same as an older BB, I'll have more options for cams, pistons, etc. If it's all different, that will just make the project more interesting, lol. More costly too, but oh well, lol.

Will the Hooker Super Comps work for headers? Or would I have to have a set made? Or do you think the stock manifolds would be fine?

I've only found a few Comp Cams for the 8100. Are the other companies around making cams, rockers, etc. for this motor yet?

If the block is like a standard 454 I could use 454 crank, pistons and rods, but is the block the same? Maybe it's just because it's a relativly new engine, I can't find much except for marine applications. Thanks in advance for not making me look too much like an idiot, lol.

P.S. I know someone will chime in regarding emissions tests, but that's not an issue since this car will only see the strip and maybe a few shows.

HanSolo0260 · March 16, 2004

No one has any info huh? well dangit lol. I'd at least like to know about the Super Comp headers, better ign. coils/MSD DIS ignition system and CSI electric water pump fitment. I've found at least cams, computers/chips, intake and rotating assemblies. Not much, but I found some.

Any idea if the NOS NOSzle system will work? Looks like it should, but I'm not sure since I don't have an 8.1 here to look at. I guess time to bug my friends at the Chevy dealer lol.

GM GIMP · March 16, 2004

I'd like to have an 8.1 with 4L80E to put in my Camaro.

Wish I could help but you probably know more than me

right now.

citydriver · March 16, 2004

RESEARCH RESEARCH RESEARCH Better do a visual check,I think the new BB's r a little different.A buddy of mine builds race engines,if I can get ahold of him in the next couple days I'l let you know what I find out,

HanSolo0260 · March 16, 2004

I have researched til my eyes hurt, then searched some more lol. Then I posted the ?'s on some other forums. I seem to have stumped at least a few people, lol. I did manage to get a decent picture printed off to compare to an older BB.

But, it looks like the front of the motor is totally different, of course. I'm talking under the whole alt./PS/WP bracket deal they have on there. So, my plan to use an elec. W/P is out. The upper waterneck is relocated to the side of the motor, so it looks like the whole bracket has to stay. I can eliminate the P/S and A/C with no problem, and just leave the crank, W/P and alt pullies. I'll have to find under drive pullies. I'll just have to engineer a way to get a second idler pully in there or relocate the one under the alt.

The exhaust, starter and motor mounts are the last things I need to figure out. And if a T-56 will bolt up or I'll have to get a bellhousing made or an adapter plate. If the front were the same as older BB's, I'd use a motor plate too, but that's axed.

But, even if nothing is the same, and parts are limited, it'll still be a fun project. Just to see how fast I can get this thing to go. I think I should be able to pull 13's or low 14's out of it stock, and in a lighter vehicle, like my Firebird. No telling where I could get it with the parts from TBYRNE and Banks.

Colorado Kid · March 17, 2004

Motor mounts and bellhousing bolt pattern are identical to other current GM engines, so they shouldn't present any problem.

Exhaust is a total guess, but my best guess is that it isn't interchangable with the 454. As you've discovered there are a lot of differences, from the front side to the firing order.

You do seem to have the attitude required to pull it together. Good Luck!

HanSolo0260 · March 17, 2004

Yeah, I have the attitude, but not the funds now lol. But, no time better than now to get all the info I can.

Update on the exhaust. It's confirmed, regular BB wont fit lol. The bolt pattern is opposite and at about a 45* angle on the 8.1, about a 30* +/- angle on 454, etc. BB heads. So, I'll have to get in touch with a chassis builder friend and get some pipes and flanges made. No biggie. Or see if Burns Stainless can fab up something, even though it would be a good $1000 to get done.

HanSolo0260 · March 18, 2004

I started a thread on my forum to follow this process.

http://www.daleotools.com/forum/viewtopic.php?t=21

May take months, days, weeks or years, but I'll document the process and research there. All depending on time and money. I'm trying to finish my '79 P/U and buy a toy hauler at the same time, so it may take a while lol.

citydriver · March 20, 2004

I've been outa toen 4 a few days...BUT although my buddy plays mostly w/small blocks he said that you got your work cut out for ya Bell housing and mounts are about the only thing they have in common HE THINKs

Alot of the details will have to be fabricated and /or modified....Sorry we couldnt be more helpfull

HanSolo0260 · March 20, 2004

No problem. The deeper I dug though, the more I found. And, it does seem to be mounts and bellhousing are the only matches.

I think since the firing order was changed on LS1, LS6 and the L18, from older V8s, the crank and cams will be completely diferent.

With better, bigger pics I found, the front of the block is totally different as well. And the exhaust manifold studs are the opposite of older BB's, and at a different angle, as I mentioned before.

Basically, if I can't find it, I'll have to have it made or make it myself lol.

o4yukonxl · March 21, 2004

Firing order is different, which means cams are different. Heads have an extra pair of bolts on each one for better head gasket seal. These were built for truck and marine use so you can also get parts from GM marine dealers. I've done a bit of research myself and it's more than a little different. Also, the cranks are internally balanced so don't try and use big block flywheels etc. Best thing to do is start with the truck drivetrain and modify it using the aftermarket truck or marine parts.

HanSolo0260 · April 1, 2004

Sort of an update. There is an 8.1 on eBay and has a good pic for reference. Now, call me crazy, but don't the mounting surfaces for the water pump, and the timing cover look like the usual BB designs?

If only I had the cash, I'd have the motor lol. But I just bought a 350 for my C-10 that I need to deal with first.

Dusterman · April 1, 2004

Try this site! http://www.ls1tech.com/forums/

Lots of good guys that'll give you some solid input.

o4yukonxl has a relatively mild 8.1L in a 'Burb that puts out over 500lb-ft at the crank. That would rock in your F-Bird!

dg

Brian1 · April 2, 2004

That is one heavy engine to put in. I would plan on some major suspension work. It may run like a bat out of hell in a straight line, but watch those curves.

HanSolo0260 · April 2, 2004

I'm on LS1Tech every once in a while. Some good stuff there.

And the weight and turning isn't going to be a problem. I only need it to go in a straight line anyway lol. It'll be no worse than dropping a 454 in. I have all that stuff figured out now.