BBC and LS bellhousing compatibility

[davepl]

It looks like companies make dedicated LS swap bellhousing, but does anyone know why?

It looks like my BBC unit (a Keisler) will fit just fine, at least dimensionally. And I added an LS flywheel, but if not for locating dowels the BBC clutch and pressure plate would -appear- like I can just bolt them up.

I've heard rumblings that the LS flywheel surface is further away from the trans than in a big block, but really don't know of any differences.

Anyone? Remove the dowel pins and it all just works, or throw it all away and buy LS-specific stuff, or some combination?

Thanks,
Dave

[davepl]

Everything so far say "pull the pin", just like my grandpa used to (logger). But...

The face on the LS flywheel is recessed, and it's by about the magical 1/4" that I keep hearing it come up about LS/BCC compatibility.

When I put a 4L80E in everyone was in there with an opinion like a dirty shirt, now I need some LS help, where'd all the modernists go???? There's more to LS motors than drop spindles, ya know. Well that made no sense, but hopefully I can catch someone technical this morning, so:

TTT

[Valarius_Starchaser]

I guess I dont understand the question here maybe I'm the only one....

Is it weather a BBC flywheel will work with a stock 4L80E torque converter or?.......

[davepl]

What I've got is a BBC+TKO-600 and I'm replacing the BBC with an LS3.

So, at a minimum, I need a new flywheel because the LS is internally balanced, even if it physically fit.

Second, the LS flywheel is normally 0.400" further away from the transmission than in a BBC.

So, I though that GM flywheel 12561680 might solve it - it's an LS flywheel made 0.400" thicker so that it takes up that extra space.

Problem is I don't -know- any of this, I'm just guessing. And you can't really see in there so I don't want to install an engine only to find out I'm completely wrong afterwards!

Really hoping I can find someone who's put an LS in front of a TKO-600 that was made for earlier motors. I can't be the first guy, I don't think!

[Valarius_Starchaser]

Okay so the difference is 10mm gm part number 12563532 is a spacer that is put between the crank and flywheel but a standard style flywheel to work. Whichever way is cheaper is the best in my mind as they should both work fine and will get the same job done.

I see no reason the manual application would change much other than the use of a flywheel instead of the flexplate. Others may have more info

EDIT: In my catalog the LS3 stock flywheel part number is 12598613 and lists at 271.91

[davepl]

After a morning of research and various forums, I'm pretty certain my clutch and pressure plate won't work with this flywheel.

I could go stock LS3 flywheel, clutch, and flexplate, which would all work together, but then require the spacer that you mention. It just requires more parts, and I'm not sure if it would work well with my mechanical linkage (no idea why it wouldn't, I just don't know the answer).

I ordered a 12561680 to see if it accepts my existing pressure plate and clutch, which I suspect/hope it will. I'm not married to this clutch and pressure plate, but I do know that it works with my mechanical linkage and I'm not as certain that that's true if I use the LS3 setup.

I guess the "easiest" way would be all LS3 parts with an LS bellhousing and a hydraulic master/slave, but that's throwing a lot of parts and money at it that I might not need to.

The flywheel is backordered at Summit so I ordered it from Amazon an hour ago, and the bolts already shipped! Not the flywheel yet though...

[The Chainsaw]

I b

[indymachinist]

I'm a big LS guy but I don't have the answers you are looking for. Sorry.

[MalibuSSwagon]

What application is that flywheel for?

When I did my 5.3L swap, I reused the stock bell for my SM465, the flywheel is the Sachs NFW1050 (stock for 99-06 4.8/6.0L trucks) which has the required .400" extra height. I had to pull out the dowels, and then the stock clutch kit for my truck bolted up after reaming 3 of the pressure plate holes larger. As long as you are using the BBC 11in clutch it should work.

[Mrturner1]

You ended up going with an LS in your blue truck??

[davepl]

You ended up going with an LS in your blue truck??

Nope, different project, but the question is general to trans-engine interfacing, not truck specific, so asked it here. My life would have been easier with the TKO in the truck and the 4L80E in the Camaro, but I wound up backwards (electronic trans with old motor, manual trans with LS motor!).

The (second) flywheel I ordered has the extra 0.400, so I think it's like the sachs but without the dowel pins.