Atomic

iTrader: (37)

I realize this section is for ls engines to fit in non-ls vehicle, but there is not a section for a non-ls engines to go into an ls vehicles, so...

Has anyone swapped a BBC into an original ls vehicle? Even better would be a truck. I dont mean the 8.1 either since that has both sets of mounting holes I believe, I mean the older bbcs, pre-ls.

Everyone seems to offer an adapter to put an ls in an originally equipped bbc or sbc vehicle but not the other way around. The only thing im worried about at this point is fitting it in there. The exhaust will be all custom and no ac, so im not worried about that.

Ill admit im a noob on bbc and have a lot of reseach to do, but thats part of the fun.

Before anyone says, "why not just use a 408 if you want big cubes?". Because I have a 402 currently with an 82mm turbo (somewhere north of 1k rwhp), and when it goes I want to build something really cool. A twin turbo 600ci bbc sounds fun. Not just for the power, but the challenge and cool factor as well.

Thanks

garys 68

iTrader: (1)

Now this sounds interesting.
Carb or EFI BBC. What trans?
One issue to consider is that all the gauges and a lot of function go through the ECU.

Atomic

iTrader: (37)

Would like to stick with EFI, 80e (maybe, if it will hold...), and actually the stock 411 type pcm. Of course this is after confirming someone makes brackets to actually get it in there.

seancarole

I think it would easy to mount up with the power your talking front & mid plates any way right?

93Z2871805

iTrader: (5)

Are the mounts the deal breaker? Do you have the ability to fab them up? I would look at the motor mounts they used for the 8100 in the 2000-ish trucks as I don't believe the mount holes are different between Mark IV, Gen V, Gen VI, and Gen VII. But then again the 8100 is kind of an oddball so it wouldn't surprise me if they were different. Now running the 0411 with a Mark IV will be the tricky part, if you were to use a Gen VI block you could run the L21s 24x electronics and use the 0411. What block are you running on that 402?

Atomic

iTrader: (37)

Mounts are not a deal breaker, and I could make some if I have to, but it sure would save me a lot of trouble if someone already makes some. Transdept makes some for the other way (ls into bbc vehicle), but like I said, finding mounts for the other direction isnt so easy. I talked to a guy that put an 8.1 in an ls truck and he said the 8.1 had the bbc and ls mounts.

I dont really want to use the 8.1 because the availability of parts for the older "real" bbc's seem much more common (ie, more options).

My thinking is find some mounts that work, then see what my options are with that block in terms of efi. I would like to use the 0411, but if I have to go aftermarket it wouldnt be the end of the world (the holley efi system looks pretty sweet). I realize this may be backwards, but like I said, im a BBC noob and bought a couple books this morning on amazon to try and educate myself on block and rotating assembly combinations.

I figure if I can get a 24x reluctor wheel, crank sensor, and cam sensor on any block I should be able to make the 0411 work since those are the important things. I realize there is a lot more that would need to be done, but this is a good starting point.

Im using an iron lq4 block in my 402, shortblock built by LME.

sprayedenali

iTrader: (11)

a motor/mid plate might be the way to go....

Atomic

iTrader: (37)

Hmm, thats a good idea actually, but is definitely a lot more work than a simple motor mount adaption. But obviously at some point with the kind of power under consideration here the factory style motor mounts just wont cut it.

garys 68

iTrader: (1)

I would think the mounts would be the easiest part. Crank sensor/reluctor might be doable, but cam sensor/reluctor seems like a pain if you're considering an early BBC.
An aftermarket tbi would be much easier but then you would need a stand alone trans controler.
You might check into the later marine 502 efi motors (Mercruiser). Not sure how easily they would be to get working with the 411 though.
Check this
http://www.pacificp.com/forum/viewto...&highlight=l21
http://www.pacificp.com/forum/viewto...er=asc&start=0

93Z2871805

iTrader: (5)

I was saying use a Gen VI block (not the Gen VII 8.1) so you can use the 24x stuff because they have the provisions for the cam and crank sensor, earlier blocks do not and cannot use the late model timing cover.

Use a motor plate or fab them up. You can use the 0411 IF you use a Gen VI block (you'll basically replicate the L21 Gen VI 7.4 liter system) because it has the provisions already for the cam and crank position sensors. If you use an older block, you'll need BS3, FAST, Holley EFI, etc. depending on the power level. It's not exactly backwards, you're doing right in figuring how to mount it, fuel it, and fire it first. Just figure out how big you want to go first so you'll know ahead of time whether this will be a short (9.8) or tall (10.2) deck height motor.

You won't be able to mount the 24x if you don't have a way to mount the cam and crank sensors, and you can't use a late model BBC timing cover on the earlier model blocks which has the provision for the crank position sensor.

I was under the impression you had a 402 BBC with about 1000 rwhp and were looking to stuff it in the truck. What kind of power do you want from the BBC project? You can eclipse that 1000 rwhp number you have now with an N/A BBC if you'd really like to.

Atomic

iTrader: (37)

Well, I had my mind made up for something around 600ci. Whats the point of a big block if its not going to be big, right?
With that in mind, the largest ive seen most go with the genvi 454 block is around 496, which isnt going to cut it. For big cubes its looking like I want an aftermarket block, and the dart big m tall deck looks like a perfect candidate for what I want, but im not sure what provisions that block has for crank and cam sensors since I want EFI.

As far as power goals for the project...im not really sure, and to be honest thats not really my main thrust for this project. I havent heard of anyone doing this type of swap and it sounds fun! For the displacement and any decent size turbo(s), I dont think the 2k hp is out of range. I would build the engine to support that power level, even though I am well aware that its basically useless except for a dyno queen. I realize an NA BBC of this size could do that without much trouble, but thats not what I want from this.

The setup now is an lq4-based 402, and dont get me wrong it makes a ton of power, but I am thinking ahead to other fun projects. Everything gets boring after a while, even 1k hp

So I guess the biggest question is how hard is that dart big m block to make work with efi, or does it already have provision for that? I read some discussion of a 598 rotating assembly that would work well in that block I think...


Thanks for the input

smokeshow

iTrader: (17)

93Z2871805

iTrader: (5)

A 10.2 deck Dart Big M block can take a 4.625 x 4.75 which would make a 632. And they can be had in either Gen V or Gen VI, so yes it would work with a 24x. The world is your oyster, the only limit on power for a BBC is your pocketbook. The cam sensor for the L21 electronics is a cam sync and the crank position is in the Gen VI timing cover. However if you plan on going for some 2000hp number, you'll need a BS3.