Starting a 3.5 swap - looking for parts

E-Twelve · Post by **E-Twelve** » Mon Jul 27, 2015 9:46 am

I'm starting to gather the parts needed for a M30B35 swap. I'm planning to keep the L-jet for a while and just swap the mechanicals. So far I have B35 head in really nice shape along with some exhaust components. If anyone has a decent B35 block that doesn't need honing and bigger pistons, I'm in the market.

There is nothing wrong with the B28, just looking for some more power. Plus I need to replace the original clutch anyway.... so as long as I'm in there....

I'm going to follow the guide for the most part. (http://www.firstfives.org/faq/swap35/swap35.html) If anyone has any tips or tricks not covered in the guide, please share.

I'll try to post some pics once I get started.

Thanks.

CabbageFumes · Post by **CabbageFumes** » Tue Jul 28, 2015 9:26 am

That post in the the FAQ is old and painfully low on useful information for you if you are planning a B35 swap (don't confuse B35 with 3.5- same but different).
If you just want the block and head and plan on using all of you original externals, it's a simple process of taking everything off of your old engine and put it on the new one. The biggest thing to consider is unless you find a block from the last year e24 or first year e32, the bosses in the block won't allow a direct bolt-on of e12 engine mounts. You'll have to fabricate them. Also, a big reason to go with B35 technology is the Motronic 1.3, which is not cheap or easy to adapt to L-Jet hardware.
You really need to decide what is most important in your swap- originality or performance. It's possible to have a B35 and keep your old L-Jet stuff to make it look pretty original, I've done it, but it's not for anyone on a budget or without fabrication experience.

E-Twelve · Post by **E-Twelve** » Tue Jul 28, 2015 10:07 am

The engine I'm working with is from an 1989 e24. I think that was the last year of them. It says 3.5L on intake, the head, and block. I was assuming that was an M30B35. I do plan on swapping over pretty much everything from the B28 to the B35(or whatever it is).

I'm ok with figuring out the bosses if needed; I read about that somewhere. Luckily this car is not my daily driver so if it takes a few days to complete that's ok.

Thanks a lot for the info.

CabbageFumes · Post by **CabbageFumes** » Tue Jul 28, 2015 10:13 am

E-Twelve wrote:The engine I'm working with is from an 1989 e24. I think that was the last year of them. It says 3.5L on intake, the head, and block. I was assuming that was an M30B35. I do plan on swapping over pretty much everything from the B28 to the B35(or whatever it is).

I'm ok with figuring out the bosses if needed; I read about that somewhere. Luckily this car is not my daily driver so if it takes a few days to complete that's ok.

Thanks a lot for the info.

That's a good engine(B35) to have because it has the correct block mounts, and the wiring harness is very valuable because it is the only B35 harness that is a direct fit for e28/e12 conversions.
Honestly if it's a running B35, I'd drop it in as-is. All you have to do is connect about 6 wires at the fuse box, swap the oil pump and pan, drill a hole in the manifold for a nipple to connect the brake booster vacuum, and you're pretty much done.

E-Twelve · Post by **E-Twelve** » Tue Jul 28, 2015 10:17 am

CabbageFumes wrote: That's a good engine to have because it has the correct block mounts, and the wiring harness is very valuable because it is the only B35 harness that is a direct fit for e28/e12 conversions.
Honestly if it's a running B35, I'd drop it in as-is. All you have to do is connect about 6 wires at the fuse box, swap the oil pump and pan, and you're pretty much done.

Unfortunately the harness is gone. The engine had a HG failure from what I can tell. The cylinders have a little rust and some minor pitting. I'm going to see if I can clean them up. Not sure how bad they are.

CabbageFumes · Post by **CabbageFumes** » Tue Jul 28, 2015 10:20 am

Falkenberg · Post by **Falkenberg** » Wed Jul 29, 2015 10:51 am

3.5 is nice but I'd never switch a good 2.8 for a shabby 3.5. A compression test would have been valuable.

RonDwyer · Post by **RonDwyer** » Sun Aug 16, 2015 2:10 pm

I'd bump the compression a bit and add a driveable Schrick camshaft to the 2.8 Header, free flow exhaust... Research some of the classic performance stuff from the Hartge days.