E30 M30B34 Firewall Modification

[De //m3]

I've beaten the firewall in but I'm still not totally happy with the fit. It fits pretty tight against the firewall, especially where the fitting for the cylinder head coolant port is located. I'm going to pull out the engine again tonight (Takes about 20 minutes to pull it out and reinstall it) to beat it back a little more, but I was wondering if there was anywhere else the firrewall needs to moved back for better fitment. It seems to fit fine all around and the motor mounts are on and bolted down. (Funkmasta mounts)

Do any of you guys modify the area around the "starter bulge" in the bell housing?

There was a picture floating around of the places to hammer the firewall but I can't seem to find it today. Thanks in advance! -Dylan

[JuanPabloBongto]

I'm interested to know as well...
I'm doing the same build (m30b34, engine pos 3) in a few weeks...

subscribed.

[euroshark]

Thinking back to my swap, I know I hammered on the passenger floor area by the rear exhaust manifold pretty extensively. For the area behind the head, I don't recall doing much more than a little hammering and prying to get some room. It was tight, but front to back motion on the engine really isn't a big issue so as long as you have a couple of millimeters you should be set. I didn't need to clearance the area for the starter bulge but I could see how that might be necessary. Just remember, nobody will see those areas unless they look hard, and unless you really go to town there shouldn't be evidence inside the car either. It's not rocket surgery ;)

[chadthestampede]

i had to install and remove the engine twice before i got it because I didn't want to hammer the firewall too much. On the third try i just beat the ever living shit out of it and now it fits fine. You'd have to do quite a bit to see it from the inside.

My big problem was the coolant hose on the back of the head, so just make sure you get that spot really good.

[JuanPabloBongto]

i just beat the ever living shit out of it and now it fits fine.

I had meself a hearty laugh.

[euroshark]

lol. It's the truth though! Don't be gentle!

[De //m3]

Yeah, I've done a couple swaps before and "gentle" was lost in my vocab a long time ago...

I beat the crap out of it for a minute or two, but I just didn't do quite enough where the collant port is. I just wanted to make sure that when I reinstall the motor I don't realize there is another spot I shoud've beat on.

Neway I'll snap some pics tonight with it all bolted up for the second time. Hope to have the car start in the next couple weeks. as for driving...Dec. 1 goal. I need to pick up an Eta driveshaft and a radiator this week.

I actually found two NEARLY new E28 radiator last time I was there but both were from 528e with the small six, so a different rad. design.

Also, since Im using an E23 head I have the E23 manifold and can source a downpipe for it. I've heard that the E23 downpipe (Becasue of the manifold which is different than E28) will fit in the e30 swap. Any truth to this?

[euroshark]

The E28 downpipes fit as well. I bought a nice rust free pair and test fit them, but then ended up getting a full exhaust from Eli instead. If anyone is interested I'll sell em for like $30 shipped.

[duodvlhntr]

Will said downpipes work for a b35??? Maybe?

[euroshark]

Yes, but you will have to use B34 manifolds. I've got a set if you need those too! They bolt right up and according to my measurements the port size at the head is the same between the two. The only big difference is the diameter at the downpipe connection is slightly smaller on the B34.

[De //m3]

Well it is firmly in and sitting pretty now. I'll try to post up some pics of what I was talking about, but the clearances make it tough to get a good picture back there.

But here is the main deal:
The first time I beat on it, I only hammered out about 6 inches from the top of the transmission tunnel. The second time I found that what I really need to do was hammer out as far towards the (Battery Tray for some, coolant tray in E30 M3) tray on the passenger side as possible, right up to the brake line or the threads (which I removed) that held the brake line clip. Pictures will make this more clear.

Thanks for the instruction guys! And I'll take those downpipes...

[mattdk318i]

it would be awesome to see some pics of how extensive the firewall modification needs to be. One day ill be doing this swap. And it would def speed up the process

[De //m3]

So here are the pics. I jsut tried to show how far you actually have to "massage" the firewall out with a 5 pound hammer.









Let me know if you have more questions...I'll also have a DIY under construction up to the engine install about this at www.BMWDoItYourself.com this weekend.

[Funkmasta]

With the B34 headers you will have to do a little "firewall clearing" for better exhaust fitment. If you are using b35 headers, the factory fitment is fine.

Also, the starter housing should not be in the way of the firewall at all.... The early coolant port you will need to get out the BFH. If you do it low enough and carefully enough, you shouldn't be able to see the modification.

[Funkmasta]

Also, since Im using an E23 head I have the E23 manifold and can source a downpipe for it. I've heard that the E23 downpipe (Becasue of the manifold which is different than E28) will fit in the e30 swap. Any truth to this?

The E23 US manifolds should be the same as the E28 Euro/US manifolds. I did use an early 3.3 manifold (single outlet) on our last swap, which ended up working well.