Idea: An E34 528i

[loftygoals]

So, I've had my E34 for exactly a year. When I first got it, I had some crazy ideas for it. I haven't done much with it, but the time has come.

So far I've only chipped it, slapped euro trim on, clears, new floor mats, new shift knob, strut brace, and UUC Stage II LTW flywheel.

I've have a bent valve, so compression is down to 60psi on one cylinder. Thus I have to rebuild the head or put in a new motor. Right now, I am toying with the idea of dropping in a M52.

M52's are cheap and fairly readily available. I know that M52's can also be converted to ODBI just like the S52's. I should be able to uses parts off of the existing M50 to do most of the conversion. From what I understand, OBDI M52's put out about the same power as a M50 w/ S50 cams. I think the torque is actually a little higher because of the additional displacement.

So, my question for the board is: What do you think? Has anyone done this in an E34?

-bj

[Brandon J]

I have done M3 cams, larger MAF, flywheel, diff, custom chips, injectors, etc. etc. on the M50tu. If you do the M52 2.8L then I would suggest S50 cams with them. After that, either whole S50 or S52.

Now, dropping in an S50 is the best overall solution and I do understand about the bent valve. Been there. The key to this is doing the work yourself. So, an M52 2.8L is a great solution. S50 is very ideal.

Also, you will spend a lot more money over the next year trying to extract more power if you don't get an S50 or S52. Trust me, whence the S38 in my 525i. So, if you have to do the work yourself, get the valve replaced, and save/search for an S50/S52. One other thing, if you get an S50, upgrade the valve springs to the S52 ones. They are stronger and will not float as easily as I am guessing you bent a valve by over revving the engine.

This is a critical time to do planning and bugeting. Hope you make the best fit choices.

I remember years back I had to work my M50tu engine hard to get it to go. It was fun, it really kicked, and with slicks, I beat an M Coupe off the line....hehe, when I engaged the clutch at ~2500rpm, the tranny knob shifted more than an inch to the side b/c of the hard launch. However, it had to be worked and could get real annoying fast. It did need more torque down low for the large sedan.

Good Luck with the project.

[loftygoals]

Thanks for you input Brandon. Right now I'm looking at a price/performance ratio. I can get a M52 for ~$700 with <80k miles. A S50 with <80k will run at least $3500.

I think I've seen stock dynos for 95 M3's run about 215-220 rwhp. M52 converted to ODBI should put down 200+ rwhp.

So looking at power per $:

M52: .29 hp / dollar
S50: .06 hp / dollar

That makes thew M52 a lot more attractive. Plus once the motor hits 100k, I can do a preventative gasket swap and while I have the head off, drop in some S52 cams. The M52 and S52 have the same cam tray, so the S52 cams are favored over the S50 cams. Additionally you can buy used S52 cams from <$150. Good S50 cams run $300+.

There a guy over on bimmerforums that has a OBDI M52 w/ s52 cams in a E36 that is putting down over 215 rwhp. That good power for a motor that is originally rated 200 at the crank.

Like I said, I'm looking for bang for the buck. I'm not trying to build the fastest E34 in the world. I just need to spend some money getting the car road worthy, so I figure why not have some fun in the process. I'm planning on doing the work myself and want to keep the total project cost to under $1500. I think I can get it done for ~1200 bucks if I pull a lot of the OBDI conversion parts off of the M50TU I currently have.

Part of the reason I'm being so cheap is that I'm saving my pennies for racing. I'm mainly going to do rentals in 2007, so I've got to saving for the fees and damage deposits.

-bj

[loftygoals]

Anyone else have any ideas or opinions?

-bj

[inkstom]

Looks like you've already got you're mind made up.

[Mr Project]

I like the idea...now what about an aluminum-block 2.8 from a Z3? How much more would that run you? That lightweight motor might make for one of the best-handling E34s you could hope for, with the 'usual' suspension work.

[loftygoals]

Looks like you've already got you're mind made up.

I have it half thought through, but I'm sure I've missed something. I'd rather someone tell me now that it's a bad idea than buy a motor and discover it was a bad idea 40 hours into the project.

-bj

[loftygoals]

I like the idea...now what about an aluminum-block 2.8 from a Z3? How much more would that run you? That lightweight motor might make for one of the best-handling E34s you could hope for, with the 'usual' suspension work.

Now there's an idea! I'll have to research what a Z3 engine is going for. I found one on eBay for $1900, but I'm sure I can find one cheaper.

-bj