BMW 318is project car

Tim,

A BMW E30 with a 4 cylinder engine is nothing if not a newer E21 that is heaver. But yes, the AC does work much better.

The swap of the M series engines will enhance the car, but with more power you will be opening the door that we hope you will open.   Your first stop down this path might be to locate a 1991 525, with a manual if you can find it.  Three reasons, the first is the oil pan.  The orientation of the E30 front cross member and the normal E36 oil pan will not work.  You will now understand why the 525's are suddenly getting harder to find as this one of the parts you have to have to make this combination work.

The next reason for the '91 is that this is the one year only, Non Vanos M50 engine.  I am not a fan of moving parts that require on oil pressure to step up engine enhancement. I prefer linear delivery of power.  Having to keep to revs above a certain point to not have "lag",  that's a gate way to drivable power.  Then there's the M50 intake manifold that everyone will tell you have to have, and they are right.

If you do find your 525 with a manual, it will work with your swap.  I know everyone will tell you otherwise.  

Then the fun starts.  Should you convert the car to a five lug pattern of parts from a Z3?  You should convert the rack to the Z3 4 cylinder, the hive will chime in.  You should not cut the fenders for wide tires, unless you buy the E30 M3 fenders.  It goes on and on. 

Now, my points of reference include my current collection of bimmers.  Understanding they are not all drivers; 1975 2002, 1982 E21, 1987 E30 NASA GTS2 NV M50, 1994 325is M-Tech and a 2005 X3. 

This is going to be fun to watch!

David 

Yes, we have done one of these before, but that must have been 12-15 years ago.

For selfish reasons I vote to keep the M42 (I've got a 318is in my garage and I want to see a restomod!)-- the E30 318is is a one year only car (for USA) and that's what makes it unique.  The "baby M3" designation is a little generous IMHO, but I think the "new 2002" comparison is very fitting.  So many of these had the little M42 thrown out for a shadetree 24v swap, that I think the original running gear should be preserved.  24v swap has been done to death in my opinion -- just the other day, there were 3 in various stages of abandonment on ATL craigslist.

That being said the M42 has its drawbacks.  The timing components are weaksauce as Irish has noted, and just recently some parts have become NLA (cam gears).  Metric mechanic can build you a 2.1 stroker using euro M3 pistons and a diesel 4 cylinder crank.  Take a look at YouTube for inspiration -- there are a couple of European hillclimb cars built with ITB setups that do look and sound more like a "baby M3."  

Tim Suddard said:

Yes, we have done one of these before, but that must have been 12-15 years ago.

I remember that one so well because it was the first GRM I ever read. 

One word... S42B20

Turbos and swaps have been done to death. Build a low-buck S42B20 replica using readily available parts. I'll see if I can dig up the exact formula, but it's a mix-and-match of BMW parts to yield a 2.1 stroker with 11.5:1  compression and ITBs:

• 88 mm M47 crank from a Euro 320d (needs some modification to nose)
• 86 mm pistons and from a US E36 M3 (shaved and pocketed if you're going to use aggressive cams)
• 135 mm con-rods from a US E36 M3
• Outer two intake manifolds/ITBs from a Euro E36 M3 (needs minor modification for injectors to fit)
• Exhaust manifold from an M44 (supposedly flows better than M42 manifold)

Pair with cams from Schrick, dbilas, or CatCams. Run on Megasquirt. Should be good for a reliable 230-240 hp, which is a useful 100 hp more than a stock M42B18.

Much more interesting than yet another turbo or swap IMNSHO.

In reply to LanEvo :

That's what I'm talking about! Would be sweet. 

Love the sound

With E30M3s becoming unobtanium, build, not a clone, but something with a little more performance for a lot less money.  E30M3 had 197 hp.  I suggest that you set your target horsepower to that +10% or call it 220 HP.  Get there with forced induction with attention to driveability, reliability and low lag.  No more tire than will fit under the stock flares, with possibly rolling the fender lips.  Get a good limited slip differential.  Make it a nice street driver with an emphasis on sporty enjoyment rather than luxury.  Said another way, make it a sports car rather than a grand touring car.  Make it handle with good balance, not neccesarily high limits.  Treadwear rating of at least 200.

Make it a fun car for a 250 mile roundtrip journey for an autocross, just for fun, not competitive times.

Robbie said:

In reply to irish44j :

I guess I didn't mean in a drag race, I meant at an autox or track event. But I hear ya na power-wise. M42/44 was the runner up in the engine selection choice for my mgb gt, so I antagonized over it quite a bit. Finally decided to go Miata though.

Ah yeah. I thought about that, but then remembered when we ran Chumpcar in an ETA, I was still able to out-drag the Haterade M42 car (barely). That said, I do love the M42 in technical rallycrosses :)

DocV said:

For selfish reasons I vote to keep the M42 (I've got a 318is in my garage and I want to see a restomod!)-- the E30 318is is a one year only car (for USA) and that's what makes it unique.  The "baby M3" designation is a little generous IMHO, but I think the "new 2002" comparison is very fitting.  So many of these had the little M42 thrown out for a shadetree 24v swap, that I think the original running gear should be preserved.  24v swap has been done to death in my opinion -- just the other day, there were 3 in various stages of abandonment on ATL craigslist.

That being said the M42 has its drawbacks.  The timing components are weaksauce as Irish has noted, and just recently some parts have become NLA (cam gears).  Metric mechanic can build you a 2.1 stroker using euro M3 pistons and a diesel 4 cylinder crank.  Take a look at YouTube for inspiration -- there are a couple of European hillclimb cars built with ITB setups that do look and sound more like a "baby M3."  

I agree, actually. The M42 is a fun engine, if not a drag race champion. If this were another e30 I'd say swap away, but the '91 318is is a bit more special than a regular 3253/i (IMO) and it's worth keeping it stock and making it handle rather than going fo rthe power.

Cam gears are NLA, but plenty can be found in good low-wear condition (the ones I got on the interwebz are pretty much "like new"). Just have to look around and ask around. IIRC you can use the ones out of the e36 318's (M42/M44) as well, and there are plenty of those in junkyards these days.

For totally selfish reasons, I'd love to see you keep the M42 in the car. I've got one in my '74 2002, and would appreciate seeing a somewhat budget friendly way to make more power.

z31maniac said:

mazdeuce - Seth said:

I'm in for reading about sourcing and fixing old interior bits and plastic and rubber on the car. The hardest part about cars this age (for me) is dealing with unavailable parts that break when you touch them. 

BMW is really good at supplying parts for older vehicles. You can still brand a new dash for E30s, for example. They aren't cheap, but they are available.

This is one of the things that draws me to certain cars/brands when I'm looking for a project. Maybe I should be plugging BMW into CL more often? 

Tim Suddard said:

I was thinking budget turbo and Megasquirt.

 

I would definitely like this series.  A really deep dive into a Megasquirt set-up would be valuable.  Start with what board to pick.  Kit vs. complete assembled unit. Get into sensor and component selection.  Weigh junkyard options vs new parts.  Elaborate on injector and fuel pump sizing.  Discuss wiring and programming hassles.  Make all the mistakes, so we don't have to!

I was thinking real hard about doing a Megasquirt and turbo setup on a TR-6 motor, but got scared by the "open source wormhole".  I find the system to be so wide open that I don't know where to start. 

mazdeuce - Seth said:

z31maniac said:

mazdeuce - Seth said:

I'm in for reading about sourcing and fixing old interior bits and plastic and rubber on the car. The hardest part about cars this age (for me) is dealing with unavailable parts that break when you touch them. 

BMW is really good at supplying parts for older vehicles. You can still brand a new dash for E30s, for example. They aren't cheap, but they are available.

This is one of the things that draws me to certain cars/brands when I'm looking for a project. Maybe I should be plugging BMW into CL more often? 

Do it!

Tim Suddard said:

z31maniac,

 

I was thinking budget turbo and Megasquirt. Ouch on your old car!

 

Here's the thing- you've done budget turbos more than once.  Still trying to get that to work on the Miata...

IMHO, a very interesting path is to go full Andrew Nelson- and find the total budget way to make the most N/A power.  From finding the right DIY port, getting decent cams, not sure about intake, for sure DIY exhaust welding (maybe even with a MIG, which is more accessible for most), and find the easiest way to make power without boosting.

Also, boosting can always happen later.  If these are that cheap, getting a second motor and building it up for an engine swap is also not a bad way to go.

But there's just not enough N/A development out there, I think.

Definitely N/A. Turbo has been done to death.

alfadriver said:

Tim Suddard said:

z31maniac,

 

I was thinking budget turbo and Megasquirt. Ouch on your old car!

 

Here's the thing- you've done budget turbos more than once.  Still trying to get that to work on the Miata...

IMHO, a very interesting path is to go full Andrew Nelson- and find the total budget way to make the most N/A power.  From finding the right DIY port, getting decent cams, not sure about intake, for sure DIY exhaust welding (maybe even with a MIG, which is more accessible for most), and find the easiest way to make power without boosting.

Also, boosting can always happen later.  If these are that cheap, getting a second motor and building it up for an engine swap is also not a bad way to go.

But there's just not enough N/A development out there, I think.

And MegaSquirt will allow flex fuel! High comp and E85 rocks for NA cars.

I have a megasquirted, turboed 1991 318is. It will come close to pacing an S52 E30 with the usual bolt ons in a straight line. Finally blew the engine at 285k miles last year, but only because I got too aggressive with the timing and I burned some pistons. tough little engine, and still gets close to 30 mpg on the street. I'll probably end up rebuilding the M42...but man, it's expensive compared to rebuilding any of the more common BMW engines.

gearheadE30 said:

I have a megasquirted, turboed 1991 318is. It will come close to pacing an S52 E30 with the usual bolt ons in a straight line. Finally blew the engine at 285k miles last year, but only because I got too aggressive with the timing and I burned some pistons. tough little engine, and still gets close to 30 mpg on the street. I'll probably end up rebuilding the M42...but man, it's expensive compared to rebuilding any of the more common BMW engines.

 

Out of curiosity, what makes them so much more expensive? 

In reply to z31maniac :

ditto. the solution to rebuilding the M42 is to find one on the forums/CL for a couple hundred bucks and just drop that in until you blow it up :)

All good stuff! We are working through all this info and developing a plan.