1 2
Tim Suddard
Tim Suddard Publisher
6/13/18 11:35 a.m.
feature_image

With the engine out of our project BMW 318is and partially apart we were able to learn a bit more.

First of great importance: the bottom end (rotating assembly) was unscathed. The oil pick-up screen and oil filter had done their jobs and the bottom end still turned over fine.

Pulling a couple of bearing caps showed no damage to the bearings and not even that much wear.

As for the head, while more than half the valves were bent, the head itself had not been damaged. The cams were also still in good shape.

Theoretically, we could have gotten a used intermediate plate—new ones are no longer available, resurfaced the head, installed some new or used valves, and put the whole thing back together. We probably could have driven another 150,000 miles like that.

Another option would be to just put a used motor in the car and go about our day. Used engines are readily available for between $500 and $1000 depending on mileage and condition.

And of course, with a decent car and a bad engine, the idea of an engine swap popped into our heads.

Installing the S52 or S54 engine ( from the E36- or E46-chassis M3) is a popular swap, but it has been done to death. And in our opinion it changes the light, simple character of the 318is that we love so much.

Time for a dose of reality: These cars are getting valuable. The rest of the car was original, and the original numbers-matching M42 engine we had was still essentially usable. With that in mind, we made our final decision and new plan.

A BMW club buddy reminded us that Metric Mechanic does some amazing things with the M42 engine.

While we had worked with owner Jim Rowe some 25 years ago on a "Big Six" BMW stroker engine, we hadn’t talked to him in years and didn’t realize that he now specialized in playing with M42 engines.

A quick call to Rowe helped us develop what we think is a great plan. First he not only remembered us, but was a huge fan of Grassroots Motorsports and loved the progress we had made with the publication since we had worked together all those years ago.

He was also more than willing to show us and our readers what he had learned about these interesting M42 engines.

His thought was to take our original engine and rebuild it with a lightened, balanced rotating assembly, and better cam profile.

He would bore it and use a crank from an M44 Z3 engine to give us 2.0 liters, instead of our original 1.8.

He would bump the compression up a bit, improve our breathing with his valve train tricks and then finish the whole thing off with a lightened clutch and flywheel assembly.

We could expect a completely rebuilt engine and roughly 40 more horsepower and still retain (cosmetically at least) the original engine with its great drivability and fun-to-drive nature.

So we would have a car that would give an E30 M3 fits, and be all in for $10,000-15,000 with about half that figure being in the engine.

That sounded like an interesting project to write about, especially if we tested it against and E30 M3 when finished. More importantly, that sounded like a car we would love to own and drive every day!

Read the rest of the story

z31maniac
z31maniac MegaDork
6/13/18 11:52 a.m.

I like!

 

What are you going to do for engine management?

AngryCorvair
AngryCorvair MegaDork
6/13/18 12:05 p.m.

in for updates

irish44j
irish44j UltimaDork
6/13/18 12:36 p.m.

Just throwing it out there that the M42 can hold about 8-10psi boost with all stock everything.....and several people have successfully and reliably turbo'd these engines for under $2k, getting close to 200whp reliably. 

$7k sounds like an awful lot for 40hp (I would hope MM is giving you guys a deal better than that), which gets you about what you'd get with a $300 M2oB25 or M50 from a junkyard.....Plus, for a magazine build, I highly doubt that MM is going to publicly share all their tips and tricks in any amount of detail.....so what's the upside for your readers?

I like the project, but nice-condition 318is's are hardly collectors models anytime soon. I've bought two rust-free 318is's in pretty good shape in the last few years for ~$2000 each. 

z31maniac
z31maniac MegaDork
6/13/18 1:45 p.m.
irish44j said:

Just throwing it out there that the M42 can hold about 8-10psi boost with all stock everything.....and several people have successfully and reliably turbo'd these engines for under $2k, getting close to 200whp reliably. 

$7k sounds like an awful lot for 40hp (I would hope MM is giving you guys a deal better than that), which gets you about what you'd get with a $300 M2oB25 or M50 from a junkyard.....Plus, for a magazine build, I highly doubt that MM is going to publicly share all their tips and tricks in any amount of detail.....so what's the upside for your readers?

I like the project, but nice-condition 318is's are hardly collectors models anytime soon. I've bought two rust-free 318is's in pretty good shape in the last few years for ~$2000 each. 

The upside is an option you rarely see people take. 

 

I'd just want to add ITB's, huge cams, and jack the compression up enough that it would make sense to run E85. 

stuart in mn
stuart in mn UltimaDork
6/13/18 4:09 p.m.

Be sure to dyno test the car afterwards to confirm just how much horsepower it's gained over stock.

irish44j
irish44j UltimaDork
6/13/18 4:20 p.m.
z31maniac said:
irish44j said:

Just throwing it out there that the M42 can hold about 8-10psi boost with all stock everything.....and several people have successfully and reliably turbo'd these engines for under $2k, getting close to 200whp reliably. 

$7k sounds like an awful lot for 40hp (I would hope MM is giving you guys a deal better than that), which gets you about what you'd get with a $300 M2oB25 or M50 from a junkyard.....Plus, for a magazine build, I highly doubt that MM is going to publicly share all their tips and tricks in any amount of detail.....so what's the upside for your readers?

I like the project, but nice-condition 318is's are hardly collectors models anytime soon. I've bought two rust-free 318is's in pretty good shape in the last few years for ~$2000 each. 

The upside is an option you rarely see people take. 

 

I'd just want to add ITB's, huge cams, and jack the compression up enough that it would make sense to run E85. 

Nobody takes the option, because nobody is going to spend $7k to build a motor to gain 40hp when there are so many better options out there (BMW and non-BMW) for fractions of the price..

Alternately, if the goal is to keep it truly original since 318is's are apparently so rare......well, I'll sell you an original, running, stock M42 for $500 ;)

varg
varg New Reader
6/14/18 7:27 a.m.

I've more experience with M42 performance than most E30 guys, and I'd say refresh it and keep it stock or, if seeking any performance, throw the M42 out. NA M42 builds are horrible bang for your buck. Several thousand dollars to make Honda B18C power. That power is fun in a 2,300lb honda but a 318is is between 2,600 and 2,700lbs. Despite having 16 valves and a BMW badge the M42 is positively asthmatic stock (seriously, a 1.8 I4 that stops making power by 6,000rpm? What is this a corolla?) and even a simple upgrade like new cams is an outrageously expensive one.

I'm not a fan of the M42 in general, it is a very flawed engine. Prone to crank walk (half shell thrust bearing wears out), timing case failure, cracked heads, leaks, corrosion around the profile gasket, and expensive in general to rebuild (price out replacement of all timing components and get ready to cringe!) 

For context, I had an M42 in my E30 with a good sized turbo on it, eventually I was pushing 18psi of boost with nothing more than head studs and an MLS head gasket. It was fun for the couple of years it lasted, could keep up with a turbo M20 car on 12psi, then it started to leak compression into the cooling system and I ditched it for a turbo M20 instead of putting any more money into the coarse, leaky little 4-banger. I never looked back.

z31maniac
z31maniac MegaDork
6/14/18 7:41 a.m.
irish44j said:
z31maniac said:
irish44j said:

Just throwing it out there that the M42 can hold about 8-10psi boost with all stock everything.....and several people have successfully and reliably turbo'd these engines for under $2k, getting close to 200whp reliably. 

$7k sounds like an awful lot for 40hp (I would hope MM is giving you guys a deal better than that), which gets you about what you'd get with a $300 M2oB25 or M50 from a junkyard.....Plus, for a magazine build, I highly doubt that MM is going to publicly share all their tips and tricks in any amount of detail.....so what's the upside for your readers?

I like the project, but nice-condition 318is's are hardly collectors models anytime soon. I've bought two rust-free 318is's in pretty good shape in the last few years for ~$2000 each. 

The upside is an option you rarely see people take. 

 

I'd just want to add ITB's, huge cams, and jack the compression up enough that it would make sense to run E85. 

Nobody takes the option, because nobody is going to spend $7k to build a motor to gain 40hp when there are so many better options out there (BMW and non-BMW) for fractions of the price..

Alternately, if the goal is to keep it truly original since 318is's are apparently so rare......well, I'll sell you an original, running, stock M42 for $500 ;)

Yeah an M5x/S5x is the easy button has been done to death.....like even I did that almost a decade ago and that was with everything already VERY well documented. Slap a turbo on is easy and has been done to death. 

They are taking a different route which is awesome. A 318is with ~180-200hp sounds about perfect. It will more eagerly rev and everything. I love'd mine with just a chip/exhaust/lightweight flywheel. Another 40hp, would have made it an absolute riot. 

 

To your last part, in most of the country, finding a clean (I have to emphasize this because I don't mess with rusty cars - life is too short), running 318is slicktop is not easy or cheap in the vast majority of the country. Finding an older person that just wants to sell it for a few grand is INCREDIBLY rare.

docwyte
docwyte SuperDork
6/14/18 8:13 a.m.

They're doing it because they're not paying nearly the cost that the rest of us would for that motor.  Otherwise, yeah, it makes no sense at all to install a built M42 vs S50/52/54/LSx

alfadriver
alfadriver MegaDork
6/14/18 9:14 a.m.

The motor change makes a ton of sense if you are trying to write a series of articles that are new.  

Boosting has been done to death, and one can find countless articles and web pages telling you how to do it.  LS swaps have been done further to death- to the point where some TV shows have even done it into BMW's, and swapping any I6 into that- how hard can that be?

Upgrading the motor to be better is a very different path, kind of old school, too- and it will be interesting to see how it's done.  And it will be interesting to see what the hard parts where a back yard mechanic HAS to go to a machine shop to do it.  How much work will that crank swap be?  

BTW, $7k for 40hp isn't that bad, I paid $5k for the same back almost 20 years ago for my Alfa.  And I'm still incredibly happy about it.

Cactus
Cactus Reader
6/14/18 10:49 a.m.

"...we would have a car that would give an E30 M3 fits..."

Shows you how overrated E30 M3s are.

Keith Tanner
Keith Tanner MegaDork
6/14/18 11:13 a.m.

Yeah, I'd like to see a head to head test against an E30 M3 to back up that claim. If it were that easy to outrun an E30 M3, then BMW wouldn't have had to make the homologation car in the first place.

z31maniac
z31maniac MegaDork
6/14/18 1:16 p.m.
Keith Tanner said:

Yeah, I'd like to see a head to head test against an E30 M3 to back up that claim. If it were that easy to outrun an E30 M3, then BMW wouldn't have had to make the homologation car in the first place.

 Can you point out in the article where it said it would outrun an E30 M3?

 

Also remember the E30 M3 was released in Europe in '86. The 318is was a one-year only special for '91. And that motor was really developed for the E36 chassis cars that followed. 

z31maniac
z31maniac MegaDork
6/14/18 1:17 p.m.
varg said:

I've more experience with M42 performance than most E30 guys, and I'd say refresh it and keep it stock or, if seeking any performance, throw the M42 out. NA M42 builds are horrible bang for your buck. Several thousand dollars to make Honda B18C power. That power is fun in a 2,300lb honda but a 318is is between 2,600 and 2,700lbs. Despite having 16 valves and a BMW badge the M42 is positively asthmatic stock (seriously, a 1.8 I4 that stops making power by 6,000rpm? What is this a corolla?) and even a simple upgrade like new cams is an outrageously expensive one.

I'm not a fan of the M42 in general, it is a very flawed engine. Prone to crank walk (half shell thrust bearing wears out), timing case failure, cracked heads, leaks, corrosion around the profile gasket, and expensive in general to rebuild (price out replacement of all timing components and get ready to cringe!) 

For context, I had an M42 in my E30 with a good sized turbo on it, eventually I was pushing 18psi of boost with nothing more than head studs and an MLS head gasket. It was fun for the couple of years it lasted, could keep up with a turbo M20 car on 12psi, then it started to leak compression into the cooling system and I ditched it for a turbo M20 instead of putting any more money into the coarse, leaky little 4-banger. I never looked back.

"They suck, they suck, they suck"

Also

"Held 18psi with no issues"

The internet loves a chance to try and poop on any and everything. Trololololol

Keith Tanner
Keith Tanner MegaDork
6/14/18 1:25 p.m.
z31maniac said:
Keith Tanner said:

Yeah, I'd like to see a head to head test against an E30 M3 to back up that claim. If it were that easy to outrun an E30 M3, then BMW wouldn't have had to make the homologation car in the first place.

 Can you point out in the article where it said it would outrun an E30 M3?

 

Also remember the E30 M3 was released in Europe in '86. The 318is was a one-year only special for '91. And that motor was really developed for the E36 chassis cars that followed. 

Tim Suddard said:
 

So we would have a car that would give an E30 M3 fits, and be all in for $10,000-15,000 with about half that figure being in the engine.

That sounded like an interesting project to write about, especially if we tested it against and E30 M3 when finished. More importantly, that sounded like a car we would love to own and drive every day!

z31maniac
z31maniac MegaDork
6/14/18 2:25 p.m.

To me "Give fits" = it can keep up/be in the mirrors.......NOT outrun it. 

And I know you know that too.

Slippery
Slippery SuperDork
6/14/18 3:02 p.m.
z31maniac said:

To me "Give fits" = it can keep up/be in the mirrors.......NOT outrun it. 

That’s how I read it too. 

We all know stock for stock, the M3 is a more capable car. Modified 318is vs M3 could be a good/fair fight ... if you modify both, then the M3 clearly has more potential. 

I like very much where this project is headed. 

z31maniac
z31maniac MegaDork
6/14/18 3:46 p.m.
Slippery said:
z31maniac said:

To me "Give fits" = it can keep up/be in the mirrors.......NOT outrun it. 

That’s how I read it too. 

We all know stock for stock, the M3 is a more capable car. Modified 318is vs M3 could be a good/fair fight ... if you modify both, then the M3 clearly has more potential. 

I like very much where this project is headed. 

Me too. Of all the cars I've owned, my 318is is the only one I regret selling. And that includes other E30s, one of which was an S52 swap car that put down 240whp.

maj75
maj75 HalfDork
6/14/18 4:17 p.m.

Owned a 318is.  Wasn’t a fan of the motor, having owned several BMW 6 cylinders from a 633csi to E46.  I just don’t get the appeal of the 318.   It’s the entry BMW with the cheap interior.  Unless you are looking for low price and economy, why would anyone have bought those cars.  The ‘is’ body styling is nice, but since you could order a six, I just don’t get it.  To spend that kind on money to try to make more power from the 4 just seems stubborn.  It isn’t even new or fresh.  

 

I love a restoration story so I’ll follow along, but I’d never spend my own money to duplicate the effort.

z31maniac
z31maniac MegaDork
6/14/18 5:04 p.m.
maj75 said:

Owned a 318is.  Wasn’t a fan of the motor, having owned several BMW 6 cylinders from a 633csi to E46.  I just don’t get the appeal of the 318.   It’s the entry BMW with the cheap interior.  Unless you are looking for low price and economy, why would anyone have bought those cars.  The ‘is’ body styling is nice, but since you could order a six, I just don’t get it.  To spend that kind on money to try to make more power from the 4 just seems stubborn.  It isn’t even new or fresh.  

 

I love a restoration story so I’ll follow along, but I’d never spend my own money to duplicate the effort.

Huh? The 318is got the leather interior and sport seats, so what do you mean it got the "cheap interior?"

stuart in mn
stuart in mn UltimaDork
6/14/18 6:17 p.m.
z31maniac said:
maj75 said:

Owned a 318is.  Wasn’t a fan of the motor, having owned several BMW 6 cylinders from a 633csi to E46.  I just don’t get the appeal of the 318.   It’s the entry BMW with the cheap interior.  Unless you are looking for low price and economy, why would anyone have bought those cars.  The ‘is’ body styling is nice, but since you could order a six, I just don’t get it.  To spend that kind on money to try to make more power from the 4 just seems stubborn.  It isn’t even new or fresh.  

 

I love a restoration story so I’ll follow along, but I’d never spend my own money to duplicate the effort.

Huh? The 318is got the leather interior and sport seats, so what do you mean it got the "cheap interior?"

The 318is got sport seats but I believe they were vinyl.  And to be clear, the 318i was the entry model, the 318is was a little more special than that.

irish44j
irish44j UltimaDork
6/14/18 8:43 p.m.
docwyte said:

They're doing it because they're not paying nearly the cost that the rest of us would for that motor.  Otherwise, yeah, it makes no sense at all to install a built M42 vs S50/52/54/LSx

This would be my assumption, that they'd get a sweetheart deal in exchange for some MM advertising.....except for they specifically said that's what they'd be paying for it. IDK

irish44j
irish44j UltimaDork
6/14/18 8:48 p.m.
z31maniac said:
irish44j said:
z31maniac said:
irish44j said:

Just throwing it out there that the M42 can hold about 8-10psi boost with all stock everything.....and several people have successfully and reliably turbo'd these engines for under $2k, getting close to 200whp reliably. 

$7k sounds like an awful lot for 40hp (I would hope MM is giving you guys a deal better than that), which gets you about what you'd get with a $300 M2oB25 or M50 from a junkyard.....Plus, for a magazine build, I highly doubt that MM is going to publicly share all their tips and tricks in any amount of detail.....so what's the upside for your readers?

I like the project, but nice-condition 318is's are hardly collectors models anytime soon. I've bought two rust-free 318is's in pretty good shape in the last few years for ~$2000 each. 

The upside is an option you rarely see people take. 

 

I'd just want to add ITB's, huge cams, and jack the compression up enough that it would make sense to run E85. 

Nobody takes the option, because nobody is going to spend $7k to build a motor to gain 40hp when there are so many better options out there (BMW and non-BMW) for fractions of the price..

Alternately, if the goal is to keep it truly original since 318is's are apparently so rare......well, I'll sell you an original, running, stock M42 for $500 ;)

Yeah an M5x/S5x is the easy button has been done to death.....like even I did that almost a decade ago and that was with everything already VERY well documented. Slap a turbo on is easy and has been done to death. 

They are taking a different route which is awesome. A 318is with ~180-200hp sounds about perfect. It will more eagerly rev and everything. I love'd mine with just a chip/exhaust/lightweight flywheel. Another 40hp, would have made it an absolute riot. 

 

To your last part, in most of the country, finding a clean (I have to emphasize this because I don't mess with rusty cars - life is too short), running 318is slicktop is not easy or cheap in the vast majority of the country. Finding an older person that just wants to sell it for a few grand is INCREDIBLY rare.

Like I said, I've done it twice. Two 318is's, both slicktops, both rust-free (here in the mid-atlantic) in the last 3-4 years. One of them I re-sold for a little profit. The other one's engine and transmisison are sitting in my garage as a spare for my (318) rally car, and its rolling body was caged and turned into a rally car (with an M50 in it  now). Both were bought from 20-something guys who probably thought they were too slow and wanted a Honda instead :)  So maybe they're rare wherever you are, but they're not that rare in big-city areas were lots of people making decent money in that era bought them as nice entry-level commuting cars. I mean, they're not all over the place, but certainly not "incredibly" rare or even running-Biturbo rare,.... 

z31maniac
z31maniac MegaDork
6/15/18 9:11 a.m.
stuart in mn said:
z31maniac said:
maj75 said:

Owned a 318is.  Wasn’t a fan of the motor, having owned several BMW 6 cylinders from a 633csi to E46.  I just don’t get the appeal of the 318.   It’s the entry BMW with the cheap interior.  Unless you are looking for low price and economy, why would anyone have bought those cars.  The ‘is’ body styling is nice, but since you could order a six, I just don’t get it.  To spend that kind on money to try to make more power from the 4 just seems stubborn.  It isn’t even new or fresh.  

 

I love a restoration story so I’ll follow along, but I’d never spend my own money to duplicate the effort.

Huh? The 318is got the leather interior and sport seats, so what do you mean it got the "cheap interior?"

The 318is got sport seats but I believe they were vinyl.  And to be clear, the 318i was the entry model, the 318is was a little more special than that.

318i was the '84-85 car with the M10 engine. The 318is was the '91 only model, there was no '91 318i.

1 2
Our Preferred Partners
0u5BXPg3C9tzWXG1Ffy9cFhcEoR0H4Z0