Is it time to give up on the E21?

When I lunched my motor, I figured I'd be able to pick up a head for it, but I'm now 0-2.  

I picked up some pistons for the 1.8, but my bores have a bit of scoring and pitting.  

I have a(n I think) good 2.0 block, and some nice pistons for a 121 head, so I took a flyer on an eBay unit.

2nd bad head.

I do have an E21 head, but now I'm stuck with an 8:1 motor, assuming my 2.0 block is as good as I think.

The shame of it is, I also picked up a 292 regrind and some valve springs to make it live, not sure how well a stock 8:1 motor will like a 292.  The 284 might be ok in it.

So, it's take one last shot to get it running on a slug motor, or just start parting it out. 

I like the car with a little pep and liveliness, which it had enough of with the 1.8 and 284, and probably wouldn't be much worse with a slug 2.0 of some configuration. 

But at this point, I'm a little ambivalent about the project. 

Is it time to move on?

In reply to ГУЛАГ мальчик УР следующий :

m42 swap time?

I thought about that, but I'm not sure M42 would be much better availability wise if I break something. 

I thought m42s were kind of notorious for cracking heads, as well, which is why availability becomes an issue.

M20s are probably more available, but those aren't growing on trees either.

What would make you excited about it as a project again?  If a motor swap is your thing, how about a k24 with one of the readily available adapters to BMW transmissions?  
 

If a swap doesn't interest you, then perhaps it is time to move on from this particular project. 

I was idly curious so I started looking for M10 info... and found a thread you were engaged in on Bimmerworld, 17 years ago!

In reply to Pete. (l33t FS) :

Yeah, I've had it a while. 

Not sure I have the patience to hunt down parts when it breaks anymore. 

I've got an extra 5 speed, drive shaft, grill parts, a K-Jet system to go back to stock, etc, etc, stuff gathered with the intent to keep it. 

Some of those motors I think were 8.5 to 1, so if that's the E21 head and flat tops, I'll do some research to see if I can shave that head to get a little more compression in it, and if I can, I'll throw the valve gear in it and run it. 

Otherwise I might just throw it together and sell it.

I think I've got a 121 head in the garage. I can look it over and see if it's decent, if you're interested.

I hate to be a vulture but what price would you seek with or without engine running? Feel free to email me at 318x at g mail.com

The e21 is still my one that got away. Twice.

In reply to captainawesome :

That's not at all why I was looking into M10 engines, or looking into if the E21 had hanging pedals like an E30 or floor mounted pedals like a 2002.

In reply to Pete. (l33t FS) :

The biggest downside to these I think is the front suspension and steering. If one were to graft e30 bits on, it would be awesome. Pretty sure it's been done before but it's been years since I read up on it. Oh and rust.

If E30 steering is an upgrade... eew

If I had an E30, the first thing I'd probably do is graft a Merkur rack to it, supposedly they're like 50% faster steering.  Or maybe a Z4 rack if possible.

In reply to Pete. (l33t FS) :

I was mainly talking about the control arms and suspension geometry. Also the e36 rack would bolt up to an e30 and improve response dramatically so that could be an easy all in one fix.

In reply to 02Pilot :

Yeah, if it's in good shape, I think I would be, but I'm about $400 in, between 2 bad heads.

I think the bad 121 head has the good rocker arms in it, so if I can sell those to recoup a little cost, that would be good. 

Let me know what you're thinking on price.

I certainly very much appreciate the heads up on the head, that's heady stuff!

In reply to captainawesome :

Let me think on it, I'm still in the planning stages of what to do with it. 

I've also got a job possibility that would have me traveling half time or a little better, and if I get it, I may move on from the E21 for some practical reasons, even if I put it back together, if you're interested in that. 

Even running, it wouldn't go for a lot, and I'd try to keep it friendly for a GRMr.

PM me if you want to chat further about it.

Pete. (l33t FS) said:

In reply to captainawesome :

That's not at all why I was looking into M10 engines, or looking into if the E21 had hanging pedals like an E30 or floor mounted pedals like a 2002.

Hanging, if that hasn't been answered....

Re: suspension, I think it's a little overblown as to how terrible it is. 

Yes, later cars do everything better, advancements in design and tech and all that. 

I've got 95a urethane in the front sway bar brackets and the rear control arms, 90a in the rack bushings, the front control arms I did years ago (but very few miles, car not running for the longest time), so figure those are probably 80a, Ireland Engineering rear subframe mounts, those are probably 80a, and a urethane diff mount, I think that's also 80a, might be higher).

It's on "coilovers" of the home brew variety; bigger strut tubes welded to the front, with Koni 8610s, and NC Miata Sports at the rear (thank you Lee at Konis before he went to SCCA...) with 550/350 springs.

The car is an absolute joy of purely mechanical driving feel, and percentage wise based on auto-x times, I'm as fast with it as I am the Miata. 

And I really don't have any problems with the steering being "slow" on course, though a faster rack would be a little easier. 

Defending my girl's honor from all you creeps that don't think she's all that and a bag of chips...  ; )

In reply to ГУЛАГ мальчик УР следующий :

I haven't looked at that head in at least a decade, so I can't tell you much until I drag it out. I'll see if I can do that tomorrow. I'll PM you with some photos and we can talk about it. I'm not looking to make a ton of money, and I'm open to trading for parts I can use for my 2002 as well.

In reply to 02Pilot :

Heard.  I'll hang tight, and if I have anything that's horse-tradable, we'll figure up from there.

You know those low compression motors like boost (coming from a guy with an M30 that he built high compression NA as I didn't want a turbo lol).

Maybe it's time to turn the E21 up to 11, I don't think there were/are any E30's as cool as a group 4/5/IMSA E21.

I'm in the keep it camp.

Ok, to sus out further; I'd like the car to run.

I'll take the E21 head to machine shop, if it's good, it's an 8.3:1 motor (so says summit racing's compression calculator and the M10 info on a couple web boards).

​​Before I floated the valves (pretty sure) on the 1800cc 8.8:1 motor, with the 284 cam I ran it to 7k, and it didn't lay over until 7, where the flesh was willing, but the valvetrain was weak. 

SO, will the half point less compression and longer stroke 2000çc motor make a meaningful difference in how the motor behaves?

Install the 292 and heavier valve springs?  

Keep the 284 and run the heavier valve springs? 

Run the 284 with stock valve springs, and keep the limiter set at 6500?

I Just don't want it to run like a dog until 4500 and then lay over at 6500, if that makes sense.  I don't think it should, but, I over think everything and worry more than I should. 

Thoughts? 

​​​​

Is this still running the stock injection, or something else? If the former, I'd want to make sure fuel and air were correct and sufficient no matter what if you go to the 2L block.

That said, and my knowledge of M10s is not deep, but I've been fiddling with them for 30+ years, so I have a little sense of them. I don't think you're going to see a huge difference between a 284 and 292; both should run to 7k, which also seems to be the point at which some people argue the stock valve springs give up when new (I'm currently trying to decide whether to go with new stock springs or heavy duty ones on the E12 head I've been (very) slowly reworking). I find these engines like a fair bit of cam, so if it were me, I'd go with the 292. I know some people use an adjustable cam sprocket to tweak the power band, but I haven't felt a need to try that.

FWIW, I've run a 300 Motorsport cam on the street for decades - it's pretty flat under 3k, but picks up by 4k, and runs strong from there (I normally run it up to 6.5k, as I think my exhaust is a little restrictive and starts to limit it above that, but it will go to 7k without a fuss) - and that's with dual 40DCOEs.

In reply to 02Pilot :

Weber 38 on a Canon manifold (supposedly runs a little better than the stock 02 carb manifold).

My car pulled really well at 3500, and in first and second would run to 7 pretty well, especially when I finally got the carb dialed in.  I don't think I ever took it anywhere with a speed limit that would let me see what third felt like in the upper ranges.

If you're going to run it to 7 with any consistency, GET the HD valve springs, and make sure your lash is 8 or better.  Ask me how I know.  ; )

What compression ratio are you running?

Another guy I'm talking to says a 32/36, 292, stock block (so 8ish:1 compression) car is a bit lazy at lower rpm, but a) he wasn't sure how well it was tuned, b) since I have a 4.27 LSD, that might mask it a bit.

I'm leaning a bit towards keeping the 284; it's a shame to ditch the 292 I just dropped a couple bones on, but, sunk cost and all that.

In reply to ГУЛАГ мальчик УР следующий :

I'm not sure what my compression ratio is. The pistons have some dome, but probably not the highest ones available (I'm going by what I can see on a boroscope). It's probably somewhere around 9:1 or so. Compression testing tells me nothing, because the 300 has so much overlap that static compression is very low. Plus, there's some blowby and the valves probably could do with lapping. And the valve seals are kind of shot. See why I'm building the other head?

Have you set the carb up with a wideband? I've been working on tuning mine since I moved from 32 to 34mm chokes. I've got it where it runs pretty well, and pulls stronger than before, but I've decided it's finally time to get a wideband and do it right. Pulling the header to weld in a bung is actually the next thing on my list for that car. The 38/38 should flow plenty for anything you're considering. Have you ported or port-matched the manifold? There was quite a bit of a lip with my TWM manifolds, which I cleaned up, but I haven't done any real porting.

In reply to ГУЛАГ мальчик УР следующий :

PM'd.

02Pilot said:

In reply to ГУЛАГ мальчик УР следующий :

I'm not sure what my compression ratio is. The pistons have some dome, but probably not the highest ones available (I'm going by what I can see on a boroscope). It's probably somewhere around 9:1 or so. Compression testing tells me nothing, because the 300 has so much overlap that static compression is very low. Plus, there's some blowby and the valves probably could do with lapping. And the valve seals are kind of shot. See why I'm building the other head?

Have you set the carb up with a wideband? I've been working on tuning mine since I moved from 32 to 34mm chokes. I've got it where it runs pretty well, and pulls stronger than before, but I've decided it's finally time to get a wideband and do it right. Pulling the header to weld in a bung is actually the next thing on my list for that car. The 38/38 should flow plenty for anything you're considering. Have you ported or port-matched the manifold? There was quite a bit of a lip with my TWM manifolds, which I cleaned up, but I haven't done any real porting.

Yeah, if you've got dome, you're probably 9:1.  The 121 head shows a 58cc chamber, and with a flat top is 8.5 according to Summit Racings compression calculator. 

That said, if you're building an E12 on the bench, I presume that's what's on the car?  It's dome on dome with these cars, colloquially speaking!

Carb I based on intuition and how well it pulls, often referencing third gear up hill acceleration.  My boy wants me to stick an O2 sensor on it, he wants proof!  Maybe when I get the car back together.  I've played with dozens of jet changes, usually 2-3 a day when I do it.  It'll run perfect low, a little sluggish on top, then it'll run perfect on top, puke fuel down low, them it'll be ok through the range, but not as crisp anywhere as it was.  Then I'll play with timing, idle mixture, jets again. 

With an O2 sensor, I'd have been done the second or third jet change, so, may I heartily encourage you do so. 

I think I cleaned up the gasket between the two sides, but nothing else.  Years ago somebody posted air flow readings for the heads at various lifts, and they all flow pretty well.  I think the 1.8 had the best numbers at average lifts, and I forget which one flowed best at max lift, but I saw that and figured getting the gasket out of the way was all that was really needed

Interestingly, exhaust port floors were really sharp on my two broken heads, this last one they're a little smoother, wonder if somebody touched them in a past life.  Given the flow numbers I remember, probably not need, but maybe won't hurt, either.