Hi Sorton and Mike,

my new wheels are ET38. My old one's were ET35 so I went for something close. The guy included some thin spacers to make up the difference.

The engine build has ground to a halt due to lack of time and a somewhat worn crankshaft. I've got a 328i crank but its rather worn at the rear bearing so I'm reluctant to use it and then find out it leaks oil. I've been on the look out for one in better condition, but there are not many around at a reasonable price.
If I can't get a decent one, I may just rebuild the engine as a stock 325i. The engine is now all cleaned up ready to be degreased, painted and re-assembled.

Besides which, I don't want to take my car off the road at present!! :madgrin:

So here's a small brain teaser....

According to Mintylamb.co.uk my new tyres are 6.54% larger rolling circumference.

My speedo is driven of the BMW diff reed switch sensor, so for the same numbers of pulses I will travel 6.54% further.
So my fuzzy old brain says that means my speedo will now under read by 6.54%.
Have I got that right?

And apparently I should now have an additional ride height of 0.8" which with my under-slung exhaust is a nice bonus.

I better dig out my speedo calibration instructions....

Spot on. The wheels go around slower if the radius is larger so the speedo will under read.

Also means that if you can get to max rpm in top you will be going 6.54% faster!

Thanks, Chris.

I'll have to put your theory to the test :madgrin:

Just bought another 328i crank so the engine rebuild may be back on....
Not seen it yet, so fingers crossed it's in good condition :wink:

:gossip: Crossing finger........!!!!





:blabla:
John Galt
ConEd, Sales Consultant
Borough, New York

Latest crank looks in good condition, so the M20B28 build is back on :madgrin:

http://farm7.static.flickr.com/6005/...c356e78399.jpg
M50 328i Crankshaft by marlinpeter, on Flickr


One confusing thing is it has two different coloured paint blobs, both Yellow and Green?

http://farm7.static.flickr.com/6121/...5378427130.jpg
M50 328i Crankshaft by marlinpeter, on Flickr

Anyone got an idea why this might have happened? I hope it hasn't been re-ground?

Sweet, no idea on the paint colour :/ Suppose the way to check for re-grinding is measure the diameters. Would be a simple case of getting thicker shells suitable for a reground crank if it has been :)

Just found this on another forum...


"Data removed as it wasn't relevant to M20 engines"

The quality certainly looks good in the photos

Could you check with BMW or ask the same question on any of the BMW related forums. Have noticed also in the top photo it shows two green paint marks, something odd there

On further inspection, I don't think it's a re-grind.

From looking at the box of caps and shells that came with the crank, it looks like it was fitted with a mixture of Green and Yellow shells.
(Hence, the Green and yellow blobs of paint). I think they are the original factory assembly marks.

My plan now is to the check the bearing clearances with some of that Plastigauge stuff ( http://www.plastigauge.co.uk/index.html )with a new set of Yellow shells to see if I need any Green ones.

Peter
Crank tolerances are so important for a long lived engine. Why not take it to an engine building engineer and have it checked properly: I'm sure it would be money well spent.
Mike

What, and spoil all my fun :lol: :lol: :lol:

I had a closer look at the bearing shells tonight, all marked with original BMW part numbers. This confirms that its a standard size crank and not reground. The bearing shells are still mostly the light grey matt finish, so this engine shows very little wear. Looks like I've got a good crank :smile:

For anyone else building or rebuilding M20 engines here's useful datasheet...

http://www.flickr.com/photos/peters-...in/photostream

My 'mixture' of coloured dots just means that I have some Yellow bearing shells and some Green. There is a 0.007mm difference in diameter.

In fact, my engine was fitted with 5 Green shells and 2 Yellows.

OK, so after my cars winter break and off the road to fit it's new 2793cc engine , it's now all back together.

As well as the new engine, I've rebuilt the front suspension with new QH ball joints, Superflex top wishbone bushes and new steering rack gaiters. I've got rid of the cheap Rally Design lower wishbone bushes and I've gone back to the original rubber ones. (and a lick of paint to spruce things up). Oh , and a new windscreen to replece the cracked one from last year.

So we are now ready for road testing the new engine :madgrin:

http://farm8.staticflickr.com/7202/6...0febc2b9_b.jpg
Ready for test drive by marlinpeter, on Flickr

Looking GOOOOOOOOOOOOOOOOD!

Have you fitted the new servo to hold back that rampant engine?

No, but it's next on my list of things to do! :thumb:

I don't like changing too many things at the same time. Once I'm happy with the engine running, then I'll change the servo.
I'm really looking forward to spending time in the drivers foot-well so will have to mentally prepare for that task :lol:

I taxed my car on line this morning and took it out for a short run to get some fresh 97 octane petrol and make sure everything was working OK. The car seemed to have much more power and sounded much louder and 'fruity' :smile:
After visiting about 4 petrol stations I had to settle for some ordinary 95 octane stuff as the greedy petrol hoarders had drunk all the good stuff. I took the car back home to check things over and found that injector #4 was not firing which explained why it sounded like a V8 rather than a smooth 6.
After swapping the ECU to eliminate any electrical problems we got the injector going by giving it a sharp tap with a large spanner! (I really wasn't looking forward to getting the injectors off again)
The second shakedown of about 25 miles was fantastic!! The whole car feels transformed. The power is awesome and it's quite amusing to see how it will accelerate quickly even in 5th gear :eek:
The engine is much quieter and runs so smoothly, I was grinning all the way.:madgrin:

My front suspension has also been transformed with the new bushes. Even my son travelling in the passenger seat could feel the difference.

Hopefully #4 injector was just a bit gummed up and will now run OK, but i'll treat it to a bottle of injector cleaner just in case.