No start turned into bigger problems

[Preyupy]

If you are using a Cometic MLS gasket the surface finish on both the head and block needs to be virtually mirror smooth. If you can run your finger nail across the surface and feel ANY ridges the gasket will not seal correctly. I use them all the time and I do spray them with Cooper Coat before instillation. When you remove the head look carefully for signs that the piston dome has been hitting the head (or the gasket, you said the bore was 91mm, if the gasket bore is 90mm the pistons may be hitting the gasket) this may be your noise. 

[andyleonard]

10 hours ago, Preyupy said:

 When you remove the head look carefully for signs that the piston dome has been hitting the head (or the gasket, you said the bore was 91mm, if the gasket bore is 90mm the pistons may be hitting the gasket) this may be your noise. 

 

If the noise isn't upstairs, it's got to be downstairs.

[Train67]

On 6/25/2018 at 7:13 PM, andyleonard said:

 

It looks like you are adjusting the valves by turning the little eccentrics in toward the center of the motor. Look at the contact point of eccentric to valve stem and see if the eccentric is centered on the stem...or almost. 

Boy I really thought this was it because I looked and the eccentric was only touching the edge of the valve stem. I flipped the eccentric around and adjusted them and the contact area was much more centered. Unfortunately the noise is still there...arghhh. I’ll have to get a stethoscope on it. 

[Train67]

I reviewed the videos before and after the eccentric adjustment and now I’m thinking there is an improvement. Here is what it sounds like now. Do you notice a difference and does it sound right? I’ll repost the before video again. 

[Train67]

On 6/23/2018 at 3:00 PM, Train67 said:

 

 

Video of before eccentrics were corrected. 

[andyleonard]

That's a huge improvement. One or 2 of 'em still sound loud/loose but the nasty clattering's gone. The video distorts the sound but it doesn't sound to me like there's head/gasket/piston interference.

 

How long has it run? Minutes? Hours? You changed all the eccentrics? What oil is in there? Bar is oiling happily from all holes?

 

If it were mine - and I had that coolant leak issue pending - I'd run the motor for 30 mins or so varying the revs and reassess the noise afterward. Stethoscope can be done during test running.

 

Obvious problem is it's too clean. If there are no visual problems, the car will have to manifest something.

[Tommy]

Well it's better for sure. To what spec you're adjusting them? Maybe try a bit tighter gap and see what happens. The noise is now on a level that on a cell phone  I'm not sure if there's anything wrong anymore.

[Train67]

Wahoo!  I was hoping I wasn't being optimistically biased

 

All 8 of the eccentrics had to be flipped around. Oil delivery appears fine, everything was/is oily.  I adjusted clearance to 0.007".  I'll check again and adjust to 0.006" and run it again.  The motor has about 20-25 minutes of run time so far with the first 15 min having run between 2000-2500 RPM. I'll run it for 30 min more as suggested and see what happens.

 

Coolant leak is still there but this small victory has certainly helped morale! Thanks for the input! 

[tzei]

Coolant seeping thru like that - cracked head. Get it pressure tested/magnafluxed to be certain it's good/no good. 

[Train67]

On 6/8/2018 at 9:14 PM, Buckeye said:

Hope that you will find is just the gasket. Next time use OEM or Erling head gasket and use torque and angle method.

That 60 ft-lb torque in 3 steps was for old gasket and gasket technology of 60 and 70's .

Instruction from reputable manufactures tells you to use torque and angle and even service bulletin published by BMW in June 1986 says so.

4. Service-Information - Group 11, Engine June 1986 (Pdf file)

Let us know what you find out and Good Luck.

Does Erling make a head gasket for 91mm bore?

[TobyB]

20 hours ago, tzei said:

Coolant seeping thru like that - cracked head. Get it pressure tested/magnafluxed to be certain it's good/no good. 

 

Or corroded.  I had a head with an eroded passageway that leaked out one of the head  bolt passages,

That made a mess...

 

Usually the OE gasket is good to +1 mm in piston diameter.

 

I don't know why people punish themselves with the all- metal gaskets-

in an engine that isn't going to run at the edge of det for hours,

the stock gasket holds up fine.  I raced the stock gasket at 12:1 and 

never had one fail.  

 

 

t

[2002Scoob]

Didn’t someone have problems with misalignment between valves and eccentric due to using badly installed rocker locks?

 

That woulda been me courtesy of the shit-head over at Vogt Tuning here in Freiburg. But it was the retaining hardware installed backwards, not the locks.

 

 

Worst. Mechanic. Ever.

 

That was just scratching the surface of his ineptitude.

 

 

Sent from my iPhone using Tapatalk

[Train67]

Here’s the culprit ?

I had 3 machinists tell me the stress cracks were no big deal. Pretty big deal to me. 

 

Is is it able to be welded? Going to talk to machinist today. 

[kbmb02]

This is hindsight for you (bummer)...

 

For others: An early step of an engine rebuild includes visual inspection / magnaflux of the block in those areas to check for cracks, like shown in your photo. This is when a builder / machinist familiar with M10's is to your advantage.

 

6 minutes ago, Train67 said:

Is is it able to be welded? Going to talk to machinist today. 

 

When those cracks are found, I personally have not attempted to repair / weld them - the blocks go to scrap (reluctantly). -KB

[tzei]

2 hours ago, kbmb02 said:

When those cracks are found, I personally have not attempted to repair / weld them - the blocks go to scrap (reluctantly).

Same here. Local machinery shop bought a block from me when they had a customers engine with crack like that.