First ride and shavings in the oil -PICS-

[1950split]

Hi guys,

So tonight I went for a first ride with the car fitted with the new engine (2276, 86c, 44x38 heads and idas)

I did an oil change, actually I didn't refill so far, and found a few metallic shavings in the oil (sump plate & oil filter). They are soft, very shiny (looks like they were rubbed off somewhere) and are not attracted to a magnet. The largest are about 4mm long   but ultra thin..

After cam breakin the oil was changed and there was nothing of this kind to see.

I did what might be a silly test, I used a torch to see whether they catch fire (as the case has magnesium in it), no reaction.

I lean towards bearing material, piston or maybe oil pump cover (berg)

Any idea what it could be ?

http://s1084.photobucket.com/albums/j403/1950split/

Phil

[David Ward]

That's odd.  I thought you were talking shavings, but those are "pieces."  Was your case properly clearanced?  Is it possible your rods did some clearancing on the case?

[1950split]

I got the cleranced case from Brothers and while mocking the engine up I checked everything so that nothing was hitting.

I just remember that after the 3rd breakin session, the glandnut of the flywheel was loose. I was lucky not to loose it.

The engine revving with a loose flywheel could perhaps have caused damage to the n°1 bearing  ??

[maui]

I say the case wasn't cleaned good enough wen machining was done to it and maybe something was in a journal and now came out. Up to you but I would take it out and apart and check everything for yourself and piece of mind.

[fiatdude]

When in doubt --- whoop it out

[Donny B.]

What kind of timing gears are you running?  Once I ran a set of straight cuts with and aluminum cam gear and had aluminum particles in the oil.  When I replaced the gears I found that they had small chips missing like they had been scraped off.

[1950split]

All oil galleries were opened and I thoroughly cleaned the case, using the compressor to clean everything.

The case is a as41. As far as I know, magnesium can ignite quite easily. In this case woudn't the "chips" have caught fire when I used a torch on them ?

I use a bugpack straight cut cam gear,  steel on steel.

After initial cam break-in we change the oil and there was nothing in it except some cam lube. Weird that this occurs now.

I think I have no other option than to pull the engine and take it apart. I'll do a leakdown test previously in order to check if valves and rings are sealing properly.

What do you think about my theory of the crank rubbing off main bearing #1 when my flywheel got loose ?

[John P]

Man, that sucks, and I feel for you.

What do you think about my theory of the crank rubbing off main bearing #1 when my flywheel got loose ?

It could be, as the crank would have "walked" a bit with the loose gland nut.



I'm glad that you're going to take it apart, as those "shavings" are verging on "pieces." Every time I've seen someone leave it together and pray to the VW gods when finding disturbing signs, they regret it. Credit to you for being thorough and checking.

Good luck - take some pictures and let us know what you find.

My 1.5 cents.

JP

[1950split]

Well, I'm learning it the hard way but I got a glimpse of the potential of this engine, it's just pushing amazingly above 4.5k rpm !

I just hope that these shavings didn't damage anything (case, crank, rods) too bad, although I can reasonably think they got caught by the oil filter after they got sucked by the oil pump. And at least it is "soft" material and not steel..

Parts are too expensive for gambling.. I'll consider what I've done so far as an extensive mock up  

[David Ward]

If the flywheel got loose then your end play loosened up and if the crank "walked" forward a connecting rod might have touched the case.  Even though you mocked it up and all seemed fine, if the crank moves forward what was once clear may now have hit.  Just sayin...

I was going to mention the cam gears too, but I would have thought you would have seen evidence of a tight situation.

My bet is on the connecting rods hitting the case near the center cam bearing.  My Brother's clearanced case (building now) was "clear" until I set the end play and then it hit.  I had to split the case and hand clearance the case.  Again, center cam bearing area.

H-beam rods require a bit more clearancing.

[1950split]

I got your point David and actually I clearanced  the case where the cam seats because as for your case it was too tight there. However if the case has been rubbed-off these chips should have magnesium in them and would have ignited with the test of the torch on them or am I wrong?

[Ohio Tom (DdK)]

if the flywheel comes loose, then something else takes the thrust.
Could be #2 bearing or the case like David says above.
Either way, yes take it apart and check for sure. Don't risk those parts.
If the rods were "clicking" the cam, consider replacing it as they are cast and break like glass from that sort of thing.

Also, tearing down a short run motor will let you know how all the other parts are working (rockers, ring seating,etc..). It will give you piece of mind that everthing is happy.

[David Ward]

Tom raises a good point... those pieces could be off the camshaft.  They wouldn't burn with your torch.

[Bruce Tweddle]

Here's an idea.  Take the biggest one and grab it with your tiny pliers then touch it to your grinder.
No sparks = aluminum or Mag
yellow = steel
orange = cast iron

[Dougy Dee]

I'm wondering whether the oil slinger could have caught something in the case when the flywheel loosened off and crank moved.
I remember, years ago, screwing up and putting the slinger on backwards. It made pieces similar to what your pic shows. Also loaded up #4 main and locked the bugger up.

[owdlvr]

I got your point David and actually I clearanced  the case where the cam seats because as for your case it was too tight there. However if the case has been rubbed-off these chips should have magnesium in them and would have ignited with the test of the torch on them or am I wrong?

Assuming we're talking a propane torch, chips that size will require holding the torch on them for quite a bit of time. I've got some filings from when my case was machined and they don't just light up right away, you've got to hold the heat on them for a fair bit.

-Dave

[1950split]

Hi Guys,

I finally managed to take the engine out of the car and opened it.

There were no additional shavings inside and there was no damage to see. I'm not sure but I think that maybe a rod bolt hit the top of the case and shaved some of it away. I still have to check the main bearings. Cam bearings look perfect.

However I was surprised to see the top of my CB lightweight lifters after cam breakin and roughly 10 miles of driving.

I think it is the beginning of a pitting issue but would like to have your opinion. I took some pics of them.

I will also post some pics of my 1.4 cb rockers in order to have your opinion.

To all CLF members, happy New Year !

[David Ward]

Those don't look "right" to me.  In doing my tear down my CB lifters looked practically new and definitely didn't have marks like that.

[fiatdude]

that is not good at all

double check everything in the valve train and make sure there was not a point where there was coil bind or worse

what do the top of your pistons look like?

[Ohio Tom (DdK)]

yeah, those lifters look worn pretty badly.
I would check the cam for loss of lift.
You will likely measure some loss.

[David Ward]

Looks like it was a good thing that you did the tear down.  (before a complete failure occured.)

[1950split]

Yes, looks like it was a good thing.

I've taken some pics of the lobes of my 86c. Generally speaking it looks ok to the exception of this small mating on top of the lobes. Do you think I can reuse it or should I buy a new one ?

What do you think of the wearing marks on my rockers where the lash caps are in contact with them ? While doing the rocker geometry I tried to achieve similar angle a full lift and no lift and to be in line with the valve stem at half lift.

I identified the spot where de rod hit the case. You can see it at the bottom of the machining for the stroker crank.

[fiatdude]

Looks like like new cam and lifter time -- just to be safe -- Do you think the shavings all came from this area???

To me, I would try to find out why all the abuse on the cam and lifters and rockers-- check and see if when the valve is at 100% compression that there isn't any interference between the guides and the retainers or springs - and make sure that your rockers have plenty of movement past the full opening and full closing of the spring -- I had to grind my pauter rockers for more clearance because they were hitting the stud at full open on the intake rockers and at full close on my exhaust rockers -- -- something is causing something to bind and put that added stress on those parts and it appears to be at max lift IMHO

[David Ward]

The cam looks hosed.  I'd replace it.  As for the pic of the case, it doesn't look like its a large enough spot to produce the bits you found.  It may have been hitting, but I think there's another source as well; could be another spot on the case somewhere.

As for the rocker, I can't really tell from the picture.  As fiatdude suggests, you may have some sort of binding/clearance issue in the valve train.

[Meandean]

You didn't mention how strong the valve springs are.  With high lift ratio rocker arms and a high lift camshaft I recommend breaking in the new cam and followers at 2500 rpm for 30 minutes using stock valve springs (or at least remove the inner springs from a dual set). 

[toysandprojects]

Are the crank/flywheel dowle holes ovalded from gland nut coming loose?

[1950split]

Well I know it seems weird that this area could be the only from where the shavings came but I carefully checked the case and could not see any other impact.

The springs are CB 650's that have 160Lbs load @ 1.54" installed height and 420Lbs load @ .630 lift. The 86c has theoretical lift of .545 with 1.4 rockers. I did the breakin with the two springs fitted.

I guess it is definitely wiser to use new lifters and cam.

What would be the obvious evidences/damages for coil bind ? I checked retainer/valve guide clearance while building the engine. The top of the pistons look pristine, no evidence of a hitting valve on anyone. Could a binding spring be the reason for the engine sinking and skyrocketing revs during the breakin? I thought of a lack of fuel due to a bad electrical fuel pump on the stand.

I had trouble maintaining a constant rpm. These inconsistant revs are in my mind the reason for the damaged lifters and cam.

Luckily I ran the engine on a stand an found out about the loose flywheel before going for a test ride and used some medium strenght loctite on the threads. Therefore the holes of the flywheel and the pins in the crank look ok.

=> Just came to my mind : I had my lifter bores bronze sleeved, could it be that not enough play for them to spin could have caused this ? <=

[David Ward]

Interesting idea on the lifter bore - could be.

If you measured your springs at .630" and your actual valve lift measured .545", I doubt sincerely you experienced any coil bind.

[Bruce Tweddle]

I had my lifter bores bronze sleeved, could it be that not enough play for them to spin could have caused this ?

Could be.  Measure them and compare to the specs in your Bentley.

[1950split]

It's been a looong time since my last answer on this topic. However I finally found the source of these shavings after having taken off all rods from the crank. Bearings from the rod on Cylinder 2 are totally shot !






I did the cam break in and drove 20 miles so I'm very much surprised of this.

Any ideas of what could have caused this ? I noticed that the edges of the oiling holes on the crank were very sharp so I smoothed them now. This might have been the problem ??

[David Ward]

Yikes!  I'd be curious what the journal on the crank looks like. 

Could be lots of things that caused that from a lack of lube at start up to some shavings from the machine work that were left over in an oil passage some place, to a freak bearing failure.

[fiatdude]

If that is the rod that hit the case then it is a no brainer what caused that bearing to look like that -- that little bit of tapping can screw some stuff up quick!!!!

You should see what a little detination does to rod bearings and that is with nothing hitting anything

[1950split]

Thanks for your comments !

Fiatdude, indeed the small spot where a rod hit and the destruction of the bearing are probably linked ! I'm glad that I pulled the engine, it could have ended with a total mess..

The rod journal look suprisingly good, no evidence whatsoever. I polished it with some WD40 and 1200 grit sandpaper.Smoothing the edges of the oiling holes will anyway improve the situation.

[Bruce Tweddle]

You should Mic the rod journal of the crank.  If it's too big and the brg clearance is too small, it will pick up like that.

[fiatdude]

I agree -- maybe take it down to the machine shop and have them do a quick check for you, maybe do a resize just to make sure -- simple insurance