Engine strip down.

[Julian B]

Thanks again everyone; I'll have another play with the components in the morning and let you know what I find.

[SAM]

Hi Steve

Do you have a part# for the copper shim?

Also do you know if they are still available?

Sam

[HaffyHunter]

Hi Sam,
Yes, the copper shims are still available from Haflinger Technik and from Robert Prokschi. The part number is 501.2.02.035.1 and is described as "Cu Gasket" (Dwg Nr. 105/1, Item 15) in the Parts Catalog.
Julian:
I measured the end of one of my crankshafts from the end face to the bearing track on the web. That distance is 31.32mm.
Cheers,
Steve

[SAM]

Thanks Steve

Sam

[Julian B]

Armed with a new set of micrometer screw gauges I have been doing some more measuring. My main bearing does have worn slightly worn flange (the side that touches the flywheel), and this therefore gives a width of between 25.40-25.32mm. So 0.08mm could be "found" if I used a new bearing.

With the flywheel attached to the crankshaft (complete with all bearings and gears etc) and bolted together (hand tight), the end float now measures approx 0.20 - 0.275mm; add in a 0.1mm copper shim and the end float goes up to just under 0.4mm. If I got a new main bearing this would come back down to, say, 0.32mm and I would be relaxed to say that this is "acceptable", even though it is slightly outside spec (0.17-0.29mm). I will now decide if I want to spend EUR100-200 on one or two new repro main bearings. QUESTION: Would it be acceptable / good practice to only buy one new main bearing, or do I owe it to myself to buy them as a pair?

Moving on from this the comment that the rattle sounded like valve train rattle has made me think that I must now concentrate on these components. Two years ago (and very few miles since) I had the cylinders re-honed and the valves re-done, so I will concentrate on the lifters etc etc. This is once again very much outside of my knowledge zone. The curved faces of the cam followers "look" smooth, but if you rub your finger across them you can feel some wear. I have no idea how one measures or quantifies this wear though, nor how important it is. Perhaps now, whilst I wait for the new bearings to arrive, would be a good time to re-install the cylinders on to the crank case halves, and look for any problems / misalignment etc etc.

I also measured the diameter of the crankshaft pins, and they are still the maximum 45.00. And the crankshaft journals also the maximum 49.00mm. Good news.

To answer a couple of other questions raised ...

• No, the governor has not been fitted for a while, but I would like to think that I am aurally in-tune with what the Haf engine revs should sound like, and do like to think that I never thrash it Maybe I ought to re-fit it though ...
  The distance between the flywheel end of the crank and the web is approx 31.3x mm, so very close to what Steve mentioned earlier. So hopefully the crankshaft is OK.

[HaffyHunter]

Hi Julian,
So far everything sounds encouraging. Slight wear of the cam lobes is inevitable. That is why there are clearance adjustment screws on the rocker arms for the tappets. Note that motor oil manufacturers have now eliminated the zinc content in there consumer grade oils and the zinc is vital to prevent wear in these older engine designs. Racing oils (don't use synthetic types) are exempt from the zinc ban and I use Valvoline VR1 as it has the highest zinc rating they I can find.
Examine the cam follower parts and cam bearings carefully for signs of wear, damage and freedom of movement without slop. With the amount of cam gear damage you experienced you can expect bearing damage from the metal fragments. Also check for bent valve pushrods.
Yes, do yourself a favour and replace both crankshaft bearings now as well as the connecting rod bearings. Check for wear on the pistons' wrist pins too. These are often worn on older engines and will need to be replaced if wear is found.
Be sure to thoroughly clean the oil pump assembly and fuel pump actuator as they are also likely to contain metal fragments from the cam gears.
Note that the crankshaft main bearings will slightly elongate and the copper gasket (shim) will compress when everything is tightened to recommended torque values. The total end float will reduce slightly from calculated value.
As for the use of the governor, I highly encourage it. See my post of earlier this week in another Topic of this forum. Don't rely on sound alone as there is very little audible difference between 4800RPM and 5200RPM when on the road but a big difference in mechanical stress on valve train components. Some of the issues you are currently facing can likely be attributed to engine overspeed which is why I asked about the governor in my last post.
Cheers,
Steve

[pathfinder700ap]

Hi Julian,

if you assemble flywheel, crankshaft and main bearing and there is a resulting gap of about 0.3 (or 0.4 mm with copper gasket), I cannot understand where the end float of 2 - 3 mm mentioned in your first post comes from. Assuming that the main bearing has a fixed position (because it sits tightly between the crankcase halves), the crankshaft just cannot move more than 0.4 mm in axial direction.

Is it possible that the seat of the main bearing in the crankcase halves has become loose? If the whole main bearing can move in axial direction inside the crankcase, a bigger end float is possible. But I would think that this is nearly impossible as long as the dimension of the bearing between its flanges is the same as the wall thickness of the crankcase.

One more question: You measured a bearing thickness of about 25.40 mm, but Steve measured 24.90 in an earlier post - how does this go together? Am I maybe understanding something wrong?

Kind regards,
Constantin

[HaffyHunter]

Hi Constantin,
I wondered about the overall length difference between measurements I took on NOS bearings and those that Julian read on his. I can only attribute some of this difference to the elongation of the bearing when fasteners are torqued as I know this occurs in these engines to a small extent. Over time heat may have also contributed to the elongation.
I had also mentioned in an earlier post to check for wear in the bearings seat locations. This wear would be evident as a result of diminishing bearing diameter with elongation. Seat wear could also have occurred if the bearing were not set properly prior to torque being applied to the crankcase bolts which must also be tightened in correct sequence. The main bearing movement on the seat would easily allow for excessive end float.
I get a sense that this engine may have endured over-revving and overheating at some point in its life which is very common to many Haflingers. They are just too much fun to play with and too reliable to give up easily when used beyond their design criteria.
Cheers,
Steve

[Julian B]

If you assemble flywheel, crankshaft and main bearing and there is a resulting gap of about 0.3 (or 0.4 mm with copper gasket), I cannot understand where the end float of 2 - 3 mm mentioned in your first post comes from.

I will double check all of my measurements tomorrow, but I did notice that end float seemed much more apparent when the crank shaft did not have the flywheel attached; maybe the flywheel end of the shaft could move "into" the engine more when the flywheel is not present? Apologies for the confusion caused, but more tomorrow!

[HaffyHunter]

Hi Julian,
Just to clarify, the end float tolerance published in the Repair Manual is with a fully assembled crankcase having the flywheel and copper gasket attached to the crankshaft and torqued to spec. Thought this should be mentioned in case you had measured the bare crankshaft only.
Cheers,
Steve

[Julian B]

I had (before today).

[pathfinder700ap]

That's good news, because in this case, the end float is probably at least almost within the tolerance of about 0.3 mm when the engine is assembled!

Kind regards,
Constantin

[HaffyHunter]

No worries Julian. We're all here to learn something
Cheers,
Steve

[Julian B]

I have once again been checking my measurements, and I really hope that I have got them right this time ...

• The camshaft gear diameter is 118mm
  The crankshaft measures 49mm where the two main bearings sit, so I would need to buy "full size" replacements
  Both big end bearings measure 45mm, so I would need to buy "full size" replacements
  The main bearing flanges measure 2.75mm and 4.12mm, so very very similar to Steve's. The outer (flywheel end) face is slightly worn, so I would think a replacement bearing would be very slighter thicker. The overall width is approx 24.86-.88mm (difficult to measure due to worn area), so again very similar to Steve's.
  With the flywheel attached, and with a 0.1mm copper shim, the end float between the flywheel and the main bearing is 0.33mm. Between the main bearing and the crank web is 0.356mm - slightly more due to a built-in "shim" on the face of the web & I couldn't get feeler gauges right down to the bottom of the bearing. This is with the flywheel tight, but not torqued up, so the 0.33mm should reduce a tiny amount when all done. This is so close to tolerance (max 0.29mm) that I will regard end float as a non-issue.
  The camshaft end float is approx 0.38mm with one washer in the "end cap". I forgot to measure this washer before I re-constructed the crank & cam shaft etc, but the parts book suggests the nominal thickness was 0.2mm. Mine may be a little less than that. Question: The Workshop manual doesn't give a spec for camshaft end float. Does my 0.38mm sound "acceptable"? Or perhaps should I insert two washers to bring this figure down. The Parts Manual suggests the number of washers can be "as required" ...

Question: Would it be wise to use a 2nd 0.1mm copper washer to bring the end float down to well within tolerance (0.23mm)? I have two in the workshop, and using these would save having to order another.

I will check the cam lobes & valve trains tomorrow, and see what's what.

Sorry for the confusion before, but as ever thank you all so much for your patient help & guidance!

[HaffyHunter]

Hi Julian,
From your latest measurements it seems you have excess end play in the camshaft. The camshaft end play should be 0.17mm to 0.20mm. I would correct this using a new bearing and a single shim (washer) of appropriate thickness.
Cheers,
Steve

[Julian B]

Armed with two new main bearings, 2 pairs of new con rod shells and a replacement #2 camshaft & associated crankshaft cog, the re-build started today. All went well until I joined the two engine case halves together and tightened them up, after which it became almost impossible to rotate the crankshaft, even when the flywheel was attached.

I am 99% sure that the three bearings located properly into the small lugs that project into them from one side of the crankcase, but I'm at a loss to think what might have caused this problem. Any ideas? I really doubt that it is a case of "fire it up and watch it loosen up", as it is much too hard to turn by hand.

Currently the pistons and cylinders are still off, so it must be a crankshaft / crankcase / camshaft issue?

Any ideas as to what we might have done wrong before I strip it all down again?

[EDITED TO ADD: Should one use any sealer / gasket compound when joining the two crankcase halves?]

[heinkeljb]

I would first decide if it is the big end bearings that are stiff or is it the main bearings? If it is the main bearings then I would remove the flywheel, Loosen the crank case studs until the crank turns again. You will probably find that the crank is slightly oval and that in certain positions it moves nicely and at other points round the circumference it tightens up. If it is very apparent that this happens, then it looks like the crank might have to be re-ground (which unfortunately will render your new main bearing U/S)!

AS far as using gasket sealer on the crankcase halves. If there no obvious damage points on the two surfaces then I would say not - BUT - if the engine has been apart before it is always likely that there will be either some scratches or possibly some bowing of the surfaces which will result in oil leaks. They my not be big, but they will always bug you and only another strip down will cure them! I would put a very thin smear of a non hardening gasket sealant on one surface and wait for it to "flash off", then assemble, tightening up in stages checking that the crank shaft rotates all the time.

John

[HaffyHunter]

Hi Julian,

Without being there to see the assembly it's hard to say what the issue is but it's definitely a problem. Did everything turn freely before you started to tighten the crankshaft bolts? Did the main bearings fit easily on the crankshaft using the assembly lube or was it a bit of work to fit them on? Are the bearings Steyr Puch original parts or reproduction parts?

Something is most likely misaligned from what you've described. I'd suggest that you slowly loosen the crankcase bolts in reverse order of your tightening sequence and check for ease of crankshaft rotation after loosening each bolt. This might provide a hint as to where the binding has occurred. Hopefully nothing has been deformed or damaged by your initial bolt torquing.

When you re-assemble the crankcase halves check for binding as you tighten each bolt. If you encounter resistance stop and resolve the issue before proceeding. As for sealant of the crankcase halves, it is not recommended in the repair manual but I use a VERY thin painting of Permatex No.2 sealant but I emphasize the very thin comment. I only use enough to barely discolour the mating surfaces to seal minor scratches that might otherwise allow oil seepage. If you decide to use this sealant method you should be able to clearly see the aluminum through the Permatex before joining the crankcase halves. Any more sealant than this will leave an undesirable loose fit of the main bearings to their seats. It may well be a waste of time with this little sealant but it gives me peace of mind.

Cheers,
Steve

[Julian B]

Thanks both; it is certainly not a big end bearing issue, as the con rods rotate around the crankshaft fine, but the crankshaft itself will not rotate.

I will carefully undo the various crankcase bolts / studs etc and see when (or if) the crankshaft becomes loose again. I doubt the crankshaft is (or at least was) oval, but hopefully I will find out as I dismantle things. The chances of the crank case mating surfaces being perfectly true seems very remote (it hasn't been used for almost 25 years), so I've just ordered some Permatex sealant - thanks for the suggestions.

The new bearings are repro bearings as supplied by Robert Prokschi in Austria. I have heard that they are good to use, but if all else fails I will re-use the original ones and see if that cures the problem. With assembly lube they fitted onto the crankshaft OK - little slack, but rotated freely. The crank assembly did rotate easily when merely laid up on one half of the crank case, but I didn't think to check it after each bolt was done up.

All fingers and toes are crossed, hoping nothing has been deformed, but I'll let you know what transpires ...

Many thanks!

[HaffyHunter]

Hi Julian,

I've used those bearings from Robert Prokschi and they are very good quality so I feel you can rule that out as the problem. Are you certain you have the main bearing on the flywheel end in the correct orientation? There is a slight offset in the location of the alignment hole which would cause a problem. Also, are you certain that the camshaft gears are a correct match? This too would be another likely cause for binding.

Wish I was there to give you a hand as often two heads are better than one. Maybe three heads would be even better if we could get John to join in .

Cheers,
Steve