TheSamba.com :: View topic

Sat Jul 08, 2023 4:38 pm

First significant post after a whole lot of lurking, thanks for all the help along the way.
Pardon the long post, I didn't want to be the 'didn't post details' guy.
My daughter and I have been rebuilding a 1972 Super Beetle that appears to have been assembled from spare parts. I have some experience having rebuilt a 1963 Sunroof and maintained it for the last 25 years.
We started with a single port that had no adjustability on the exhaust valves and other issues. Rebuilt the engine to a dual port with a bit more displacement so it might be more drive-able for the kid. I put the engine specs at the end of the post.

We have a three issues that have us perplexed:
1. A significant leak at the main seal even after replacing the seal.
2. Loose dowel pins between the flywheel and the crank. This may be related to some running issues we had while working out problematic ignition and carburation.
3. 'Glitter' in the oil after ~1800 miles and several oil changes (after first break in, additional changes while working through issues).

We removed the engine to try to figure out the oil leak and couldn't find anything strange with the seal, flywheel surfaces or bell housing. The leak is motor oil, not gear oil. I felt two of the dowel pins were looser than they should be but reassembled with a new seal.

This didn't fix the leak so we removed the engine again, this time deciding that with the dowel pin issue and the leak issue if the oil was glittery we likely had an issue in the internals and would need to disassemble the engine and find it. Before we disassembled I did a leak down and all cylinders were good/very good.

Today we did that, unfortunately (fortunately?) I can't find anything abnormal in the engine. Bearings all look good (as far as I know). No area's of shine from wear, no piston scoring, no big chunks inside. All the assembled bearings feel good with freedom of movement and no wiggle.

I put the crank back in and put a dial indicator on the #2 main journal. Rotating the crank showed less than 0.001" of movement. If the crank was bent I am assuming I would see it there.

So, if you have read this far I certainly appreciate it. Here are my actual questions:

1. What might be the cause of the leak at the main seal? Checked the flywheel sealing surface diameter and condition, checked the end play, used a couple seals. Checked for cracks (best I can tell), checked the galley plugs. I also don't think the case is over pressurized. Stock venting and no oil out the pulley end. Not expecting a lot of blow by (leak down test).

2. Is glittery oil after a change at ~1500 miles (viewed at ~1800 miles) something that should cause concern? I don't recall this issue when I rebuilt the 40 horse but that was a long time ago.

Also, I know I need to deal the dowel pin issue.

Engine specs:
AS41 case, inspected by reputable machinist.
Reconditioned OEM crank, (-20), inspected by same
Rebuilt OEM rods, by same machinist
New Eagle 2280 cam, aluminum cam gear, new lifters
New main and cam bearings
AA thick-wall 88mm barrels and pistons
AA heads, stock valves, hd springs, machined for barrels and compression set to ~8.2 after doing deck height
Solid shaft rockers, OEM push rods with length reduced by 1mm to get geometry right
Volksbitz 34Pict3 rebuilt carb (after finding the aftermarket deficient)
Rebuilt Bosch DVDA distributor (came with car, this was after finding the aftermarket SVDA deficient and SVDA/Pertronix deficient - I know, slow learner)
Rebuilt with elring gasket set and elring main seal (2)
CB performance oil pump with spin on filter
New gland nut, initially torqued with the 200lb body on 2ft bar method and then on reinstallations with a torque multiplier tool
Everything checked and measured along the way and the end play set to 0.004"

Sat Jul 08, 2023 11:53 pm

Loose dowel pins : get flywheel and crank eight dowelled or replace crank and flywheel or get extra strength gland nut and do it up extra tight with loctite. With loose dowel pins, it will tend to come loose again if the engine ever backfires or runs rough for some reason.

Oil leak from seal - Is the seal in absolutely square to the crank ?

0.004 Endfloat may be too small or actually zero between the flywheel and bearing with a loose bearing allowing some of that movement on the No1 bearing.. resulting in it eating the bearing up causing glitter. Were your shims perfectly flat ?

I agree it should have stopped producing glitter in the oil very quickly.

.

Sun Jul 09, 2023 6:46 am

Is the glitter magnetic? Did you put oil slinger in correctly? Recently took apart a 40hp to put in case savers, found that it had the slinger in backwards from a previous build, wore a groove in case snout, I'm sure it left lots of magnesium dust in engine! Bearings showed the results of that, engine did run ok tho

Sun Jul 09, 2023 7:53 am

The seal was installed flat and recessed about 1/16" into the bore.
The shims (3) are flat
Trolling the glitter with a magnet shows very small magnetic particles but the bulk of the material in suspension is non-magnetic. The oil pan has settled overnight so I will get a better look today.
I measured the bore alignment with a precision straight edge as described in Wilson's book and did a quick measurement of the bores and they looked to be in spec. With the case halves cleaned up today I will check the bore diameters more precisely.
I cannot feel any movement of the #1 main on the assembled crank.

Sun Jul 09, 2023 8:07 am

Checked the slinger, it is in correctly.

Sun Jul 09, 2023 8:12 am

I tend to think that if you find two issues physically close to each other they are likely related, I also like to have a complete explanation for a problem. Does it make sense for misfires caused by aftermarket mis-adventures got the flywheel it move and the out of balance flywheel caused the oil leak? My concern with this scenario is that I would have expected case or bearing damage at #1 and I can't find it.

Sun Jul 09, 2023 7:59 pm

I don't think things need to be related.
You can have any number of problems at once.
A lip seal is a lip seal, the fact it's in a VW isn't critical to the diagnosis here, IF it IS the seal leaking.

Size of the hole, size of the shaft, and runout, and shaft clearance.
Also lube, you want to have some lube on it initially.
Surface should be reasonably smooth, no sharp edges that would tear the seal on installation.
Seals can accommodate a LOT of misalignment, housing being .004" oversize or undersize or oval, a LOT of shaft clearance, and a lot of shaft runout......but not all at once.

you have checked the shaft for size and surface, (0r rather the flywheel part it rides on in this case) that's good but i would also be checking the other things.
you might find the hole is .004 out of orund and flywheel surface has .002 runout, but that's not too bad, good enough, then I would have total faith that it isn't the seal.
Has nothing to do with balance.

Also might want to double check that it is leaking at the seal.
If you think it is, then it's probably true, but why?
Is the clutch and interior of the flywheel dry?

Sun Jul 09, 2023 10:24 pm

I agree with you that a double lip seal is a durable and adaptable seal. Thus far everything I have measured is within the working range given in the Bentley manual, so I continue to question what the problem is.
The area around the clutch only had a little oil while the bell housing walls were soaked. The clutch was working properly.
With a case apart I will be able to look closer at the other possible leak points and redo a couple of the parts that may be leaking.
The plan now is to make sure the crank face and flywheel face are flat and rework the parts for 11/32" pins.
Then we will reassemble with a new seal and see what happens. Unfortunately, I am not set up to bench start an engine, need to find a bell housing!

Sun Jul 09, 2023 10:43 pm

Set it on the flywheel and watch for where it leaks?
Pressure lube it and watch for oil plugs leaking?

one other thing, long shot.
The end of the crank should be tightly spigoted into the flywheel, so the flywheel will be centered even without the dowel pins.

BUT, IF you are using an older flywheel on a late crank then ONLY the dowels are centering the flywheel, then you could easily have a runout problem.

Mon Jul 10, 2023 7:01 am

The flywheel fits tightly on the crank.
Is pressure testing the case before installation a procedure anyone does? I could fabricate a seal for the pulley side.

Tue Jul 11, 2023 3:46 am

X3... is the oil slinger on the crank installed properly?? If it is installed the way many feel looks right... it's installed wrong

Tue Jul 11, 2023 2:42 pm

100% sure it is correct.

Tue Jul 11, 2023 4:02 pm

I suspect I’m in the same boat but no glitter.
I have yet to drop the engine to see where it’s actually coming from though.
It’s an all new engine case and all but the seal I used was from 1998.

Tue Jul 25, 2023 10:21 pm

So I took the engine apart then checked the case for cracks and found none. I reworked the flywheel and crank for 11/32" dowel pins and reassembled/sealed everything up. Engine is back in the car and thus far has no leak from the flywheel area (woohoo). As far as the glitter in the oil I found no obvious areas of wear. The bearings all looked good and everything measured out in the acceptable ranges.

Edit: Taking the woohoo back, leaking from the bellhousing connection area again. I am at a loss at this point. Thinking of putting another seal in (#4) and not recessing it...

Sat Aug 05, 2023 1:59 pm

Last post on this. Seems like this is a pretty common issue and nobody has a good answer to it so add me to the list.
I added a fluorescent agent to the oil and ran the engine for ~20 miles. Pulled the engine and with UV visualized oil around the seal, crank snout and gland nut. No significant signal in the oil in other areas around the bell housing so I believe that is just oil spreading over time. The cam plug and the bungs also did not show signal.
So I cleaned everything up, made a flywheel seal installation tool per Hoover Tulz drawing, installed elring seal, added some sealant very sparingly around crank snout, oring and dowel area. Installed flywheel with big washer gland nut, torqued it properly and checked the endplay (0.004").
Still have a one or two drop leak when the car parks after ~20 mile drive.
Looks like I will have to learn to live with it, hopefully the oil stays away from the clutch. The only thing I can think of now is that there is something wrong with the case/crank/flywheel that was missed in the inspection before the rebuild. At some point I will need to disassemble the engine and get the parts to someone to re-check.

Sat Aug 05, 2023 2:10 pm

VWs, just like any good German Shepard, like to mark their territory! Just a characteristic of the breed. :D

If it's not dripping once in a while - it's probably out of oil! :shock:

Sat Aug 05, 2023 2:22 pm

The first engine I built with all used parts I used cheap (grant) rings plus I did a course hone job. I had glitter big time the first two oil changes then a little on the third. It still ran for years the compression was low but drove the crap out of it. If it runs okish just go with it what's done is done.

Sat Aug 05, 2023 7:29 pm

Did you check the oil drain hole behind the main seal for any obstruction? Flywheel O ring good / new?

Fri Aug 11, 2023 8:15 pm

Yes, I checked the drain hole. The o-ring and seal were new every time I replaced them.

Sat Aug 12, 2023 12:22 pm

i have been know to snip about 1/8" off of the spring inside the seal lip before installing it. i also spend some quality time with a flat file on the case mating surfaces--especially in this area and below it.