End Play Questions....

[rick m]

I've built most of my own motors over the years and never had an issue when building a new engine (with new case, crank rods, flywheel, etc.) setting up the end play. The case was not line bored, the bearings are all new, the #1 bearing by the flywheel fit snug (as it should) but something has gone off.  Checked the end play with the flywheel on and got .033 with my dial indicator.  Went to set it up with three shims at .028 - .029, to get a .004 to .005 end play and re-installed the flywheel and ended up with.012 end play???

In the 40+ years I've been doing my engines, I have never run into this with all new parts.  Anyone ever run in to this? I am beginning to question the quality of the flywheel on this combo.  The MFG over cut the o-ring groove. I am wondering if they got the back of the flywheel machined flat too?

Any one have any thoughts?

Rick M

[danny gabbard]

Checking with crank in case only? Are you useing a dial indicator? and how are you moveing crank from front to rear?

[TexasTom]

Is the endplay consistent checking at multiple points while rotating the assembly in the case?
I have run into clearance issues with some crank/case combinations that were only evident when first checking endplay.

Is this a factory/mag case? Crankshaft welded or aftermarket?
TxT

p.s. getting ready for the new contest! LOL

[rick m]

Yes, I always use a dial indicator.  The flywheel run out is dead on, so I did not suspect the flywheel mating surface being off.  I checked the bearings for fit in the case as well as rotated the crank assembly in the case without issues.  It is a factory mag case but after market crank and flywheel.  I will not mention the manufacturer at this time until I check everything. I have never run into this before even with welded strokers or counter weighted cranks. Very odd.

I checked the end play about 10 times and started to question the #1 bearing moving. So, I set my dial indicator up to measure the bearing by moving the crank in and out of the case from the pulley end and there was no movement in the bearing. I had the whole motor together and ready to shove in my street car but have a suspicion I am gonna have to tear it all down and start over to find out what is causing the issue.  I hate to blame the after market crank and flywheel combo but cannot figure what else would cause it.  The case is a standard/standard brand new factory VW mag case.

Rick M

[j-f]

Do you already install the camshaft? maybe his pulley has some wrong tooths that prevent the crankshaft to move freely?

[Torben Alstrup]

Have you checked that the shims are what they "say" ? I have seen shimms that were both warped and larger/smaller than the stamp said.
T

[rick m]

Yes...used my dial calipers to check all shims to ensure the size.  I have straight cut gears so I doubt that is holding up movement.  It is extremely odd.  May just tear it down and start over again.

RM

[TexasTom]

I suspect the crank.
I've seen and dealt with cranks that interfere with the case along the middle saddle ... the counterweights are too wide at the outer circumference and interfere requiring trimming of the case/crankshaft counterweights.
Funny thing is I personally haven't seen this with a welded crank. I guess VW knew how to make them best? LOL

[Tony Wilkie]

Hi Rick,
Sounds like the counter weights are hitting inside the case. This would give you a inaccurate initial reading (more than the .033 measured) with no shims.
Just add an additional (.008) in your shim stack to get  .004 clearance.

tw

[Taylor]

I would split the case and leave the flywheel on. then check it on the bench

[rick m]

Taylor,

Just what I am planning to do.  At this point,  I won't even go any further.  Need to get to the root cause. Have way to much in this motor to not disassemble and look at everything. I  will let everyone know what I found out and who's parts not to use if it ends up being the flywheel cut wrong or the crank.  May even put a longer stroke in it while I have it apart! :-)

Rick M

[Fasterbrit]

Rick, I have come accross this problem on two or three brand new engine builds. It took me ages to figure out what the problem was as there seemed no logical explanation to the crank end float measurements seeming to change.  Then the penny dropped... There was a slight machining tolerance issue with the o-ring groove on the flywheel. This caused the o-ring to be lightly pinched between the end of the crank and flywheel. This explained why when the flywheel was torqued up for the final time with o-ring and seal installed that all of a sudden the end float jumped to 25 thou! In all three engines I had to trim a little off the o-ring with a scapel. Bingo! Perfect end float.
It took a lot of head scratching to work that one out. Amazing what a tiny little bit of rubber can do when it gets in the way! Even when torqued to 350 ft/lbs, it has the ability to mess up things up in a big way. 

The downside of trapping a little bit of the o-ring is a flywheel that WILL come loose. Gauranteed!   

[rick m]

Alltorque,

This was taking place before the flywheel o-ring even goes on.  In addition,  the idiots who machined the oring groove cut it too wide. So much for the quality control issues from this particular supplier.  I've resigned myself to have another stock GERMAN flywheel 8 doweled and then try the end play.  If it does not come around then, I will disassemble the motor and see what is causing the issue.

BEWARE of any of the CHINESE cranks you buy. Check every single dimension (Journal widths, etc.) before spending the time balancing the internal assembly and putting the motor together. The first BUGPACK crank I purchased in the mid 90's was dead on.  I have not run any other brands since other than welded strokers or BERG parts.  Again, I will leave this vendors name unlisted until we check all things.  How can you ship out a flywheel with the o-ring groove cut wrong with a conscience?  I guess you get what you pay for. In this case I paid over $100 for the so-called FORGED flywheel.  The dowel pin holes are also loose enough you can push the flywheel on and off without using your traditional two large screwdrivers to walk it off.

RM

[Sarge]

The easy way around end-play "fun" is to do your set-up while the crank is still on the workbench... especially with a wedgemated flywheel. 

[rick m]

Looks simple.  Never done it this way but will try on future builds. Having a new non-aftermarket flywheel (GERMAN) 8 doweled for my motor so I can get it done.

Rick M

[rick m]

Took off the after market flywheel, went to CE and had them 8 down a lightened GERMAN flywheel, came and checked the end play once, added the three traditional shims and was done with the end play set up in less than an hour. So much for the quality of the aftermarket 4340 flywheels.  The best I can tell the back surface that the shims ride against is not true.

I will never understand why certain companies will go to the trouble to make new parts and not check the quality and tolerances of all the machine work. I plan to ship this disappointment back to the manufacturer of the part.

Rick M