Post Conversion - Crank Rotation Tight

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
12,222
Location
Memphis, TN
It should spin free with no leverage enhancers. You should be able to grab the end of the crank and it should glide with ease. Although a million engines have been put together with lithium grease, it’s not my favorite. It does not melt in engine oil so a glob of it can end up in the oil pan. 1/2 engine oil 1/2 STP is pretty good for bearings. Cam and lifter faces like moly assembly lube for break in. The oil STP mix is good for lifter in case too. If tightening the case changes anything except maybe drag from two bearing faces touching the crank and cam, something is not right. It should be like butter. The case is either tight or not.
 

fly2kads

Well-Known Member
HBA Supporter
Joined
Jan 2, 2010
Messages
1,513
Location
Justin, TX
My concern is that torqueing up the smaller bolts all around the case will distort the case, and bearings. Should I follow some special torquing sequence to prevent that, i.e. Torque the main 6 bolts first to full 25#, then bring the outer bolts up 5# per round alternating bolts on opposite sides of the case, until all are up to spec? or what do you recommend.

on initial assembly I used typical aircraft permatex sealant on the case half faces which is thick and hard to spread evenly. Is there a better product?
Different manuals call out different torque sequences for the case. For example, the Great Plains assembly manual says to do the large nuts (M12) first, then the M8 nuts by the rear camshaft lobe (but only to 10#), then do all the other M8s, going in a circular pattern around the case. The Bentley VW shop manual, on the other hand, calls for tightening the M8 by the cam first, then the M12s, then the rest of the M8s around the perimeter.

I also note that the Great Plains and the Bentley manuals differ on the torque values for the M12 nuts. Great Plains calls for only 18#, whereas the Bentley says 24-26#. (Both agree on 14# for the M8s around the perimeter.)

I have used Permatex on my ground-bound VW cases, and it has sealed well. The Great Plains manual calls for Loctite 518. Don't obsess over perfectly even coverage of the Permatex. As long as you get a reasonable film on there, pressing the case halves together will spread it out for you.
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
12,222
Location
Memphis, TN
Silk thread with sealant or correct RTV is acceptable for Lycoming. The cats meow is the milled case for a continuous strip of O ring material they do as an option. I put two silk threads on my case, thread from the fabric store. I would use what is recommended. Just be careful with rtv, you don’t want squeeze out into the case with that.
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,739
Location
Rocky Mountains
Pla
on initial assembly I used typical aircraft permatex sealant on the case half faces which is thick and hard to spread evenly. Is there a better product?
Johnc
Yes. if you are using the kind of Permatex I suspect I suspect it causes all kinds of case distortion problems on the VW. It may work on a C-65 but not the VW. I've tried Halomar and even it is too thick.

Gasgacinch was the de-facto standard among the old school German VW mechanics and I used it for many years with good results. But it got hard to find for a while and i was forced to find an alternate. It also leaked if the customer had nicked the case halves (common) during their disassembly and I missed the gouge.
I now use Ultra Grey silicone. Applying it is kind of an art. You need just enough to seal with almost no squeeze out* and you have to get the case halves together and torqued in 10 minutes or less** (while it is still thin) or it's just as bad as the Permatex and you have to start all over.

Don't put any sealant on the main or cam bearing saddles. It's not needed and just makes for something to creep/flow out and loose clamping pressure.

There is a VW specified sequence for torquing the case bolts. You should be able to find it pretty easily on the internet.(edit: Just returned to this thread and found I forgot to poke 'send' before I left. #18 is not enough for the 12mm nuts. I suspect someone mixed up the 8mm head stud torque?)

Though I've not tried it I suspect that some the anaerobic sealants would work very well.

* ideally the squeeze out should all be on the outside. I've seen engines ruined because the cheap blue/black/red silicone squeeze out flaked off and plugged an oil port.

** the coat hanger trick on the lifters helps here.
 

proppastie

Well-Known Member
Log Member
Joined
Feb 19, 2012
Messages
4,167
Location
NJ
Yes. if you are using the kind of Permatex I suspect I suspect it causes all kinds of case distortion problems on the VW.
I have used Permatex Form a Gasket 2 or 3 for about 40 years. The non-drying characteristics should not warp a case. I do not like silicone. I have found that usually a mechanic likes one or the other. I once ran into a mechanic that used contact cement on VW s.
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,739
Location
Rocky Mountains
I have found that usually a mechanic likes one or the other.
What we like is not important. It's what works that matters. I've used, and still use, Permatex when appropriate. The case halves of a VW is not one of those places.
VW case halves, just like any other bolted structure need a firm and permanent base so the fasteners can maintain their clamping pressure. I could go on a related rant about re-torquing, but it's too far off topic for this thread.
 

proppastie

Well-Known Member
Log Member
Joined
Feb 19, 2012
Messages
4,167
Location
NJ
When all else fails read the instructions. ....what does the VW overhaul manual say to use.
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,739
Location
Rocky Mountains
When all else fails read the instructions. ....what does the VW overhaul manual say to use.
To be totally honest I don't know what the last official VW manual specified. The Gasgucinch product was the over the counter version of the factory sealant into the 60's. The supply chain dried up for a few years in the late 70's, at least for independent VW shops, and we were forced to come up with our own replacement.* By then VW saw the end of the air-cooled VW in the US was eminent, due to EPA and DOT regulations, and didn't spend any more money than was needed to keep the bug/bus on the market until they had the water-cooled models ready for production.

*The local VW dealer was not too friendly - and it wasn't just because I had more customers then he did. But that's a story(s) to be told over a cold drink.........
 

Pops

Well-Known Member
Log Member
Joined
Jan 1, 2013
Messages
7,658
Location
USA.
To be totally honest I don't know what the last official VW manual specified. The Gasgucinch product was the over the counter version of the factory sealant into the 60's. The supply chain dried up for a few years in the late 70's, at least for independent VW shops, and we were forced to come up with our own replacement.* By then VW saw the end of the air-cooled VW in the US was eminent, due to EPA and DOT regulations, and didn't spend any more money than was needed to keep the bug/bus on the market until they had the water-cooled models ready for production.

*The local VW dealer was not too friendly - and it wasn't just because I had more customers then he did. But that's a story(s) to be told over a cold drink.........
I always used #3 Permatex with no problems. I was lucky, I had one of the top VW only machine shops in the nation that is local and they answered a lot of questions and did excellent work for me in building engines.
With your knowledge of VW's, I'm sure that you had all the business you wanted and more.
It was just a side business for me and it got so I had to quit my day job or the side job, so I quit the side job.
 

BBerson

Well-Known Member
HBA Supporter
Joined
Dec 16, 2007
Messages
12,775
Location
Port Townsend WA
I think a narrow bead of sealant on the outside edge would be best. It would crush like plastiguage if you could buy a roll of sealant the size of plastiguage.
 

Tuneturkey

Well-Known Member
HBA Supporter
Joined
Dec 29, 2018
Messages
63
Location
baton Rouge, LA 70816
Seven (7) responses, That's awsome!!!
Thanks Guys for the input. I have come to the opinion that VW engines (especially type1,2) are like babies. All unique, all different, a definite challange!!! I am definitely a glutten for punishment thinking that I could rebuild an engine, and a 1/2VW at best. But "ForumU" is making it doable, even for an 80 yr old. Thanks loads guys!
 

Pops

Well-Known Member
Log Member
Joined
Jan 1, 2013
Messages
7,658
Location
USA.
Seven (7) responses, That's awsome!!!
Thanks Guys for the input. I have come to the opinion that VW engines (especially type1,2) are like babies. All unique, all different, a definite challange!!! I am definitely a glutten for punishment thinking that I could rebuild an engine, and a 1/2VW at best. But "ForumU" is making it doable, even for an 80 yr old. Thanks loads guys!
Yes, you can do it. VW engines are just "Different". When built and run correctly, they are a tough little engine
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,739
Location
Rocky Mountains
Ok, it thought it might be a good idea to bring my case sealing knowledge into this century. What better place to check than the guys building Subaru engines? After all they are similar architecture and even if their cases are substantially more rigid than the VW the same basic physics applies.

What I found was the usual mix of back yard builders that use whatever the guy at the NAPA counter said would work and the guys that do some thinking. Long story short: HondaBond (and similar from other manufacturers), Three Bond 1215, and the anaerobic sealants with Locktite 518 or 510 and Permatex 51031 looking like the thinking mans choice set.
For a VW case I'm thinking that the Locktite 510 may be the best choice?
 

fly2kads

Well-Known Member
HBA Supporter
Joined
Jan 2, 2010
Messages
1,513
Location
Justin, TX
Just looked up the two Loctite and the Permatex products. Of those three, I agree that the Loctite 510 looks like the best choice. I'll be rebuilding a VW car motor for my current project in the coming months (a 1300 for a '66 Beetle), and I may give that a try! (Airplane should be the next project after the Beetle is done....)
 

Pops

Well-Known Member
Log Member
Joined
Jan 1, 2013
Messages
7,658
Location
USA.
Just looked up the two Loctite and the Permatex products. Of those three, I agree that the Loctite 510 looks like the best choice. I'll be rebuilding a VW car motor for my current project in the coming months (a 1300 for a '66 Beetle), and I may give that a try! (Airplane should be the next project after the Beetle is done....)
If Hot Wings says its good, I'm going to try it. I have always used the #3 Aviation Permatex.
Last year I bought a 1966, 1300 cc and a 1965, 1200 cc engine for a total of $50. Both complete engines with carbs and generators as pulled from a car. Have the 40 hp overhauled except for the new piston, cylinders kit. It was a good engine with very little wear. Also last winter bought a complete, good 1600 cc engine for $75. Building the 1600 as a 1835 cc for my pipe buggy.
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,739
Location
Rocky Mountains
If Hot Wings says its good, I'm going to try it.
Didn't say that it is good, only that I think it might be based on the spec sheet and some internet chatter. I do intend to try it, but I urge you to do your own due diligence.
 

Pops

Well-Known Member
Log Member
Joined
Jan 1, 2013
Messages
7,658
Location
USA.
Didn't say that it is good, only that I think it might be based on the spec sheet and some internet chatter. I do intend to try it, but I urge you to do your own due diligence.
Will do.
 
2
Group Builder
Top