Bearing to cam gear clearance question

[TouringBubble]

I'm assembling my crank and have a question.

Today, I slipped on the bearing that sits right behind the cam drive gear, installed the woodruff key and slipped the cam gear on. It's a CB straight cut gear. I simply heated it and slid it in to place. I did not try to push it as far back as possible or anything, but I'm worried I may have a clearance issue.

The bearing I have isn't the same as stock. They are Mahle bearings and this specific one is a bit wider than the stock one and has a shoulder on it. I'm guessing it's some type of thrust bearing. These were recommended by my machine guy ... I know nothing about bearings for VWs. These seem to be the bearings ... http://www.iapperformance.com/Main-Bear ... -p930.html.

With the cam gear in place, there is essentially 0 clearance between the bearing and cam gear. There is even an occasional scuff on the bearing shoulder if i rotate it, but it's very minimal. I'm a little worried that when I install this in to the case that the bearing may want to move one way or the other to align properly and it will cause binding.

If this might be an issue, I'm not sure how to fix it. The cam gear is snugly fit on the crank now and it's a pretty beefy piece, so heating it with a torch worries me being so close to the not-beefy-at-all bearing. With no clearance and the shoulder on the bearing, I don't know what I could get around it to pull the gear back a little. This is all that's on the crank currently.

1: Is it an issue
2: If so, What can I do about it? Safe to heat it? Try to pull it? Plan to get a replacement bearing?

[dragvw2180]

The only thrust bearing on the crankshaft is the one at the flywheel. Without a picture I have to guess you have gotten them mixed up. There are only two full circle bearings that will fit on that journal, the one with the flange and the other without it. I hope this helps,if not put up a picture so we can see the problem. Mike McCarthy

[TouringBubble]

Man. Not cool. =( Guess I did mix them up. The guide I used said that only one bearing fit this area.

I used the one on the bottom right of this image ... http://www.texasaircooled.com/catalog/i ... ING-05.jpg. Guessing I was supposed to use the one on the top right?

[56speedster]

Man. Not cool. =( Guess I did mix them up. The guide I used said that only one bearing fit this area.

I used the one on the bottom right of this image ... http://www.texasaircooled.com/catalog/i ... ING-05.jpg. Guessing I was supposed to use the one on the top right?

Yes sir you should have used the top right bearing. When you do put the correct one on, you'll want to make sure that the dowel hole is in the correct position as well as it can be installed backwards.

Here's a good set of instructions with pictures: http://www.chirco.com/tech_articles/?p=149

[TouringBubble]

Lol, that's what I was using. I made the incorrect assumption that this was some type of upgraded bearing, kind of like the better cam bearings.

This is what threw me off ...

There is only one bearing in the box that will fit this first journal.

I guess they meant fit the width, because the incorrect bearing is definitely the correct ID. They never show the bearing by the flywheel, so I didn't have a comparison. Live and learn ... no harm done, just some extra work. Oh, I did manage to align the dowel hole the correct way! 1 for 2 I guess.

Thanks everyone for the help.

[56speedster]

The good thing is that you'll never do that again.

[dragvw2180]

One of the best investments you can make is the VW shop manual, I still use mine for specs and to refresh my memory. The best thing is you have the right attitude , if you make a mistake just realise that this is a hobby and it is supposed to be fun . If you are not positive about anything on this build do NOT hesitate to ask for help. Make sure you use the correct sealant for the case halfs , do not use silicone. Mike McCarthy

[TouringBubble]

Yeah, I have a few books that I borrowed from my brother, but he still has the shop manual. What I have is more about theory and application than assembly, tq specs and the like. I was using online resources for that.

I understand that this is a hobby. This is my first engine build ever. I've done a lot of bolt on work and ECU tuning and have extensive knowledge of how things work mechanically, but I'm new to building engines and I've been out of the aircooled game for over 10 years. I know I will make mistakes. It's part of learning. I'm just glad that this forum has such great members that also realize this and are so helpful. I really do appreciate it.

On the sealant note, I've read all about that. I've got some of the proper Locktite on the way from CB with the rest of my short block parts. I'm still on the fence as to the best sealant for the barrels. CB said silicon is fine there if used sparingly, but I was considering the Indian Head sealant, as I've used it in other applications and it seems to be accepted. I could use the Locktite there as well I guess, but I haven't seem many people suggest it beyond the case halves.

[56speedster]

I use the Permatex Ultra Copper high temp RTV and have never had a problem. The best thing is that you can find it just about everywhere.

[dragvw2180]

Silicone on the barrels , just pic your color. I use Ultra grey but have used others.

[turboblue]

CB said silicon is fine there if used sparingly, but I was considering the Indian Head sealant, as I've used it in other applications and it seems to be accepted.

We build several 12-15 engines each year here at the shop.
I tried the Indian Head/Aviation Permatex on a few engines several years ago.
First two or three were fine then the next 2 leaked at the cylinder base.

Back to the high temp RTV for us.
We use the aerosol version like this: