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914World.com _ 914World Garage _ single thrust cam bearing

Posted by: malcolm2 May 30 2020, 12:57 PM

Assembling my engine. I noticed that the cam thrust bearing as a smaller tang. My case does not have the notch.

Since this is a smaller tang, designed a bit different. I am I supposed to tap it in place and let the action of bolting up the case crush it in place?

I built a 1911 about 7 years ago, and I do not remember having issues like this. I am pretty sure I bought all my innards from Type4 store back then too.

Clark

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Notice no notch in the saddle..... ?

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Posted by: 914Sixer May 30 2020, 01:07 PM

Look at your old bearing shells and see what you have. Thinking case should be notched.

Posted by: malcolm2 May 30 2020, 01:14 PM

QUOTE(914Sixer @ May 30 2020, 02:07 PM) *

Look at your old bearing shells and see what you have. Thinking case should be notched.


Old thrust bearing is tang free. No sign of this small tang there and having been crushed.


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Posted by: SirAndy May 30 2020, 02:19 PM

QUOTE(malcolm2 @ May 30 2020, 11:57 AM) *
I am I supposed to tap it in place and let the action of bolting up the case crush it in place?

That sounds like a great start for a engine rebuild horror story ...
icon8.gif

Posted by: Jonathan Livesay May 30 2020, 02:30 PM

QUOTE(SirAndy @ May 30 2020, 01:19 PM) *

QUOTE(malcolm2 @ May 30 2020, 11:57 AM) *
I am I supposed to tap it in place and let the action of bolting up the case crush it in place?

That sounds like a great start for a engine rebuild horror story ...
icon8.gif

No crushing is probably a good general rule of thumb for any bearing, eh? dry.gif

Posted by: dr914@autoatlanta.com May 30 2020, 02:32 PM

the cases have relieved places for the tabs

Posted by: 914sgofast2 May 30 2020, 07:11 PM

That won’t crush; it will distort and pinch the bearing if you tighten it up in the case. Camshaft probably won’t turn easily, if at all.

Posted by: porschetub May 30 2020, 07:19 PM

Tang is to prevent rotation of the bearing,there must be notch in the other case half otherwise that's the strangest case I have seen.

Posted by: malcolm2 May 30 2020, 08:02 PM

QUOTE(dr914@autoatlanta.com @ May 30 2020, 03:32 PM) *

the cases have relieved places for the tabs


The picture shows that there is no notch in the case. The other picture shows the old bearing had no tang. Doc are you saying you have never seen a case without 6 notches for 6 tangs for the cam bearings?

Posted by: malcolm2 May 30 2020, 08:05 PM

QUOTE(SirAndy @ May 30 2020, 03:19 PM) *

QUOTE(malcolm2 @ May 30 2020, 11:57 AM) *
I am I supposed to tap it in place and let the action of bolting up the case crush it in place?

That sounds like a great start for a engine rebuild horror story ...
icon8.gif


Just throwing out options. Don’t remember how the cam bearings in the last engine I built were set up.

Anybody got pictures of a notch on the thrust saddle for the cam?

Posted by: malcolm2 May 30 2020, 08:15 PM

QUOTE(porschetub @ May 30 2020, 08:19 PM) *

Tang is to prevent rotation of the bearing,there must be notch in the other case half otherwise that's the strangest case I have seen.


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Close but no cigar. Even if it did fit, the last bearing has a tang and the saddle has no notch.

Fuzzy pic but i tried to install the thrust bearing in the right half and the tang and the notch don’t line up.

Posted by: malcolm2 May 30 2020, 08:23 PM

Jake’s video screen shot. NO TANG ON THE THRUST BEARING. I am not crazy.

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And he is inserting the thrust bearing into the distributor side of the case mounted to the engine stand. So it can’t go in the other side.

Posted by: malcolm2 May 30 2020, 08:24 PM

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Posted by: Mark Henry May 31 2020, 06:57 AM

biggrin.gif

Grind or file the tang off, I do this every build.
The cam bearing has a fair bit of crush plus the cam only spins half as fast as the crank, so it won't go anywhere. Just be careful, go slow, make sure to only remove the tang, but at the same time you have to remove the whole tang.

Every build I do I use two thrust bearings, so yes I use two sets of cam bearings to get the 2nd thrust, but you can buy sets that are already dual thrust.
This is the term "dual thrust bearings", it's not talking about the bearing function, it means there's a pair (2) of thrust bearings, which is of course a mod.

Cam bearings are VW generic so the bean counters must of decided to only make one style of thrust bearing...with the tang.
Interesting note the Porsche /6 intermediate shaft bearings are VW cam bearings, just the hole is in a different spot, but dimensional it's identical.

Posted by: malcolm2 May 31 2020, 08:35 AM

Thanks Mark. Filing was one thought. Glad you confirmed the best way to move on. BTW: type4store sells the double thrust set. +$20 vs the single set.


Thanks to all,
Clark

Posted by: 930cabman Dec 3 2021, 06:45 PM

A bit late to the party, I came upon this a few days ago. The tang for this thrush bearing is smaller than the rest of the cam bearings. My gut is telling me to cut a tiny notch in the case, Dremel.

And why the single thrust bearing?? Another victim of a bean counter?

Posted by: KSCarrera Dec 4 2021, 06:03 AM

QUOTE(930cabman @ Dec 4 2021, 01:45 AM) *

And why the single thrust bearing?? Another victim of a bean counter?

All VW Type 1 engines came from the factory with a single thrust bearing – the 'hot tip' when building a performance engine was to use two sets of cam bearings and steal the thrust bearing from the second set, filing off the tang so it would fit the case. Nowadays you can buy double-thrust bearing sets with a tang on just one half.

Posted by: Montreal914 Dec 4 2021, 11:33 AM

QUOTE

Nowadays you can buy double-thrust bearing sets with a tang on just one half.


Is the type4 store the only source?

Posted by: Shivers Dec 4 2021, 12:21 PM



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Posted by: zig-n-zag Dec 4 2021, 09:12 PM

VW made these cam thrust bearings with a copper-impregnated bearing surface.

Part number 113-198-541.

I have no idea if they are available now.


Posted by: Mark Henry Dec 5 2021, 08:59 AM

QUOTE(930cabman @ Dec 3 2021, 07:45 PM) *

A bit late to the party, I came upon this a few days ago. The tang for this thrush bearing is smaller than the rest of the cam bearings. My gut is telling me to cut a tiny notch in the case, Dremel.

And why the single thrust bearing?? Another victim of a bean counter?


Type 1 and 4 only ever came with one thrust bearing, for a stock engine it doesn't really need more than one, the 'dual thrust' is a mod that has been done by independent hotrod engine builders since the 60's. The dual thrust is mandatory for any performance build that has heavier than stock valve springs.

See my previous post, file the tang off.

Posted by: Jack Standz Dec 5 2021, 12:01 PM

Normally, it's less $ to buy two sets of cam bearings & use the thrust bearing from each set to create a "double thrust bearing" for your motor. Or just pay the premium to have the vendor do the same thing for you.

Your choice about what to do with the extra bearing shells smile.gif.

Posted by: 930cabman Dec 5 2021, 12:42 PM

I used a tiny (3/8" diameter) Dremel cut off wheel and created a very small notch in the case. All is good.

Posted by: Superhawk996 Dec 5 2021, 12:44 PM

Nice! Minimizes risk of unwanted rotation.

Posted by: Mark Henry Dec 6 2021, 12:25 PM

QUOTE(Superhawk996 @ Dec 5 2021, 01:44 PM) *

Nice! Minimizes risk of unwanted rotation.

Since I've been grinding off the cam bearing DT tangs (30 years) I have not heard or seen of one instance of a spun cam bearing.

I use the KS (steel backed) bearings as I don't like the silverline DT sets. I buy two KS sets and one silverline DT set toss the extras and I have an extra trust to make two sets.
In the past I've bought 911 intermediate shaft DT's, the hole is wrong, but you just put the 911 bearing half on the dead saddle.

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