Cb crank oiling question

mark tucker · Posted: Tue Oct 28, 2014 8:48 am Post subject:

I dont realy fully grove my mains, I do a partial grove leave about1/2" un groved like the calies bearings I used to get for v8 stuff.I dont have bearing issues.over bearing issues...... Shocked

possiably

AlteWagen · Troll Joined: February 23, 2007 Posts: 8501 Location: PNW

some pics to make it easier

On the left is a KS bearing for use on a non cross drilled crank. The bearing on the right is for use on a cross drilled crank.

Image may have been reduced in size. Click image to view fullscreen.

Here is a late VW of Mexico cast crank with cross drill oiling (any 1600 forged German crank is the same)

69mm 1500 and many aftermarket stroker cranks are not cross drilled requiring the use of the KS bearing to allow full 360* oil to the rods. Below is a 82mm Scat crank that is not cross drilled but has the journal modification to allow full oiling while using a non cross drilled type bearing.

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Northof49 · Posted: Tue Oct 28, 2014 11:39 am Post subject:

Can I 360 groove the split bearings on a lathe?

SRP1's work:

http://i46.photobucket.com/albums/f102/vwparts86/Mobile%20Uploads/2013-02-02_172051_zpsa9f69018.jpg

On second thought, as the back side of these bearings are already grooved, that doesn't leave much bearing left if they are grooved internally afterwards.

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1958 Karmann Ghia owner

bugguy076 · Posted: Tue Oct 28, 2014 2:27 pm Post subject:

Yes, the center bearings can be grooved on a lathe. A fixture must be made to hold both halfs at once. It's not that difficult to do by hand with a Dremmel tool. I tape off both sides of the bearing to protect it and it gives a straight edge to go by. As I said before, I make the groove about .030" wide and as deep.
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85burb · Posted: Tue Oct 28, 2014 5:02 pm Post subject:

I went and looked at his bearing today. He did groove it but I don't think it was wide enough. And was not centered well. He does have a lathe and he is pretty smart so I am betting he can groove them better some how. He tore a core motor down when I was there that he is gonna build for his next race motor. So we will get to try again.
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Northof49 · Posted: Wed Oct 29, 2014 8:35 am Post subject:

Would it help or harm to make another hole through the bearing at the midway point?
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1958 Karmann Ghia owner

85burb · Posted: Wed Oct 29, 2014 9:50 am Post subject:

AlteWagen · Troll Joined: February 23, 2007 Posts: 8501 Location: PNW

If I remember correctly Wasser engines also have the slots in the mains
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Grapes of Wrath $200 Engine Rebuild
Official Dual Carb Thread
Cylinder Head Quick Reference Sheet

rs58rag · Posted: Wed Oct 29, 2014 9:12 pm Post subject:

here's another way center main is drilled.

drumbum68 · Samba Member Joined: October 15, 2010 Posts: 566

It's all Bergy and stuff.

neil68 · Posted: Thu Oct 30, 2014 1:15 pm Post subject: Re: Cb crank oiling question

rs58rag · Posted: Thu Oct 30, 2014 3:54 pm Post subject:

Neil68.. do you use 26mm. Or 30mm. Oil pump? And what weight oil?

modok · Posted: Thu Oct 30, 2014 5:47 pm Post subject:

I refrained from....... refraining because it wasn't part of the question...........BUT.
The FIRST question to ask is what was the rod bearing clearance??

Second what oil and lets see the air filter.

Then we talk about bearing grooves Wink

85burb · Posted: Fri Oct 31, 2014 4:22 am Post subject:

I am not sure about the rod bearing clearance. But he turns them so they are all strait up and makes sure they fall at a good speed and all the same. The oil is 15-40 for sure. He has a holley 500 two barrel carb and uses a big round tall air filter that has a outer wrap on it. I think he has a 30mm pump in it. Non full flowed. He is very against full flow cases and of all things duel carbs.
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1964 beetle
1974 standard beetle

raul arrese · Posted: Fri Oct 31, 2014 5:49 am Post subject:

mark tucker · Posted: Fri Oct 31, 2014 10:20 am Post subject:

agnist full flow??? just smile and sell him some more parts and a box of chockalattee candies. stupid is as stupid does. ( not including spellen teacher test's)

modok · Posted: Fri Oct 31, 2014 4:24 pm Post subject:

Ok then it's pretty clear cut. the 15-40 oil is OK choice, but Failed because you can't use thick oil with tight bearings.
Have the crank ground for .0025-.003 bearing clearance and try again.

I am sure the main and cam bearings are ruined too from not having an oil filter.

raul arrese · Posted: Fri Oct 31, 2014 4:53 pm Post subject:

modok · Posted: Fri Oct 31, 2014 4:59 pm Post subject:

you betcha!
And also consider oil flow and flex. There is a lot of flex in the crankshaft, so not a good idea to have your rods significantly tighter than the mains. If the rods are trying to keep the crank straight it will certainly result in more friction and heat!!

mark tucker · Posted: Fri Oct 31, 2014 5:01 pm Post subject:

and skeered of dulling crabs......he's lost without hope of finding him self.those are the kinda guys I refer to toyota for a car.sorry but I call it as I see it. some have it some dont,some think they do and those who do just smile and nod thier head.kinda like cant teach old dogs new tricks but they sure do buy a lot of defective parts to eat up.


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