Main bearing and crank compatibility

[baz]

Hi all,  hoping to get some good advice on my crank and main bearings. I have this DPR 82mm crank



You can see the oil passages in the crank don't have a wide trough around the passageways, I've read elsewhere that you need internal grooved bearings for this type of crank.

The bearings I have are externally grooved NOS KS,  can I use these?  Is there any benefit in having the crank or bearings modified with a groove on the journals or inside the bearings.?

Really would appreciate some help with this as I've been ignoring my engine build for the past few months due to uncertainty over this, and I'd really like to get my finger out now and get back on it.

Thanks

[baz]

Ok I've found some interesting reading on this topic and I have decided to have my bearings modified with a small groove on the inside.

Now I need to know who can do this work for me in the UK ?  Anyone got any ideas? 

[leec]

Have you spoke to DPR directly, I have always had a quick response via email from them
Lee

[baz]

Have you spoke to DPR directly, I have always had a quick response via email from them
Lee

Hi Lee, yes emailed jose and just got a 'use silverline ' response.

Spoke to jim at stateside and he thinks it unnecessary to mod the crank or bearings.

From reading a lot this morning I'm of the mind it certainly wouldn't harm anything either and any way to increase oil flow has to be good.

[brian e]

Here are a couple topics from the other site.  Read the ones posted by SRP1.  He does a bunch of baja 1000 engines, and has the oiling topic figured out. 
http://www.thesamba.com/vw/forum/viewtopic.php?t=542619&postdays=0&postorder=asc&highlight=internal+groove+bearings&start=0
http://www.thesamba.com/vw/forum/viewtopic.php?t=570244&highlight=internal+groove+bearings
http://www.thesamba.com/vw/forum/viewtopic.php?t=499960&highlight=internal+groove+bearings

Your crank needs the internal groove bearings.  If you were here in the US, I could chuck them up and add the groove for you.  I do it on most all my engines. 

Brian

[richie]

Hi all,  hoping to get some good advice on my crank and main bearings. I have this DPR 82mm crank

Thanks

Hi Lee, yes emailed jose and just got a 'use silverline ' response.

Spoke to jim at stateside and he thinks it unnecessary to mod the crank or bearings.

From reading a lot this morning I'm of the mind it certainly wouldn't harm anything either and any way to increase oil flow has to be good.

Baz

unless I missed something, you asked the crank manufacturer? and then Jim@stateside?  and they gave you the same answer right?  now you want the "experts of the internet" to give you a different answer?  Sorry but I don't understand why   

cheers Richie

[baz]

Thanks Brian I found those posts from srp1on sunday and what he does with the bearings makes sense to me.

Richie I hear you but just because something may be unnecessary for the engine to live isn't the same as saying it would not be beneficial to the life of the engine and bearings in particular.

I'm sure there's a tonne of unnecessary work gone into your engines

I'm just trying to do my best with this, after watching it seize up on the dyno earlier this year and going through the expense and trouble of building an engine twice without even getting to drive the thing, then you can maybe forgive me if I am overly anal with my approach to building it. I don't need it built anytime soon so I can afford to take my sweet time getting the finer details right.


Ps you got a lathe ritchie?  

[richie]

I'm sure there's a tonne of unnecessary work gone into your engines

Nah I am to lazy  

Personally I wouldn't be modifying the bearing, if it needs a internal groove then I would find bearings to suit it

cheers Richie

[baz]

I'm sure there's a tonne of unnecessary work gone into your engines

Nah I am to lazy  

Personally I wouldn't be modifying the bearing, if it needs a internal groove then I would find bearings to suit it

cheers Richie

Why's that Richie?  Think the bearings would suffer damage during the cutting or think the bearing would be too thin afterwards?

Finding internal grooved metal backed correct size bearings has me stumpted.

[richie]

Yes I would be worried about strength of bearing, until I see one in real life that's actually cut/modified I can't say for sure though

[baz]

Yes I would be worried about strength of bearing, until I see one in real life that's actually cut/modified I can't say for sure though

I have some old bearings that I'll have cut first for a sample of the finished article.