Title: Main bearing and crank compatibility Post by: baz on August 20, 2016, 08:40:03 am Hi all, hoping to get some good advice on my crank and main bearings. I have this DPR 82mm crank
(http://i.imgur.com/hbZ14hh.jpg) 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 Title: Re: Main bearing and crank compatibility Post by: baz on August 20, 2016, 09:49:41 am 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? Title: Re: Main bearing and crank compatibility Post by: leec on August 20, 2016, 12:05:06 pm Have you spoke to DPR directly, I have always had a quick response via email from them
Lee Title: Re: Main bearing and crank compatibility Post by: baz on August 20, 2016, 12:31:57 pm 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. Title: Re: Main bearing and crank compatibility Post by: brian e on August 22, 2016, 22:59:47 pm 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=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=570244&highlight=internal+groove+bearings) http://www.thesamba.com/vw/forum/viewtopic.php?t=499960&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 Title: Re: Main bearing and crank compatibility Post by: richie on August 23, 2016, 11:32:46 am 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 Title: Re: Main bearing and crank compatibility Post by: baz on August 23, 2016, 11:55:39 am 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? ;) Title: Re: Main bearing and crank compatibility Post by: richie on August 23, 2016, 17:28:23 pm 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 Title: Re: Main bearing and crank compatibility Post by: baz on August 23, 2016, 19:33:43 pm 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. Title: Re: Main bearing and crank compatibility Post by: richie on August 24, 2016, 09:26:50 am 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
Title: Re: Main bearing and crank compatibility Post by: baz on August 24, 2016, 10:13:11 am 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. |