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CNC Blocks and Straub Tech are having a custom run of babbitt bearing 55MM cam bearings made. These will feature just 1 hole and a groove. This will fix any hole alignment issues.

Available 1st of October

Contact either one of us for pricing. Pre orders will be discounted.
 

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Where do you like the hole Carl? 4 o'clock?
Chris

On that big of housing bore 4:00 would be best.

I wish I could figure how much bleed off there is with the GMP-55 cam bearing with 3 holes every 120 degrees apart. It has to be a lot on a housing bore that size.

Sorry for the late response.
 

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Was 55mm previously available in roller bearing?
Yes it was but on a SBC standard deck height block boring the cam tunnel to 2.477 there would not be much to bore on the cam side of the cylinders, Plus you would be into the dist. hole quite a bit and sealing that up might be a problem.
 

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Yes it was but on a SBC standard deck height block boring the cam tunnel to 2.477 there would not be much to bore on the cam side of the cylinders, Plus you would be into the dist. hole quite a bit and sealing that up might be a problem.
Sorry, what i meant to ask was "

Was 55mm previously only available in roller bearing?
 

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Sorry, what i meant to ask was "

Was 55mm previously only available in roller bearing?
No. There is a 55MM Babbit bearing P/N GMP-55 which has 3 oil holes 120 degrees apart. Which causes a huge hemorrhage or bleed of from 8:00 to 4:00

The new bearings should cut back on the a lot.
 

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Do you have any pics of this cam bearings after being used in the engine? How much press fit are they setup for? I'm interested...
 

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Do you have any pics of this cam bearings after being used in the engine? How much press fit are they setup for? I'm interested...

Seeing they are band new cam bearings none have been used in any engine as of yet. I have used quite a few set of the GMP-55 and GMP-55-T in SBC,BBC and Ford small blocks with zero problems.

These bearings were built exactly to the same spec as the GMP-55 Durabond bearings. Only difference is the new bearing only have one hole.

The ground OD of the bearing is 2.286/2.287 recommended bore size is a 2.282 which would give you .004 to .005 press fit.
 

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What's best position for 3 hole bearings? 4,8,12? or just stick with 6,10,2? or something different?

There is really no good answer, No matter where you clock them you still end up with a massive hemorrhage.

You surly will get plenty of oil to the cam bearings.
 

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Why 1 hole instead of reducing the diameter and keeping 3 holes?

Why do you need 3 holes??? You can put the one hole at 6:00 and drill 2 more holes what ever size you want.

I am trying to get rid of oil blowing out every where. All you need is oil just before the load area.

I have been putting another hole at appox. 3:30 and grooving on the OD of the bearing with the other oil hole at 6:00 done this with GMP-8, GMP-1, GMP-12 with zero problems.
 

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Just curious... Why are we getting away from 55mm roller brgs ?
 

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Just curious... Why are we getting away from 55mm roller brgs ?
Try putting 55MM roller bearings in a Bowtie, Little-M and Dart SHP blocks and let me know how that works out.

If you wanted one of those blocks I would machine 2.477 cam tunnel for you if you thought it would work.

2.477 cam housing bore in a standard deck SBC on a large bore block there will not be any cylinder left on the inside of bore plus you will cut most of the dist. hole out.

The Durabond GMP-55 has seemed pretty popular in the SBC, BBC and the Ford SB's at least at my shop.

I still see a lot of 50 MM rollers cam bearing in the SBC and BBC still machine for roller is some of those blocks, as a ratio I may machine 1 block for roller cam bearings compared to about 10 blocks machined for Babbit cam bearings.

The Problem with the GMP-55 with 3 hole there was a massive bleed off now with the new bearings oil bleed off is minimized a lot.
 
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