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MG Midget and Sprite Technical - Race 948 Main Bearings- Advice please!

Not sure who might be an expert on this, but I need advice. New bearing shells needed for a 948 race engine.

The 1.75 diameter 948 MG / Sprite main bearing shells are about 30mm (1 3/16") wide, as were 850 Minis. 998 Minis were also 1.75" diameter, but reduced to about 27mm (1 1/16" ) wide. It seems that the original wider main bearing shells are becoming impossible to find. I have two choices. Can anyone advise which is best?

1. Some old stock Vandervell ( non lead indium, I believe) in the correct width.

2. Great quality race shells from Mahle, but these are the narrower width 998 Mini shells.

It's complicated by the fact that I have a lovely new steel crank, so want the best. pic attached!

Any ideas?

Andy

A Cross

When you say impossible to find, have you tried asking the performance engine builders (MED, Swiftune, Peter May, Classic & Modern, Steve Harris, Keith Calver, Cameron Gilmour etc etc) as they may well have old stock on the shelf.
If the Vandervells are VP2 then they should be fine.
David Smith

Thanks Dave
Yes VP2 is what I've used before. Some on your list I've yet to try so I will do so.
Most responses have been either "out of stock" or that the narrower 998 Mini size is OK. I guess the bearing loads should be no more than seen in a 998 Mini racer.
Andy
A Cross

also try CCK, and Gordon at Classic Revival, plus anyone who runs or looks after Sebrings.
David Smith

Love the crank!

Peter
Peter Blockley

Can we have some details on the crank like who made it, how much lighter is it, spec etc
Daniel Stapleton

A number of Minis here ran King alloy bearings for a whole season, no problems. They do the 948cc wide version of the 1.75 mains.
Paul Walbran

Hi Paul
Some UK folk don't seem to like the County 'King' bearings. We love em and have had no problems with them whether the SA variety of tri-metal ones. The Israeli made bearings are of extremely high quality, better than the AE Ferderal Mogul ones ( we knew soemone who worked in the testing labs who told us they always bought opposition bearings etc to test and found the quality and control of the King ones was tighter than theirs!)
Peter
Peter Burgess Tuning

Is it not important to consider which oil is used in conjunction with bearings of different metal composition?
AIUI some combinations work very well and others suffer rapid wear due to the particular additive pack in the oil.
David Smith

Can you elaborate on that David and give specific examples in terms of make/material of bearing and make of oil which caused rapid wear in tests? We have used all sorts of bearings and customers have used all sorts of oils so I am intrigued as we have not had premature wear, only twice when we had some hidden crud somewhere which wiped the engines in minutes.
Or do you mean ZDDP content?
Peter
Peter Burgess Tuning

Hi Peter
The person who built the engines with those bearings was the top man over here for Mini engines, and was very happy with the results when he stripped for the scheduled rebuild at the end of the season. And I have used the King bearings in the engines I build with similar results.

And in relation to premature wear, how about when someone let the oil level get too low, suffered oil starvation as a result, and didn't confess to it!
Paul Walbran

I've no examples Peter, it was a question not a statement; yes I was thinking along the same lines as the ZDDP example for 'boxes and diffs.
David Smith

Phew, you had me worried there David.
as stated no reported probs yet. Most of my customers seem to use Valvolene Racing VR1....awash with zinc :)
Valvoline™ VR1 Racing Oil's high zinc provides race-level protection for high performance engines on the race track and is compatible with passenger vehicles. Additional product benefits include:

On the Valvolene websitem Mr Monte, he say;

High zinc/phosphorus for anti-wear protection, including push-rod and flat tappet applications
Formulated to increase horsepower
Enhanced anti-foam system protects engine during extreme stress
Recommended for engines burning gasoline and full or partial alcohol fuels

Peter
Peter Burgess Tuning

Thanks everyone, some good advice there.
I won't get into the oil debate; everyone has their preference.
I have used King and ACL bearings before. It's really a question more about the bearing size and area. I've had more experts advise that the mini 27mm bearings are good, but I'd just like to maximise bearing area so want the best shells I can get at the full Midget/Sprite shell width. If anyone can recommend a source I'd be very happy.

As to the crank, thanks Peter and Daniel, I'm afraid I don't know the manufacturer. Can anyone identify it? It's replacing one put in by Oselli in 1984, raced almost every year since!

Andy

A Cross


IT MIGHT be
An American RODY crank with a part no. like that- has it got cross drilled bigend journals ??

Nice looking piece of metal
William Revit

are there not books with details of different cranks and bearings in? :-D

cheers,
Malcolm
Malcolm Le Chevalier

Andy, if you are happy with King bearings I could get some sent direct.
Paul Walbran

This thread was discussed between 15/11/2016 and 22/11/2016

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