Would a post-Rotoflex (swing spring) GT6's rear wheel bearings be able to handle a 2.5" wheel spacer/adapter to increase rear track by 5"? Light street use only (no competition, maybe 1000 miles a year, car at least 500 pounds lighter than the donor GT6).

See http://www.carcentric.com/StraightSix.htm if you're curious about the project.

Thanks.

[Edited on 7/8/03 by carcentric]

The effect on bearing life would partly depend on the type of bearing used - as far as I remember the original herald/spitfire had a ball (probably angular contact) and needle roller bearing set up - is the GT6 the same?

It will affect bearing life certainly, particularly with an extra offset as large as you are talking about, but the amount would be difficult to predict.

You could also factor in that a new bearing would almost certainly have a substantially higher capacity than the same part number manufactured 30 years ago (when the car was new) due to bearing manufacturing improvements.

According to the parts catalog I have, the rear bearings in post-Rotoflex GT6's are the same as in Spitfire 1500's.

If a pair under "normal" use would wear out in 50,000 miles, could I at least expect 5,000 miles of life (10% of normal) with the extra load?

[Edited on 7/8/03 by carcentric]

If the bearings are the same as the Herald (which I think is the case) then they are as I mentioned above. Please understand to start with that I know much more about tapered roller bearings than other types, so I may not be totally correct here.

I would say that with the factors I mentioned before you would be quite likely to easily manage 5000 miles on a set of bearings. I would also suggest that you would be unlikely to suffer a "catastrophic" failure of the bearing without some warning - you normally hear the bearings wearing for some time before they fail completely.

Try having a look at some of the bearing manufacturers websites to see if they give you any details of expected life (try SKF, FAG, NTN, NSK-RHP, Timken etc.) Even for a GT6 I would expect the original bearing life would be more than 50000 miles. Just make sure you buy new bearings, not new old stock as tey will not be as good.

Hope this helps.

[Edited on 8/8/03 by andyps]