Hi all,

I am in the process of installing a Gen 2 13 B Turbo in to a Gen 1 RX7. Have purchased a Gen 2 1989 front cut. Removed the exhaust from the turbo and noticed that there is a little bit of movement (say 1-2mm) in the turbine in a direction perpendicular to the axis of the shaft. Thre is no movement of the turbine in the direction of the shaft. Is this a bad sign, or does the turbo expand somewhat when hot removing this movement? I have not owned a turbo vehicle previously.

Is replacing the bearings in the turbo likely to fix this (apparent) problem?.

Arran
Brisbane Aust

 

It's probably just fine. Whilst it's VERY hard to describe just how much radial movement is too much it nearly always is more than a person expects who doesn't examine lots of used turbos. The shaft rides on a high volume oil film of considerable thickness when the engine oil pump is turning and this play disappears. That is also the reason people sy a BB turbo feels much easier to turn than a bushed one Feed the bushed one an oil pressure supply of hot oil and it will feel the same to spin. Not saying a BB will not boost earlier at a given exhaust flow, but you see what I mean, I hope. If in doubt find someone with a known good turbo you can "feel" as a comparison. If there is axial movement 9you can pull the wheel in and out of the casing along the axis of its shaft then the thrust bearing is gone or going, re build time. Good luck, hope this helps a bit.

 

I just went down this road with my t04e, getting a number for the amount of play that is acceptable is hard, basically if the wheel scrapes the housing with radial play, its screwed, also even if its not touching it could be close to being fubard, judging how my turbo feels and looks since repair, a good test would be to see if you can slide an ordinary piece of white paper between the compressor blades and the housing, if it binds up on this, its probably worn, before my turbo got fixed, you could not do that even where it did not hit, now that its fixed, you can stick a peice of paper in between the two and still turn the wheel..Max