Guys I wanted to know how to tell if a set of turbos have been rebuilt or not. This is probably the only part of the RX-7 that I haven't gone fully into and I don't know everything about, so my bad if that sounds like a noob question. If a set of twins are rebuilt, is there supposed to be no shaft play whatsoever? Would there be any other way of telling if the turbos were rebuilt or not? If you know of a place that sells twin turbo rebuilding kits that'd help a lot as well. Thanks a bunch beforehand guys....
-Erik

 

You usually can't tell unless the rebuilder puts tags or stamps on.

To appraise a set of twins you usually look for cracks in the turbine housings where they mate to the exhaust manifold. More cracking here means they've seen more heat, and more stuff further inside will be worn/heat damaged as well.

You will always have a small bit of shaft play...about 0.5-1mm side to side, and almost none in and out. You're also looking for any oil in the compressor housings, any leakage of oil between the center cartridge and turbine housing. You also want to compare the turbine inlets from the motor to the outlet to the downpipe...if the inlet is clean and tan/brown coming from the motor, yet the downpipe is black and carboned, then the turbos are burning a lot of oil. If the inlet from the motor is also dirty, then it was probably the motor burning the oil. IF both inlet and outlet are clean/tan, then neither was burning much oil.

Aside from this, you just have to bolt them on and see what happens...turbos and transmissions are 2 things that can't really be "tested" before put into use.

 

thanks for all the help so far kevin; the info you gave really summed it all up, haha. so even if they were recently rebuilt, there is going to be a little bit of shaft play, right? you wouldn't know of a place where i can get turbo rebuilding parts would you?

 

yes, and turbocity.com. $150 each plus shipping.

 

shouldn't rebuilding kits come with new compressor and/or turbine wheels? i haven't FULLY taken apart my twins, but i don't see any part in that rebuilding kit picture that i recognize. if i were to send my twins and get them "rebuilt", the parts in that picture are the only parts that they would change? the link to the pictures is as follows: http://www.turbocity.com/images/300-050.jpg
-erik

 

What is pictured is what comes with the kit. Just like if you tear down an engine and you need rotors or housings, those dont come in a master rebuild kit...just seals, springs, bearings, etc. Same here...the rebuild assumes all your major hardware is reuseable.

 

If you rebuild them they still need to be rebalenced . Any turbo rebuilder should have the equipment, be sure the shop can do a good job of it as the balance is of great importance .