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what turbo/manifold options for turbo esprit

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So finally after much swearing the manifold is off. Surface rust but generally in good condition. The turbo is pitted with rust on the surface and it feels like the bearings need replacing. The wastegate is unknown condition but will probably need a refurb. The car is a low mileage, matching numbers, 1984 turbo esprit.

Option 1 would be to keep it original and refurbish the turbo and wastegate. Are the parts still available to refurbish the turbo?

Option 2 replace with the later water cooled turbo.

Option 3 is anything available in stainless steel?

Any other options?

Looking for advice from those who have done the job. We would not want to change anything which could not be reversed.

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GST at Newmarket managed to refurb and refit my manifold,turbo and wastegate.difference is amazing

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Bear in mind the early turbo bearings have maybe upto 10 thou lateral play which is taken up by oil pressure. however there should be no end float.   All 3 options you mention are viable, but you would need to use the later turbo for a stainless manifold, or the later manifold for option 2 (or the very rare 'non wastegate' adaptor for the early manifold).   So option 1 is the most original and by far the cheapest.   It would be my choice unless you are looking for a performance hike, which isn't really recommended if you still have the original cast pistons    

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I dont know if the later cars with the integral wastegate make the same kind of "thwunk" sound when the wastegate closes. I am rather attached to that noise and would be a reason for me to keep it original!

 

Neither of the early Turbo cars I have owned have had any work done on the turbo but both have had manifolds and wastegate adaptors. The condition of the valve seat in the adaptor is quite important as any leak means the boost doesnt come in until higher up the rev range. When I replaced this on the dry sump car the difference was night and day.

 

When reassembling its much better to use studs and nuts for the joint of exhaust pipe to the wastegate adaptor rather than the stupid bolts they used originally. Whoever specified bolts there needs a severe talking to!

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You can buy turbo rebuild kits...but not in the UK; at least, I neve found a source. HOWever...in the USA there is an outfit called the GPOP SHOP...

 

http://gpopshop.com/

 

Who will sell you everything you need, and give all the advice you can handle!! I successfully overhauled my turbo using the kit from them. As long as the whirly bits are OK...no bits of turbine or compressor blades missing...then it's a straghtforward process. If you mark the orientation of the compressor to the turbine and put it back in exactly the same position, then the balance will remain unaffected. The kit contains all the bearigs and seals and nuts and bolts and washers....it's exactly the same as the professional rebuilders use, but costs about £90 iirc instead of the several hundred a rebuilt turbo will cost you.  As Steve says, the early carb turbo uses oil film bearings...plain bearings with a bit of play to allow the oil to form the film. Also the seals are labyrinthine, and seal by the rotation of the shaft and the way that this thrown the oil film outwards. You can read of my dealings with my turbo on my first ever post to this forum..."Bridge to Engine Room: Make More Smoke" which you can find here....

 

http://www.thelotusforums.com/forums/topic/1939-bridge-to-engine-room-make-more-smoke/?hl=%2Bbridge+%2Bto+%2Bengine+%2Broom

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Thanks for the advice that's really helpful. There is end float in the turbo bearings. We have still to strip the engine down far enough to know for sure what pistons are in there. We also have to find out what is wrong with the inlet valves so cross your fingers it isn't going to be too expensive. Is there a way of testing the wastegate?

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If you have the external wastegate coming from the bottom of the manifold, then it works by an internal diaphragm which is moved by the air pressure from the compressor. There is a pipe from the compressor to the top of the wastegate. Disconnecting the pipe from the compressor and putting some air pressure down it ought to move the diaphragm and open the valve to the manifold. If you have a workshop compressor, this is easy...but don't use too much pressure. Even a footpump and a bit of ingenuity will work!  You can hear the valve clacking about . The usual problems with the wastegate are the valve stem sticking in it's valve guide or the diaphragm splitting. If the engine is in the car and running, then driving it and applying a bootful of throttle will tell you if the wastegate is working; if the boost gauge stops at something sane, 7psi or a bit more, than it is OK; if the boost keeps climbing upwards and the car goes like the proverbial off a shovel, lift off fast before it self destructs, as the diaphragm has probably split and overboost can really spoil your day.

 

Inlet valves are cheaper than the sodium cooled exhaust valves, at least....(!)

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Most reliable / cheapest over time, is replace the turbo core with a original replacement CHRA.

Independent aftermarket cores are not always good quality. And if it is from the US when you have any issues, difficult to set straight. Or send turbo for rebuild to Owen developments in Oxfordshire

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