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Phoenix manifold - which throttle linkage?


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For those with the Phoenix extractor manifold, have you found you have had to move to an overhead throttle linkage due to thermal expansion in the rods?

 

For those with the Phoenix extractor manifold who are still using the underslung linkage, is your manifold wrapped or coated?

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Not sure which part of the throttle mechanism would cause the thermal expansion:

Ferritic steel ( the material which the linkages are made from in the original design falls in this catergory) expands with 1.2 mm/m/100 degr.C.

So a linkage of say 100 mm and working at 70 degr.C will expand only 0,06 mm, assuming it was adjusted at ambient temperature, 20 degr.C.

The aluminium components however expand at a much higher rate, almost double of ferritic steels (around 2,2 mm/m/100degr.C.

You can check your design by estimating how the respective materials expand.

Have you set the float (clearance in closed position) correct on the linkages?

Waldi

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My 6 has a Phoenix manifold and the normal CP series under-slung throttle linkage. The manifold isn't wrapped or coated.

 

All works fine, though my fingers get very hot adjusting the linkage to balance the throttles!

 

 

Nigel

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Not sure which part of the throttle mechanism would cause the thermal expansion:

Ferritic steel ( the material which the linkages are made from in the original design falls in this catergory) expands with 1.2 mm/m/100 degr.C.

So a linkage of say 100 mm and working at 70 degr.C will expand only 0,06 mm, assuming it was adjusted at ambient temperature, 20 degr.C.

The aluminium components however expand at a much higher rate, almost double of ferritic steels (around 2,2 mm/m/100degr.C.

You can check your design by estimating how the respective materials expand.

Have you set the float (clearance in closed position) correct on the linkages?

Waldi

When I collected my reconditioned PI equipment the reconditioner supplied a different linkage kit to the original, this meant that following the manual wasn't any use. There really isn't any adjustment possible other than the throttle rod length, I have been setting these such that they fit without opening the butterflies with all the parts warm, although not at full temp.

 

I started the car earlier, idle at 1100 RPM, within a few mins the exhaust manifold was up to 236C on my infrared thermometer and the idle was up to 1500 & rising.

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So Nigel & Niall's posts would suggest my setup should work, it's been adjusted multiple times and it just isn't right, don't know where to go from here, I can't drive the car anywhere to get it looked at, £00's wasted with "specialists" already!

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HI Ian,

 

I'm only over in Market Harborough, about 15 minutes from Corby. If you would like me pop over and take a look sometime, drop me a PM. I can bring my '6 so you can see the throttle linkage and exhaust manifold.

 

 

Good luck,

 

Nigel

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Thanks Nigel, PM sent.

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Hi Ian,

To add to the discussion my TR6 is fitted with the Phoenix extractor manifold with the Revington overhead throttle linkage. There is presently no coating or wrap fitted to the manifold and all works well. The manifold and exhaust was fitted by TRGB as part of a stage II engine rebuild. I discussed the option of wraps and/or coating for the manifold and was advised by TRGB that based upon their experience it wasn't necessary for a road car. I guess time will tell but for now I am delighted with the results and the service received from TRGB.

 

Best Regards, Peter

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