twin charged diesel mercedes

[mantahead]

hi,
hello i am new here.
i just read an interesting thread on here on valve spring pressure and boost.

i have built a diesel mercedes drift car with home built exhaust manifold, scania turbo(holset hx52, 13cm exhaust housing)eaton m112 supercharger. Engine is straight 6, 3 litre, 24 valve idi with mechanical Dieselmeken injector pump.

the problem i have is multiple misfire in low revs under load, light grey smoke followed by a pop and then as soon as the wheels break traction the engine clears and is sweet all the way to the redline.
If i remove the supercharger it is not near as bad but still there.
i think my problem is valve springs are not strong enough.
i overspeeded the supercharger to give me quick spool up for the turbo and bypass flap then opens and relieves the supercharger,i was running 2.66 drive ratio over crank, i then reduced it to 1.77 over crank.
Also i have a major overheating of coolant, although exhaust gas temps remain ok.
the supercharger feeds the turbo, then the turbo feeds the engine as normal, i think the small exhaust housing on the turbo(13cm)is restricting and causing back presssure in low rpm, the two external wastegates open at 2.1 bar

https://flic.kr/p/Ha8PzP

 

[MikeHalloran]

I'd try the truck radiator _instead_of_ the alloy one; the water capacity probably matters less then the developed fin area and the tube and fin material.

Putting a radiator in the trunk adds weight, both for the pipes and for whatever aero you need to get air through it, plus the power to run more fan motors.

A long time ago, I saw a picture of a Corvair that had an oil cooler installed like a sail, projecting up from the l/r fender. It looked illegal as hell, but I think it was within the letter of whatever rules he was racing under, and it worked well enough.



Mike Halloran
Pembroke Pines, FL, USA

 

[moon161]

Did the OP ever have a resolution on this problem?

 

[MikeHalloran]

I'm guessin' he's gone racin'.



Mike Halloran
Pembroke Pines, FL, USA