engine breathing combustion blowby.

[Deans Sprint]

Hi and thanks for the reply. Its oil and if you look at the Weber you can see oil in the body. What puzzles me is there is no engine crankcase fumes that can return to the air box! They all vent to the road/catch tank?

I did originally think it was the fuel or by products of the fuel but I always run Shell V-max 98

I'm running full syn oil which is why you don't see any blue smoke on start up

Any other ideas/suggestions out there please!

[Deans Sprint]

Hi and thank you for the reply. It looks clean as i washed the area down took the car for a quich blast up the freeway that this is what was deposited after a 1/2 hour run.

It feels like oil and traces of this was on deposited in the air box as well. If you look at the Weber body you can see a deposit in the body. I am confused as no crankcase fumes can get to the air box as the cam cover vents to a tank and the Head vents to the road. The bottom of the air box breather hole is sealed.

Any suggestions as this has me confused!

Cheers

Dean

[rgh0]

Agree it looks like fuel condensate. There is a continuous shower of fuel mist in the airbox and this evaporates and leaves a heavy oily residue. It would only take a little time for it to build up on the trumpets like in the photo

cheers
Rohan

[Deans Sprint]

Hi Rohan thank you for explanation. Can I ask if you or any one else has this oily deposit situation with your engines.

Lastly the engine has what I was told the Kawasaki grind cams 1.65 inlets std exhaust and an estimated 135hp and std valve springs.

The Webers are main 110 choke 33mm Air correction 155 Slow jet 50-F8 Emulsion tube F11 and just changed the pump jet to a 30. With these cams it pulls well from 2800rpm but as I don't go past 5500 these days (my track days are over according to the cook) what are you thoughts on chasing more bottom end with smaller chokes?

[rgh0]

yes I see it regularly in my plus 2 and esprit when I open the air-boxes. In Australia at least it normally has a strong red colour which is the die in the fuel.

The Kawasaki grind is a popular one among the Sydney Lotus crowd promoted by one of the cam grinders up there. Somewhere I have its profile recorded but I cannot remember its details off hand but I recall I was not impressed with it. I suspect the cam duration is too long if your getting 135hp with standard lift. You will get better bottom end out of a high lift short duration cam. You should not need to go to smaller chokes, I get great bottom end with 36mm chokes in my competition Elan. The different emulsion tubes and jets that Keith has developed ( see the yahoo sidedraft _central group ) also improve bottom end performance. My Plus 2 pulls from 1500 rpm in 5th happily with an early version of these jets.

cheers
Rohan.

[Deans Sprint]

Hi Rohan and again thank you for the reply. The cams etc came with the car and head work was done by Peter Simm's ex 26r boy many years ago and he "thought" it could produce about the 135hp.

I will search out that site and educate myself more!

Always enjoy reading your replies to owners. Glad we have you, pity your in Melbourne.

Regards

Dean