Thread: Super CT26

Originally Posted by c.h.i.e.f

I agree the smoke is a bit annoying but that was retarded a fair bit actually...I retarded it that much at idle it was puffing white smoke but as I've said before its just an experiment vehicle after this video was taken it was then that my torque cam was modified and then I snapped my turbine wheel off so did not have time to play with timing etc etc def90 I would recommend Dougal's suggestion about finding a torque cam first as it isn't too hard to get off...

When you increase fuel rate in the usual fashion, rather than larger elements, you are actually increasing the end of injection - so fuel is burning later.

IMHO the timing should be advanced, never retarded when the fuel rate is increased substantially.

Obtaining high torque from a diesel depends on injecting more fuel in a short time at the top of the stroke, not injecting and burning later.

Two side affects (for different reasons) of this are increased diesel knock and higher NOx. The CR systems can overcome these to an extent, by using higher injection pressures.

Originally Posted by Bush65

When you increase fuel rate in the usual fashion, rather than larger elements, you are actually increasing the end of injection - so fuel is burning later.

IMHO the timing should be advanced, never retarded when the fuel rate is increased substantially.

Obtaining high torque from a diesel depends on injecting more fuel in a short time at the top of the stroke, not injecting and burning later.

Two side affects (for different reasons) of this are increased diesel knock and higher NOx. The CR systems can overcome these to an extent, by using higher injection pressures.

Sorry forgot to mention I also advanced it also but thought I would retard it testing what dougal has said about retarding causing more boost but later in the rev range I found this to be true but as you said advancing is better and I personally prefer the feel when advanced too...

AFAIK the 4BD1, doesn't have the automatic timing advance with the timing gear, as fitted to the 'T' engine. I would keep this in mind when deciding upon, or evaluating static timing values for a 4BD1 with turbo added and the pump turned up.

I know of one example of a 4BD1T with maxed out IP, larger turbo and turning much higher rpm than stock, where the timing advance was replaced with a solid gear and static timing set to (from memory) 25* BTDC.

Also keep in mind that Isuzu have changed the injection timing of both 4BD1 and 4BD1T over the years, as they have made other changes. Also one should wonder why they wouldn't have changed the timing had they made similar changes to boost pressure, fuel rates, etc. to ourselves.

Hi All,

Posting for a mate.

Does anyone have the contact details for the block in Perth who made the Turbo on the red beast.
(i've tried to message def90 but inbox is full)

Or anywhere else to get a suitable core
(ie have the same housing just want good internals)

Cheers,
Ray