8V71, C65 injector timing

[Jsrcaptain]

My MC5B has a 8V71 naturally aspirated with C65 injectors. I'd like to run the rack if it ever warms up here in Wisconsin. I believe the 1.460 timing tool is the correct one for my setup. Am I right?

[Bill Gerrie]

According to the book C65 is advanced timing. 1.484 is the tool. 1.460 is listed for the 8V71T.

[luvrbus]

My MC5B has a 8V71 naturally aspirated with C65 injectors. I'd like to run the rack if it ever warms up here in Wisconsin. I believe the 1.460 timing tool is the correct one for my setup. Am I right?

the 1.460 is fine I use 1.470 just to advance a tad bit

[Rick 74 MC-8]

I don't want to hijack the thread.
But I don't know if my 8v71 na is advanced timing or not what would be a safe injector height.


                    Rick

[chessie4905]

There is a procedure in the DDA service manual tune up section on how to check for standard or advance timing.

[Jsrcaptain]

Thanks for the tune up hint. I just looked it up in my DD manual. My 1976 8V71 with C65 injectors says to use 1.484". Looks like the model of injector indicates the timing. Am I reading this right? Should be safe using the manual specs I would think.

[dtcerrato]

Unless you have modifications you don't know about?

[chessie4905]

To be sure, you can check it, although it is probably std.

[Rick 74 MC-8]

Thank you I'll have to check the book I was hoping there was a way without taking the back of the motor off


Rick

[luvrbus]

Thank you I'll have to check the book I was hoping there was a way without taking the back of the motor off


Rick

Depends on the injectors most are not A timed unless over N65 injectors ,if the injectors are like the numbers 8Gxx or any 3 numbers and letter it will std timing 92 series are never A timed unless you making huge hp with a couple of turbo. The timing has nothing to do with amount of fuel the injector delivers that stays the same regardless of the setting.I never A time a 71 series,very few of the old engines are factory settings ,sometines C-65 were set at !.500 in the buses   

[Rick 74 MC-8]

My bus was ordered by a small charter company to be converted by executive coach in 1974. It has Brown tag n65s. Assumed it was probably a timed but I'm not sure

         Rick

[dtcerrato]

Brown tagged N65 injectors we also have on our IL671 DD & they are not A timed.
Gene Russell, a vintage bus guru told me that brown tag N65s should be standard timed - on our engine anyway...

[luvrbus]

Brown tagged N65 injectors we also have on our IL671 DD & they are not A timed.
Gene Russell, a vintage bus guru told me that brown tag N65s should be standard timed - on our engine anyway...

You A time the white tags N65's C's are crown type injector and N's are a needle type injector  FWIW ,truck engines with N65's were the only thing A timed from the factory,A timing a bus engine with a 4 speed would not accomplish anything