930 cam timing

[ostudog]

looking for the 76 stock 930 us cam timing tdc overlap Thanks for any information Stu

[930gt-40r]

I could only find ROW non us, but what I got was:

Intake opens 1 BTDC
Intake closes 53 ABDC
Exhaust opens 43 BBDC
Exhaust closes 3 ATDC

I didn't do the calculations but I am pretty sure you can calculate overlap/duration from this. I would do the calculations myself but do not want to mess up and give you false info. These numbers came from one of Bruce Anderson's publications.

[gtu935]

I think what you're looking for is the cam timing. If so ...here you go

.65-.80mm or
.026-.032 inch.

This is from Bill Andersons 911 Performance book

[spuggy]

Originally posted by 930gt-40r
I could only find ROW non us, but what I got was:

Intake opens 1 BTDC
Intake closes 53 ABDC
Exhaust opens 43 BBDC
Exhaust closes 3 ATDC

My factory turbo shop manual (with supplement 7) gives the following figures, with no qualifications for different years/models:

Intake opens 3 ATDC
Intake closes 37 ABDC
Exhaust opens 27 BBDC
Exhaust closes 5 BTDC

It does provide (on the same page) different ignition timing advance figures for 930/50, 930/52 and 930/51 (USA), 930/53 (USA) and 930/54 (Japan) motors. Overleaf, (but again, on the same physical page), it gives ignition timing for 78-up 930/60 through 930/68 (except 930/67) motors.

It says "Timing at 1mm tappet clearance", but gives the tappet clearance in the para before as "0.10mmm cold for both intake and exhaust (measured between valve and rocker arm)", and then later:

Originally posted by gtu935

I think what you're looking for is the cam timing. If so ...here you go

.65-.80mm or

Factory manual agrees with that:

Intake valve stroke in TDC overlap at 0.1mm tappet clearance 0.65 - 0.80 mm


Hope this helps.

[ostudog]

Thank for the information guys 0.60 -0.80 mm
Just rebuilt engine. as i was turning around (by hand) and
engine locked up.
Will set out this weekend to adjust the cam timing.
Hopefully i wont have to disass engine.


Stu

[gtu935]

You shouldn't have to split the case. Just get all the pistons in a "half way down" position and reset the cams accordingly. Keys straight up to begin with the engine crank mark on "0"