andy-gts

Noob question,
can the device be used on custom grinds of camshafts also?

PorKen

Yes. Set up the custom cams with the dial indicator the first time, then record what the 32V'r indicates for both banks. From there you can restore this 'zero' setting when changing a cam gear, or advance or retard in 1° increments from there.

IIRC, Louie (Ott) uses it this way.

Stromius

With the long wekeend, I am going to go for my timing finally after the RL group deal. Tack Ken!

chaadster

Porken (or anyone),

Two basic questions: 1) advancing timing nets lower rpm gains, while retarding benefits higher rpms (for n/a engines)? 2) what is the torque spec for the cam gear bolt?

I'm gonna throw the 32v'r on mine Sunday, and go with the recommended setting values in the instruction book, but I'd like to understand more about how the advance/retard thing works.

PorKen

Advancing or retarding moves the peaks to lower or higher rpm. It may also trade HP for TQ, and vice versa. If I understood him correctly, Louie explained it depends on how close together the TQ and HP peaks are. If they are spread far apart, then the trade will be higher than if they are close together.

Retarding will make more HP under the curve, IE it won't drop as fast after the peak, but it will be more and more near or past redline. Advancing is much more satisfying for an immediate feel, as torque begins lower in rpms.

For the auto, I like +3° over the stock settings (cold engine: ¼ -2°, ⅝ 0° => ¼ +1°, ⅝ +3°).

I've tried up to +8° with my S³, which is awesome stoplight to stoplight, but I wouldn't recommend over +6° for safety.

chaadster

Thanks, Porken. And the cam gear bolt torque spec? 47lb-ft, is that correct?

docmirror

Good, having never used the tool, and have my cams out, can the tool be used to set back to factory timing? Although I've set them by the book, (90GT) I would like to start at 0TDC rather than the 20deg ATDC called for in the cam timing diagram.

BTW, my opinion of the factory cam timing procedure is that it's some of the worst technical writing I've ever seen.

Nicole

...and a really nice one, too!!!

PorKen

You can set it to -2°/0° with the 32V'r and call it good. (If the belt is new, you'll want to recheck at retension or 1K miles w/PKsn'r.)

The 20° called for when using the dial indicator isn't the actual advance, it's the motion of moving from 0|T to 2|0 that moves the cam far enough for the cam lobe 'lift' to register on the dial. S³, S4, GT, GTS cams have different amounts of lift at 20° compared to each other, so the dial indicator measurement is different in the specs. In degrees, however, they all measure -2°/0° with a 32V'r (cold engine).

Tampa 928s

86 5-Speed S/C

I have been trying to figure this out, but really I am trying to not have to retard my passenger cam if possible.

Setting cold base-line P=0 D=0

Since the Passenger bank expands 2 Degrees that means 0 setting ends up at degrees advanced and drivers side stays at 0.
If I leave the Passenger cam at 0 Degrees and advance the drivers cam 2 Degrees will this place the cams in tune?
If so, does the total timing advance equal 2 Degrees or a total of 4-Degrees.

Does this make any sense, I'll be glad when the weekend is over

PorKen

They'll be in sync, but advanced 2° when warm, which is OK. Because of valve spring pressure, it's easier to advance than retard.

+2° each side is +2° total.

Shane E.

Tampa:

Are you running stock ignition timing or are you running with the AA clone chips?

Tampa 928s

Well I think you said "leave it alone" or advance the Drivers side 2 Degrees just not sure which one .


Stock chips with Low octane jumper connected.

PorKen

Or retard the passenger side 2°. Pick one.

Tampa 928s

I would like the Advance the drivers side, seems lot easier.
Would the present set-up of 0/0 effect the power, idle or really does not matter?