Trans-Am

My crappy haynes manual does not list the specified torque for the lifter reatiner plate torque, the one with the 3 bolts. Also how do you install the opti for TDC?? It says install it at mark 2 in the manual WTF, what is mark 2??? LOL any help apperciated!!!! thanks~~~rob

Soma07

15lb/ft for the lifter guide retainer. I would use some loctite as well.

Dont worry about the opti, it only goes on one way correctly.

Trans-Am

Great thanks a lot Jason! So that would make the opti point at 6 for a TDC install right?

shoebox

Your opti needs to go on only one way. Does not matter where the dowel pin is as long at the correct slot on the opti goes over it.

Trans-Am

Rob your a life saver bro!! thanks a lot

Janny

Just finished this.

With the cam gear mark at 6 oclock and the crank gear mark at 12 oclock, the opti drive pin will be at 3 oclock. Or so it was on my 95Z

shoebox

If you look at the back of that pic I posted above, you will see that the #6 reference mark is right at that 3 o'clock position (mirror image because you are looking at the back of the opti). What you describe is correct. Gear dots together is #6 and both dots at 12 o'clock is #1 (and cam dowel at 9 o'clock).

JIMS1999CONVZ28

I just sent shoebox an email on this and the more I think about it the more it all makes sense.
You can't screw it up as someone stated above, unless you are doing a cam swap and turn the crank over more than one time and/or put the timing chain on wrong.

Here is why: the cam gear has 36 teeth, the crank gear has 18 teeth. Two revolutions of the crank equal one revolution of the cam. So that dot on the crank will go around twice for on revolution of the cam gear! Therfore the cam gear can only be in number 1 or 6 postion as stated above. Draw it on a pc of paper and you will see that you can only have the cam dowel in the correct positon.

Shoebox or anyone else; have you ever seen instuctions that say you can torque Roller "tip" rockers to 18 foot pounds after zero lash and not positon the crank for the standard way ( set it on #1 and do certain intake and exhaust, then do it for #6)?

Thanks,
Jim

shoebox

I have not seen that for our rockers and don't believe it will work because for one thing, the stock rocker nuts are "prevailing torque" nuts. That means they have an interference fit with the stud, so that they don't come loose. That would interfere with a proper torque reading as well.

Specs that I have seen say you need to tighten the nut to get .030" (+-.010) preload on the lifter. So however many fractions of a turn after zero lash, is what it will take. Usually 1/2 or thereabouts.

JIMS1999CONVZ28

That makes good sense!

To figure what one turn of a nut would be on a stud you would have to calculate the number of threads per inch on the 3/8" stud.

Just for example: if a stud had 10 threads per inch you would divide 10 into 1 inchand come up with .1 or .100 (one hundred thousands per inch), so each full revolution would be .100

I would guess that the 3/8" stud has fine threads and that would be 24 threads per inch. So, 24 / 1 = .0416, then take .0416 ( a full turn) and multiply by .75 or 3/4 of a turn and get .0312.
A half turn is .0208 and within the +/- .010 tolerance.

shoebox

When I have mine opened up next time, I may play with my dial indicator and see how many turns does what in real life.