F/51 LRS

Thanks for the offer, but I have the Z-block and have been timing the cams initially with that and a mechanical rocker, but used the factory 993 cam tools this last go-round since I have 993 cams/lifters.
Since the engine is in the car I'm going to start with the low-tech dowel in the spark plug port to find TDC then see if/how far off the Z1 mark is.

wallra

don't forget to pop the distributor cap off and check that mark also. If you don't want to pop the engine out right now If you find the pulley mark off you could paint a mark to set everything up just to see If it run's.

Peteinjp

You're on the right track here. I took my balancer apart too and have to bolt the hub to the crank in situ to get the mark back in the right spot. I wish I had marked it before I took it apart. Based on the many of the threads I've come across I'm basically planning on having to drop the motor (if not rebuild it a second time) to make things right after the first install.

Pete

F/51 LRS

Well...the pulley was reassembled correctly. TDC #1 lines right up with the red Z1 mark on the pulley, and the distributors line up to the tick marks...

I am well and truly at a loss.

wallra

are you sure you have the firing order right. I watched your video again and the way it tried to start almost like the firing order is off like it bound up for a second before it cranked. just recheck it. so hard when I can't see it.

F/51 LRS

I checked the firing order earlier this week. Pulled all the wires off the caps and off the plugs and installed them again.

It sure does sound like the firing order is off, though, doesn’t it?
EDIT: had the wrong video uploaded

wallra

did you get to try another computer just for the hell of it? maybe it got hurt from your injector wires shorting. and when you checked the firing order you made sure they way the distributor rotates.

F/51 LRS

I did, put a known to function computer in, same same.

Yessir, clockwise from the screw starting with cylinder 1.

Peteinjp

Did you confirm a solid spark at a few of the plugs?


Pete

wallra

when you made the new injector wiring harness did you go from the plug by the fuse box to the injectors? also you have all the wires in the right place. positives all go together it's the negatives that go in order. I'm just thinking this is something you touched.

F/51 LRS

I confirmed spark at all 6 exhaust plugs (easier than intake). For the injector plugs, I just bought plugs with pigtails on them and spliced them in individually. I kept the wire orientation the same as the OEM plugs.
I have one of the local 911 gurus coming by the garage Tuesday to take a look at it.

F/51 LRS

Potential progress! Going through anything and everything and it turns out my hydraulic lifters have non-existent seals. The theory here is that they're not holding oil pressure therefore collapsing under load causing issues similar to cam timing being off.

So, as things stand here are the options I'm considering:

• Buy new hydraulic lifters, install, and hope everything turns up great
• Send cams out to be re-profiled (Dougherty) to a DC21 profile and buy mechanical lifters
• Buy DC21/DC24 cams from Dougherty and buy mechanical lifters

I understand the benefits of hydraulic being no adjustments necessary, but they do go bad eventually which is a drawback.
The benefits of the mechanical set up is 1) I know the profile and it's deliberately chosen for my application 2) more stable for track use
The draw back 1) $2K in cost is a lot to stomach 2) adjustments every ~15K miles.

I'm not overly concerned about the adjustment aspect, it's a couple hours every other year realistically.

What do you guys think? Advise? Anyone have a screaming deal on a good used set of rocker arms/lifters/rocker arm rods?

wallra

importin thing is at least you found something.

cobalt

I machined and modified my 993 rockers making them solid. It required a bit of work and a stepped threaded insert along with welding up the remaining openings so no oil pressure loss but nothing close to $2k. The stock 964 cast iron rocker is on the left the others are 993 forged rockers I modified. It saved around 1 pound of weight over the 964 cast parts.

r-mm

pretty cool nice work. the 993 are forged ?