Hello All,

I am nearly ready to start the engine in a project that has stretched to three years and gotten me way over my head. My engine builder has gone out of business. The shop that is finishing this wants to have a TDC pointer. This is a '94 LT1 383 with forged internals, standard opti spark, Fluidamper harmonic balancer, and a Bigstuff 3 computer. They are an experienced EFI shop but not with 4th gen stuff. I've searched for some kind of step by step on adding a pointer but come up empty. Can anyone advise me?

Thanks to you all in advance

 

I havent seen any pointers LT1 specific.

On mine I found TDC and marked the opti with a paint pen at that point.

You could also fabricate a pointer and bolt it on there someplace.

 

I think it is the finding TDC that bothers them. He mentioned the headers being in the way. The shop is getting stuck doing some finish up on the intake and kind of finishing an incomplete engine build. I'm sure I'll be paying but they seem to shy away from extra work. They have had the car since last May. Mainly they rewired entire vehicle, relocated battery to back, plumbed a crankcase evap pump, replaced radiator, replaced steering column, installed Kirkey racing seat and re-installed dash with new gauges in place of stock and no airbag.

 

Out of curiousity, what would be the benefit of a pointer over any other corresponding mark on the block and crank hub...not the pully in stock setup because it can move on the LT1 hub as the stock hub is not keyed.

Edit....not sure what I was thinking before(regarding incorrect statement I removed)....carry on.

 

I've made some Timing covers with a Billet pointer built into them... takes some fab work and you have to take off the front cover to do it (meaning you need to yank the oil pan.)

Bret

 

They can pull the #1 plug, stick a finger in there and crank on the crank untill they feel the pressure from coming up to TDC, then have one guy keep cranking and another guy looking in the plug hole with a dental mirror until he sees the piston come up to TDC. He'll be able to see it. Then mark your damper with paint. I just marked mine at the 12:00 position at TDC.

Ken R.

 

let me be the first to say > ?

How about a piston stop and a degree wheel.

http://www.shopcranecams.com/craneca...stoptopde.html

Works every time.

 

Thanks for the suggestions.

The shop says they are all set now. They e-mailed the following response to my latest query.

"We got the setting for TDC. All done.

It must be done because the aftermarket computer must be setup AND checked for the proper timing. Can't do this unless you have some way to actually check the timing. The stock computer is not adjustable and does not need to be setup."

It is getting sort of exciting now. After waiting this long just to start motor. I don't know what kind of pulls on the dyno we will do with a fresh engine but I am hoping to see in excess of 400 RWHP at 6500 and I expect this engine to make power to 6900+ and then we can start adding nitrous. My biggest question still is how will the opti perform and to what rpm level?

 

If you're only using the Opti to feed the cam position to your aftermarket ECU, it will be good to over 8,000rpm. It may be good beyond that point, but that's as high as I've actually seen an LT1 turn with the Opti feeding an aftermarket ECU. Mine works fine to 7,200rpm with a 300-shot. A buddy of mine made 1,125HP with over 20# of boost, and was running it to 8,000+rpm. That's with the Opti feeding a MoTeC ECU, and using their IEX 8-channel ignition driver to fire 8 LS1-style coils.

 

Thanks for the encouraging words Fred. Cam should make power to 6800-6900 and I was hoping to shift about 7100.

 

Ive seen the optical portion live like fred said pretty high. The opti rotor is a totally different story. Best to take it out before it flings off and takes out the entire opti.