Putting a Caprice engine (L05-7) into a 92 g30 van (has L80e trans)

[Danboquist]

EST is a new one for me. I see that it stands for Electronic Spark Timing. What is the difference between disconnecting this to set base timing and removing the vacuum line to set base timing?

 

[Schurkey]

In principle, not so much.

In actual operation, the TBI distributor has no mechanical weights and springs, nor vacuum advance--all the spark advance is done electronically, so the timing connector has to be disconnected to remove the electronic advance to set base timing.

 

[Danboquist]

In principle, not so much.

In actual operation, the TBI distributor has no mechanical weights and springs, nor vacuum advance--all the spark advance is done electronically, so the timing connector has to be disconnected to remove the electronic advance to set base timing.

Call me suprised. I've watched a ton of videos on setting initial timing on a SBC on youtube and I dont think that I've ever heard anyone mention the EST. I'm have to see now if I can find one. Crazy.

 

[Danboquist]

Found this.

 

[Schurkey]

I've watched a ton of videos on setting initial timing on a SBC on youtube and I dont think that I've ever heard anyone mention the EST. I'm have to see now if I can find one. Crazy.

Find one? You don't have a computer, an EST module and knock sensor, the electronic-advance (8-pin) module, and the "set timing" connector?

 

[Danboquist]

Find one? You don't have a computer, an EST module and knock sensor, the electronic-advance (8-pin) module, and the "set timing" connector?

I have a computer, knock sensor I know. I'll have to wait until morning to look for the timing connector. It should be there.
I just found these hillbillies disconnecting the EST. They just set the initial timing to TDC, cleared the computer, plugged the EST back in and say that the computer takes care of the rest.. lol

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[Schurkey]

Yup. That's all fine...on an engine that reliably starts and runs.

YOU need to static-time the engine so that it'll start and run. Static-timing gets the distributor close enough to get the engine running, but probably not "exactly" where it should be. THEN you can do what they sorta-kinda talked about, to get the base (initial) ignition timing correct using the timing light.

 

[Danboquist]

So the process would go something like:

1. Set static timing at 12 degrees BTDC.. or whatever to get the thing running.
- I assume that this is done by installing the distributor while the engine is at 12 degrees BTDC?
2. Once running, bring to operting temperature, turn engine off and disconnect the EST.
3. Start engine and set timing at TDC.
4. Turn engine off, clear computer, plug EST back in.
5. Start engine. It should show an advance with the EST plugged in.
6. Done.

 

[L31MaxExpress]

In principle, not so much.

In actual operation, the TBI distributor has no mechanical weights and springs, nor vacuum advance--all the spark advance is done electronically, so the timing connector has to be disconnected to remove the electronic advance to set base timing.

Yep all electronic although the 8-pin module itself has a backup advance curve in it. With the distributor at TDC with the OEM 369 module atleast the timing bumps from TDC to like 8* @ 1,600 rpm then climbs to about 22* @ about 2,400 rpm. That is one of the reasons GM specifies the engine be at operating temp when the timing is set so that it is at low idle. The other is that a cold engine will have a tendency to stall when the EST is disconnected.

I have used the TBI distributor in a carbureted marine application without any timing control although Delco also offered other marine specific 8-pin modules with varying advance curves for their Voyager line of marine distributors. With the screw on cap and flame arresting distributor vent screen in place the TBI distributors are actually USCG approved.

 

[Erik the Awful]

I understand that the cam/lifters do not need a break-in the heat up and cool down cycle is to harden the parts in the head.. the rockers esp. Seems like a good idea.

There is no "hardening" of the parts during break-in.

Flat tappet cams are ground from a steel blank and don't receive a hardening process. They harden during break-in, and sometimes they wipe out rather than break in. Back in the day it wasn't common, but modern oils aren't made to allow that work-hardening friction. That's a good part of why there are a lot of issues with wiping cam lobes now.

Roller cams don't develop the friction to harden, and must be hardened before they're installed. That's a good part of why roller cams are 3x the price.

If your rockers are getting hot enough to harden, there's something seriously wrong with your engine. Most of their heat should come from the oil flowing across them.