MDchanic

Does anyone know if there is any sort of a guide listing mechanical and / or vacuum advance specs for various models and years?

You know, like that great Delco QuadraJet guide that gives rebuild instructions and lists the tuneup specs of every carb from the '60's to the mid '70's? Maybe something from GM or from Sun?

It'd be a great resource, not only for checking compatibility of parts, but for just seeing whether your own setup is within spec.

Also, is there any consensus on whether static timing should be set at idle or at 1,100 RPM? I've seen both listed, and on my car it makes a 4° difference. Yes, obviously, I plan to tune it to wherever it runs best, once I get the vacuum advance can I ordered (with no vac. advance, 4° advanced is definitely better), but I'd like to know anyway, and since I have no idea what year or model my motor came out of (nope, no number stamped on the side), I can't get the right manual and check it myself.

Thanks.

- Eric

Rickman48

Back in the mid 80's I was able to order the correct vacuum advance at a dealer, but the Olds Parts guy was pretty knowledgeable on Hi-Po Parts, even asked if my '69 442 was automatic! Rich at Ray Olds in Park Ridge.
But, since the brand and dealers are gone, I don't know if anyone gives a **** anymore!
Was a guy in Des Plaines, Il. called DR. OLDSMOBILE, that was also a partsman, I think, but I've not heard about him for quite a while. Kinda guy who would've saved lists like that.

MDchanic

Thanks, at least that's a lead.

I'm thinking there must have been something that covered all GM, though, like maybe a guide that came with Sun machines, so you could see if a given unit was within spec.

One reason I'm asking is that I've got the usual pile of old parts lying around, some labeled, and some not, I've run a number of Olds, Chevys, and Buicks over the years, and never thought much about compatibility - I'd just bolt something on and see if it worked, and if I didn't have what I needed, I'd go buy a parts car and strip it. I'm starting to realize that there aren't quite so many of these cars around as there were thirty years ago, and thinking maybe I should show some love to all that junk in all those greasy milk crates.

- Eric

rocketraider

I've never seen one covering all GM applications, but the Oldsmobile specs for individual years are in the factory chassis manuals for that year. They list mechanical and vacuum advance specs at different RPM and vacuum signals and give the factory vacuum advance part number.

Basic timing RPM varies from year to year. The 1100 RPM spec came about after emission controls were phased in.

Sun Machine? What's that?





The local community college had one that they weren't using anymore and I tried unsuccessfully to wangle it out of them. Not sure what happened to it; haven't taken the summer shop classes in several years. If it's still there I can guarantee none of the current crop of auto tech students has a clue what it's for or what it does.

Run to Rund

Its in the factory chassis service manuals.

MDchanic

As they are for all the GM divisions...

That's just my point.

I've got a few manuals from a few years, but I do not wish to purchase every book for every model from every year - I'm wondering whether there's a guide where all this information is put together in one place.

So far, it's looking like the answer is "No."

Okay, makes sense. The late seventies motor in my car has a mechanical advance that starts off at zero at 500 RPM, advances 4° by the time it gets to 900, stays put until about 2,400, then another 16° until it's done at about 3,400. (I wonder whether it's supposed to do that?).

1,100 catches it above idle but before it gets up on the curve.

My old man used to have two of them, but this year gave the better one to a buddy who would use it.

One of them was from a community college as well.

I've got a Sun ignition machine as well , though I don't have it set up right now.

- Eric

OldCar_Mechanic

Are you talking about specs like:
Dist. No. - Centrifugal Advance Degrees @ rpm of Dist. for when Advance Starts (like 1 degree @400 rpm) & Full Advance (like 11degrees @2000)

Inches to Start Plunger (like 6-8) and Max Advance Dist. Degrees @ Vacuum (like 15 degrees @ 19 inches of vac.)

These specs would be if checking the distributor on a Strobascope. Double the R.P.M and Degrees advance to get crankshaft figures if checking on the vehicle.

If this is what you are looking for, check any Motors Auto Repair Manual.

Ron

P.S. I lived in Des PLaines for 25 years up until last year and never met the man that goes by Dr. Oldsmobile and I was at all cruise nights and car shows that went on in the town with my 69 Cutlass W31. I would have liked to meet him.

MDchanic

Oh. Alright then.

That's the information I'm talking about.

I've got a stack of old Chilton's (easy to pick up dirt cheap over the years), but the Motor manuals I've got are all '40's and '50's. If Motor's got that info, then I'll keep my eyes open for copies and collect a few.

I'm still surprised there's no central reference source for this info, but a bunch of Motor manuals would do the trick.

Thanks.

- Eric

rocketraider

MDchanic, I have Oldsmobile chassis manuals from 1950 thru 1987. What year specs do you need?

I don't remember seeing those specs in a generic Chilton or Motor. They might be in the Professional Trades editions, which go into more depth than the Saturday mechanic bookstore editions.

BILL DEMMER

Delco 1.2 manual has all the specs. for all gm vehicles.


bill

Run to Rund

If you join the Olds Perf. Club, you can download whatever portion you want of service manuals.

MDchanic

Now that's exactly what I'm talking about.

A quick internet search shows this to be something of a rare bird.

Know of any sources, or should I just keep my eyes and ears open?


Interesting. My olds is anything BUT performance, but that's actually a pretty cool feature. These would be the usual shop manuals, though, I would imagine, and not oddball Delco books.

Thanks to both of you.

- Eric