Joy to the Tune up

[Merle Coggins]

Last night I finally had a change to tinker with my truck after noticing that it was running kind of rough on the return from Minnesota. It didn't idle well and was lacking power. It never did have great power, but now it was getting hard to drive.

I pulled the top off the carb and adjusted the float level a bit lower to assist with the flooding condition I was experiencing after shutting down and restarting hot. I also checked the accel pump since I was getting a nasty cough/hesitation upon acceleration. That was all good, so I reassembled the carb top. Then I checked the points. I hooked up my dwell meter and was getting very strange readings. It would either read between 8 - 12 degrees or it would jump up into the 50's. I shut it down and popped off the cap. There was almost NO POINTS GAP! I readjusted them to .020" gap and tried it again. Now I have 25 degrees dwell. Then I rechecked and readjusted the timing. Now it sounds nice again, so I HAD to take it for a test ride.

WOW... is this the same truck??? It now runs GREAT. It actually feels zippy compared to what it was. No more cough or hesitation during acceleration. No more babying it when I leave a stop. THIS THING IS A ROCKET SHIP!!! I don't think I had it right from the beginning. It always seemed like it should have more power, but I just figured "that's all this little flattie has". Now I know better. This thing's a pleasure to drive now. I LOVE IT.

Merle

[smallblockjunkie]

glad that all it took was a little repair. nice when everything works like it was made to

[grey beard]

You'all gentlemen pro'lly never noticed, but I tend to be a litle on the (gulp) chubby side, as Jackie Gleason used to say. Now our Wisconsin friend, Merle Coggins, might be able to stand flat-footed and adjust his points to .020-inch with the distributor in the motor. Me, I can SEE the distributor, and I know it's gotta' be down there somewhere. On a good day, I can even stand on a block and pop the cap loose, but adjust the points from that distance, surely you jest. (Not only am I vertically challenged, but I am also going blind very slowly more than 25 years of diabetes.)

Having said all that, I have found from repeated practice, that I can remove the dkistrbutor in less than five minutes - one wire, one bolt and one vacuum line - and put that little sucker in my bench vise where I CAN see what I am doing, and adjust those points like the good Lord intended them to be adjusted.

AND, whilst that there little ole' distrubutor is outa' there, I like to pull the breaker plate off - two more screws and one more wire - and take a gander at the centrfugal advance unit, and lube things up good if they're happy. I also like to check out that short ground pigtail wire that connects the breaker plate to the distributor body. Already found one with a loose pivot post and a few with loose springs. Why, if you pop one more drift pin outa' the shaft, you can have it out, too, and really look things over.

Gentlemen, I've learned that most distributors I have had the opportunity to look at do not have a workkng vacuum advance. One gent on this forum offered to me a used unit, but when I asked if the pot held vacuum he checked, and then replied that he has three and none of them hold vacuum.

How many of you actually know if your vacuum advance really holds vacuum and works? How many of you know how to check this out? I can tell you from first person impirical experience that the same engine runs completely different with a working vacuum advance unit. You need to experience this to beleive the difference, just like our friend, Merle, said earlier.

These vacuum pots really seem to be leak-prone. I had one good one that actually held vacuum and worked, and tried to epoxy a broken pot metal bracket on the side of it. To get the epoxy to cure, I parked a trouble night nearby for just a few minutes. You gessed it - just that little bit of heat from the lamp ruined the pot diaphram. These things seem to be really fragile.

It is my considered opinion that the vacuum and centrifugal advance units in these MoPar flattie engines are the most often ignored - and maybe the least understood - components of the entire power train. These two advance units can be checked out using a degree advance timing light - if you are smart enough to understand how they work, and how to separate the centrifugal readings from he vacuum.

I'd give at least one of my eye teeth for a good old fashioned Sun Distributor Test Bench. Those puppies were a marvel of clear thinking. They not only checked both advance curves but also tested for worn distributor cams and bushings and allowed you to set the dwell right smack on the schnoozola - ten times more accurate than any feeler gauge reading anyone can make. They were simply the best.

I wish someone on this forum had one of those machines, and would offer to bench test and adjust our distributors for us for a reasonable fee. Were this to happen, we would all have much better running cars and trucks - just like that lucky big screen TV winner from Wisconsin.

Way to go, Merle!:)

[Merle Coggins]

Easy there big fella... I'm not exactly lean either. And my eyes aren't what they used to be since going past the "40" mark. But I suppose my "youth" does have some advantages yet.

Also, I wasn't exactly "flat footed" during this work. Where the truck is parked there is a rise in the edge of the lawn next to the driveway. So it's kind of like standing on a 12" platform. That gives me the boost up needed to reach the distributor. And with the aid of a flashlight I was able to see just enough to "get 'er done". I also discovered that a spark plug gap gauge works great. I searched and searched for my feeler gauges but they must be in my tool box at work instead of at home. But I did have a spark plug gap tool with the different size "wires" to measure the gaps. This .020" wire worked great. I could feel the gap better with the "wire" than I can with a standard feeler gauge. (I guess even an old dog can learn a new trick )

I had my distributor all apart when I did the engine rebuild. It needed a good cleaning and lube then. However, I believe that the rapid decline in performance, and loss in points gap has to do with a lack of lube on the points cam. What lube do you recommend for that, Dave?

Merle

[grey beard]

Merle,

Back in the high performance days of the sixties, I was a service rep and then a service school instructor for the Ford Division of FoMoCo. At that time I bought a tube of Ford breaker point lube, and I've been using it ever since. There'll still be some of it left when my grandchildren sell the Pilothouse to THEIR kids. Good stuff, too.

Vaseline works just fine - petroleum jelly to the politically correct among us . . .

[Dave72dt]

Some of the points sets used to come with a little capsule of cam lube that a lot of times got lost or tossed when the box was opened. I had a small tube I think I got from Snap-On YEARS ago. You might get some at a parts store but they will probably have to order it for you. It's got a little higher melting point than petr jelly.

[Merle Coggins]

I've got a tube of synthetic BMW grease that was recommended to me for the rear wheel spline hub on my previous Gold Wing. Like Dave says, it'll last me forever since I don't have that bike anymore and I don't use it often otherwise. I'll smear a little of that on the cam and run with it, for now.

Merle

[Allen I.]

Hey grey beard,

Is this what you are talking about? My grandfather may have one in storage. I know there is something like it at a warehouse.

http://binghamton.craigslist.org/pts/1181797459.html

[Don Coatney]

Hey grey beard,

Is this what you are talking about? My grandfather may have one in storage. I know there is something like it at a warehouse.

http://binghamton.craigslist.org/pts/1181797459.html

No that is not a distributor machine.

This is a distributor machine.

[Dave72dt]

No. The unit he, and others would like, like me for example, spins the distibutor, has a vacumn pump on it, some gauges showing dist RPM, dwell, and advance degrees. What you showed was an engine diagnostic center, also not a bad tool to have. Old tune-up centers may have one stored in the obsolete tools collection as all these functions are now computor controlled.

[Jerry Roberts]

[quote name=Merle Coggins;...<snip>..... I believe that the rapid decline in performance' date=' and loss in points gap has to do with a lack of lube on the points cam. What lube do you recommend ....<snip>...

I don't think that you should use vasaline here . Vasaline turns to a liquid in hot weather . I bought my cam lube for the points from MACS auto parts , they sell stuff for the old fords . 1-800-777-0948 or www.macsautoparts.com . Perhaps NAPA would have it too .

[grey beard]

Hey Don Coatney,

Where did you get that pic? Is that item in your personal inventory? Do you or anyone you know have a distributor test bench like the one you pictured who is willing to do work on forum members' distributor units?

Wouldn't it be nice to drop a distributor into your own engine that had just the correct advance curves for our motors - in the centrifugao and the vacuum advance departments? I'll bet they would run very sweet.

Anyone know where I can find or buy a Sun distributor tester? Sure would be nice . . . . . . If I had one, I'd likely offer my services to other forum members, too.

[moxieforme2]

Good thing you didn't have a "rocket" when carrying the nice 61" projection TV... Merle! But I wouldn't DWELL on it too much.

Jim Masters:D

[Frank Elder]

Don would't use vaseline...KY is more to his liking!

[Don Coatney]

Hey Don Coatney,

Where did you get that pic?

Dave;

The picture came from eBay. That machine was located in New York state with a pick up only option no shipping. That auction has ended. Starting price was $150.00. It was sniped with 5 seconds left for $236.49. I have seen others on the bay from time to time.

[MBF]

I'll throw something out here. Neither my 52 1 ton, or my parts truck even have a vacuum advance, but my 36 Plymouth, and Worthington Golf Chief Tractor (Chrysler industrial 6 powered)do. I know from first hand experience on small engine that point gap is critical. A worn set of points will slowly decrease in gap to where it will run w/o any power. Just resetting the point gap in a Kohler will make it run like a different engine. I'm sure the same applies here. Mike

[Dave72dt]

That Kohler, and others, doesn't have any advance system at all for ignition and when the point gap closes down it retards the timing making it difficult to obtain proper timing when they are running at governed speed

[grey beard]

Lots of engines were made that way - Onan two cylinder engines set the timin with a timing light but do the adjusting with the point gap setting.

Mike - my PH sure runs nicer with a vacuum advance that works. Still looiking for a pot to fit my original distributor, but finally got a diz that has a good vacuum advance - just the wrong one for my application, but it works okay. Go figger . . . . . .