63 Power Loss on Acceleration

[Michael H.]

Re: 63 Power Loss on Acceleration

John/Stuart;

Based upon one of Duke's posts a while back I did swap the vacuum can to the B28, picked it up from Napa.... While I will check it tomorrow my recollection is that vacuum is down in the 12-14 inch range, but don't hold me to that number until I check. The cam is not a Duntov but rather a Competition Cams CS 282S-10, including a set of new solid lifters.

Joel,

I have to agree with those that suggested a fuel starvation problem. That's the first thing I would look into.

The vacuum advance unit has absolutely nothing to do with your problem. It's completely ineffective under hard acceleration.

[Stuart F.]

Re: 63 Power Loss on Acceleration

Joel;

Again, after you have ruled out fuel starvation, change the plugs.

Congrates on your rear gear change. That's a good moderate approach (3.70). Since I changed out my vacuum advance and put the correct black throttle return spring on, mine practically idles off from a start now. Before, with the 3.36, I used to have to feather the throttle or slip the clutch a little.

By the way, mine still has just the four tail lights, in case you're looking at me as I pass by on the highway (Ha!).

Stu Fox

[John D.]

Re: 63 Power Loss on Acceleration

Joel, Since you already have the 30-30 vac advance and as Michael pointed out with the pedal to the metal the VA is useless. What spark plugs are you running? If this were a fuel car I would say that it was the fuel unit or a fuel delivery problem as you appear to have the ignition in good shape. Are you running a repro coil? Do you have another carb you can bolt on for a test run? Wouldn't hurt for sure. You are running a lot of repro items that you might want to swap out on at a time and get back to us with a report. John

[Joel T.]

Re: 63 Power Loss on Acceleration

John...

Right now I'm running Delco R45 plugs in the car... have been right along with no fouling problem that I can see.

I just picked up the Echlin points this morning and will change them during lunch time. Assuming that the ground here in NJ dries up this afternoon, I will take it out to see what's what.

I am running a repro coil, one from Corvette Specialties of Maryland. I also have an 087 coil from (should I mention the name??) Goat Hill (don't ask - just buy from him in person!) which I will pop in if the points do not fix the issue.

My recollection when I put the distributor together months ago was that I used a set of El-Cheapo Napa points... so let's rule that out first.

I do not have an extra carb but know where I can lay my hands on one if push comes to shove...

More later on today..

Joel

[Duke W.]

Re: 63 Power Loss on Acceleration

You should be running the high breaker arm tension points (28-32 oz.) on a 327/340 or any engine with a redline greater than 5500. Also the distributor must be right on - end play two to seven thou and no bushing wear. If any of the above are not correct, the points can start to bounce as low at 4000.

The NAPA high breaker arm tension point set is CS89. The CS786 is standard 19-23 oz breaker arm tension. (John - please take note of this.)

The same high breaker arm tension point set is also sold under the BWD brand (A112HP) Niehoff (DR8P) and Blue Streak (DR-2371XP). They are all the same point set manufactured by Standard Motor Products.

All '63-'64 SB mechanical lifter camshaft engines were originally equipped with the 091 coil and 0.3 ohm ballast.

Duke

[Stuart F.]

Re: 63 Power Loss on Acceleration

One other last thought from this corner; I once had a problem which acted similar to yours which turned out to be a tipping plate in the distributor. When I disconnected the vacuum advance and ran just mechanical it was fine. I cured that by changing out the plate for a ball bearing unit which I have run to this day. I don't recall the brand, but it works real smooth. The bearing circle is just inside the outer circle of the plate. I doubt if you can get such an animal anymore, nor should you have to. If yours turned out to be tipping on the bushing, just a change to a new one should suffice. This is a long shot, but the symptoms were similar and that's why I mentioned it.

Duke; have you ever seen one of these ball bearing animals? I haven't for many years.

Stu Fox

[Duke W.]

Re: 63 Power Loss on Acceleration

Yes, a worn/wobbly breaker plate will definitely cause spark breakup. One way to test whether the points are operating properly at high revs is to use some test lead extensions to rig up a dwell meter inside the car while you are driving. If dwell drops off significantly at high revs, you've got a distributor problem.

The ball bearing breaker plate is something I just learned of a couple of years ago when I ran across a guy with a new one in the box. I think it was a Niehoff. Up until then I never knew of their existance, but sure wish I had before they disappeared. I don't think they are available anymore, but what a neat piece!!!

In fact, I don't know of any available OE replacement plain bearing breaker plates, either, but a good machinist can probably rebush a worn out breaker plate, which is now about the only option.

Duke

[John D.]

Re: 63 Power Loss on Acceleration

Duke, We typically don't use the CS89 anymore because they are hard on the cams. Don Baker tried them and gets better results and higher RPM on his Allen and Sun Machines using the CS786P. But what do I know.
My old deceased friend Joey De Lorenzo loved the CS 89's. Seems each one of us has his favorite stuff. Thanx, John D.