Too Much Cam?

[1964 pan]

Trying to get '64 engine running after complete rebuild. Starts and runs. Only at higher rpms. Will not approach idle. At lower rpms it spits back out carb and dies. Have checked and rechecked and rerechecked point gap, static timing, not 180 out, lifter adjustment, intake leaks, battery. Used 2 brands new plugs. 2 carbs. S&S Shorty and early Keihin. No improvement.
I installed an Andrews BH grind cam on the rebuild that it was running as a shovelhead before rebuild. Ran good then. I am out of ideas. I am thinking this cam has too much duration and too much lift for a stock pan. Have an old H cam I am going to put in. See what that does. Will gladly accept any ideas as what else to look for. Thanks.

[Bosheff]

I don't know the specs of the BH vs. the stock H cam, but I find it hard to believe that the root of yer problem is the BH cam. Too much cam could possibly give ya an unresponsive/soft throttle response condition in yer lower RPM range, but if all else is correct it shouldn't produce the run condition you describe. Possible the cam was installed a tooth or two off?....bosheff

[Cotten]

1964 Pan!

It still sounds like typical EML to me.

(Evil Manifold Leak)

Did you pressuretest your manifold assembly with soap bubbles, or just spray crap around while it was running?

....Cotten

[1964 pan]

Just sprayed crap around it. Will have to fab up a pressure tester. Thanks.

[Cotten]

1964pan!

When you bubble-test, don't forget to snoop around the pan cover screw over each intake port.

Its diabolical when they have punched through into the port, but a little teflon tape works wonders.

Good luck, and let us know how it goes,

....Cotten

[Panacea]

Mine runs fine with the solid version of that cam, the B...Mike

[1964 pan]

Installed Harley "H" grind cam over the weekend. Still doing same thing. Hooked up pressure tester last night. Backed off intake pushrods. Cranked pressure up to 20psi. Soaked manifold down with soap and water solution. Nothing. Not one bubble. Manifold is tight as a drum. The search continues.

[Bosheff]

Does it start easily, or is it an ordeal to get the thing runnin?....bosheff

[panhead_jim]

This may be a long shot, but the previous owner told me that the cam in my '64 needed a different adjustment than what the book called for (although it is stock). He says that the adjustment in the book calls for four turns of the pushrods once they are seated, but with this cam, it will only run correctly with two turns. He told me the cam is an unusual shape with the lobes being almost flat on the tops and bottoms. Any idea what kind of cam it is? This is a one owner bike, so no chance it has been changed from stock. Anyways, maybe experiment with different pushrod adjustments.

[1964 pan]

Does it start easily, or is it an ordeal to get the thing runnin?....bosheff

Naturally, it is more difficult to start because something is not right. But, All considered between 1 to 10. It is about a 5. But, my knee is waiting to recover. Hard to diagnose a problem over the internet. All ideas are appreciated. Motor has been rebuilt from crank pin to valve collar keepers. When it fires I can keep it running at higher rpms. As it idles down it wants to die. If I keep blipping the thottle I can keep it running. As it approaches idle it spits back out the carb bad. Even shooting flames out the carb. Running stock early shovel auto advance distributor. Watch front intake pushrod go up and start down. Turn engine over with socket on engine nut. Rear mark comes up then front. Turn point cam to full advance. Point fiber on mark on point cam mark. Use ohm meter to tell when points open. Even took point cam out and turned it 180 and then pulled distb. out and repostioned to be sure point cam was not 180 out. I do not claim to be a PHDM. Good shade tree on these things for 36 years. All ideas appreciated. I am stumped. Thanks. Lee.

[steve_wood]

Okay, maybe a shot in the dark, but it sounds like it's running way too lean. Have you tried adjusting the mixture?

[Cotten]

This may be a long shot, but the previous owner told me that the cam in my '64 needed a different adjustment than what the book called for (although it is stock). He says that the adjustment in the book calls for four turns of the pushrods once they are seated, but with this cam, it will only run correctly with two turns. He told me the cam is an unusual shape with the lobes being almost flat on the tops and bottoms. Any idea what kind of cam it is? This is a one owner bike, so no chance it has been changed from stock. Anyways, maybe experiment with different pushrod adjustments.

Panhead Jim!

That sounds pretty fishy to me.

To begin with, the four turns down is to place the hydraulic's piston in the middle of its travel.
You do not want it anywhere else.

And hydraulics require a very friendly cam profile to allow them to compensate correctly.
(Even a mild Andrews A, which is wrongly claimed to be hydraulic-compatible, can allow them to leak down and knock dangerously at hot idle in a Pan.)
Any cam that has an aggressive profile such as you describe should be limited to use with solid lifters.

.....Cotten

[Pomike]

Yup, and that is the reason for the A-B cam. The A is a good paper weight. It just never ceases to amaze me, all the BS there is about a simple machine like the older HD's. I have been hearing the same self induced problems since the 60's! I can't believe the thousands of dollars the guy that had my '72 before me waisted on trying to make it a "performer". It took me about two years and a lot of learning and patience to get it sorted out so it finally runs fine. Of course, I still have to put up with the close ratio gears because I can't afford the change it back. And carbs? A guy that knows a little about Harleys told me what I already knew. The best street carb for the Harley is the CV, hands down. Of course I use a stock Linkert on my '65 and it works great, but for any of the newer HD's the CV rules! S&S Super? Yes, it is easy to tune and install, and it will get you home, and is a decent competition carb, but gas mileage and smooth control are not good. And the price? Look around and for the price of a Super you can buy three or four CV's. Oh, and the guys name was Jerry Branch. If you have any questions about his knowledge, get one of his tuning books. He doesn't have an opinion, he has proof. Mike

[Cotten]

Mike!

As far as later carbs,
I wouldn't forget the immortal DC either.

But as you found with your '65, there is little practical need for anything newer than the machine was produced with.

Mr. Branch is legendary of course.
But I'll never forget the set of sportster heads that came back ported all the way to daylight between fins.

We all make mistakes, but.... !

....Cotten

[panhead_jim]

The cam issue in my '64 is rather interesting. Does anyone know if HD produced a cam such as this from the factory? This is a one owner bike and the owner is a machinist/engine builder with 50+ years of experience, so I trust him when he says this is how the bike came from the factory. The only possibility I can think of is this was a demo bike, with a sidecar for Rocky Mount Harley Davidson. Maybe they changed the cam before he bought it, although I would think they would mention that...