Hot Rods Nailhead idles fine but can't make it up the hill...

Just got my nailhead back together. Started right up so I was stoked. The minute I put it in gear and hit the gas, it starts sputtering and has no power.

I set the initial timing at 12 degrees without vacuum. It has a brand new Edelbrock 600cfm carb. Running a carter electric fuel pump with fuel regulator set at 4.5psi. New spark plugs, wire, points and condenser. Also have the vacuum running off the manifold (not carb).

At this point I'm thinking it has to be something distributor related.

Thoughts?

 

Any back fire thru the carb?

 

No. Also, new timing chain. Forgot to mention that.

 

Why?

Port above the throttle plate goes to dist

 

Are you sure the carb is working like it should, check the Accelerator pump to see if it has a stream right from the get go
I had a similar problem after a rebuild and a bigger cam etc. It was a Q-Jet I had to fatten up the primaries. I have seen new carbs with lots of metal crap in them from the manufacturer.
If the timing advances I wouldn't think it was the dizzy.
Good luck.

 

Was told the engine will run cooler. I had it on the carb so this is one of the things I changed to see if it would help. Runs the same.

 

I'd have it ported to carb. You need to check total advance....to make sure the vac can is working as well as mech advance is working.

 

I did check advance after initial timing. Total advance looks to be around 35 degrees.

 

If it's getting plenty of gas, I say timing or spark. Hate to ask this but are you sure you got the alignment correct on the crank and cam gears during chain install? Did the cam gear have more than one position available for installation? Correct timing tab and balancer? Was this a good running engine before you got it back together? Healthy spark at the plug? Do you have a points or an electronic distributor?

 

exhaust isn't plugged?

 

I'm still leaning to the Carb, inquiring minds want to know.

 

Any time I've ever had problems of losing power when climbing steep hills its always been a fuel delivery problem.

Gary

 

Assuming you mean for the vacuum advance. A port in the intake manifold will work fine as a source of full manifold vacuum. A port on the carb to a full manifold vacuum source will work just as well. It usually is a port located below the throttle plates, but it's best to check it with a vacuum gauge to make sure.

You do have a vacuum gauge, don't you? If so, this might help you with your diagnosis.

http://www.autospeed.com/cms/article.html?&title=Using-a-Vacuum-Gauge-for-Engine-Diagnostics&A=2393

 

Metering rods, power valve, accelerator pump. Sounds like carb. Also check heat riser valve on exhaust manifold exit to see if it is stuck in closed position.

 

If the little piston that moves the metering rods in that Q-jet sticks the motor will start and run fine but will have no pull power because there is no enrichment.. Been there done that. In my case it was a little piece of dirt caused the piston to stick. Two minute job to fix.

 

What nailhead is it? Early ones the initial timing was a lot lower- like 5 BTC. I think it wasn't until the early 60's sometime that they changed it to 12. Not sure, but it might be a factor.

 

had a 4 cyl once that would idle great and had nothing off idle. couldn't get out of its own way. turned out the former owner put it together with the timing gear 2 teeth off

 

Had a bad coil new out of the box on a Y block where all it would do was idle. Check your coil.
Jim

 

And the answer is....... Bad vacuum advance! Changed it on desperation, $12 part. Started right up and went down the road.

You're all wrong lol

 

Well, we were trying to steer you in that direction...

 

Rev up the engine while looking down the carb you should see fuel coming off the boosters. I got a new Holley that was not getting fuel to one side of the primaries made the 396 a 4 cylinder.

 

Cool glad you found it

 

Thanks for letting us know how you corrected it! Glad to hear it's finally running well.

 

On the Edelbrock 1405/1406, looking at the front of the carb, the there are 2 dist vacuum ports, the one on the right is ported vacuum, the one on the left is full time vacuum, use the one on the right