First post. 401 needs help.

[Davan]

Hi Everybody,

My 64 wildcat runs bad. Symptoms include loss of power, loud popping noise on acceleration and blow back through the carb. The 401 has 70.000 miles and 130 psi all around I have always had a lot of lifter noise which leads me to think it might be the cam and lifters. I understand the nailhead was prone to rocker shaft wear which can cause improper valve operation. I have done some of the basics... I have changed distributor ,plugs ,wires, fuel pump/ filter and carb. It starts well and seems be be in time. This car always had lots of power up until this problem. What Is my next course of action.?


Thanks,
Davan

[flynbuick]

Did you look for a vacuum leak? It will cause these sx since it will cause the air /fuel mixture to be lean.

[doc]

Yep,,,, Ck all of the basics, vac lines, spark plug routing, ck the vacume advance diaphragm, and the lube on the mechanical advance.... and then pull the rocker arm covers and see if you are getting oil up to both of them... take a close look at the valve springs, rocker arms, pushrods, rocker arm shafts... ect... If you dont find anything unusual there , pull the intake assembly and the valley cover and look at the cam lobes and hydrolic lifters... look for rounded lobes ect....I would suspect that the engine has turned a cam bearing and you are not getting oil up to the rocker arms....You can install new cam bearings in a nailhead without pulling the engine or tearing it down but one needs to really know what they are doing to do it ....

[wkillgs]

Did you change the distributor cap too? Carbon tracking can cause popping thru the carb.
Double check wire routing and firing order. Nailheads have the #1 cylinder on the passenger side, not the drivers side. A common mistake.
If you have the Carter AFB carb, there is a metal gasket between the intake and carb to seal off the heat passage. If it's rusted thru, it could lead to a huge vacuum leak if the carb base is corroded too.