440 engine help

[TRAMO]

I bought a car with a 1975 motorhome 440 engine with less than 5k miles,keith blk dome pistons,452 heads,750 demon carb,performer intake,elect ignition, 509 purple cam and lifters.headers. when the engine was built a couple of years ago on the first start the valves clattered and 5000 miles later they still do.the guy that built the engine said he took it to a mopar mechanic and the mechanic said it probably was weak springs in the lifters. any ideas out there on how to cure it. new lifters? adjustable push rods? adjustable rockers. could it be the dementions on a motorhome block because moore than one valve is clattering. oil is very clean no sparkles in oil.thanx tramo

 

[RustyRatRod]

I likely needed longer pushrods at the time of assembly because those cams are ground on a reduced base circle. Only way to tell is to get an adjustable pushrod checker and mock it up with the correct (between .020-.060) lifter preload), remove the pushrod and measure it against the others. I bet you'll find the others come up short.

 

[benno440]

dementions on motorhome block?

the 440 block are the same dimensions throughout the years

 

[Meep-Meep]

Yep, I'm also bettin' push rod length is not quite right.

 

[TRAMO]

what would valve guide issues sound like?

 

[eric383]

Correct me if I'm wrong Rusty, but unless you had very severe guide wear they wouldn't make alot of noise. X3 on the pushrod length or I had a header leak that sounded like lifters too.

 

[TRAMO]

TALKED to the engine builder today. when he built the engine he installed compcams stock length pushrods, edlebrock performer rpm valve springs, fel-pro stock thickness head gaskets. if this helps

 

[RustyRatRod]

If they were stock pushrods, that's probably your problem. Read post #2 and do it.

 

[TRAMO]

ok I found the exhaust valve stems in # 3 and 4 were sitting about an 1/8 inch lower than the rest.i used a straight edge to check it. I guess the machine shop didn't check after the heads were worked. thanx for all your help. randy