Congratulations Robert... I love it when a story has a happy ending! Also good to know that NAPA stood behind their product, since other less-reputable firms would've blown you off with "musta been somethin' you did!"


Jay

 

Hi guys,
I don't know how to post a new thread so I'm gonna try here and hope for the best.
Here's the situation: I had a new 390 built for the 72 f250 C6 2WD CS Been runnin great no trouble. I drive 2.5 miles to work in it and around town to get supplies so mostly city driving. The other day I was coming up to a stop light and it started missing real bad so I checked it out and #4 was dead. I took the valve cover off and the valves were moving and it was getting spark. Vac guage was reading low and jumping around from 9 to 11 in Hg full vac on throttle shutdown was around 18 in Hg. normally about 23 in Hg. Did some reading and figured it must be a burnt valve. Mind you this motor has about 2000 mi on it. So I'm driving it back to the barn to continue investigating the issue and she gets about 2 blocks from the house and starts cackling and raising all kinds of hell. Remove valve cover and the #4 rocker and shaft fall on the floor. WTF over? Push rod is bent and come to find out the double valve springs had the outside heavy spring broken( wish I would have caught that) Tore it down popped off the head and the valve is not bent as far as I can tell. This motor is new would a broken valve spring cause all that? Is this a warranty issue ? I think so. It was properly broke in and ran like a stripped *** ape till it took a dump. My builder is in Redding and I'm in San Francisco so getting it back to him to fix is out of the question. Is there any thing else I should look for as the cause or just suck it up and put in a new rocker shaft, valve spring, push rod and drive it up there and shove it up his bum. Sorry but I'm a little more than pissed right now seeing as this clown took a year and a half to build the damn thing, overcharged me 500.00 cause he can't keep his paperwork straight, then he painted it black, on a 72 WTF again.

 

Hi Joe,
Sorry to hear about your troubles! I wouldn't trust that that valve is not bent... as long as you have the head off, I'd pull that valve and roll it on a piece of glass or chuck it in a drill press to be sure. I'm guessing you've already checked its seat to confirm that that's okay. If all is well there, I can't think of anything else to check before you reassemble with the new parts you already outlined. Perhaps others will chime in with suggestions.


When re-installing the rocker shaft, you'll want to use Loctite, but I'm sure you already knew that.


Best of luck,
Jay

 

The company that built the motor called a few weeks ago and said they couldn't find a problem with the motor BUT that is crazy because I put all the exact same stuff on the new motor they sent and it runs perfect. They are missing something and I hate it because I wanted to know what it was. It stumped me and several more really good mechanics.

 

how much did you pay for the 390 from napa iron clad?

 

It was around 1700 plus tax for a 390 long block

 

They must have found the mistake was theirs!