All;

Has anyone else experienced problems with the valve train on their 460s? If so, what? Please read the following and comment if you have any ideas.

Two years ago, I had a problem with the valves on my 460, a bent pushrod, two bent valves, broken valve springs. My mechanic sent the heads to one of the best machine shops in the Seattle area, I had the heads totally reconditioned, with new valves, valve guides, valves ground, new springs, rocker arms, pushrods and lifters. Approximately 3 months later, a broken lifter (shattered), and a broken rocker arm and bent pushrod.
Last weekend more valve train problems, not sure of extent as yet, but sounds the same.
My mechanic has found no indications of what the problem may be, no flat spots or wear on the cam, sticking valves etc. After three problems like this, I will probably install a new engine, a pretty expensive fix, but all this valve work is expensive too, not to mention towing, loss of the vehicle, and lack of confidence on long trips.

Thanks in advance for any ideas, Paul

 

what kind of rocker arms and pushrods are you using? stock, or what kind and brand name. how big is your cam shaft?

 

Besides what "Cobrajet" is asking we need to know how many RPM's are you turning? Did you also rebuild the rest of the engine, is there any timing chain slop, what's your oil pressure?

Deen Hylton
Ford F250 460 C-6, K&N, Headers, Dual Exh.,Comp. Cams,Shift Kit
Pioneer CD w/Bose Speakers.
Other Passion: Blown 77 Corvette (Sorry Guys/Gals)
How I can afford to Drive the above: 93 GEO Metro

 

[font size="1" color="#FF0000"]LAST EDITED ON 30-Jun-01 AT 06:47 PM (EST)[/font][p]Thanks for the replies.

Truck has stock rockers, stock pushrods, stock camshaft as far as I know. I believe the bottom end was rebuilt when I bought it 3 years ago, only has stock oil pressure gauge, always reads in the normal range, but from what I understand, the gauge is on or off on most Ford trucks. No evidence of lack of oil on the top end, with the prior two top end problems, no camshaft wear, no evidence of sticking valves, etc. When it's turned over when valve covers are off, it seems to get plenty of oil on the valve train. When my mechanic rebuilt the top end, he used a quality machine shop and quality parts, he will not use cheap parts on a rebuild, it just isn't worth the money. He has stood by his work with a 12 month parts and labor warranty on his engine work. Have been using quality oil, Castrol 10w40 and Castrol synthetic 5w50, since last top end problem.

Don't know about timing chain slop, but am unaware of any problems there, normally has no engine noise when healthy, would assume (maybe a mistake) that timing chain was done when bottom end was rebuilt. From the looks when we took it apart the first time, the previous owner probably installed a short block and failed to do the top end.

Engine is stock except for Banks Power-Pack, MSD coil and wires. Truck has C-6 and no tach, but is not run hard except for hauling a 9-1/2' camper (2100 lb) and small 5x8 trailer with two motorcycles, no more than 1500 lb. if I'm climbing one of the many mountain passes in the northwest and it drops to 2nd, I usually back off and run at 45mph until the hill flattens instead of running it back and forth between 2nd and 3rd.

No evidence of cracks in the heads, but wonder if valve guide or valve seat insertion caused cracks not visible without x-ray or magnaflux??

Generally, the truck is not used hard, I could understand if it was raced, hauled a heavy trailer, run hard in hot or dusty conditions, etc.

Thanks again, Paul

 

hey, when you mention your mechanic is he a qualified mechanic or is he like just your neighbor? now please don't take this the wrong way i'm just tring to find out is this person experienced. now when you sad you had the heads totally rebuilt did they machine or resurface the bottom of the heads? if they did say cut .030 off the bottom of them then it would cause a binding condition on the valves, they would have to be shimmed to restore proper valve train geometry. are these the rail or fulcrum type rockers? there could even be coil spring bind. hope some of these idea's help. what are the casting numbers of these heads if you can get them. c.j.

 

Priley.....What machine shop in the Seattle area did the head work?

 

Fordzzzz77;

Eastside Machine did the head work.

CJ;

<<hey, when you mention your mechanic is he a qualified mechanic or is he like just your neighbor? now please don't take this the wrong way i'm just tring to find out is this person experienced.>>

My mechanic is a qualified mechanic, runs his own shop and has raced and rebuilt 460s. He had one in a stock car that ran 6000rpm on a 3/8mi. oval track all day long without valve problems.

<<now when you sad you had the heads totally rebuilt did they machine or resurface the bottom of the heads? if they did say cut .030 off the bottom of them then it would cause a binding condition on the valves, they would have to be shimmed to restore proper valve train geometry>>

Good point, I don't know if they were machined, don't believe so as they were not warped, however, they may have been machined in a "past life".

<<are these the rail or fulcrum type rockers? there could even be coil spring bind. hope some of these idea's help. what are the casting numbers of these heads if you can get them>>

I'm afraid I don't know the difference between rail and fulcrum type. The truck is 150mi away in a shop, so when they pull the engine, I'll ask and see if they can get me the casting numbers.

Thanks for all the ideas,

Paul