Valve Tip Damage
Thread Starter
|
Elder User
Joined: Dec 2006
Posts: 559
Likes: 4
From: On a farm.
Valve Tip Damage
An update from a previous post:
If you remember, I was speculating as to what caused this:
I don't have an answer but I have eliminated one "suspect." I wondered if too much material had been removed at the previous valve job which, in theory, might get down to softer material. I measured all 16 valves and their appears to be very little material removed from most. Some with the most removed (0.018") were in the best shape and some with the worst damage had the least material removed. There was no clear pattern. I guess this will remain a mystery. Well, I got new valves coming and will lurk over the machinists shoulder during the valve job.
If you remember, I was speculating as to what caused this:
I don't have an answer but I have eliminated one "suspect." I wondered if too much material had been removed at the previous valve job which, in theory, might get down to softer material. I measured all 16 valves and their appears to be very little material removed from most. Some with the most removed (0.018") were in the best shape and some with the worst damage had the least material removed. There was no clear pattern. I guess this will remain a mystery. Well, I got new valves coming and will lurk over the machinists shoulder during the valve job.
Thread Starter
|
Elder User
Joined: Dec 2006
Posts: 559
Likes: 4
From: On a farm.
Not an unreasonable assumption just looking at the tip but the there should be other clues that are not present, such as similar signs of damage on the rocker pivots, excessive wear at the ball ends of the rocker and the pushrod (oil is fed thru the pushrod). Heat would also show more of a blue-black coloring. The upper end is exceptionally clean, as is the rest of the engine. The funny thing is, the rocker tips don't look near as bad as the valve tips.
Thread Starter
|
Elder User
Joined: Dec 2006
Posts: 559
Likes: 4
From: On a farm.
Hmmm... now there's a though? I haven't noticed any blueing, which would be a sign of excessive heat but I'll look again.
Postmaster
Joined: Jan 2010
Posts: 4,319
Likes: 4
From: Elk City, OK
oil pressure comes up through the pushrod, onto the rocker but nothing says that there wasnt an obstruction on the tip of that rocker that stopped the oil from oiling just that piece. and your right, you only supplied one pic so its hard to pinpoint.
Trending Topics
Thread Starter
|
Elder User
Joined: Dec 2006
Posts: 559
Likes: 4
From: On a farm.
I suppose that's a thought too. I didn't specifically check those oil holes at teardown. There were a total of six with damage to various degrees, with the one pictured being the worst and one not too far behind. As clean as everything was inside, it seems doubtful that six could have plugged up. I'll look at them again, but they've sat in a box now for six months so I'm not sure if what I'll see will be useful. I'm pretty sure I'll be checking oil flow at the rockers once the engine is together, as much a PITA as that will be.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Thread Starter
|
Elder User
Joined: Dec 2006
Posts: 559
Likes: 4
From: On a farm.
Not nearly so bad. Unfortunately, after staring at them for a while in their installed order, I cleared the workbench to start reassembly and just tossed them into a box. Not sure which is which at this point.
Senior User
Joined: May 2010
Posts: 337
Likes: 0
From: Des Moines
You had too much slop in your valve clearance. If I remember right, without looking, it should be .017 cold. (Damn my bad memory) Anyway, it had too much, probably about .025. The inertia gained from the extra clearance made your rocker 'slap' the valve stem too hard, right through the oil resulting on metal-on-metal contact.
Posting Guru
Joined: Jul 2004
Posts: 1,627
Likes: 0
From: West Valley Utah
Jim, have you been the only one driving this truck? Do you have a teenage boy that has been driving the truck?
I ask because it almost looks like the engine has been over revved either by the throttle or by gearing down at a very high rpm, or both and floating the valves.
I ask because it almost looks like the engine has been over revved either by the throttle or by gearing down at a very high rpm, or both and floating the valves.
Thread Starter
|
Elder User
Joined: Dec 2006
Posts: 559
Likes: 4
From: On a farm.
I'm the only driver and have owned it since 1987 and 7K miles. Heck, the number of times my wife has driven even can be counted on my fingers and I only loaned it out once in the '90s to a trusted friend who had it for a whole hour... in town the whole time. I've hit the governor a few times in it's life, but not regularly nor recently. The closest parallel with your idea would be that with 4.10 gears, it's running down the freeway at 2900 rpm. Never seen that to be a problem with these engines... a lot of them came with 4.10s... but it's certainly an idea that might be in the "plausible" category.