460 tear down surprize, anyone seen this?
 

I'm in the middle of rebuilding the 460 out of my 87 F250. The main reason I tore it down (besides the fact that it had 240,000 miles on it and leaked a quart of oil every 300 miles) was it suddenly lost compression on #8. When I tore it down, I found 2 surprizes. The first was the intake rocker arm on #8 loosened up and fell off! That's why she lost compression, nothing to compress. The #1 cylinder leaked exhaust at the manifold so bad I never heard anything clanking around in there. Just a hint, if you ever lose compression on an otherwise good running motor, pull the valve covers before pulling the motor! I could have fixed this on the side of the road in 15 minutes.

Now here is the weird one. Has anyone ever seen this? When I started to clean the oil pickup tube for re-assembly, I found a gouge in the side of the tube that looked like someone took a hacksaw to it. It was about 3/4 of the way through the metal. A few more thousands of an inch and the pump would have been sucking air! When I position the tube in the pan approx. where it would be in the assembled motor, it looks like the dip stick is what cut into the tube. Has anyone ever seen this? Any suggestions on how i can make sure this doesn't happen again to my new pickup tube. The pan has to be on the engine to accurately position the dip stick but once the pan is on the engine you can't see anything.

Wasn't the dipstick man, it was one of the metal termites that have been showing up in greater numbers all the time. I suppose it is possible but I never heard of it.

I had an 86 460 that lost compression in one cylinder. Ran like a beast any ways. Never burned or leaked oil so maybe thats what happend to mine.

The only motor i have seen like this was for clearance issues with the counterweights on the crankshaft. Turn the motor and watch to see if the groove is cut either from or to prevent the contact between the two

Put clay on the pickup and reassemble the engine. Turn the engine over once, pull the pan and check for marks in the clay. Same trick used for years to check valve/piston clearence.

Clay, I should have though of that. I'll have to look at the old pickup tube again and see if the cut is on top or on the bottom. If it's on the bottom, it can't be the crank but the clay idea will work for the dipstick too. Thanks!

Why install the pan?

To check clearence between the pickup and bottom of the pan. Metal contacting metal is an indication of some clearence issues. I would stick the pan on with gasket, run in a couple of bolts and turn the engine over. Yank the pan off and look for marks in the clay....Besides this stuff is fun! I need a good deal on a 460 performer intake. You would'nt happen to have one around would you?

So you think the oil pick up is both hitting the pan and the crank is hitting the pick up? Why not install it without the gasket and then if it hits, check it with a gasket? Form his original description the metal mark was in the pickup tube. No extra 460 manifolds for either in or out of the engine.

The pan to pickup clearance was ok as far as i know. I'm going to check it with my new pan & pickup anyway. If I was putting the original stuff on I probably wouldn't bother, but I've had enough bad experiences with aftermarket parts to make me paranoid. The cut in the pickup tube is right where the dipstick goes by and it looks just like someone tried to cut it with a hack saw. I will definately use the clay method to check clearance in this area with the new parts. Thanks William for that suggestion.

Performer Intake - I just bought one off of Ebay for $106 including shipping. Used, but excellent condition. Sorry, no extras. I do have a stock 87 cast iron manifold if you want it, HA HA HA HA!

I rebuilt my 1987 460 and also had the cut in the oil pickup. I assumed it was from the dipstick itself.

Tim