Long weekend, not on the water... tow pig not healthy

[cadunkle]

Hope you all enjoy the long weekend, or did already for our Canadian friends if you've splashed yet. Last weekend was low tide early morning and windy in afternoon but the tides are high early this weekend here so was hoping to get two days of early morning riding in before the holiday madness, but my tow pig has thrown a wrench in the gears. Tow pig has a valve tap and is down on oil pressure, won't build much over 40 psi. Trouble began shortly after getting some gas that was clearly not 93 octane and I have a feeling it was detonating badly for 20-30 mins on the highway with windows down and music up before I noticed. So my weekend will be spent pulling the ol' 460, evaluating the failure, and freshening it up. With a little luck I'll have it back together to tow to the river on Monday morning.

Hope everyone has a great long weekend and can enjoy the water if it's not too crazy out there.

[Jetlink]

Not sure what your fund situation is with the whole mess going on with the tow rig but, perhaps you can salvage it a little one day with a Uhaul pick up rental, I think $20 is what they charged me once for a day.

[cadunkle]

Haha, same thoughts going through my mind. My buddy who is always out with us picked up a drop hitch and 7 to 5 pin adaptor last weekend, perfect timing, so if it's not all wrapped up he can tow on Monday. Only problem is tow pig is my daily driver, it's been raining a lot lately so can't (comfortably) ride my Honda, and my Galaxie is stripped down (no glass, interior, seats, etc.) to go to body shop next week. I got a plan in my back pocket though if I'm not quite finished but close enough to have a few hours of fun!

[cadunkle]

Sweet mother of carnage! Taking a break but been goign at the tow pig motor all day. Cracked top compression rings on 3 pistons, hammered upper rod bearings on those three particularly, wiped lobe on cam, and chewed up main bearings. Fortunately the bearings seem to have absorbed most of the damage and the crank is okay. Cam failure may or may not be related, but low octane fuel and the detonation that resulted certainly shattered the rings and hammered the rod bearings. Gonna be a long weekend getting her back together!

http://i121.photobucket.com/albums/o234/cadunkle/F-250/P1020845.jpg

http://i121.photobucket.com/albums/o234/cadunkle/F-250/P1020859.jpg

[kvand347]

Oh man! You are in balls deep my friend. I will be having several drinks for you tomorrow!

What are the plans on the rebuild? OEM parts or are you going to be throwing in some performance parts?

[cadunkle]

Yeah you could say that! It's my daily driver too, so no pressure. Not a relaxing weekend for me at all, I'd rather be out on the river. Have some fun for me.

Plan is to freshen it up with new rings and bearings to put it back like it was. Fortunately the pistons and crank look good and the bearings took most of the abuse. I built this engine 3-4 years ago to be a torque monster. It is. It's a 460 with flat tops for 9.7:1 compression, ported E6TE head, Comp XE 262/270, Holley 750 DP, long tubes, etc... Makes around 425 HP 550 ft/lbs and comes on strong just off idle. The idea was diesel torque out of a gasser, and it does it well but due to weight, compression, and cam it's not tolerant of lower octane fuel at all. Hoping to have it back together by the end of the weekend.

After doing some more cleanup, detective work, and thinking, my best guess is the cam failure was a result of the loss of oil pressure from detonation hammering the bearings. #6 intake lobe failed, which is almost at the end of the line for oiling on a 460. I figure the lifter collapsed from low oil pressure and proceeded to beat the ever living crap out of the lobe. As soon as that began the cam was doomed.

[pap]

Wowza! Now THAT is a weekend project. You're in way over my head but given the fact that you appear to have a well used engine stand sitting in your garage I guess you're not as panicked as I would be in that situation.

[cadunkle]

8 slugs in, all clearances check out. Rotating assembly is complete. Still going strong on motivation so just gonna keep rolling for now.

http://i121.photobucket.com/albums/o234/cadunkle/F-250/IMG-20120527-00009.jpg

[pap]

My respect for you went up even further when I note the Ron Paul sign :)

Keep rocking onwards and upwards!

[cadunkle]

Glad to see another advocate for liberty! So few and far between these days.

Coming down the home stretch now. Taking a brief breather then it's a race to get it together and break in the cam before it's late enough that I'll piss off the neighbors.

http://i121.photobucket.com/albums/o234/cadunkle/F-250/IMG-20120528-00014.jpg

[cadunkle]

For what it's worth I got it Finished last Tuesday after work. Drove to work Weds/Thurs and was off Friday AM to Carlisle, PA for the All Ford show. Truck ran great, smooth and torquey. Picked up a new door at the swap meet, so just about ready for paint! Had some slight vibration on the highway when getting on the throttle a little, which I attribute to running solid motor mounts now. Sick of doing annual motor mount replacements so solid it is. I would have liked to clean up the engine bay better and paint it, but of course due to the time crunch I couldn't.

Got a whole whack of stuff to catch up on this week in the evenings but hopefully will find time Sunday to get out on the river and remind the tow pig's engine what it's real purpose it.

http://i121.photobucket.com/albums/o234/cadunkle/F-250/IMG-20120529-00016.jpg

[86 century]

40psi would have been the best oil pressure I have ever seen from a bb ford.

How did the plugs look sounds like it may have been a bit lean to start out.
At 9.7-1 I would think it would run on 87 just fatn it up a bit and back the timing down abit.

[cadunkle]

40 psi was definitely low for this engine. Pressure is now just shy of 40 at hot idle and at 1800-2000 RPM I'm in the 58-62 range. Definitely need an oil cooler though as after extended highway it'll drop to 53, when it cools a bit it'll creep back to high 50s. Just heating it up too much. Truck weighs 6000 lbs, 4" lift on 35" tires with only 3.55:1 gears so lots of load. Add 5500 lbs of boat and trailer and it doesn't help. Highway cruise in overdrive is 70 MPH at 2000 RPM. Plenty of power, but it'll heat up the oil. For comparison my car, which also has a 460 is around 30 psi at idle IIRC and at cruise 2500 RPM is around 55. Car weighs a little north of 4000 lbs, no pressure drop when heating it up on the highway or at the strip.

Plugs looked good, maybe a little lean on a couple cylinders that have poor distribution in the intake, but not significant (the leaner looking ones had intact rings). Forget my exact jetting but it's two sizes above where it lean surges, and I have the secondary side plenty fat. I may go up one size on primaries for a little protection. I was running 10* initial which was already way retarded from where the engine wanted it, and a fairly modest timing curve. I am running this engine at 8* initial with good results and no audible detonation, and will keep it there until I get a knock sensor on it. It's definitely down on power and I can already tell economy is suffering.

I was mistaken about compression ratio, looking over my build this engine is right about 9.9:1. I went with thinner gaskets to decrease quench distance and improve detonation resistance. Cam is also on a wide LSA at 111* which puts dynamic compression fairly high for a heavy towing application knocking on 8.3:1. Definitely needs pump premium. Marginal for 91 and should be safe on 93. I've been knocking on 9:1 dynamic compression in the past, but those were in lighter cars with deeper gearing and at the time we have pump 94 with MTBE.

I'm looking at an ignition setup with a knock sensor and individual cylinder timing retard to protect from this in the future.
http://www.jandssafeguard.com/safeguard.html