Unforgettable Moments...

I couldn't help but reflect on some unforgettable moments in a young man's life today. His first day of school, his first fight, first kiss, first time driving, first date, his marriage...his first time experiencing cavitation in a 401...(the other events were much more fun.)

Started Friday when I ran my 8700 for a few hours w/the blade and happened to notice the blowby looked unusually thick. I panicked since I had plugged a hole in the water jacket 2 yrs ago, but the temp gauge hadn't moved, so I kept blading. Never got hot like it was losing water, but trouble was brewing then.

Started it Saturday and ran it a few minutes while I unhooked the blade & hooked up the bale fork to move the cornhead out of the shed & blowby looked worse still & the temp gauge showed it getting hot - putting water in the oil. Moved head out quickly & shedded tractor, pulled dipstick, & found lots of gray oil. Got oil pan off today and poured a couple of gallons of water through radiator and it ran out the engine midway - looks like #3 or 4 cylinder. Looks to have come from above the camshaft. Couldn't tell for sure - it was dark & my trouble light broke. Going to check again in the morning. Anyone remember what they payed to have a 401 sleeved? I still need to check bearings & kingpins on the TW & get ready to shell corn...(sigh)

Is it coming from the area of the cam, or out of the cylinder wall?

I've got to double check this morning, but I'm going to say it's from the cylinder wall. Saw it leak down from above the cam. I was trying to keep my troble light out of the waterfall last night but didn't succeed - shattered the bulb, so I called it a day.

For what it's worth, in April 2011, I had the same symptoms and it was a hole in the water jacket near #6 cylinder. I drilled & tapped it & ran in a bolt w/locticte. That's still holding fine. I'll post back when I know more.

Found it. #4 cylinder, on the side, about 1/4 inch from the very bottom. When the stream of water shoots out, it hits the camshaft. I've been pricing blocks this morning.

That, IMHO, is not cavitation. It's too close to the bottom. It's good old fashioned rust due to poor cooling system maintenance (or more specifically, the lack thereof). I had that happen once on a 9700 as well. Not sure if those series of 401 blocks are more susceptible to this problem or not, but the bottom line is that unless you sleeve all 6, you will have problems in the future.

Further complicating things is the fact that the hole is so low in the cylinder wall. I suspect that at least some machinists will tell you that the block is not repairable. If this happens, I would look into pouring some sort of liquid metal into the cooling jacket and raising the floor about an inch or maybe even two.

After seeing it, I wouldn't call it cavitation either. I'm interested in your suggestion. How exactly would I go about that?

Not sure really. I have heard that race engine builders do that sometimes for engines that only run the 1/4 mile. I would ask a machinist.

I would have no issues raising the floor a couple of inches after seeing how high Ford raised it on the Genesis blocks.

(quoted from post at 17:32:51 09/24/13) Not sure really. I have heard that race engine builders do that sometimes for engines that only run the 1/4 mile. I would ask a machinist.

I would have no issues raising the floor a couple of inches after seeing how high Ford raised it on the Genesis blocks.

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It sounds like what pullers call hard blocking. It is done to support the block when aggressive machining is done. It is a special compound that I would say looks like concrete. A fellow here in NH brought his 9000 to some pulls this summer. He bought it out of the weeds with a perforated block. He sleeved all six. It runs great now.

Hey, I think you guys have something here. Found this website and I plan to check on it tomorrow. Here's the link: http://www.hardblok.com/product-info/

Looks like what you need. If you do it right, you may not even have to pull the head. I don't know how fluid this stuff is when "wet", but you may be able to insert it through a soft plug hole.

My only concern would be how much crap is existing down there in your water jacket. If you don't get most of it out first, it may not set up well. You'd have to ask the folks who sell the stuff.

Let us know how it works out for you if you end up using it.

I've been thinking about that too. Wondering how I'd clean that out. Take off the water pump and pull a few freeze plugs & pour in some coolant flush maybe? I'll ask when I call. Let you know how it works if I go that route.

(quoted from post at 21:13:56 09/24/13) I've been thinking about that too. Wondering how I'd clean that out. Take off the water pump and pull a few freeze plugs & pour in some coolant flush maybe? I'll ask when I call. Let you know how it works if I go that route.

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I have found some really deep accumulations of crud in water jackets, especially towards the back. I would want to be pressure washing in there if I were you.

I tend to agree with that assessment. I once cleaned a 3000 block that was full of crud right up to the core plugs. Antifreeze had never been changed since it left Highland Park in 1973. This was... 3 years ago. So just about 40 years on it.

Rod

Sounds good. Thanks.