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You guys may remember me helping a friend pull a '63 IH cab-over out of a field a few days ago. Well, tonight I asked him if he's gotten the engine to turn over, and he presented me with a puzzler. The engine is the 304 CI V8:
#1 Cylinder: He puts air into #1 through the spark plug hole and gets very little leakage.
#2: Puts air into #2, the front cylinder on the other side, and water and air comes out of #1 as if there's a straight connection between 1 & 2.
#1: Goes back to #1 and it still shows no/little sign of leakage.
How can this be. Neither of us can imagine what would cause that. Any ideas?
I am guessing a broken valve spring on No. 1, he pressurizes it and the valve lifts and seals. Take away pressure and the valve has nothing holding it closed so pressure from No. 2 cylinder can enter... I'm not sure what all else is involved as far as engine problems but that's the only reason I can think for pressure getting into No. 1 but not any pressure getting out.
Did you guys try turning the engine at all while doing this? However... The air has to be traveling through the intake manifold to get over there right? And I have no idea how air can go one way but not back the other under identical circumstances... Interested to see what people say on this one, I'm just gonna help you brainstorm on this one!
The valve/spring idea seems to explain the "check valve". But, according to him there's no air coming out of the carb, implying that it didn't get between #2 and #1 via the intake. However, since he says it can't be going via the sump as there's no air coming out of the breather, it has to be going through the intake.
As for turning it over, it is locked up. He devised a cunning plan of putting the tranny in top gear, removing a wheel, and using a lever on the studs and a jack on the end of the lever to turn the engine over. And it slipped the clutch.
Well I admire his ingenuity! I'd say just go along with rebuilding the engine if you guys are going to use it, whatever is going on in there you'll find it when you tear it down. I'd also shoot over to the older truck's forums and get those guys' opinions if you want to try to get it running before the rebuild. If it's seized it's obviously gonna need it, plus possibly a good oil bath
He's very ingenious. And, he knows his way around Binders as he's a retired IH mechanic. Said he's probably rebuilt over 500 of these engines, but can't figure out what is going on with this one. Anyway, when the penetrating oil finally breaks things loose he's going to rebuild the engine.
Puts air into #2, the front cylinder on the other side, and water and air comes out of #1 as if there's a straight connection between 1 & 2.
When you mentioned water, do you mean coolant? Or is this rainwater that collected in the engine?
I like the broken valve spring idea, but maybe there's more than one issue. You mentioned the truck came out of a field. Perhaps the exhaust is completely plugged. Maybe a family of mice turned the muffler into a condo. Blowing compressed air into a cylinder (with an open exhaust valve) then compressed the nest and made a tight plug. Now air can get from one bank to the other via the Y-pipe (if single exhaust) or via the heat riser passage in the intake manifold. He may have checked for air escaping from the exhaust but thought that was good because he didn't hear anything, not realizing it could have been plugged.
Still not sure about the mystery water, unless the exhaust was full.
Just a theory, basically thinking out loud. Not responsible if anybody hurts themselves laughing.
He's very ingenious. And, he knows his way around Binders as he's a retired IH mechanic. Said he's probably rebuilt over 500 of these engines, but can't figure out what is going on with this one. Anyway, when the penetrating oil finally breaks things loose he's going to rebuild the engine.
Ah ok cool, tell him I wish him the best of luck! I'm currently 499 engines behind him but I'm going to try to close that gap as best I can!
Houston, I think we may have a plausible set of circumstances. A broken exhaust valve spring on #1, a plugged exhaust system, and #2 sitting with the exhaust valve open would do it. Cool!
As for the water, it was rain water - the PO left the cab up and water probably got in via the carb. But, he says the cooling system is full and the coolant checks good.
Well, he played with it more today. Put air to #2 and he heard a clack and air came out #1's spark plug hole. So, he stuck his finger in #1's spark plug hole and air came out #7.
Turns out the carb's throttle plates are jammed shut, effectively sealing the intake. #2 is sitting with its intake valve open, so 100 psi air is hitting the backs of the intake valves and overpowering the springs. #1's spring is apparently the weakest, and #7's is second weakest.
Well, he played with it more today. Put air to #2 and he heard a clack and air came out #1's spark plug hole. So, he stuck his finger in #1's spark plug hole and air came out #7.
Turns out the carb's throttle plates are jammed shut, effectively sealing the intake. #2 is sitting with its intake valve open, so 100 psi air is hitting the backs of the intake valves and overpowering the springs. #1's spring is apparently the weakest, and #7's is second weakest.
So, thanks for the ideas!
"In-digestion".....ouch Time to intubate ! Go for the throat !
That was the other thing I was wondering... about how much pressure he was putting into the cylinders. RacinNdrummin on the diesel board hit 50 psi of boost and got valve marks on top of all 8 pistons even with Comp Cam 910 valve springs, so they were floating! Of course he only found that out because a rod exited the block and the rest were bending. Stronger springs, stronger rods and lower static compression ratio next time