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Bob is hurt...

tarafied1

Well-Known Member
The Bobcat has been running rough lately. I got home from Atlanta and had some time to look at it with him before I fly out tomorrow to Europe. It had low and fluctuating manifold vacuum. Played with timing and carb and just couldn't get it to smooth out. So I did a compression test. #1 60 psi, #2 30 psi, #3 150 psi, # 4 140 psi.
Some time ago it sucked up crud in the carb and was running lean. Lean enough to melt an electrode on one of the plugs. I think it either burnt a couple valves or maybe even hurt some pistons. It's not blowing oil out of the breather or overheating so I hope it's just valves. I squirted oil in the hurt cylinders and checked again, Got the same numbers. Again I hope it's just valves. He is going to pull the head tomorrow. I called the machine shop and they said they could turn around the head in a couple days so we hopefully can get it fixed before the Hot Rod Power Tour.
Not having good luck with all of our junk Fords lately.
 
I really hope he can get it fixed in time. He has been looking forward to driving it on the tour since he got it!
 
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It was two burnt exhaust valves


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in the second picture, you can see evidence of leakage starting around the fire ring between the cylinders, and above that you can see evidence of leakage between the transfer holes, note how the gasket is soaked around the holes.
 
I think that's just from when we pulled the head. The head still had some oil in low spots that ran all over when we lifted it out of the engine compartment. Also some could be from me squirting oil in the cylinders for the second compression test to see if it was valves or piston/rings causing the low values.
 
not between the cylinders. around the other side i agree, that is oil, but if you look between the two cylinders in the picture, you can see some browning of the fire ring. i have seen that way too many times to think any different.

the good thing though is that you caught it soon enough that no damage has been done.
 
it's quite possible. The cylinder temps had to be pretty high to burn the valves. Could have warped the head too. We'll have it checked. Thanks
 
if the guy you take the head to is any good, the head gasket surface is the first thing he will check after disassembly.
 
yeah, they are good. The head had some flatness issues already. When we bought the car the head was off. When we had the valve job done they had to mill some off to clean it up. I don't recall how much but my son has the receipt and the details are on there. The motor had chewed up the cam and had huge ridges on the cylinders. It was worn out! They had to bore it .040" to clean up the cylinder walls.
I'm pretty sure the carb issues we had caused this issue. It was running real lean. After we got the carb cleaned up it ran better but not like when we first put it together. I was thinking we could have hurt the motor and suggested to my son to check compression but we didn't do it. My bad. He kept driving it to school and I got busy and we finally took the time to look into it. First thing I did was check compression. It was like I had feared. Hopefully the head isn't warped too bad, we can find lots of Ranger 2.3 engines but the heads are different. Hard to find carburated 2.3's
 
the latest on Bob the Bobcat. My son got the head installed and mostly the engine is back together. he decided to wrap the header too. Looks like all he is waiting on is the confidence to hit the key (and maybe install the radiator). In the mean time he installed some gauges to monitor things a little more closely. (notice also the Holley is gone!) He bought a Street Demon.
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I guess the next time I shoot a Bobcat, I need to send him the skin!
lol, that would be something!

He did get it running. He had to jet down the Demon. I think it will be a better carb for the 2.3. It is a lot like a Q-Jet, small primaries and big vacuum secondaries. It uses metering rods too which may not get clogged like the Holley did. It looks good on there too. He is still fine tuning things but it runs better now that it's back on on all four cylinders.
 
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