The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by Klunker77, Mar 21, 2020.
My money is still on Squirrel .
If you can turn the crank while watching the rocker gear and the rocker gear operates, the cam gear is good. If rocker gear does not move, cam gear knackered. If cam gear good and truck has manual gearbox it could be input shaft getting tangled up in gearbox. Push clutch in while cranking. If auto 'box I'm out of ideas.
Stuck valves are common
if it’s got the fibre timing gears these can strip and break.
could be a stuck clutch.
I would pull the valve and side cover while turning the engine over by hand.
tje trans comes out easy on these as well if it’s a stuck clutch.
Had an o/t vw bug with a stuck clutch acted like the engine was seized, clutch pedal felt fine.
If the cam gear is broken the distributor would not spin with the crank
Yes that is an easy check pull the dist cap turn the engine and see if the rotor turns, if the rotor turns there is nothing wrong with the cam gear
I had the rust in cylinder thing from rain on my big paper air cleaner thru A model hood sides. pull plugs, put trans fluid in, turn back & forth. Leave valve cover off for viewing valve train....don't rule out squirell's real life experience also.....
While we're thinking outside the box a little, get the fan belt off it and make sure that the generator and the water pump turn freely and smoothly.
Lots if possibilities.
Had a 272 act similar. Dirt dobbers built a nest on the head.
Engine turned fine then stopped.
You couldn’t see it through the spark plug hole.
Also agree on checking things like the water pump, alt/gen and possibly the starter.
Had a stuck clutch once but you couldn’t turn anything much.
The 235 in my sons truck turned at first then stopped. Had a little rust in one cyl and stuck valves.
My daily driver is an OT Thunderbird with a 4 cylinder. Two years ago I turned it off and an hour later it would not turn over. I thought battery but I jumped it and it wouldn't start. I tried pushing it and it drug the wheels. I tried turning with a 3 foot breaker bar. That didn't work either. I was building a stroker motor for it so I resolved to go ahead and pull the engine. When I got to the starter I removed the bolts but couldn't get it out. I moved on to the driveshaft and it turned. I was sure I had it in gear. I went back to the starter and I could get it out. The starter had jammed and the engine couldn't turn. Replaced the starter and it was good to go. May be worth removing the starter just make sure.
The crank and piston relationship doesn't change. The cam to lifter to valve doesn't change unless the valve sticks open. If one valve were sticking the stoppage should be at appx the same place each time but the op says that is not the case.
A changing relationship between the crank and the cam could cause random stoppages and forcing the engine past that point can damage things. If you remove the valve cover you can check which valves are closed and which valves are depressed when it sticks..........and see if a valve is stuck by checking the rocker arms. Rotate backwards then come forward again and see where it locks up. If the rotation point of lockup changes, I would check the timing gears.
Also, I would check the starter as suggested above.
I have had old starters that would turn an engine a little then start dragging and stop. Took them off tried to run it on the bench, same thing. Lippy
Never played with a 235. But a 270-302 GMC will absolutely run the rods into a cam lobe if the cam timing is off. For sure.
Im still betting on Squirrel,,,,,and now Richfox !
I had a similar situation with a 261 (rotated at first then tightened up, and with rest rotated again). In my case the oil
pump was not working correctly, because the oil pump was not primed before starting the engine. You probably already know that the distributor drives the oil pump. I took the distributor out and used a flat head screwdriver shaft attached to a drill to prime the pump. That may not be your problem, but I thought I would share a similar experience and resolution.
Starter ,cables,timing,battery,ignition switch,wiring. Start with the basics. It did run not to long ago right?
Likely, stuck valves since it has been sitting. Pretty easy to narrow that down. Definitely try it with the clutch pushed in first. If working alone, block up the wheels and jam the pedal down with some wood. Try to spin it at the damper with a socket and breaker bar.
Hey everyone. Just thought i would give an update. I added some Mystery oil and let it sit for a day and a half. Good news- it turned over freely. Bad news- I still can’t get the truck to start now. Timing seems good. All my cables are good and clean. I have spark. My battery was fully charged. When I went to start it it went “Wuh Wuh Wuhrooooo” and then it quick cranking ( hope those sound effects make sense) Tried again, same thing. Hopefully I can get this mess sorted out sooner than later! I think I’m going to swap out the battery regardless and also am beginning to think the starter is worn out. Any new suggestions on this?
That GMC is rejecting the lowly 235 Chevrolet engine and wants it's 270 Jimmy back.
Yep. Sounds like the starter.
Has that got a key start or foot stomp start?
new 12 volt starter and new battery plus cables.
Good idea to clean all the battery and ground connections. Verify the battery and starter cables are in good condition and the cable ends are firmly connected/crimped to the cables and corrosion free. Best to do these things before buying parts.....that may not be needed.
It has the foot starter
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Nope. It's the starter. I could tell by the way it sounded.
Before you start swapnostics, why don't you check what the battery voltage does when it quits cranking. It should have 6.3 volts or above before you begin to crank, and stay above 4.5 volts while cranking. Also check the voltage at the positive post while cranking and at the starter terminal. They should be within about 0.2 volts. More than that means you have a voltage drop in the positive cable. Also check between the starter housing and the negative cable while cranking. Anything over 0.1 volts means you have a poor ground.
If the battery voltage is above 6.3 and drops below 4.5 volts while cranking it means either the battery has given up the ghost or the starter is drawing too much current. Having the battery tested is the easiest unless you have access to a high current ammeter to test starter draw.
Or he fouled the plugs with the oil
Thanks for the Info, I’ll be sure to test this first before yanking anything apart. This is however a 12v system. Will those voltages just double?
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Yes, your battery should be at least 12.6 volts and shouldn't drop lower than 9.6 volt while cranking. The 0.1 volt drops remain the same.
From your post Engine is hard to turn by hand so there goes the starter idea. Did the engine turn backward after lockup? If it did could be the cam gear but my first thought is carbon because of blue smoke and oil driping from tailpipe. I'd pull the head sounds like the engine need work any way.
I had a similar thing happen on my '47, and it turned out to be the foot operated contact on the starter was black and full of gunk. I took it apart, cleaned and filed all the contact surfaces, re-assembled it, and it has'nt missed a beat yet.
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