View Full Version : Hydrolocked caused this....
04-21-2016, 07:50 PM
Buddy hydro-locked his 1981 350 and ended up stripping his starter bendix. I pulled the plugs, put another starter on and expelled the water. Put the plugs in and still no start. He thought he may have jumped his timing gears yet they were ok. Chain seems pretty slack to me. Then we noticed dist. rotor pointing at firewall, like 180 degrees out yet we never pulled distributor. Could something shear or move on dist shaft??
04-21-2016, 10:57 PM
Camshaft and dist turn 1/2 speed of crankshaft you could have been on exhaust stroke no 1 instead of compression stroke
Try turning it one more full revolution
The gear on dist is held on with a roll pin
But if it was sheared off dist wouldn't turn when you turn motor over
Hydro locking it is highly unlikely to shear it though
But if it had water in oil and was frozen it would shear the pin
I'd be suspicious of it having bent rods more than anything
04-22-2016, 08:40 AM
I'll try that today. Buddy said something like he went to go start it and it would not start. From what he said coolant leaked into engine cylinders overnight on drivers side. Sounds like a head gasket to me. I'll quiz him some more. I'm hoping rods are ok. Push rods appear all straight. It was a low mileage engine so he was really choked when this happened. I'm thinking pull heads and see how much ridge on top of cylinders and rotate it to see if pistons all come up. If it truly is a low mileage engine have block, heads checked for cracks, check rods and rebuild it. Thank you for the help.
04-22-2016, 09:20 AM
So once I turn crank one revolution, timing mark on cam gear will be at 12 o'clock and rotor should be pointing at #1 cylinder which will be compression stroke. So if connecting rods are slightly bent it would cause it not to start? I think buddy before I came over he took plugs out and expelled water and then started it up and that's when it hydro locked. I'll ask him again today. Here's photo of timing gears. Teeth look really worn. I wonder if Buddy had a high mileage engine installed? Maybe check compression before pulling heads off too.
04-23-2016, 10:23 AM
Looks like dist is fine.
04-23-2016, 02:10 PM
Did u pull the dizzy and look at it? May have stripped the cam gear on it,
04-24-2016, 06:18 PM
So pulled dist and laid it on bench. Then pulled intake and heads. Gasket between 4 & 6 cylinder was where coolant was leaking into engine. Then suddenly noticed pool of engine oil under dist. Oil was leaking out from where coil pick-up is. Took dist shaft out and coil pick-up. All soaked in oil. Picked oil sludge out of dist base and blew it out. So this could have caused a no start situation and just happened to occur at time of blown head gasket. Pistons all come up to tdc.
04-24-2016, 06:19 PM
Dist gear was good.
04-25-2016, 09:11 AM
So what caused the hydro lock
Was the truck submerged ingested water through intake ?
Or coolant from fucked head gasket ?
Did you check for spark before tearing it all apart
The oil in dist could be a plugged or inoperative pcv system
Excessive crank case pressure (blow by)
The dist bushings are lubed by engine oil so a small amount could be present
A bent rod might not be obvious
Anytime you Hydrolock a engine it's sort of a crap shoot fixing it
It could be ok or it could blow up a week later
05-14-2016, 09:17 AM
So a week later or more...
05-14-2016, 09:50 AM
So finally got back to working on this engine 4SKIN. Quizzed buddy. He said coolant was leaking into engine - it was smoking white and coolant level was dropping in rad. The reason he stripped starter bendix was he guessed water was leaking into engine causing it to not want to crank over cause of water above piston. It would crank a bit then he would try again and it would start. Once running he would top up rad. He did that for a week till he finally stripped starter. He was only driving it 3 km back and forth from home to corner store. When bendix finally stripped he gave up.
It had spark. So I took the heads off and sure enough head gasket very rusty between 6 and 8 cylinder. Number 6 combustion chamber was amazingly clean. I flipped both heads upside down and filled combustion chambers with diesel. Next day only 2 still had diesel. I have pulled all the valves on pass head and it looks like most were not sealing properly. Many faces of valves where valve seats were black. Also when lapping exhaust valves lots of black spots that take forever to lap away. Some intake valves on pass head had lots of carbon behind them and cyl 4 combustion chamber intake valve had 1/8" of hard carbon on top circular flat area of intake valve and 1/8" of carbon behind it lodged in seat of head. Buddy also had said he would have to crank engine forever and pump the gas till it started up. So talking to a friend the other day it sounds like it would not start for me due to poor compression due to too many valves leaking. I lapped most of the valves on pass head. The head # is 462624 and researching on net they are crap heads by high performance people and could be cracked already. I bought top end gasket kit and new head bolts before I had a chance to take valves out. I think I am wasting money fixing this engine. Cylinders have very little too no top ridge and all pistons come up to top of cyl so suspecting block has little cylinder wear and connecting rods still straight. However 4SKIN, I'm thinking you would say scrap heads and see if block is a 4 bolt main for a future engine block.
I have a 350 v8 that starts awesome with eldebrock performer intake. This engine is in a truck that is no longer highway safe police say. It got DOT'd last winter - its really beat up body wise. I figure cheaper route and more reliable to scrap the hydrolocking\leaky valve engine and put in the v8 that starts really good?
Thanks for your help!! [cheers]
05-14-2016, 05:26 PM
Yup, don't polish a turd
05-14-2016, 07:15 PM
Yes as harvester Said turd polishing works but is usually futile
Swaping motor is a better way to go good luck
05-14-2016, 07:55 PM
Swap costs you time. Turd polishing cost money and time.
05-15-2016, 08:03 AM
Thanks guys!! The turd is getting dropped out!
05-28-2016, 11:26 AM
So turd is out. The engine I'm putting in is 1974 350. I took off the flywheel and discovered the crank is they type where you have to drop oil pan to remove rear bearing cap to change rear main seal. I figured be a lot easier to do now with engine upside down on engine stand vs once back in truck. I'm not even sure if it was leaking there yet lots of oil crud built up on pan. Could be oil from valve covers too.
I changed front timing gears chain a couple years ago and I read later I should have put some sealant on crank where harmonic balancer slides on since oil can get by. I know I had an oil leak temporarily at front of engine shortly after I did the gears chain and then it took care of itself lol.
so for preventative oil leaks figure check harmonic balancer, do oil pan gasket and rear main seal. I can do it later to if there is a persistent leak because there appeared to be no oil leaks when this engine was in my 83 plow truck this past year.
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