Is it possible to hydro lock an engine with fuel (i.e stuck open injector) and bend a rod while cranking trying to get the car to start?

 

It is possible. Fuel is a liquid correct?

 

Ha! I could see, and would answer my own question if I had been at cruising speeds say above 2k rpms and sucked in water, but while cranking? it would seem to me the engine would lock up but not bend a rod, see what I'm asking? Still think crank speed be enough force if it locked up with fuel to bend the rod?

 

I have seen a diesel do it.. On a 6.0 ford.. Did not bend it a lot but it did bend none the less..

 

Yes, I have done it while cranking and busted the starter. Injectors stuck open due to a wiring era cause a hydro-loc. I was told you would not bend a rod as long as it does not try to fire, thats when you start bending/breaking things.

 

yup, if it fires you are screwed, but generally on the starter it will just stop it and you'll be ok

 

Thanks to everyone that replied! Well I'm think that is what happened to my car. On my 89 GT, the car ran perfectly, I changed to NGK plugs and Accell 300+ wires. When trying to start the car fuel was spraying from the fuel rail, found a broken rail bolt and had to fix that. Before restarting I installed my #42 injectors and mass air. I tried to start after that and it just wouldn't and even though I have a high torque starter while cranking the engine just froze. I pulled the plugs and was able to rotate the engine. finally got it started and now I have a knock!! Was totally perfect before

 

Some powdered metal rods will bend under just starter force. Seen several Ford 4.2's have a head gasket leak and bend rods just cranking them. One of them was after diagnosis of the leaking head gasket. Customer wasn't sure if they wanted to fix it, so we parked it. A week or so later they gave us the go ahead. Went out to run it in and start on it. Engine cranked half a round and stopped, never got a chance to fire. Drug it in, pulled plugs, and pumped anti-freeze out of cylinder. Stuck plugs back in and fired it up to find a nasty knock. Turned out it bent one of the connecting rods just enough to scrape the bottom of the cylinder as the crank was coming around.

 

Wow that sucks. Well, I've resorted to pulling the engine. It really stinks because I have yet to drive the car with boost. It's been 1 step forward and 3 back. I'll let you guys know what I find.

 

Anything yet?

 

Hey, no nothing yet. I haven't turned a wrench on the car. I've been helping my dad install a new 347 in his 87 Cougar so when that's done and out of the garage mine will be next!

 

Ok, I was finally able to spins some wrenches on the car last night. I submitted to the idea that I was going to have to pull the engine the last time I posted as I thought I had a rod knock. As I was starting to remove piping etc. on a whim I thought I would go ahead and pull the driver side head just to check since that is where the sound was coming from.

I was shocked at what I found after pulling the head...a small chunk of metal was embedded in the cylinder head!!! I have know idea where it came from or what it is. The piece is about an inch long and not quite an 1/8 thick. At first glance it looks like a piece of the ring, but the cylinder walls are perfect and the piston circumference is undamaged. I was able to pick the chunk out with my fingers. The damage doesn't look too bad on the head or piston, I may be able to smooth out the nicks, totally nuts!!

What do you guys think??

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well it hit the outside of piston so its probably screwed, it will bend the top of piston and pinch ring so it wont seal and have blow by, can always just test with old head gasket and do a leak down test,if comes up good put a good gasket on. I would take the intake to a pressure washer and blow it out. had this happen to me. chunk of old ring from a previous blow up lodged in intake for 100k$ miles and broke free in a gasket swap. after blowing intake out with pressure washer found more pieces.

 

Might as well try the patch job. An engine w/ that much oil/? on the pistons isn't going to last long under boost.....

 

Thanks for the reply! Well I'll give everything a thorough check.

I agree that there was more oil crust then expected, the heads have been on for 11 years and the engine hasn't given me any trouble and doesn't smoke at all.....hmmm

 

Easy way to check for a bent rod, is to see if all 8 have the same deck hgt, when you rotate the crank.

 

It's been just a bit but got the car put back together and it ran pretty smooth with just a slight miss it seemed but with no knocking sound now. Ran a compression test after the engine had thoughly warmed up...the results are not good which was to be expected I guess.

Cylinder PSI used to be 135... I didn't test all cylinders beacuse after a few there was no need too.

The results are as follows:

CYL-1 100 psi
CYL-3 80
CYL-5 80
CYL-6 70
CYL-7 60

Well out it comes but now what to do, BOSS or Dart block 331/347 or go 351 based 408 etc. or just rebuild this turd.