Wobble

Bad start to the season, bad gas.
Took my boat out Friday after finishing up my oil cooler upgrade. Travelled about 3 miles untill I saw the oil temp guage start to move and picked it up to about 4000rpm and felt it start to miss. About the same time I lost my power steering.

Turns out I burned a hole in a piston and the power steering quit because the dipstick blew out and wnet through the power steering belt.

I was watching the guages good fuel pesssure, 165 water temp, 200 oil temp. EGT was about 1150.

Only thing I can figure is that my gas had gone bad since October.

I only had 50 or so hours on the motor since a complete rebuild.

This really sucks. I am going to pull motor next week and see how bad it is. I'll let you know.

For those of you with hi-perf motors. Be sure and drain your tanks and start with fresh name brand gas when you get started this year.

I filled my tank to the brim with super and taped off the tank vents in October. Guess that was a bad idea.

PatriYacht

Sorry to hear of your problem. A number of people have complained about the short shelf life of modern gas. I have been running my tanks down near empty in the fall and filling up with fresh in the spring. So far no problems with condensation in the tanks.

Wobble

Patriyacht,

I thought I was being clever, with gas prices headed up and no releif in sight. (and that was October) Used to do what you do.

Learned another expensive lesson.

Hopefully just a piston or two. Oil pressure didn't change.

Wasn't planning on seeing the engine builder this year.

88Fount33

Sorry to hear about this, could it be a clogged injector? leaning out that Cyl? and not just the bad gases fault? Just something to think about. Unless you already know for certain it was the fuel.

My old 330's wouldn't know what to do with "good" fuel, probably could not even start them!

Wobble

88Fount33

No injectors. HP 850 holley. I have an Exhaust gas temp probe on each bank. Didn't see any high temps. So I am fairly sure it detonated badly. Will have a better idea when I pull it apart. But blowing the dipstick out is a fairly sure sign of a ventilated piston.

offthefront

iTrader: (1)

Obviously I have no clue .....but why would bad gas burn a piston ? Similar to low octane ? I guess you did not have any stabilizer in the fuel ?

your giving me chills .....I have a post about my port motor consuming oil at an alarming rate ... one symptom is blowing the dipstick out .....

88Fount33

Just wanted to make that comment as I melted #8 down and lost the top ring, pushed pieces of the ring into the Al head, all from too lean WOT on a small block 406 CI, traced it back to too low fuel pressure, due to anti-siphon valve on fuel tank fitting restricting flow (after several fuel pump changes, mechanical and electric). Who's that Knockin'? don't let it in!

Wobble

OTF,

you are correct, no stabilizer in fuel. I thought that with vents taped off the fuel would be fine......WRONG.


Not trying to scare you, but excessive crank case pressure is either worn out/broken piston ring or hole through top or down side of piston.

Wobble

I wish I could hear it knock/ping, but that dam loud exhaust won't allow that. Hold on....I spent a lot of money to get a loud exhaust.

I have #10 line and pick up from tank through Hollley black marine fuel pump and #10 return line to tank from regualator. Can flow way more fuel than I should need..

hillbilly24

OTF,
Before you get too wild and tear that motor down make sure youre breather system isnt plugged that would cuase all the symptoms you have.