I have a 360 I am starting to tear down. Was running badly when I got it and it ended up pushing fluid out of the oil dipstick. This is when I found out the oil has gas in it. Was told a broken piston ring might be the cause? From what I can tell it’s a LA motor. Any other thoughts what it could be?
360 Dodge
- Thread starter Nihms
- Start date
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Could be the fuel pump diaphragm has a tear in it pumping fuel into the crankcase.
It has a electric pump near the gas tank and a Holley efi unit on it.
Gotcha, it won't be the fuel pump then, lol.
schwinger
1972 Dodge Dart Swinger
Looking at the lifter valley i wonder if you got a late 80s early 90s pre magnum block seeing that theres mounting holes for a roller cam lifter guide retainer plate.
I was wondering the same thing. It has the 5 bolt valve cover heads and the iron water pump that exits on the driver side. But then I saw the middle threaded holes and confusion set in. I’m new to Mopar, so this motor has the provisions to be a roller cam?
schwinger
1972 Dodge Dart Swinger
Believe so which would be a good score, also you can check to see the casting number on the block next to the cubic inch casting and look that up. hears a link to casting numbers mopar casting numbers
If the block numbers match to a 360 LA, it’s a great score. They originally came outfitted with 308 high swirl heads, 9:1 compression, high volume oil pump, double roller timing set, and a windage tray.
Look on the passenger side of the block and see what the date is that's cast into it.
Professor Fate
Push the button, Max...
Okay, let's take this step by step.
If you have enough gas in the oil to be pushing fluid out of the dipstick, it ain't because of a piston ring. You'll know soon enough anyway, since you're tearing the engine down, and can see for yourself.
It's an LA motor, since
A.) There are heat crossover passages in your heads. Magnums didn't have heat crossovers.
B.) You've got TBI. Magnums never had TBI, they had multi-point injection. More on this later.
Yeah, that's a factory TBI. Mopar used a Holley-manufactured throttle body. The giveaway would be if you've got a 2 bbl. cast iron manifold, and a controller that looks like this:
The excessive fuel problem could be due to several things, none of which are piston ring related.
A blocked or kinked return line can cause excessive fuel pressure, loading up the cylinders with fuel, as can a defective or shorted injector coil. Lots of sensor issues with the old factory "speed density" systems that can also cause an over-rich condition (as opposed to other "mass airflow" systems).
But most likely, from what I see in your picture, is that the factory roller cam has been replaced with a flat-tappet cam of unknown specs, which completely confused the computer.
If you're going to rebuild it and re-use the TBI, you'll need to go back to a factory-spec cam, since the factory controllers have very little tolerance for any modifications, and there are very few, if any, people left that can or are willing to re-flash the factory computer.
Here is a picture of a Magnum engine with the “Spider” that holds down the tappets. The lifters are independent and use a link bar that rides on the lifter directly. The lifter has flat surfaces and the oiling hole of the lifter should point towards the camshaft when installed.
The use of a Hyd. roller cam is an easy bolt in. The Hyd. lifters should be an OE unless your doing a very high performance or race engine. The OEM lifters are cheap.
FWIW, the timing cover, water pump and if it had a mechanical fuel pump are made of aluminum. Nice and light weight.
The use of a Hyd. roller cam is an easy bolt in. The Hyd. lifters should be an OE unless your doing a very high performance or race engine. The OEM lifters are cheap.
FWIW, the timing cover, water pump and if it had a mechanical fuel pump are made of aluminum. Nice and light weight.
It is a holley. but I thought it was after market with a harness and box on the fenderwall. 4 injectors 2 up front and two in back. Have to get the date code tomorrow. Too cold and no light atm. Can you normally see it from underneath. Up top the header covers everything.
Pic of the injection
Professor Fate
Push the button, Max...
Okay, that looks like a Holley Terminator system. (Aftermarket, not OEM). No experience with them. Yet.
If the dipstick is getting pushed up after a high rpm run, then that is caused by blowby: combustion pressure escaping past broken/worn rings into the crankcase, building up pressure & forcing up the d/stick.
cudamark
Well-Known Member
The broken ring would cause more blow-by which can make oil push up the dip stick tube, and leak by other seals as well. If the crankcase ventilation system isn't working correctly, is overwhelmed with blow-by, that would make it worse too. The fuel in the oil probably raised the oil level which also added to the problem. I suspect fuel leak down past the rings was where the gas in oil came from. Residual fuel pressure in the system after shut down and leaky injectors can cause that.
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