318 Poly shakes like a wet dog

[Dave145]

I did not try the compression test again. I may give it another go later this weekend because now of course it's raining up here again. I'm not too happy with the 90PSI either. But being that the oil in the cylinders didn't increase it much, that tells me it's gotta be bleeding off somewhere!

I've never water misted this engine (though that would be a good idea). I have seafoamed it in the past with excellent results though. Thing smoke out an entire industrial park at 1AM! It's been awhile since I did it, so I may give that another shot again. I just let is get I inected into the engine through a vacuum hose and then let the car sit for a little while before firing it back up.

The heads are a bit sludgy but it's really not all that bad considering the age of the car. I've never run a flush of any sort through the oil because I'm afraid of either dislodging enough deposits to plug something up or wiping out a bearing somehow.

The car has somewhere around 80,000 miles on it and had been severely neglected. It sat in a field in TN for 20+ years untouched. I wasn't lucky enough to be the one to drag it out and bring it back to life, but I've slowly been fixing everything that time has so far degraded.

 

[toolmanmike]

I did not try the compression test again. I may give it another go later this weekend because now of course it's raining up here again. I'm not too happy with the 90PSI either. But being that the oil in the cylinders didn't increase it much, that tells me it's gotta be bleeding off somewhere!

I've never water misted this engine (though that would be a good idea). I have seafoamed it in the past with excellent results though. Thing smoke out an entire industrial park at 1AM! It's been awhile since I did it, so I may give that another shot again. I just let is get I inected into the engine through a vacuum hose and then let the car sit for a little while before firing it back up.

The heads are a bit sludgy but it's really not all that bad considering the age of the car. I've never run a flush of any sort through the oil because I'm afraid of either dislodging enough deposits to plug something up or wiping out a bearing somehow.

The car has somewhere around 80,000 miles on it and had been severely neglected. It sat in a field in TN for 20+ years untouched. I wasn't lucky enough to be the one to drag it out and bring it back to life, but I've slowly been fixing everything that time has so far degraded.

Isn't that fun to do? Makes the neighbors fly out of their homes to see what's on fire. Good to hear you have it running on all 8 again. Without an overhaul, that might be all you get.

 

[Ron H]

If the car has been run on unleaded gas valve seats could be beat up. I'd be inclined to run additive in the oil for 500 or so miles then change the oil and filter and see what it looks like and also run cleaner in gas. This is a aside from or delaying need for rebuild. On the other hand if you're satisfied with how it runs all fine. With my CA poly was surprised to find motor had been rebuilt in 1981 with hardened seats upon rebuilding it 3 years ago.

 

[Dave145]

Yeah my motor has never been out or apart. Being that the car had sat for 20+ years with the hood open I'm pretty impressed that it actually runs the way it does.

I'll probably put a lead additive in it to see if I can stave off a rebuild for a little while longer. It certainly can't hurt anything.

 

[Don Frelier]

With 50+ year old iron that's been heat cycled. I think the heads would be quite hard.
I haven't used any additive in mine for 20+ years. Still runs well after 30,000 miles or so.

 

[Ski 61701]

I've had really good luck with berryman carb cleaner...stuff your pour in the tank. I'd put the whole bottle in no more than half a tank of name brand premium gas. then drive on interstate for higher rpms drive at least 50miles. if you have build up on valves, the cleaner and fuel should start to eat deposits away. Now if the valves are so coked up... no mechanic in a bottle is going to help.
But when you get a chance, a compression check is your best bet to figure out whats going on..

 

[Scott Engelhardt]

If you spray carb cleaner in the carburetor venturi and see if the idle smooths out. Also a really quick check of your exhaust valves is to turn idle up to about 1100 rpm then hold a piece of paper buy the exhaust pipe if the paper sucks to the pipe once and awhile you could have a poorly seating exhaust valve.
There has been talk on this thread about soft motor mounts, I read a trick to stiffen them up by using windshield urethane. Use a caulking gun fill the voids in the motor mount with the urethane. This should make them nice and stiff

 

[Dave145]

This morning I did a water list while the engine was running to help break up the carbon in there. I did it just enough to make it shudder, but not enough to fully stall it.

Then I went and grabbed some seafoam. I sucked half the can into the engine through the PCV hose, then dumped what was left into the gas tank and crankcase. After sitting for 20 minutes i fired it up and ran it around the back roads for a bit. It didn't smoke a whole lot quantity wise, but it did smoke for a good while. Once I got back home I noticed it definitely feels a lot smoother. It even seems to rev smoother as well.

My oil is already coming due for a change so I figured now was as good a time as any to put the cleaner in.

 

[toolmanmike]

This morning I did a water list while the engine was running to help break up the carbon in there. I did it just enough to make it shudder, but not enough to fully stall it.

Then I went and grabbed some seafoam. I sucked half the can into the engine through the PCV hose, then dumped what was left into the gas tank and crankcase. After sitting for 20 minutes i fired it up and ran it around the back roads for a bit. It didn't smoke a whole lot quantity wise, but it did smoke for a good while. Once I got back home I noticed it definitely feels a lot smoother. It even seems to rev smoother as well.

My oil is already coming due for a change so I figured now was as good a time as any to put the cleaner in.

Tune up in a can. Perfect!

 

[Ron H]

Yeah, good idea changing the oil & filter soon now that ya did this. As a fellow WI-nite I take a 30 mile cruise to put eth-free gas in my plymouth as around my parts, ya can't get it so a trip and nice cruise at the same time.

 

[Dave145]

Agreed there. Most stations down here have the ethanol junk in em. There's a handful of them that have the good stuff so it's always worth the short trip to get it. Plus they're all ma and pay type gas stations so it's nice to support them too.

 

[Mick56]

Sometimes, a smoke machine works better than spray to find vacuum leaks. I've never had luck with spray, even when I knew where the leak was.

 

[62savoyguy2]

I did basically the same as you as far as changing to a 4 bbl on my 64 Polara. It always idled rough with the 2 bb or even after I put the 4 bbl on....I did a compression check and 2 cyls were 100 and 6 were 90#. Seems like a burnt valve or maybe 2....Also took a trip of around 200 miles round trip and it burned 3 1/2 quarts of oil......will be anxious to tear engine down....am building another complete 318 poly bored .030 with new everything.....will post what I find wrong with old engine....