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harrywt 07-04-2018 10:55 AM

Cluster F**k
Now I know exactly what Gunny Highway meant.

As you may recall I rebuilt my 304 just before leaving for Korea about 5 years ago. In korea I could not get a license plate so I mostly drove it off road in the hills (they prob called them mountains) and farm roads around my house. I have been back and in LA for 10 months and now use my Scout as a daily driver. The engine has maybe 20K on it now since rebuild.

The motor has run excellently. In first and second gear you can imagine yourself in a sports car, I have been really pleased.

Past couple of weeks I could feel a miss while cruising the freeway and I was planning to have a tune up done.

Two weeks ago I am driving on surface streets and when starting up at a green light it loses power above say 2K revs. Got home and went over the electric, checked a spark plug, (crudded some, not real bad but overdue for replacement). Brought it up to temp, sounded good but no test drive.

Next day starts up idles ok, pull out of driveway and then downhill from there. Backfire, popping up through the carb. I turned around and just made it back to the house and no go no how.

Towed it to my mechanic as I figured this needs someone who sees things like this all of time instead of me the weekend warrior doing it all step by time consuming step. I am presently pretty busy at work. And you know I am not a dummy.

They call me and tell me that the distributor is not triggering the coil and bottom line the photocell points replacement from MSD is dead.

FYI, I like my mechanic. My wife says that I never say nice things about mechanics and contractors so she always checks her ears when she hears me compliment one of these guys....

So they replace the module in the distributor, new coil (I just replaced the MSD blaster a couple of months ago, need to solve that) and new plugs. I have a set of LiveWires from our favorite vendor and forum host.

So even though the electric needs an evaluation it is now functioning nominally. They call me to come get it. I jump in and she runs but not as before. They kind of thought that it was OK because they didn't drive it before this issue.

We played with the timing and got it better but not right. They also showed me constant light smoke from the right tailpipe. There is no equalizer pipe between the two pipes from manifold to tail.

So went to meet a carburetor/distributor guy who has been around forever. My mechanic "warned" me about him but being at heart a small town hillbilly I could recognize a kindred soul.

So Paul rebuilt the carb (Holley 2300) and I bolted her on and she did run better but it is still sick.

I drove it a little and stopped to visit a shop where the guy mostly works on daily driver classics, including Scouts, to have him listen to the engine and offer suggestions. He would do a remove and rebuild of te heads to the tune of $3-5K. I did like the guy and I recognized that for him this was the best as he was so busy making good money with his present customers only this kind of repair was worth his time.

So I am driving home and made a stop. Jump back in, turn the key and the starter dies! One of the low gear ones from IHPA that I had jeff ship to korea.

I have never experienced so many things going wrong at once!

Through all of this I ntoiced that I was 2-3 qts over on oil. I had changed the oil a month before. When I checked before draining, the level barely touched the dipstick. I have been going through oil lately. I hadn't noticed the smoke at the tail pipe yet. When I refilled after draining I noticed thatt he level was high but I figured that since I was going through it that it would come down on its own. Plus I forgot about the dangers of too much oil. Aslo I typically run an extra qt as many of us do.

I have been very pre occupied with re locating and the new job.

After perusing the web about too much oil (after running with too little) I became very depressed and figured that I'd lunched my engine.

So here's where we stand;

No one has heard any lower end noise as in main or connecting rod bearings.

This past weekend I replaced the month old oil, very dirty looking but still slippery in the fingers, no stickiness. No metal chips that I could see.

Replaced the starter.

Removed all plugs and took photos. All but 2 and 4 look nominal, maybe a little hot. 2 & 4 are oily but you can see small carbon deposits at the tips. The pops back through the carb.

Did a compression test on warm engine. Meaning that I ran it 5 minutes, let cool 20 minutes then tested. 150psi each cylinder +/- maybe 2psi? And after 4-5 strokes. Did not do a wet test since dry test so excellent. One could argue that 2 & 4 were wet tests and maybe the rings could still be bad.

Put it all back together and timed it to about 4 BTDC.

Idled it up to operating temp. If you put your hands by the tail pipes the left exhaust is MUCH hotter than the right. Light smoke, meaning easy to see through, constant from right pipe, cylinders 2,4,6,8.

Drove it about 6-8 miles, pops occasionally, no backfires. Not full power, engine vibrating like it is unbalanced inside. Near the end of the trip it began to lose power. When I parked it and checked the oil the dipstick was SUPER hot, 1,3,5,7 side of motor. I am guessing it lost power as it was overheating. When I drove home later starting a cold engine it had as much power as when I left home.

My present idea is that the valve seals of 2 & 4 are leaking preventing 2 & 4 from firing except when they pop back up through the carb. This would explain the smoke, the lack of power, the pops and the other cylinders being so hot with hot looking plugs.

Before I pull the heads I plan to replace the seals on cylinders 2 & 4 and see what happens.

I searched the forums to see if anybody has had an issue like this. Not the wrath of zeus part but the smoke and fouled plugs in only 2 cylinders. Found bits and pieces.

I wanted to see what you all thought. Plus it is an interesting problem although not as much for me!


FDChappie 07-04-2018 12:01 PM

Re: Cluster F**k
Hi Harry, The only way to raise the oil level, without it being grey, is fuel. The 2 possible sources are a leaking fuel pump diaphragm or flooding carb. What could be happening is the oil is so thin that the bearings overheat.

harrywt 07-04-2018 08:56 PM

Re: Cluster F**k
sorry, the oil level is not rising, put too much in when I changed oil a month ago. I didn't think much of it at the time. 2 or 3 quarts too much is supposed to be BAD. The model is that the crank now dips into the oil in the pan and churms it up. Oil get so foamy that it doesn't pump well, bearings dry out. when my engine went downhill so fast I wondered if this happened to me. No one who has listened to the engine can hear any lower end issues

The carb was dumping too much fuel intot he manifold. the power pump was shot and leaking. Carb is rebuilt now.

Somehow cylinders 2 & 4 are not firing consistently except to pop once in a while back up through the carb suggesting pre detonation

Scoutboy74 07-04-2018 09:36 PM

Re: Cluster F**k
Do you have a real oil pressure gauge (not the crapball stocker) hooked up and been monitoring it regularly during this time?

harrywt 07-05-2018 07:19 AM

Re: Cluster F**k
yes. transducer type near dip stick below odd cylinder exhaust manifold. Never lost pressure that I noticed

harrywt 07-05-2018 07:28 AM

Re: Cluster F**k
the really confusing thing is how all of these things could go wrong at once. having a major lubrication issue would tie it all together but I can't find a smoking gun pointing to lubrication failure.

I noticed in the forums that one should check the drain back holes in head. If they were clogged though the oil would tend to collect at cyls 6&8 as they are downhill.

I will be changing oil seals this weekend

Robert Kenney 07-05-2018 08:34 AM

Re: Cluster F**k
In regards to your miss firing 2 and 4.
Have you verified the plug wire order? Possible that they got swapped. Also make sure the dizzy cap is not carbon tracking.

Regarding oil usage, two cylinders not burning, making power will pass a lot of oil from raw fuel washing down the walls, and the rings not seating properly from lack of combustion pressures.

harrywt 08-17-2018 07:45 AM

Re: Cluster F**k
So I am pleased to report a happy ending.

I decided to take a cautious approach and have my mechanic replace the valve seals on the even side of the engine to see if there was any improvement.

I printed out the engine specs and I noticed that the 2 & 4 cylinders were on opposite sides of the distributor and gosh maybe they COULD be switched and they wouldn't cause large backfires.

Well sure enough, I switched them and everything got better. No more smoke, even heat from both tail pipes etc etc.

I've done some more tweaking and will post soon.

I feel really stupid, but not as stupid as I would feel if I had yanked the heads off....

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