2011 at the Hammond Barn

[Phil Waterman]

Concerning the poor start and rough running the, improvement with a change in plugs along with the age of the spark leads, are interesting one of the ways I check for problems like this is to with the engine running, (no small task sometimes) take a spray bottle and mist the leads one at a time you should be able to hear the crack if you have a leak. This trick also seems to work if the plugs are firing down the outside of porcelain also.

But it sounds like you maybe on to the source of the problem or at least part of it.

Concerning moving stuff around on the ice you really need to get Bob to put the cable on the winch and get the scotches set-up the pulling ability of the truck sitting on the scotches is amazing. But them again you have the tractor with takes a lot less rigging that the winch.

Can't wait to see the spring progress photos of the HUP.

Cheers Phil

[Bob Carriere]

HI Phil

I discovered that process in the 1958 GM shop manual for my Dad. It claims to give more information thanjust a compression test.

Anyways.... we first warmed up his 235 for about 20+ minutes..... I know it is not like a good road run by it had to do.

Did some adjustment on the timing.... newer 235 are recommended to be set at ) TDC but earlier manuals talk about 5 BTDC...... we went with the 5BTDC and seems to run better..... re adjusted the idle speed and mixture..... vacuum was a very steady 20/21 inches. After the adjsutment the engine did not b pop back through the carb anymore but still had a rough/out of balance feel...

Then I tried the balance test... it calls for setting the idle at 1500 rpm and grounding out 4 of the 6 cylinders in a particular paired order.

Goes like this.... firing is 153624 ...
......sliced in half 1 / 6 5 / 2 3 / 4 ...... first 3 numbers over last 3 numbers.

So at 1500 rpm I removed the sparkplug wires from 5 and 2 and 3 and 4 holding them between my fingers so they would not spark all over....th-th-that was f-f-f- fun.....

Well expectedly rpm dropped BUT engine kept running.

Did the same with 5 and 2 and the engine stalled out.

restarted the engine and did 3 and 4 and it ran OK.....

So the unbalanced cylinders were the 5 and 2....

Still not sure what to do with that "information" but it was obvious the 2 and 5 had something wrong.

We changed for new plugs..... engine started better and ran smoother with only a small hint of vibration.....

Lack of time prevented me to repeat the process with the new plugs. Rob was to pick up a new set of universal spark plug wires from the tractor shop for the next adventure.

When we removed the plugs we noticed most had a light black deposit as if too rich a mixture BUT since in the past we had to run the engine with some chole to keep running that partly explains it....... two plugs seemed to be wet or wetter..... can't remember which tonite. We did a compression test and got between 135 on the low side and lots of 145/150 .... which greatly relieved us.....

On the spray bottle approach..... I always verify sparks by sticking a screw driver in the wire cap and hold it bare hands.... very stimulating.... how deep you bite your tongue indicates the K voltage.

However, on my engine it's a different story... I installed the Pertronix with a 40k coil ...... which is border line painful.... in fact I have to refrain from pulling sparkplug wires, when running, even with leather gloves as the spark is strong enough to be felt ......

I understand Rob has jumped on a Pertronix system for his engine so we will be setting that up soon.

The Pertronix made a big difference on my engine.... ease of starting... no points to set and reset and then burn..... no need for a ballast resistor.

One caution on the Pertronix..... to run good you have to regap your plugs to 45 T or it will run rough.

Next opportunity we will redo the balance test with the new plugs and wires then repeat the process on my engine.

I will be redoing the valve adjustment on mine as I suspect the small intermittent popping in the exhaust is sign of a miss adjusted valve. It still runs very good and can idle at 450 / 475 easily.... but you the hear this faint clicking noise..... vacuum is good at 22 inches at 600 rpm. I had ti out of the box this past weekend....started first spin.... ran it for about 2 hours at 600 rpm to boil off any humidity it may have accumulated.

Well enough for now.... I have caught up with my need to replenish my MLU fix.......

At time like this I appreciate MLU running well......

Bob

[Phil Waterman]

Hi Bob

Interesting diagnostics, the pair test I’ve never done but will definitely have to try, I’m getting ready to do a test on the engine out of the HUP so I will have to try it. Though I may have to ask for more explanation of which pairs should be the running pairs, I think I understand.

Concerning disconnecting vs grounding particularly with your high voltage coil be careful of burning holes through the insulation on the new wire or carbon tracking the distributor cap or blowing the coil. I’ve played with this on test stand, (think I have video of the test). If you ground out a lead there is no problem but if a lead or more than one lead is off the spark potential goes way up. With a standard 6 volt coil it will jump ½ to 3/4 inch but at some point the spark potential doesn’t jump the gap and goes looking for an easier jump like down the insulation on the coil or through the wire insulation. My understanding is that once it starts jumping where it shouldn’t it doesn’t take long to create a permanent path for the spark. When I was running my bench test I had use a 1 inch thick block of oak to hold the adjustable spark gap at the point where the spark stopped jumping the gap it started flowing through the oak to the metal bench underneath which I was leaning against at the time. Then I put it on some ½ thick plastic.

Not sure I follow the logic of which cylinders are the strong ones and which are the weak or problems, it would seem to me that if you can run the engine on three pairs of two then all the cylinders are relatively the same. Conversely if it will not run on any of the pairs then all the cylinders are relatively weak (or there is a different issue). But if any one pair or two pair causes the engine to stall then that one or two pairs are the strong cylinders which are carrying the others.

“Did the same with 5 and 2 and the engine stalled out.” To me that the engine stopped when you had grounded out all but 5 and 2 would seem to say that they are the strong cylinders

One thing I think your test is showing is that there is something different between the cylinders. Now the 64 dollar thousand question what? Mouse sleeping under and intake valve.

If all of the cylinders are showing compression at cranking speed of 135 or better sort of says it is not a compression issue.

That your vacuum gauge indicates good vacuum I assume without any flicking of the needle, would seem to rule out a stuck intake valve or badly burned exhaust valve. Out of curiosity did have the vacuum gauge attached during the pairs test?

I’ve got a though about another possibility but want to try to figure out a test that doesn’t require taking the engine apart. Let me do some playing with the 216 on the test stand and see what I come up with.


Cheers Phil

[Bob Carriere]

Hi Phil

My assumption is that the balance test pairs off two cylinders that are firing about 180 degrees apart.... if they are of equal strenght/power they can keep the engine turning...... if they do not support the engine on two cylinders one of the two is not powerful enough.... as in a faulty plug..... but which one..... we obviously need to do it again....

With the good compression readings it may have been just a bad plug or two bad ones.....

Now when we do it again..... following your advice and the instructions in the GM manual.... we will insert a insulated copper into the plug connection of four plugs centrally connected to a switch that is gorunde.... so when we swithc to ground only two will run and NO sparks will be flashing around.

I remember ready about sparking leaving a carbon trail and one done the parts are usually no good anymore. I may have to use an old spark plug wire set to devise a four lead grounding system that will not spark in our hands...particularly if working on mine at 40K volts.

I plan on modifying an old 235 valve cover by removing the top one inch.... keeping the sides to minimize hot oil splashing when adjusting the valve train so we can watch the action while the engine is running.

So the pairing is 1/6 and 5/2 and 4/3 ...... the first one went fine and the second one 5/2 caused the engine to die out.... engine ran on the 4/3.

Will need to pay more attention to vacuum fluctuation while redoing the balance test.

Maybe some old mechanic or old Chilton manual can answer the 64K ????

Stay tuned

Don't know about you neck of the woods but things are melting nicely here....muddy yes.... but melting.....

Bob

[Phil Waterman]

Hi Bob

Thanks for the further explanation of the pairs testing had to digest your pair testing experiment a little further. I've learned the hard way not to rush to a conclusion, what I try to do now is list all of the possible causes for a problem, then take that list and put it in order of easy to confirm or check to most difficult. Saves taking the carb apart to discover the gas tank is empty go ahead laugh I did it once fuel gauge switch was left and the selector valve was right and it wasn't till I had the top off the carb to figure out no fuel.

Concerning running the engine with valve cover off not a major problem, see engine test videos http://www.canadianmilitarypattern.c...ineTesting.htm Particularly video 1 http://www.canadianmilitarypattern.c...20001_0001.wmv or 3 http://www.canadianmilitarypattern.c...20003%20--.wmv just glue the gasket to the head with gasket cement it then acts as a cofferdam to keep the oil in. Generally you don’t need to put any gasket cement on the side to the cover, that way you can remove the cover without having to replace the gasket. I have a lexan side cover for the push rod gallery, which lets me see if the lifters are actually rotating.

But back to your diagnostic test, you are doing, it would be interesting to match your pair testing with the compression test figures and think about the logic of why the engine runs with two of the pairs but not the third pair. Of course replacing the wires with known good ones will also help clarify the issues. Hopefully the problem will completely disappear.

Sounds like you are going down the line of check the simple stuff first, which is why I was reluctant to suggest one possible cause, until I check that you can check it with out taking the engine apart. That problem is cam lobe wear below is a picture of two intake cam lobes on the cam that came out of my 235 the really worn one is .08" shorter than the other in lift. Before I mentioned this pain in the ass to repair issue wanted to be sure that their was a non-invasive way of checking. Does the manual you have this section on checking Lobe Lift?

Yesterday I did this check on the 216 out of my HUP, first step in determining how extensive an over haul it needs, biggest problem I had was getting the mag base of my dial indicator to really clamp tight to the head and be in the same plain as the push rods.

Forgot to put the rest of the phrase “64K dollar question” as from the quiz program but you got my point.

Back out to the shop temperature out side high 50s F, mud season just beginning, roads look like someone had been using them for mortar practice, some of the pot holes are so big they look more like shell craters particularly when there are bits of cars laying around after hitting them.

Cheers Phil

[Phil Waterman]

Hi Bob

Well I was pretty much right about running 235 without the valve cover in place. When out lifted the cover off the 235 on the engine test stand and hit the starter. At 400-500 RPM no splash no drips but at 1400 RPM a few drops of oil start coming out and landing on the manifold.

Added some higher resolution video of the 235 engine running topless. http://www.canadianmilitarypattern.c...ineTesting.htm Click on 3-18-11 235 running 001
3-18-11 235 running 002 these don't work well with dial up work good on high speed internet.

Cheers Phil

[RHClarke]

There is not much to report from the barn. This weekend was fairly quiet. Bob headed to the sunny climes of southern Ontario to talk carbs (no, he is not on a diet), and maybe swing a deal to pick up a few more CMPs…I didn’t make it out to the barn until Sunday morning. It was a balmy 0oC with no noticeable wind to drive the temperature downwards. The sun shone brightly all day long, which turned the once frozen approach to the barn into the usual springtime quagmire.

The warmer temperatures over the past few weeks served to knock back the snow drifts and to reduce the amount of ice on the roads leading to the barn. This meant more water and mud, but like the return of the Robin (the flying type), they are welcome signs of a change of season. Later that morning, Grant arrived at the barn to perform some administrative chores. My first chore was to remove the accumulated snow from around my shelters. If left in place, the melt waters will gravitate to the shelter floor. Much like it did in “Club HUP”. Grant and I dug a drainage ditch to drain the water on the floor of the shelter.

The rest of the last day of winter was spent babying the HUP. After winching it out of its shelter, I spent the most of the morning fabricating and installing an electrical system kill-switch and mount, and then I changed the oil. The electrical work went well, although it is not hooked up yet…so the jury is still out on that one. The oil change was interesting. After running the HUP for about 15 minutes, I shut her down and prepared to perform her first oil change. With all due regard for the environment, the HUP was prepared for her transfusion. The oil pan bolt came out with no trouble at all – right into the oil container. After fishing the nut out of the oil container, I watched the dirty oil drip out, fascinated by how dirty oil gets with only about 10 hours of running time on the clock. After the dripping ceased, I replaced the oil pan plug (had you worried there, didn’t I?).

The next step was to remove the two oil filters that were hidden under the frame rail. Sometimes I am amazed at my physical strength. I put both filters on “hand tight”, but it took a considerable amount of positioning and grunting to get them off. After a five minute fight, I managed to get number one to twist ever so slightly. Encouraged, I gave a mighty heave and finally, the filter gave up its fight. But not before it dripped dirty oil down its sides. No problem, says I. My latex gloves will keep my hands oil free. After spinning the filter, off it came. Oil, I am told, has some slippery properties. Combined with latex gloves, it is like grabbing onto a greased pig. Needless to say, the filter slipped out of my hands and plunged directly into the container of oil previously bled from the oil pan. Now these filters are not the little ones found on your average small car – they are quite big and have considerable heft – judging from the cascades of oil that landed on my coveralls, the front tire, and the cardboard box used for a ground sheet.

After a 20 minute clean up, I tackled number two filter. No mistakes this time – it came off nicely and was gingerly emptied into the oil container. Next, I filled the new filters with fresh oil and screwed them on – hand tight of course… Both filters were then marked with the date of the oil change with permanent marker. The rest of the new oil was dumped into the opening in the valve cover. Not a good idea. Too much oil at any time causes a flood over the valve cover gasket and the oil seeks a way to escape. My valve cover has a few dents and dings in it and it does not exactly fit the gasket perfectly – as was witnessed by the oil oozing down the drivers side of the engine block. After a 20 minute clean up, I declared that simple task done.

Feeling like I had accomplished something, I decided to tackle a persistent problem with the accelerator linkage. The linkage binds when you first press on it with your foot, and then it gives way suddenly. This makes driving the truck very exciting. Grant and I studied the linkage and determined where we thought the binding occurred. After some tinkering and lots of lube, it was decided that the problem was the linkage lever that ultimately connected to the carburetor. The trick was taking the little rig apart. Off came the “C” clip. Attempts to remove the lever proved futile as the exhaust flange was in the way. Brilliant idea! Remove the pin that holds the lever. No go - still no clearance. Next, remove the exhaust bolts and lower the flange. Success! Off came the lever. Now, call it curiosity, or just plain stupidity, but I decided that the pin could use a cleaning. Out came the wrench and the pin was removed with no fight at all. My delight turned to horror, for as soon as I removed the pin, a torrent of nice green anti-freeze sprayed out of the block. It is amazing how your memory works (or does not work at the proper time) when faced with a crisis. In my mind, I recalled that I had seen this happen before – some fellow named Bob, I think, pulled the same stunt a few years earlier. Good laughs all round then…not so much this day. The pin was promptly returned to its home and left there.

After a 30 minute clean up, I took the lever to compare it to one of the engines in the barn. The lever configuration was somewhat the same, but the angles were different. It was then that it struck me – the engine was out of a North American commercial vehicle and the lever was actuated from behind the engine – not from the front. To fix this problem, I cut a “V’ into the upper portion of the lever and carefully forced the gap to close. A few zaps with the MIG welder later, the lever was ready for its test run.

The linkage was reassembled and it worked somewhat better. There still seemed to be a lot of resistance. This was problem was traced to the two return springs I had set up. I took off one of the springs and tried it again. Success! Giddy with excitement, I started up the HUP and tested the gas pedal. Outstanding! But what was that noise I was hearing? Oh yes, the exhaust bolts…After a quick shut down, the bolts and the flange were reinstalled. Now it was approaching time to go home. After driving the HUP back into her shelter, I bade her a fond good-bye, wondering where the day went…

Lever photos:
1st - "Normal lever config"
2nd - Comparison - after bending the original
3rd - Final product (less dressing up and paint)