New Hampshire CMP Barn 2011- 2012 HUP Overhaul

[Phil Waterman]

Hi All

New Topic for a moment, with several HUP restorations going on around the world at this time. Thought I would mention a fitting problem related to the gas tank and the running boards, possible rub or wear problem.

The HUP family of vehicles like other CMPs mounts the gas tank on supports coming down and out from the frame. Originally there was a tar coated strip of fabric that went around the tanks to protect the tanks from wear from the support and the hold down straps. With the HUP family of vehicles the tank supports extend out to also support the running boards, that's the rub.

While finishing up on fitting the fenders and side tank protection plates I happened to notice that the under side of the gas tank was just in contact with the edge of the diamond plate running boards. All that was touching was the high points of the ribs on the diamond pattern. Fix is easy increase the amount of strap padding on the bottom of the tanks.

The contact was not great had not even scratched the paint on the tank but movement on the road my have caused problems. I mentioned this as once the side plates are bolted in place you can not even see the contact area.

I'll post pictures later today.

Cheers Phil

[Bob Carriere]

So if I am spinning the oil pump with a 3000 rpm drill...... allow for some 30% reduction for oil drag....... the oil pump is turning the equivalent of 4000+ engine speed.... am I correct...? that could explain my 42 pounds of oil pressure.

???????? Bob

[hrpearce]

Originally Posted by Bob Carriere

So if I am spinning the oil pump with a 3000 rpm drill...... allow for some 30% reduction for oil drag....... the oil pump is turning the equivalent of 4000+ engine speed.... am I correct...? that could explain my 42 pounds of oil pressure.

???????? Bob

Correct Bob you were probably between 4 and 5,000 engine revs depending on the torque of your drill.

[Phil Waterman]

Hi All

Well I took the process of checking the Oil Pressure and Flow to the next level. First I confirmed that the distributor shaft and hence the oil pump drive makes one revolution for each revolution of the crankshaft. Then I brought the engine up to operating temperature which is 170 F with ambient air temperature of 75-80F this is with a 180F thermostat.

I shot video of the engine oil flow in the valve gallery at various RPM levels. In the photos below you can see the differences. Then I changed the oil and did a new set of videos. Which is when I noticed what I think is the problem excessive oil flow from the rocker arms. The shafts are new but the individual rockers are the originals.

It was looking at the video and stopping it and going back and forth that really clued me into what it the problem of. Take a look at the Video http://canadianmilitarypattern.com/R...stem%20DSL.wmv

Still looking for input but I think it is worth putting the engine in the truck, road test it.

Cheers Phil

[Bob Carriere]

Granted there seems to be a large amount of oil flow on the rockers....


..... but let's go back to the beginning of the oiling system.....

The rockers are the lasts step in the oiling process...... first the crank, camshaft and then to the top of the engine where it eventually get dumped in the return channels/holes in the head back to the crank case.

If all the other bearing clearances are tight or at least according to specs. the oil pressure doesn't really start to fall until it reaches the loose rockers...

.... the oil pressure sensor is located early in the oil galleries... then why would it be so drastically affected by a leak further down into the system....

Is there anyway that you can reduce the flow to the rockers to confirm that the looseness of the rockers are in fact affecting the overall oil pressure??? some kind of temporary restriction inside the line...?

If you can confirm that the rockers are at fault it would be relatively easy at this stage to correct before installing into the truck.....

Now some rockers can be bored out and brass sleeves installed... not sure if that is feasible on the 216..... so rocker tubes are new and rockers as is.... it would not be too complicated to measure for clearance.....

When you got your NOS head did it have the full valve train or was it bare....?

If you need rockers I may be able to help you out...... how similar are they between 216 vs 235 vs 261...... 235 and 261 are usually interchangeable but not sure if low pressure 235 would interchange with high pressure 235 rockers

Keep us posted...

Bob

[Phil Waterman]

Hi Bob

Good idea about isolating the rocker arm assembly to see what it does to the oil pressure. Think it can be done fairly easy, if that makes the pressure jump up then that is fairly easy to rectify.

Couple of choices, as you suggested, I've got the bushings to bore and bushing the rocker individual arms, but a complete new replacement is $250. Plus I've got another used assembly that I think is good condition.

I'll try isolating the supply today, if that identifies the problem then great, if not then I think the next step will be to drop the oil pump, or brink the 216 that came out when I swapped over to the 261. I kept it complete so it would be a half days work to get it all set up again.

Don't think there is a suction leak because there doesn't seem to be any air bubbles showing in the oil. Just the normal air bubbles as the last of the air is pushed out of the oil filter even with filling the filter body with 2 quarts of oil before putting the cover on.

By the way I recovered all the oil from the oil change into clear bottles and there doesn't to be any large chunks of stuff.

Cheers Phil

[Phil Waterman]

I'm now to the point in the reassembly of the HUP that the wiring harness, fuel lines, break lines have been all installed. One small weeper leak in the brake system of course it is the big fitting on the master cylinder which should seal OK just needs to be tightened but of course will mean bleeding the entire brake system again.

In painting small parts to reinstall I came across one brass marker light I'd heard that these existed but this is the first one that I actually seen.
HUP May 2012- 007.jpgHUP May 2012- 008.jpg

Cheers Phil