[Bob Carriere]

Interesting comments about the oil pressure..... I was so busy staying in the seat and watching the raw gas leak out I never checked the gauges. As you know I have extra mechanical guages for the test runs. The strange part is that even at high angle the engine never faltered.....same steady fast idle.... and I repeated going up the stack of wood chips at least 3 or 4 times....rear end of the frame was almost dragging on the ground.

Will try a repeat performance this weekend if the weather cooperate and I can get a Rob to video the event.

Now I am concerned about dropping oil pressure..... it may be that with such a short duration at high angle and with the two large spin on oil filters it akes a while for the air to travel in the line by the sensor for the gauge.

In any event it seems I need to find the kind of carburator that may have been installed on the GMC 270..... but.... from my 1955-59 civvy GM manuals they show and list the same Rochester B as the 261.

CarbKing from Stovebolt recommended the YF879S as an alternative.... foundout they were used in Internationals 6 in the 261 to 282 c.i. size.

So far no such carb is for sale with any of the carb places I checked on the web.

This weekend I will dig out a spare intake manifold and design a jig that will allow me to test various carburators at different angles.... basically an oversize protractor..... load up the carb bowl with red diesel ... less danger... and have a one gallon tank piped in above the carb to simulate some line pressure......tilt by hand an record finding. Will photo for the record.

I will try out a proverbial W-1 for base line followed by various Rochesters and YF that are the wrong size but basically same configuration. I even have a nos military 235 mid 70 Rochester that I can try....

While rummaging in the various boxes of spare carbs I found one I had squirrelled away back in the mid 70s....NOS taken from a 6 cylinder military engine stored in old plywood box.... it is the waterproof type....Holley I beleive and double barrell..... possibly an early 2 1/2 deuce.... will show to Grant he should recognize it.....According to pictures in an old motor truck manual circa 1953...Carb is a Holley 885ffg from a large international engine....or a GMC 270 or 288 c.i.

The other more dangerous but more fun plan is to run the engine at fast idle and lift the front end gradually with the front loader of the tractor and record oil pressure and leaks at various angle..... than lift the rearend and repeat the tests.....

The oil pressure issue maybe easier to solve with baffles, a in-line pressure tank with a gallon capacity like the extreme 4x4 rock crawler use to maintain oil pressure...... or a dry sump hihihi.

I am more concerned with raw gas leaking around a hot manifold within an enclosed engine compartment.....

There as to be a way as original 216 with Carter W-1 were tested in very steep hills just outisde Ottawa at the DND proving grounds.... they have various hill sizes.... the interesting ones are at 45 and the steep one at 50+degrees...... or may be it is just my imagination.... but the last one still visible from the road way would be hard to walkup on foot.....

So stay tuned and if one finds a YF 879 let me know.

Bob