CMP fluids question ..........

[Phil Waterman]

Originally Posted by Bob Carriere

HI Phil

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Now get this..... it idles very low and steady at around -10 inch vacuum.....38 pounds oil never above 150 Degree F....... revs up real fast to about -22 inches vacuum.... Dizzy travels well with the vacuum advance..... at speed it reaches 42/44 on the oil.....

Should the vacuum be that low.....??

Old hot rod guy down the road has the old dwell meter gauge which I hope to coach him on showing me how to optimize the settings...

Any suggestions...?
....

Bob

Hi Bob

Checked my notes from the test stand running of 261 and 235

Concerning oil pressure- Only time I saw oil pressure under 30 PSI was when the engine temperature was 190+ with oil temperature above 170 and RPMs down to 400 RPM. At 300 RPM it got down to 24 PSI.

Concerning vacuum I'm getting 22 inchs at idle 400-500 RPM, running down the highway at indicated 50 MPH on flat ground I'm seeing 5-7 inches. Max vacuum under deceleration is 27-28 inchs.

Just discovered that coil position with the 261 in a Pattern 13 and stock coil holder has the coil hard against the side of the dog house. Which seems to add noise to the cab.

As to your comment about the 216 vs 261 thermostat water outlet to the radiator, looked back at my flow testing notes on the 261 engine running stock 261 water pump and outlet vs 261 engine with 216 pump and thermostat. There doesn't looked to be a measurable difference. I believe that the thermostat is the flow restriction that is really controlling flow through the radiator. One point though in getting the 261 engine to come up to temperature smoothly it looks like this engine really needs to have a connection between the inlet ant outlet for the heater. I installed a 3/8th copper U between this seems to keep the flow going through the engine so that the hot water actually gets to the thermostat. See picture

[Bob Carriere]

HI Phil

I am satisfied with my very steady oil pressure...... lowest at 38 high of 42/44.

I am curretnly running a rubber hose bypass on the water pump outlets BUT will convert to a copper pipe for more dependability.....

I hope this guy who has the dwell meter also as a scale on his meter to read low RPM... I rmember the old Snap-On model had one......

I find it strange that I hae such a low vacuum reading at low rpm..... running a steady 8 to 10 inch vacuum.... picks up vacuum very easily when reving up and tops 25+ when you blip the throttle.....

I can't remember what was the temp setting on the new thermostats 160 or 180....... but the temp never got any higher than 150 on the mechanical gauge.

Will play some more on the beastie this weekend..... and keep you posted...

On the various carbs I used...... the one I would like to use was an original NOS 261 carb.....allows the original airfilter to fit perfectly... Installed out of the box...... never idled properly.... runs fine but needs small amount of choke to idle fast or dies out...

The second carb was an Ebay special.... NOS sealed with diseccant....
intended for a mid 1960 250 cu. in engine so should have the necessary CFM for the 261. Ran fine than quit idling during the BB3 last Summer. NOw this could be dirt..... NOTE.... I am using a new plastic outboard motor fuel tank and all new lines and a NOS glass top fuel pump.....

Plans are to install an original AC (circa 1950) ceramic inline filter between the pump and carburator.

Also, being curious......I plan to buy a new gallon of the stinky carb cleaner solution and do a strip down/rebuild of the NOS 261 carb.... and check the float setting....

The third carb that runs very good is an identical copy of the second NOS carb.... ran fine right out of the sealed packaging.....

How do I test for fuel pressure....? I think I have a vacuum gauge that has a positive scale for about 10 pounds....? would a modified oil gauge work..?

ALSO..... look for a new thread in resto section on spot welder.... need your advice.....

Bob

[Phil Waterman]

Hi Bob

The combination vacuum fuel pump gauges are best as they are low range. Most oil pressure gauges just don't give fine enough gradations.

I've got an old Heathkit combination dwell, hi-low tach and volt meter, still works great after 40 years. (Got the manual out for it last year and check the calibration and it was still dead on.)

Talking of tachs what ever you do don't buy one of those little self contained small engine hour meter and tach units. I've tried 4 different types and non-of the ones I have worked well or for very long. All the ones I've had have non-replaceable batteries and they don't work worth a dam below 40F loosing memory.

Cheers Phil