W-9 compression

The Dukester

Well-known Member
What is the normal compression pressure on a 1946 W-9 with the gas engine? My brother's tractor checked out a little low on horsepower (46)
on a dyno recently so even though it starts and runs very well I want to check out the engine condition. Thanks for any information.
 
Not sure what stock compression ratio is however I would consider the engine to be in decent shape if at or above 90psi. All cylinders should be + or - 10%.
 
its best to check compression then post your results. give it 5 puffs for each cyl. and throttle off idle.
plus check the valve lash, and points and timing set to spec. every little adjustment is a plus. i just dyno,ed my 660 this last weekend at 87 hp. the little w4 was putting out 35 hp. 46 h.p. for your's seems in the ball park.
 
Well, a old sales brochure I got says the horsepower is a little over 52 on the belt pulley for W-9's. Maybe they lose some in the PTO gearing like my old John Deere G does, it dyno's a little over 60 on the belt, but only around 55-56 on the PTO which has a power robbing 90 degree turn with little puny gears. Mebbe the W-9's PTO gearing robs some power too. I'm gonna check the old beast out anyway. If it needs a little "extra tuning" I can do that too I guess.
 
By calling it a W-9 Gas, is it a spark ignition W-9, not a WD-9 start on gas, run on diesel, or is it a high compression gasoline engine with a suffix code, think it's X on the serial number plate signifying Gas engine option. A '46 tractor was normally built as a distillate/kerosene engine with lower compression, the small auxiliary gas tank for starting, radiator shutters, etc. Think it was 1947 before gasoline engines became "standard".

46 pto HP would be good for an early distillate engine on gasoline. The pto gear train on a W-9 was pretty straight except for the constant mesh gears in the front of the transmission. The belt pulley gearbox did have a small sized pair of bevel gears to sap some hp but they only run when belt pulley engaged.
 
Nebraska Test for 1941 first Distillate second Gas

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I presume it a straight gas model, has gas manifold, no small gas starting tank or any provision for one, battery ignition complete with "bullet" coil. It starts andvruns very good, but just didn't seem to "get with it" or bark very loud on the dyno and does seem a little lethargic pulling hills in 5th gear. I check it out real good when I get time and go from there, I guess. Maybe needs a new governor spring or timing bumped up a little or ??. I was just wondering what would be acceptable compression pressure....Thanks everyone.....
 

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