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Post by onewheeldrive on Apr 3, 2014 16:13:44 GMT -5
Does anyone know if the oil pump designed for the 16 tooth crank and oil pump/gear (most common), is interchangeable with the rarer 22 tooth oil pump gear? Not sure if this would be an engine case issue, or if the pumps themselves are different sizes?
To make a long story short, I have the oil pump and pump gear designed for the rare 22 tooth crankshaft. Most high end cranks are 16 tooth, so I'd have to swap the pump and oil gear--- is that possible?
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Post by onewheeldrive on Apr 3, 2014 16:40:12 GMT -5
The only difference besides the teeth on the crank and pump gear (as far as I know, it's why I'm asking), is that the pump gear bolts onto the oil pump itself-- for the 16 tooth. The 22 tooth crankshaft pump gear that I have doesn't bolt onto the oil pump, it has a bushing protruding from the gear that sits in the engine case, holding it into place
To eliminate any confusion, the 16 and 22 teeth mentioned are not how many teeth the oil pump gear has-- it's the sprocket on the shaft that I'm referring to.
Am I making sense?
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Post by larry001964 on Apr 3, 2014 18:59:44 GMT -5
Yes your making perfect sense, there are two different styles...
Mine was originally a 22 tooth on the crankshaft, but when i build my stroker the crankshaft was a 16 tooth... Had to take it to a machine shop have the 16 tooth crankshaft gear pressed off and the 22 pressed on.
you can use either pump gear but if you want the 16 you will need that gear and have it pressed on the shaft.. In my case i had a 22 on my old crankshaft and a 16 on the stroker.. I could have bought a new pump and gear or simply have the one on the old crank pressed off and put on my stroker, and that's what i did..
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Post by onewheeldrive on Apr 3, 2014 22:53:20 GMT -5
I was planning on replacing the oil pump, just to be on the safe side. You bring up a good point--- I could just replace the oil pump with the same and pull the gear off the crank and swap that out, and not even worry about it this tooth or that tooth or anything else. I had to do that before--- I didn't find out until I was putting the case back together, luckily I kept my old crank back then to swap the 16 and 22 out. Still the pumps just look different, from these pics they just don't look to be interchangeable-- that question remains. I don't have both in hand, to where I can just bolt on and see how it looks and fits onto the crank with the matching gears-- I just can't visualize it right now at all. The 16 tooth looks thicker at the base. That's my primary concern as of now. Here's the 16.  Here's the 22.  |
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Post by triker on Apr 4, 2014 2:38:35 GMT -5
There are two different oil pumps for a 139qmb engine. One pump uses a 47 tooth driven gear and a 22 tooth drive gear on the crankshaft. The second pump uses a 33 tooth driven gear and a 16 tooth drive gear on the crankshaft. The first pump turns at a ratio of 1:2.1363 and has internal gears that are 10mm thick. the second pump turns at a ratio of 1:2.0625 and has internal gears that are 8mm thick. The first pump has thicker gears and would move a greater volume of oil if both pumps turned at the same ratio. The drive gears on these two pumps are not interchangeable. I have taken the shaft out of a 47 tooth gear and machined the hub that was imbedded into the plastic gear off. I then bored the hole in the center of a 33 tooth gear and pressed it onto the machined shaft. The crankshaft I have has a 16 tooth drive gear and I can now use the pump with thicker gears turning at the faster ratio of 1:2.0625. This should increase oil flow volume and pressure. I have not tested this yet, but I will do a test on oil flow volume and pressure at given rpms for the two stock pumps and the pump with the modified gears. Also The 16/33 pumps I have have the locator dowel pins in different locations. I could still use these pumps without the locator pins but must make sure the pump is in the correct position so the ports are open and the gears mesh properly.
Roy
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Post by onewheeldrive on Apr 4, 2014 3:07:43 GMT -5
There are two different oil pumps for a 139qmb engine. One pump uses a 47 tooth driven gear and a 22 tooth drive gear on the crankshaft. The second pump uses a 33 tooth driven gear and a 16 tooth drive gear on the crankshaft. The first pump turns at a ratio of 1:2.1363 and has internal gears that are 10mm thick. the second pump turns at a ratio of 1:2.0625 and has internal gears that are 8mm thick. The first pump has thicker gears and would move a greater volume of oil if both pumps turned at the same ratio. The drive gears on these two pumps are not interchangeable. I have taken the shaft out of a 47 tooth gear and machined the hub that was imbedded into the plastic gear off. I then bored the hole in the center of a 33 tooth gear and pressed it onto the machined shaft. The crankshaft I have has a 16 tooth drive gear and I can now use the pump with thicker gears turning at the faster ratio of 1:2.0625. This should increase oil flow volume and pressure. I have not tested this yet, but I will do a test on oil flow volume and pressure at given rpms for the two stock pumps and the pump with the modified gears. Also The 16/33 pumps I have have the locator dowel pins in different locations. I could still use these pumps without the locator pins but must make sure the pump is in the correct position so the ports are open and the gears mesh properly. Roy Thanks for your input--- you are a lot better putting this into words than I am. Am I correct saying that the engine cases are different depending on if it has 16/33 or 22/47? If the locator dowel pins are in different locations--- then the cases must be different to allow the pins to fit? |
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Post by triker on Apr 4, 2014 11:57:29 GMT -5
The cases I have are identical except for the position of the pump locator dowel holes. I don't know if this is true for all pumps and cases. it probably varies depending on manufacturers. either pump can be used if you change the gears. You can just drill out the correct holes for the dowels or just not use them.  The pump on the left is the stock 22/47 pump and the one on the right is a 16/33 pump. notice where the dowels are located.    I preferred to use the stock 22/47 pump because the shaft is supported in a hole in the outer case, the 16/33 pump does not use this support. Roy |
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Post by onewheeldrive on Apr 5, 2014 2:17:30 GMT -5
Interesting about the pump tests.
I wonder when they started making the 22/47 pump and gear, and if they, along with the 22 tooth crank, are becoming more common. Eh... who knows. It's not a very common item on parts websites, that's for sure! Neither is the 22 tooth crank. I can think of a few sites where I can find each part, but that's about it. I never even heard of either before, until I took my last engine apart.
I think all my main questions have been answered. I most likely won't be doing a whole lot of tinkering with the pumps. Again, thanks for the informative responses.
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