Demon V8 water pump

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rrocky

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Hi all, the O ring that sits on the pump shaft how does it seal the water in the pump? does it seal with water pressure? I cannot figure it out any info welcome. thanks all Peter (Australia)
 

stevehuckss396

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The oring goes into a counter bore in the housing and the shaft slides through it. Coat the o-ring with a little silicone grease and assemble. Mine does not leak but I do regrease every couple years.
 

Gabe J DiMarino

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Sorry for jumping in I have modeled the block in cad software and I am having a hard time to get both idler gears to mesh with the crank and cam gear .Do I need to adjust something to get both in? One will work fine but I cant seem to fit both ?Thank you sir .
 

bluejets

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Could be wrong here but shouldn't the driver be 1/2 diameter of the cam gear i.e. 0.52085, not 0.5417...?
Either that or visa versa on the cam gear.
 

stevehuckss396

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Numbers look good. Must be the way the gear teeth are drawn. The second gear is optional so I wouldn't spend alot of time worrying about it. If you machine the block to the drawings they will work.
 

GailInNM

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I think that the confusion comes from the gear diameters specified is the OD of the , gear. The pitch diameter, where the teeth touch is different.

The OD of a gear is equal to (N+2) / DP and the Pitch diameter is equal to N X the DP, where N is the number of teeth and DP is the diametrical pitch.

Thus for the 48 tooth gear the OD is ((48+2) / 48) which is where the 1.0417 dimension comes from. But the Pitch diameter is equal to (48 /48) or 1.0000. Same thing applies to the 24 tooth gear which equals a Pitch diameter of 0.5000.

Thus the ratios of the pitch diameters is the 2:1 that you were expecting.
 

petertha

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Sidebar question - Steve, what is the (I assume) black sealant you use, picture post #5
 

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