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Discussion Starter · #1 · (Edited)
Old pump was shot (bearings froze)....got a new one....it leaked like a faucet.....sent back and the "fixed pump is coming. (Boats can be frustrating)

My question is does anyone else have a bunch of shims, washer, and a "washer with bearings" on where it mounts? The new pump did not seem to fit right with all of this on there...... What is yours like? Thanks!
 

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River Rat Pumps

Bob, I've been working on getting my GN "Tinman" going and am using this same pump. I too have run into some fitment issues. I'm going to go out on a limb and suggest that there is a thrust clearance measurement that you need in order to keep the roller cam from waking forward in the block. I'm no engine builder but if you push the cam back into the block as far as you can(carefully) then take a measurement of the clearance between the spud and the back of the water pump. I do not know what that measurement is supposed to be without researching but I bet someone on this forum will speak up shortly. Sorry I couldn't be of more help. Good Luck with the build. I hope you can make Long Beach. I will be there racing in UBF. Come by and say hi if your in attendance

Paul
 

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Bob, I've been working on getting my GN "Tinman" going and am using this same pump. I too have run into some fitment issues. I'm going to go out on a limb and suggest that there is a thrust clearance measurement that you need in order to keep the roller cam from waking forward in the block. I'm no engine builder but if you push the cam back into the block as far as you can(carefully) then take a measurement of the clearance between the spud and the back of the water pump. I do not know what that measurement is supposed to be without researching but I bet someone on this forum will speak up shortly. Sorry I couldn't be of more help. Good Luck with the build. I hope you can make Long Beach. I will be there racing in UBF. Come by and say hi if your in attendance

Paul
Bingo! Those are there to set the cam thrust for a roller cam. As explained the stack of shims is to get the cam thrust just as you want it. I usually shoot for around .006 to .008 if I can. Mix and match the shims as needed. Off the top of my head I don't know what the manufacturers recommendation is for the thrust clearance.

Paul
 

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Any of the ones I have set up have had the thrust bearing and washers inside the timing cover, so that changing water pumps doesn't change the thrust (assuming you check to make sure it does not bottom out)

I don't quite understand why someone would do it this way, adding the thrust after the cover is on? I basically agree with Paul, looking for under .010" thrust, but more than zero, based on the fact that the aluminum cover should grow with heat. (Cloyes makes a cover with adjustable button that they instruct the user to set at zero thrust cold). I set mine up carefully with a dial indicator, not quite sure how to measure yours without the intake manifold off, or the rear cam plug out.
 

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Any of the ones I have set up have had the thrust bearing and washers inside the timing cover, so that changing water pumps doesn't change the thrust (assuming you check to make sure it does not bottom out)

I don't quite understand why someone would do it this way, adding the thrust after the cover is on? I basically agree with Paul, looking for under .010" thrust, but more than zero, based on the fact that the aluminum cover should grow with heat. (Cloyes makes a cover with adjustable button that they instruct the user to set at zero thrust cold). I set mine up carefully with a dial indicator, not quite sure how to measure yours without the intake manifold off, or the rear cam plug out.
That is a standard Enderle setup to set up thrust with the MFI fuel pumps. That way the thrust is held with the body of the pump instead of the shaft itself (which could damage the pump). I have never used this type of setup with a RR pump, but I don't see why it could not work.

Paul
 
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