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End float - 1973 RV8 oil pump gears
Posted: Tue Apr 14, 2009 9:38 pm
by vaultsman
Hi all,
What should the bolted-up clearance be between the oil pump gears and the cover? Haynes talks about .0018" to .0058" between the gears and the cover, and with a .006" gasket (uncompressed) this gives a final clearance of .0002" to .0042".
That sound about right, do you reckon? .0002" seems mighty small to me.
Stan
Posted: Tue Apr 14, 2009 10:09 pm
by ged
Hi Stan,
I've found through trial & error If you check the height that the gears protrude from the pump (should be about .004"-.005") & use a .012" gasket & the cover faces are clean you'll get about 20 psi at idle with 20/50. I calculated for approx .004" of gasket compression. I once tried to reduce the end float somemore & even though I checked that the pump would still turn freely, after about 2 miles the car cut out. After inspection it appeared that the pump had nipped & broke teeth off the distributor drive & also the cam gear.
Also if you are using new pump gears make sure you stone off any burrs from machining.
Hope this answers your question.
Ged.
PS
I've just noticed you were asking about an earlier oil pump & all the pumps I have set up are the SD1 type.
Posted: Wed Apr 15, 2009 5:31 am
by vaultsman
Thanks ged,
Yeah...4 to 5 thou end float sounds a bit more like it to me. I've fitted the taller gears upgrade kit and the they stand proud by about .004". The gasket in the kit's .006" and when I bolt up on this I can barely turn the gear shaft.
Thicker gasket then...or grind a few thou off the gears?
Posted: Wed Apr 15, 2009 5:48 am
by ged
Hi Stan,
I think I'd make a thicker gasket. It'd be less work than grinding the gears & it keeps your part sizes stock.
Ged.
Posted: Wed Apr 15, 2009 6:02 am
by vaultsman
Hi ged,
Quicker to pop the gears on a surface grinder at work..but yeah..stock is best!
Cheers mate,
Stan
Posted: Wed Apr 15, 2009 10:32 pm
by vaultsman
Nipped to the local LR dealer at lunch and got an OE gasket for the princely sum of 56p. Which mics up at 12 thou...twice that of the one in the upgrade kit!
So that clearance becomes 6 to 10 thou..or more likely 3 to 7 with the gasket compressed. Spacer plate licked up on the surface grinder, and the bolted up clearance now seems about 4 to 5 thou. Happy with that!
Stan