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V6 oil pump clearance

Posted: Sun Jul 01, 2007 7:48 am
by AlfaBeta
Hi gang,

In the middle of rebuilding my verde and since I had the oil pump out I figured I would check the clearances. The clearance between the inner and outer rotors was fine at 0.0025". However the rotor "endfloat" (difference in hieght between the top of the rotors and lip of the housing) was out of spec. The spec is 0.001 to 0.003" mine was at 0.004". Does anyone know what this clearance means? If it's too high or too low what happens? Also is being 0.001" over mean I should replace the pump?

thanks
AlfaBeta

Posted: Sun Jul 01, 2007 9:02 am
by Barry
AB,No,dont replace the pump just for that.This is where "blueprinting" the pump comes into its own..The excessive end float can now be meticulously sanded down on a surface table and 600 grit water paper.

Check for excessive score marks on the rotors ,Id be more concerned with those..Deep score marks within the housing also not great.If the pump passes these 2 criteria,Id use it again..

Pumps hardly wear as they live in oil..Its the debris going through them that is the killer..

Posted: Mon Jul 02, 2007 5:48 am
by AlfaBeta
Hi Barry,

Thank you for the reply. it looks like I'll be replacing the pump! The housing had the score marks you talked about (a lot of them). The rotors looked pretty good though.

thanks again!
AB

Posted: Mon Jul 02, 2007 7:30 am
by Barry
Can you post a pic of the scoring?If they're not bad you might get away with some light scoring..
If they're deep and comprehensive I would rather get a new one.Dont forget to "blueprint" the new one..

Posted: Mon Jul 02, 2007 7:48 am
by MR2 Zig
Barry,

Is there a way to change the plunger for the relief to a ball type arrangement? Is that even worthwhile?

Scott

Posted: Mon Jul 02, 2007 11:02 am
by Barry
Scott,I dont really know..if its worthwhile that is..Ive never had a problem with the std.setup on the v6 pump yet..
4cyl.,yes,burst oil filters from sticky plungers..but then I modify the 4 cyl. pump extensively..

Id leave the v6 well alone and simply de burr and radius sharp edges where ever I could reach..
Untill I have a problem that is..

Posted: Mon Jul 02, 2007 11:05 am
by Barry
AlfaBeta wrote:Hi Barry,

Thank you for the reply. it looks like I'll be replacing the pump! The housing had the score marks you talked about (a lot of them). The rotors looked pretty good though.

thanks again!
AB
AB,Keep the old pump..Its amazing how you can build a "new" pump from a few old ones..Good parts from several pumps..

Posted: Mon Jul 02, 2007 3:02 pm
by AlfaBeta
Hi guys,

Thanks for the replies, I'll try to get a picture of it tonite to show the scoring. Barry, could you explain what you mean about "blueprinting" the pump? Do you mean modifying it to get the clearances if it's not in spec when you say this? (sorry if I'm being dense, I just want to make sure I have everything set right before I install).

thanks again
AB

Posted: Mon Jul 02, 2007 8:32 pm
by Barry
Yes,Your correct AB..It simply means getting all dimensions to within the smaller size of the given specifications..on the oil pump at least.Im a firm believer in using "engineers blue" to do some of this type of work.
Simply measure the clearences given to actual and get sanding,machining etc..

Posted: Tue Jul 03, 2007 6:38 am
by AlfaBeta
Hi Barry,

Sounds good, thanks again!

AB