OIL PRESURE

[74baja1915]

WHAT SHOULD IT BE IN A 1915 NEWLY REBUILT.
AND WHAT IS THE MAX AND MIN
30MM MELLING OIL PUMP

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If its not broke don't fix it, but if it can be made better by all means do it!

[stealth67vw]

I like my oil pressure(when hot) to be around 15-20 at idle and 50-60 at 3500rpm. My last motor I used a Melling pump and when cold it would peg my 150psi gauge at 2000 rpm. At 3000 it would pop the oil cooler. I bought a Berg relief cover and it did absolutely nothing except empty my wallet. Now it sitting on a shelf along with the Melling pump.

[74baja1915]

so the min is 15 and the max is 60psi
and you telling me that the 30mm melling pump is not good but wouldn't that depend on what type and wieght of oil your useing?

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If its not broke don't fix it, but if it can be made better by all means do it!

[vw1303sb]

My melling has been good so far.

[Hank Winning]

I read somewhere that 10 psi per 1000 rpm
and the motor will live a long life
hank

[stealth67vw]

Many people have varying reports about Melling pumps. Some absolutely love it and some hate it. Some say that's all they'll use and some say they would never use one again. In my case I used 30 weight Kendall and I thought the pressure was to high when cold. I would have to warm up my car for 30 minutes so I didn't blow off the filter or an oil cooler. When the oil got to normal operating temp(180-200F)the pressure seemed a little low. When hot(210F) it ran at 10 at idle and 30-40psi at 3500rpm. This is just my personal experience and not set in stone facts. Other people may have completely different experiences. And for max oil pressure, my oil coolers would pop above 150psi so my suggestion would be 100psi or so. I don't think there is a problem with too much pressure if your not popping coolers, filters or oil lines.

[74baja1915]

i was thinking on going with a 10w-30 or
10w-40 so there wouldn't be so much difference between hot and cold oil what do you all think about this.

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If its not broke don't fix it, but if it can be made better by all means do it!

[verbeekb]

Baja, you are right in thinking that a more stable oil would show less difference between hot an cold, In theory, a 0w40 is just as thick when cold as when it's hot, but pour it into your VW, like I did (Shell), and still the gauge pegs. I run 5w50 Valvoline now, I am told it's not available here and that Penzoil has a similar 5w50. After a long highway run I see about 1 bar or a little over that on the gauge and say 3 bar at 3000 RPM, I wouldn't know how much that is in PSI.

Hope it helps,

Brian

[stealth67vw]

If I was in your shoes I would run the Melling pump and 10w30. If you have high oil pressure problems, the pump isn't that hard to change. You may or you may not. Another contributing factor to the variance from hot to cold is case expansion. The case is magnesium and the pump is cast iron, therefore the case expands more than the pump. Some say when the this happens the pump leaks a little pressure back into the case. This might have been my problem. When I replaced the Melling for a 30mm Shadeck the variance was not as bad, cold was 60psi at idle and 110psi at 3500rpm. Hot(210F)was 15psi at idle and 50psi at 3500rpm and 80psi at 7000rpm.

[This message has been edited by stealth67vw (edited 03-26-2002).]

[sparkmaster1]

I think the problem with too much pressure 80lbs+ is that it can actually blow off some bearing material. Kind of like a high pressure washer on concrete. Besides all of the other problems like blowing filters, and oil lines off. Maybe Jake can shed some light on this topic, but this is my 2 cents worth. I've used lots of Melling pumps but they are a little rough on filters in the cold mornings up here in the NW. Not a good choice if you're always running late for work.. Tim

[superdrag73]

I like the Gene Berg pumps, it's one of the few Berg parts I use. Oil pumps and shifters.

[stealth67vw]

I like their pumps, sumps, shifters, and the bus nose cone conversion, thats about it!

[vw_bug_owner]

I have :

1914cc (newly rebuilt), 110 cam, stock pump, and I run straight 30 weight oil.

Mine is around 50 when cold, but idles at about 7psi.

[badcase]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by vw_bug_owner:
<B>I have :

1914cc (newly rebuilt), 110 cam, stock pump, and I run straight 30 weight oil.

Mine is around 50 when cold, but idles at about 7psi.</B><HR></BLOCKQUOTE>

If your engine is idling at 7psi when hot, your case is probably junk or close to it. When the center main saddle gets pounded and spread out you get a low oil pressure problem that there is no good way to fix. You could possibly have a releif valve hung open, but that really hardly ever happens.

[danimal]

74baja1915, if the stock oil pressure relief system in the case is set up incorrectly, you can have major problems with too much oil pressure regardless of the pump size.

if you have a dual relief case, you need to be running stock springs and the correct plunger types in each hole... for dual o.p. cases, the only thing useable in those cheap aftermarket kits is one plunger... throw the rest of it away... a lot of people screw this up.

the stock oil pressure light sender is factory-rated to turn on at ~6 psi at idle; that is about the minimum oil pressure the motor needs.


dan
oceanstreetvideo.com