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Previous Next Up Topic Public / Dune Buggy Build Advice / oil pressure for vw 1600 single port engine (34116 hits)
By andrew s 1965 Date 2012-03-13 23:36 Edited 2012-03-16 22:43
We have some great temps in CT. two days in mid 70's so took the buggies for rides.
Deffinatly have sping fever now!!!
My buggy ran great. Real joy to ride after all the work done but i am questioning the oil pressure.
I put all new electric VDO gauges in including a oil pressure gage and a idiot red lite if pressure drops below whatever the sensor says is not enough (vdo sensor too)
My Allison has a 1600 sinle port engine with single carb and is not built very much if at all...
Last year i had new balanced pistons, rings, sleeves,and piston arms put in so i fugured all was good.
They said the rest was fine and i left it at that. Runs real nice.
Right now it has fresh oil it in. My mechanic just changed it with i think 10-30 or something 30. He has been a mechanic for 40 years and i am sure he knows what is what. I thought we should use 20-50 but he said in the south but not in ct.
Anyways the gauge always read higher when first running till it warms up and with a few RPM's we are looking at 30 psi or so. When cold at idle it is 20 psi or so
Once it warms up with a few RPMs going it drops to say 20 psi or so and at an idle down to 5-10 psi and then at about 5 psi with idle the red lite comes on.
My question is should light come on? should I put heavier oil in it? should i change oil pump?
Hey not sure this is normal or not but now that i have a good gage that works (well i think it does) just want to make sure i do not starve this engine and to be honest with you i do not want to see the lite come on every time i stop!
By ManxBug Date 2012-03-14 01:35
All my friend's that I've asked and I all run 20 50 in all our air cooled VW's in Canada (Alberta). But we only run the cars and buses in the summer.

I've been told that they were designed for 20 50 in a German climate. Which is only a couple degrees warmer than where I live.
By andrew s 1965 Date 2012-03-14 01:53
70's past few day. Just had to pull It out!! Kind of like summertime in Canada ??
Any idea what the oil pressure should be?
My thinking is pressure will go up with 20 50
By Brad H 1498 Date 2012-03-14 02:15
The general rule of thumb is 10psi per 1000rpm. If you are close to 10psi at idle you're OK. I also ran 20W50 for 20 years with none of the "blown filters and motor" horror stories people tell on thesamba all the time. I switched to 10w30 and hardly notcied any change in oil pressure hot or cold, maybe 5psi.

Make sure you run an addative in your oil with a ZDDP package in it for flat tappet cams. Zinc and Phosphate act like a cushion between the lifter and cam lobe. Without them the engine will beat the cam and/or lifters flat. The oil companies have taken just about all of these out of modern oil as it contaminated O2 sensors and Cat converters.  There are may manufactures of these addatives, at work we use one from Comp Cams and I've used a GM EOS (engine oil supplement) for the last couple of years. Lots of guys run racing oil, but it doesn't have the addatives needed to run on the street. It is formulated for engines that run all out at elevated rpms and get oil changes after every couple of hours of run time, not for cruising around town in stop and go traffic and frequent heat cycles. They don't emulsify moisture or have many detergents in them and their molecular structure is taylored towards constant, high rpm.

By andrew s 1965 Date 2012-03-14 02:30
Brad, I will look into the additive this weekend. Makes sense to me.kind of like when they took the lead out of the gas.
Now when you switched oil you saw maybe 5 psi difference in psi. What gave you higher psi? 20-50
I ask because when warmed up it seems to drop to 5-10 psi range and red warning lite comes on which I do no like.really do not want to see it come one every time I stop
Thanks for your help. Appreciate it
By Brad H 1498 Date 2012-03-14 12:35
20W50 gave me a bit more pressure.

What does your engine idle at?

The light shouldn't come on if you are at propper idle speed. If it does, you may have internal parts starting to wear out, bearings or the oil pump itself. One quick thing to check is the oil pump cover. Pull it off and see if it is badly grooved on the face from the pump gears. If it is, you can clean it up on some sand paper on a piece of glass and then rotate it 90* before you put it back on. And while it's off check the clearance on the gears to pump body with a feeler gauge. I think spec is around .002-.003 but you'd best check those numbers. You'll need a new pump cover gasket if you do this

By ManxBug Date 2012-03-15 03:56
70's past few day. Just had to pull It out!! Kind of like summertime in Canada ??

It's usually in the 70's and 80's in western Canada in the summer.
By andrew s 1965 Date 2012-03-15 10:55 Edited 2012-03-15 11:05
That is not really much colder than us except fornthe killer hot year last year Actually had the top made so I can extend the buggy season a litte and believe it or not if the sun is out this thing really heats up nice.
As for the oil pressure I am thinking I want to go back to the 20 50 and maybe just have a new oil pump put in because they are cheap and important. I am also going to add the stuff brad mentioned.
Thanks guys.
By andrew s 1965 Date 2012-03-15 11:04
I am going to look into the oil pump and maybe just replace if I am going to pull out. I will also think of going back to 20 50 with additive you recommended
As for what I idle at not really sure. I think I idles higher than I want it to and have not messed around. 1000 Rpms is a total guess. It is no where near stall and shake stage so could turn down some. Only guess on rpm no tac
By Brad H 1498 Date 2012-03-17 02:28
Andy measure the pump when you pull it out. If it isn't worn you may consider going to a bit bigger pump. It's a bandaid fix for a motor but it will keep the pressure up. these are tough little motors as long as the oil is getting where it's supposed to.

The idle could be set high to compensate for low oil pressure at idle, seen it before. Your best bet would be to get a pressure gauge and a tach or timing light with rpm indicator to check things out. Also look at getting a new STEEL pump cover if the pump doesn't come with one already.

Push the new pump into the case (no gasket) and make sure the oil inlet and outlet line up with the case, if not, open the pump housing up where it covers the case opening, you can't do much with hte case side without splitting the motor.

Another thing I always do is take the pump with the gears in it and put them face down on some 600 grit sandpaper on a sheet of glass, and scrub, in a circular motion, the pump body till the gears and pump body are completely flush. You can tell when you're done becasue the pump body and gears with have the same finish (look the same) this will make the pump a bit more efficient.

By andrew s 1965 Date 2012-03-17 03:17
Thanks brad
I will be looking into this and appreciate your advice
Lower end of engine has been partly re built with new sleeves balanced pistons/rods etc and I am sure they put in crank bearings they called it a piston and cylinder set.
I was told rest was okay I do not use these guys anymore so can not ask.
I think many people skip oil pumps to save few bucks which in my opinion is cheap enough to just replace.
I think I will re place with heavy duty one if I am going to go thru the effort
Thanks again
By Brad H 1498 Date 2012-03-17 16:38
No  problem Andy. One thing I wanted to clarify. I told you to test fit the pump with no gasket. That was just so the gasket does't get damaged checking the fit. RUN THE GASKET on final assembly.

By andrew s 1965 Date 2012-03-17 17:17 Edited 2012-03-17 17:25
i also looked on line because sometimes you tube vid's help me out a lot and here is my next question.....
i can figure out my block year by the numbers but besided the work i had done when i bought three years ago the gentleman said engine was re-built 1500 miles only on it.
Now i have to figure out what cam i have. is it a flat cam or a dish cam
here is the vid i saw.

should i pull it out and go by this?

Brad and Leroy i also have decided to drain the 10-30 today and throw in some 20-50 with the addative.
I want to see what that does to my oil pressuer for the heck of it
thanks again guys
all help is appreciated because i am new to VW's.
By Brad H 1498 Date 2012-03-17 22:35
If you don't know what cam you have you'll have to pull the pump and look. I've seen some strange things done to the ACVW motor

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