Help - Search - Members - Calendar
Full Version: oil pump cover
914World.com > The 914 Forums > 914World Garage
mightyohm
I just got my new Schadek oil pump and cover from aircooled.net. The cover weighs a ton!!! It's steel and over twice as thick as I expected it to be. Do they really need to be this thick (and heavy)?
Mark Henry
Show us a pic!

I use the Gene Berg covers, I don't think they are overly heavy but they are cast iron. They have to be steel, because the pump gears cause a lot of wear on the cover. Anyone who has torn down a T1 engine would see this wear on the cover.

Al covers suck big time. fighting19.gif
dmenche914
i just posted this finding yesterday on the VW forum at Smaba.com I think you want as thick a plate as possible.

I ended up installing a VW cover plate on my Melling pump on my 914. to put it on the 914 i had to grind a little off the bottom edge of plate to clear the motor mount, and alittle off the case on one of the bossses that hold the fan house mounting stud (very minor bit removed)

My 3/16 inch flat steel plate flexed, the stock VW Bug plate did not. If your plate is 3/16 inch thick or close to that thickness, i would not use it unless you can dial indicate it and comfirm no warp.

good luck

see below which i cut and pasted from the other post:


dave



ust a note on the oil pump cover plate. It is common belief that too big a gap between the gears, and the cover plate can cause pressure loss, VW recommends no greater than .004 inch clearance. (as measured without the gasket) the thin gasket is anywere from .003 to .005 inch (from new ones i pulled from my parts box) With the gasket (assuming a .004 in gasket0 clearance is from .004 to .008 inch

You will want to lap the cover (and pump body with gears installed) to acheive a flat surface. flat surface means less chance of leaks, and minimal gap between the gears and the cover (if cover is bowed out, the cleanrance will be greater).

What i found on an aftermarket cover was disturbing. This after market cover was just a piece of flat steel plate, about 3/16 inch or so thick. The VW plates have a bent raised edge all around them. this thick edge adds stiffness to the stock plate, preventing it from bowing when torqued down.

How much does the non raised edge aftermarket flat plate bow? After laping every thing flat (plate and pump) and installing a .004 paper gasket, and torquing the four cover nuts to 18 ft-lbs (per manual) I placed a dial indicator mid way between two of the studs, near the cover edge. Upon lossening one of the adjacent nuts, the dial indicator showed the plate when down when nut was released by .002 inch, which means the plate had been bowed UP by .002 inch when the nuts were torqued down. Recall this plate (and pump) was lapped flat. The non-bent edge palte thus bows out when torqued down, and pressure loss might be expected.

i then took a stock bent edge plate, lapped it flat and measured flat using same technique as the plain flat plate. Then torqued down, and repeated the dial indicator test. Upon loosening of one adjacent bolt, the plate immediatly jumped up, not down, Thus we can conclude the plate with the bent raised edges did not bow when torqued down.

I repeated the test several times on each, and even moved indicator to a differnt side of the cover, and got same results each time, so i am pretty sure this is a good result.

I will always use a plate with thick raised edges, as it will remain flat, the plain ole flat plate, will not remian flat when torqued down. VW engineers knew their stuff when putting the thick edges around the pump cover. some aftermarket pumps makers did not take this into consideration.

Since VW recommends a max pump gear to cover diminsion of .004 in (measured with out gasket) and uses a .004 inch gasket, we have a range of .004 to .008 inch total clearance with gasket installed. If the plate bows about .002 in, we can see we are making the gear cover clearance at best .006 inch on a lapped plate zero clearance plate , to as much as .010 inch at max wear limit plate. nearly 50% to 25% increase in as installed cover to gear clearance.


dave
Mark Henry
Oh yah, I forgot...most guys don't full flow a teen engine, because the mount is in the way.

On stock T1's I use the stock cover that I mill flat to get the old pump marks out. The only other steel cover (non FF) that I've seen is the one that comes with a Melling and it's a POS.
mightyohm
This cover is 0.168" (less than 3/16") thick, with no raised edge.

I'll snap a pic later on.

Dave, where did you get the VW plate?
dmenche914
I got it from a 1600 cc VW bug engine I had around here. Check out a VW shop for a new one, or a wrecker.

good luck

dave
Jake Raby
Don't use a new one..... They are not flat, and leak like a sieve...
mightyohm
Jake, have you seen clearance problems with the cover I have?

(I know I need a pic badly. It's just a 3/16" square flat (ideally) piece of steel with 4 holes.)

Dave, have you noticed a difference in oil pressure with the two different covers?
dmenche914
i haven't tried testing the oil pressure, but from talk in VW circles, too much clearance as stated in my first post, will result in pressure loss. Factory recommends no more than .004 inch between cover and gears, measured without gasket. My thin cover with no bent up edges appears to warp as much as .002 when torqued down, my VW factory cover with large raised edges does not appear to warp at all.

in both cases i lapped both the pump body (with gears installed) and the cover plate flat. I checked flatness with a flat bar, and am sure i got it to better than .001 inch i use only thin paper gaskets of about .004 inch.


dave
Mark Henry
QUOTE
from talk in VW circles, too much clearance as stated in my first post, will result in pressure loss. Factory recommends no more than .004 inch between cover and gears, measured without gasket.


OK... the best cover in the world is not going to help the clearance. Take the pump (not the cover) put a straight edge across the face and gears. With a feeler gauge check the clearance. Use sandpaper on a piece of glass and sand till you have ".0" clearance. Take an old T1 pump cover and do the same trick to it. If you can't get the pump marks out of it, take it to a machine shop and have them grind/sand it flat, then do the glass trick at home.

The gasket is your clearance.

QUOTE
This cover is 0.168" (less than 3/16") thick, with no raised edge.


Toss it! Get a OEM cover.
mightyohm
Thanks guys. smile.gif
mightyohm
Bringing back an old topic...


Are the OEM covers available new?

There is a guy who wants to sell me a new 1600 OEM cover with the raised edge. Is this what I want?
dmenche914
Thats what i used, stock 1600 cc VW cover. Had to grind a little off of one side of the raised flange of cover using my bench grinder in order to clear the motor mount, and clear a little bit off one of the bosses that support the fan house.


Even if new OEM, recheck the flatness.


dave
mightyohm
Ok thanks. :-)
mightyohm
Does the cover have to be from a 1600?

I don't know anything about type 1. Are the covers different?
dmenche914
Early 40 HP engines (1200 cc) had a smaller oil pump stud, and smaller bolt hole pattern than the later ones, I assume all 1300, 1500 or 1600 are the same and will work, only issue is diameter and spacing of the bolt holes, all 1600's should be the same.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2024 Invision Power Services, Inc.