oil pump type I in Type IV

[zerotofifty]

i just discovers a cast iron type I oil pump is installed in my Type IV engine. It is stamped "8 m m" and "USA" on the cover. gears ar 1.16 inch long (tall ones) got about .004 inch clearance between gear tops and pump body, and had a .004 inch gasket for total gear to cover clearance of .008 inch

Is this a good combination ?

Any suggestion to improve warm oil pressure?

thanks dave

[Mick]

Most type 1 pumps are no good in a type 4, and most of the aftermarket type 4 specific pumps are not much better. Whilst the housing may fit, the drive shaft is usually too long putting excessive thrust loading on the gears and the pump may be physically too long causing clearance problems with the cam gear bolts. It is posible to overcome this by either machining the drive shaft or using an extra gasket, however the extra gasket will cause malalignment between the oil galleys in the case and the pump.

Provided the oil galleys line up, theres no end force on the pump drive shaft and theres no clearance issues with the cam gear bolts then a type 1 pump will be ok.

As youve measured the pump clearance there's obviously no thrust force on the gear shaft.

I would be inclined to check that the oil galleys line up between the pump and the case.

Something else you could check is the pressure relief valve.

Are you running an external oil cooler? if so, how is this plumbed in?

I'm presuming this is a fresh install.
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[zerotofifty]

Thanks for the info, I am running only the stock cooler, using Mobil One 15-50 oil. Engine came out of a used car, engine runs great, I am putting it into another car now. Milage and last rebuild are unknown to me.

I will check the oil ports to make sure they line up, but I need to pull the pancake fan house first to check this, can only just get the cover off with fan in place, but can't see in, nor remove the drive gear, only the driven gear.


Question: could I skip the .004 inch paper gasket under the cover, and use a liuqid sealant instead? Thought is that would decrease the clearance resulting in better pressure. (I am assuming the liquid sealant would take up less thickness than the papaer gasket)

thanks dave

[Mick]

I think your problem may well be the oil you are using, VW reccomend the use of SAE30 oil, you might be suffering low oil pressure due to the fact that the oil when hot its at a viscocity of 50 SAE. VW engines, even with new parts dont have the same manufacturing tolerances as modern engines so things like oil pump gears have a higher tolerance fit and therefore have a 'looser' fit. You may well be seeing low pressure due to the oil being thinner.

Checking the alignment of the oil galleys is not an easy task, to do this properly you would probably need to unplug the end of the oil galley from the pump, this is especially true if any clearancing needs to be done to he case as you will need to be able to clean the oil galley of any swarf. In reality this is a job best done before engine assembly is done so that the case can be porperly cleaned. That said it may still be possible to clearance the pump and not touch the case if the alignment is incorrect.

I would not reccomend removing the gasket as this may put the pump too far inwards, this may mean that the pump gear will have clearance issues with the oil pump cover resulting in premature wear.

If the pump clearances you have measured are within tolerance then the gasket size is correct, liquid gasket, whist a good sealing medium, is a bit hit and miss as far as gasket thickness is concerned.

I know you will probably not want to replace the synthetic oil with a mineral based oil, but as far as I am aware there is no sythetic SAE 30 grade oil available, the real benefits of a synthetic are its ability not to break down under temperature, kinda a nescessity with say a turbo engine, but even then regular oil changes make use of a mineral based oil ok.

Ah, just one final thought, worn main bearings will also cause low oil pressure as there is less backpressure into the main oil galley (where the oil pressure sender is situated) although I'm sure you would notice some 'knocking' noises when the engine is cold.

You might also want to try a different oil pressure sender, if the sender was already on the engine it may not be the correct one for the guage you are using, although that said I presume you have good pressure when the engine is cold.

My first reccomendation would be to change the oil to a 30 grade oil, mineral and sythetics mix no problem (this is basically what a semi-synthetic is)

Hopes this helps. Let us know how you get on as the question of oil types is a reccuring topic.

Regards Mick.
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[Jake Raby]

Modified Type I Schadek pumps ar ALL I use in my engines. There is NOTHING wrong with a TI pump at all in a TIV.
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Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[Mick]

If type 1 pumps are ok, why do you need to modify the Schadek pump for the type 4 application?
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[pablovent]

[miniman82]

Lol, this is a 7 year old post!!!
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Build thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=212747

[VIN]

He used the search function!
You know, the thing that everyone bitches about no one using...
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Co-owner, 2 Brothers Guns
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[pablovent]

Yes, but Jake Raby is very actual !! ....and vw aircooled is very old!!..LOL

[ccpalmer]

[Jake Raby]

I do watch for it... Google does, and then alerts me.
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Jake Raby
Raby Engine Development
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"I've never given anyone Hell, I just told them the truth and they thought it was Hell"