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Tue Sep 13, 2005 7:11 pm

What's the general opinions out there of running the Melling cast iron oil pump in your 1700-2000 bus engine? Anyone have long-term results of using one? I have one in mine and I am happy so far. Doesn't seem like they are available anymore. Anybody know? :?:

Tue Sep 13, 2005 8:14 pm

Cast iron pumps suck because of the different expansion rates of the case and the oil pump causing the pump to suck air into the pump between the case and pump creating a frothy oil to be pumped to the bearings.

Aluminum pumps are the best way to go.

Tue Sep 13, 2005 8:29 pm

Then what's the absolute best pump you can buy? New Stock? NOS? Aftermarket? For a solid lifter 1.8 or 2.0 stock or mild daily driver bus motor? Inquiring minds want to know. Sorry, I've only rebuilt a couple pancake longblocks. Thanks for your input! :D

Tue Sep 13, 2005 8:38 pm

You can use the 30mm bug pump if yuu shorten the shaft a little, works fine and is bigger than the stock pump. Cast iron is great for cast iron blocks not VWs, always leak after a while.

Wed Sep 14, 2005 6:07 am

Shadek pumps are aluminum bodied. That's all I run in my motors.

Wed Sep 14, 2005 7:52 am

Melling is by far the worst choice in pumps for ACVW. for the reasons that eric mentions. differing expansion rates cause leaks as well as air in the oil. they got fred to design that one.

Wed Sep 14, 2005 8:22 am

I know a few people running the melling pump including me for a short time. Instant oil pressure. Does anyone have direct experience with the cast iron pump sucking air, or is it all hearsay?

Wed Sep 14, 2005 9:34 am

instant OP is a function of the gear size, and this effect can be had on a pump with an alum body. so why even risk a leak with a melling?

Wed Sep 14, 2005 9:50 am

dansvans wrote: instant OP is a function of the gear size, and this effect can be had on a pump with an alum body. so why even risk a leak with a melling?

I agree, but I have not heard any negative information from anyone actually running a melling pump.

Wed Sep 14, 2005 11:16 am

It sounds like you want to ask the question until you hear the answer you want. If that's the case, you really should just save yourself the time.

Wed Sep 14, 2005 11:37 am

Eaallred wrote: It sounds like you want to ask the question until you hear the answer you want. If that's the case, you really should just save yourself the time.

Steady Eric, I am simply asking if anyone who runs a melling pump has had actual experience with them sucking air or leaking. I understand the arguments against them on principal however real world data tells the actual story. If that data says they are shit by design I have no problem with that. When I went to replace my stock worn-out pump the melling was the only option I could afford at the time, I have no special connection with them.

Wed Sep 14, 2005 11:59 am

Melling pumps are garbage for flat-4 VW engines.

John
Aircooled.Net Inc.

Wed Sep 14, 2005 12:02 pm

[email protected] wrote: Melling pumps are garbage for flat-4 VW engines.

John
Aircooled.Net Inc.

It has been said. Let all take notice.

Wed Sep 14, 2005 6:48 pm

flabay wrote: Then what's the absolute best pump you can buy? New Stock? NOS? Aftermarket? For a solid lifter 1.8 or 2.0 stock or mild daily driver bus motor? Inquiring minds want to know. Sorry, I've only rebuilt a couple pancake longblocks. Thanks for your input! :D

i would say the best pump for your application is a new stock type 4 pump. they are still available, but they are only available from VW and the cost is astrononimcal, something like 500 bucks! the stock T4 pump is a much improved design over the stock upright pump, it is less prone to leaking for one thing. the problem again is cost. unfortunately, blueprinting or reconditioning a type 4 pump is pretty difficult, unlike a type 1 pump which can be reconditioned easily - but for a pump that costs 25 bucks or so, reconditioning doesn't make much sense.

second best is a 26mm or 30mm schadek type 1 pump for flat cam gears, but you must be aware that this pump is not "plug and play" at all, there a few modifications needed to make it work in a type 4 engine. if you have a non-stock camshaft with bolted (not riveted) gear, you will have even more mods, but again, they are simple enough and do-able by almost anyone with a decent home shop.

Wed Sep 14, 2005 7:15 pm

Thanks for everyones help! Any details on the modifications that need to be done to the Schadek pumps?

Thu Sep 15, 2005 6:12 am

Aircooled.Net sells Shadek pumps already modified for the Type 4 motor so they'll bolt right in.

Thu Sep 15, 2005 5:51 pm

Thanks Eric!

Thu Sep 15, 2005 5:59 pm

I have a Melling pump and the oil leak is a real pisser. I had my ex-mechanic build me an engine and he put a melling in and it leaked from the minute I got it back and he never fixed it.
I'm at 6,000 miles now and am going to have to pull the engine to replace the gasket - see ya next month Colin!
I am actually considering replacing the pump now after reading this thread!
Cast iron + aluminum = oil leak

Mon Sep 19, 2005 9:30 pm

Are they really only $50 bucks? That's the best deal I've seen on aircooled.net yet! :?: http://www.aircooled.net/new-bin/additem.php

Tue Sep 20, 2005 6:21 am

There are a lot of modifications to make for a Type IV if you buy from Aircooled.net.

I e-mailed them last Thursday wih questions about the mods and I still have not received a response. Now it's probably too late to order and get it before Oct 11th (my engine removal day with Colin).

I'd call them but they don't give their number...