I am building a new engine out of an old 1.7. The type 4 oil pump had indeed failed with the idler impeller shaft pushed against the cam shaft. In fact I think this is why a perfectly good car was left to rot - they thought they had "thrown a rod".

OK, I read the hoopla and bought a 26 mm Type 1 pump. I started cleaning up the old pump just for fun. That is when it struck me that the idler shaft for the Type 1 is pressed into the housing exactly like the Type 4. I don't understand how I have a better pump then, other than higher capacity. It still would seem that the shaft could be dislocated over time onto the cam. Also, that is an easy fix for both old and new - the shaft could be peened or pinned in a half hour.

So all the wise - what is the deal? Thanks much.

Well,

No one makes a type4 pump.
Aftermarket makes a type 1 pump with high flow options.

For me, a used type4 pump is still good to go provided you make sure everything is still setup properly.

That is just my lowly opinion, but I still use type 4 pumps and I will until I can no longer find them.

Rich

Thanks Rich. Somewhere on this forum I had the idea that somebody had a pile of type 4 pumps that were so badly made that they actually shot them with some sort of gun - apparently out of frustration. From that I got the idea that it was a reliability issue, and bought a new pump. Indeed my type 4 pump had the shaft move, but it is repairable, and now I see that the replacement pump shaft has the same vulnerability (and needs a spacer for clearance). I think I will go with the type 1 26mm in the end, but now wonder if that shaft will also eventually migrate. Hope not.

While I believe the oil pump failures have happened, I have yet to witness such an event, and I've been working on T4 engines of all sorts since early 1973 when I finished Porsche school.

The Cap'n

You mean the same person who:

Tells me to ditch the sodium filled exhaust valves when the local RSR race car builder tells me he actually SEEKS OUT sodium filled valves for race applications?
Or the one who:
Tells me NOT to gap my rings to a certain gap when the DESIGNER AND SELLER or the P&C set tells me that I MUST GAP them extra?
Or the one who:
Belittles their own customers and tells them on HIS FORUM that: AND I QUOTE:
"That said, from this point forward if I see your posts in other places as well as here- they will go unanswered here. Doing so is a waste of bandwidth that **I** have to pay for. I refuse to argue with armchair "know it alls" that can't work their way out of a cardboard box with a sledge hammer."

So that is a business owner telling his customer that IF HE EVEN ATTEMPTS to get info elsewhere, he will be ignored forever more. I know this person, let me think.....

Stu

Oof. Bitter much?

I believe I have broken everything else on a type 4 motor....never a pump.

Most of those were race motors.

rich

Yes, Type 1 pumps have the same shaft as Type 4 but:
1. a new Type 1 pump will probably have a longer life than an old Type 4, especially regarding the shaft fixation.
2. In Type 4 pumps the shaft end opposite to the camshaft goes into a hole. When oil finds its way into that hole and pressure rises due to the pump work and engine vibrations, that hole, shaft and oil work as a hydraulic piston pushing the shaft towards the camshaft. The Type 1 pump doesn't have that hole so there is not much force pushing the shaft out.
3. I prefer the aluminum bodied pumps since they expand and contract at the same rate with the case and don't loose pressure when the case extends more than the pump (you can add an o-ring but why go there at all).
4. The Type 1 pumps have a slightly different ports location and size. Make sure your spacer aligns the pump ports with the case ports and you can also port a bit the case holes to reduce the resistance the oil feels when passing in/out of the pump. You don't want those higher resistance points close to the pump as it can cause oil pressure loss. When you move those points deeper into the oil passage, the oil volume between that point and the pump cog works as a duper, reducing the average pressure at the matting surface.

Just to add my $0.02...

The aftermarket high volume pumps have a big drawback and it is that the bodies are steel, not aluminum. Steel has a smaller coefficient of expansion than aluminum.

Why should that matter? The engine case and pump all heat up. But if the case expands more than the pump does, the oil pressure will drop the hotter it gets, as more oil escapes between the body of the pump and the bore in the case rather than going into the oil passages.

Someday, when I manage to find the time and money to get my motor back together, it will be with a good aluminum body pump, and not the steel bodied melling...

-Josh

Use a type 901 pump. You'll have to put a different engine around it but... it's all good.

C'mon. Don't mince words. Tell us what you really feal.

Ive never seen a broken type 4 pump, but the pump i pulled out of my old motor had a loos main shaft. I would call it worn out of spec. Another parts motor i had, had a melling pump, which is cast iron. Ive had that in my motor for 3 years now, and the only good thing about it, is the oil pressure, because mine leaves an oilly film on thing directly below/behind it..

The cliche ive heard of mellings is that they'll never break, but they'll always leak around the body due to it being iron vs. Aluminum case.

If i did it again, id find a high volume aluminum pump, ideally a type 1 pump.

Ok. I'm in the market for such a pump- what do you suggest?
Thanks

It's hard to find a good type 1 pump as the tolerances (pump body to case hole) don't seem to be as good as they once were. I Oring them, but this can be a hassle and you have to be so careful installing the pump, as not to tear the Oring.

The pump should be blueprinted, the snout for the drive needs to be clearanced, the aftermarket cam bolts can not protrude to much. The drive must be pressed in enough to engage the cam drive slot proper but not bottom out. You use the thin gasket with just a hair of RTV rubbed into the gasket.
Always use a steel cover.

I've never had a type one pump failure.

This is what you want:

http://www.drdracingheads.com/xcart/Type-4-Oil-pump.html

I have, last month my buddy sheared the shaft on a pump. We discovered that the pump can NOT eat a washer! Fortunately the only damage was the sheared pump shaft. Thank goodness as the engine had only one race since rebuild. Replaced the pump and he was off to the races again.

Fat Performance has the pumps

http://fatperformance.com/home/

Don't blame the pump for operator error. The pump wasn't the problem as this would have happened to ANY pump shaft that you induce a "spare" washer into. . .

Every motor I build has a modified aluminum Shadek T-1 pump. It's a really easy mod to make.

Thanks

He does have a point. Or several, I guess.

The shadek 26mm Type 1 pump I got even 5-6 years ago from Stugray's favorite vendor was too small at the bore to make good pressure.

The type 4 pump you have to loosen the case parting bolts to remove. The Shadek unfortunately slides right in.

Despite it being 26mm vs 24mm, it didn't work any better than the original which had a chipped tooth even.

I've got a nos Febi Type 1 pump I want to try. Does anyone have a link to an online procedure of what to modify? I can compare it to the one Jake 'made', but it would be nice to think about it before I take it apart.

Thank you all very much. I vaguely remembered who didn't like the pumps, and now am reminded. But I have to say Eric had the best answer. This is the motor from the donor car for the 914-6 project to be transferred into the 914-4 with a tired out low oil pressure engine, so I hope I have it covered. Still...I look with longing on the 3.2 on the engine stand.