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> Your oil pump will fail., And it will kill your engine.
Valy
post Sep 15 2011, 09:38 PM
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I'm rebuilding a 2.0L and posted a lot of pictures in a different thread.
One of the pictures showed the oil pump and Jake immediately noticed that the pump failed. Went back to the engine and saw how the oil pump touched the cam gear and shred off the nits holding it.

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Being such an anal guy, I took same time today to understand why did the oil pump fail?

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The red axle in the picture above it the one that protruded through the pump cover. There's nothing that holds it in place except the friction between it and the cover!
So Why does it move?
This red axle goes into a cavity of the oil pump case (rightmost in the figure). The cavity is almost snug-fit to the axle but oil can infiltrate around the axle into the cavity. When the pump works, there is a bit of oil pressure in the pump that causes the oil in the cavity to push the axle out; just like a hydraulic piston. The force is small but it's constantly there. As the axle moves, more oil flows in and that keeps pushing the axle out.
Over the time, that axle is pushed out of the pump cover until it starts touching the cam gear, shredding the nits that hold it. Eventually, the nits will brake or the axle will block the movement of the camshaft and something else will brake or your camshaft bearings will give due to the vibration inducted by the hits.

The aftermarket oil pumps are build differently, with no axle that can protrude into the motor, making them a good upgrade to your old original pump.

Make yourself a note to replace that old oil pump at the first occasion. I will even recommend to create that occasion before it's too late.
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76-914
post Sep 16 2011, 08:59 AM
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I posted this awhile back and although similar in appearance to yours, Jake pointed out that the failure was cam gear related and not a clearance issue. Although one should check that clearance carefully when assembling the engine.

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jaxdream
post Sep 16 2011, 12:50 PM
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QUOTE(76-914 @ Sep 16 2011, 06:59 AM) *

I posted this awhile back and although similar in appearance to yours, Jake pointed out that the failure was cam gear related and not a clearance issue. Although one should check that clearance carefully when assembling the engine.

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Is this a Type 1 pump ??? If so what year range . I have seen that the desired pump is a Type 1 , but no mention of the year range as there is a " early " style and a " late " style . Also does this cam have straight cut gearing with the crank or helical cut gearing ?? I would suspect that a cam with a straight cut gearing would " walk " more than a helical cut gearing. The Type 4 pump can be reamadied with a little ingenuity , just drive the pin back into position , cut a grove across the face and surrouding support , fab a bar / tab that would go across the grove and be held down under the adjacenent nuts . You would have to get less thick nuts , eliminate the washer underneath , RED Loctite the nuts and all making sure that the modification doesn't get any higher than the supporting area in question already . Shouldn't be a big science project , just some real simple fab work. The idea is to keep the pin from "walking out of the boss into the path of the cam rivets / bolts , checking the distance from the rivets / bolts would give the space you need to work in +/- a few mm .
My $.02 ......

Jack
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Posts in this topic
Valy   Your oil pump will fail.   Sep 15 2011, 09:38 PM
jsconst   This may all be true, but aftermarket pumps from w...   Sep 15 2011, 09:53 PM
Valy   This may all be true, but aftermarket pumps from ...   Sep 15 2011, 10:38 PM
Prospectfarms   Thanks for passing on the good info.   Sep 15 2011, 09:54 PM
avidfanjpl   So is the case toast, or can you still use it? Th...   Sep 15 2011, 10:31 PM
Cap'n Krusty   In the 38 years I've been intimately involved ...   Sep 15 2011, 10:54 PM
Valy   In the 38 years I've been intimately involved...   Sep 16 2011, 11:16 AM
Cap'n Krusty   In the 38 years I've been intimately involve...   Sep 16 2011, 11:49 AM
nathansnathan   I've read about this over on the shoptalkforum...   Sep 16 2011, 07:04 AM
76-914   I posted this awhile back and although similar in ...   Sep 16 2011, 08:59 AM
jaxdream   I posted this awhile back and although similar in...   Sep 16 2011, 12:50 PM
jsayre914   Reading this thread, and building a 2056, I got on...   Sep 16 2011, 11:20 AM
HAM Inc   At one time Jake had a small mountain of T4 pumps ...   Sep 16 2011, 01:18 PM
914_teener   At one time Jake had a small mountain of T4 pumps...   Sep 16 2011, 04:21 PM
HAM Inc   Clearly they aren't all failing. I don't...   Sep 16 2011, 06:24 PM
r_towle   Business 101, dont do things that create warrantee...   Sep 16 2011, 07:02 PM
76-914   Is this a Type 1 pump ??? If so what year range . ...   Sep 16 2011, 08:21 PM
Jake Raby   I have posted the pictures before... 3 crates full...   Sep 16 2011, 08:26 PM
Valy   So I did some research on the possible replacement...   Sep 20 2011, 03:05 PM
nathansnathan   So I did some research on the possible replacemen...   Sep 20 2011, 03:59 PM
Jake Raby   and the O ring that the Berg pump includes is wort...   Sep 20 2011, 05:58 PM


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