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Slant 6 meltdown
https://www.slantsix.org/forum/viewtopic.php?t=67863		 Page 1 of 1
Author:  1962Valyant [ Wed Aug 07, 2024 3:41 pm ]
Post subject:  Slant 6 meltdown
Hello fellow slant sixers.

It has been a very long time since my last post, that long ago I needed to re-register as I had no access to an old email address. To further help me with my major issues please search username 62Hypapak for older threads which could unravel the mysterious to my unfortunes.

Ok here we go.
Around 3-4 years ago I had cooked the 904 at the dragstrip (another long stupid story) which had seen the car out of action for some time, however enough time had passed so it was time to get the car back on the road. The engine and trans were removed from the car so trans could be rebuilt, while the engine was removed, I thought this could be a good opportunity to inspect the internals and replace a leaky rear main. Long behold I could not believe what I had found inside I was guttered, however luckily the transmission cooked, otherwise I would have kept driving the car.

So here are basics of my build, engine has done around 10k miles to date

225, balanced reground crank .010" mains and rods.
Wiseco pistons, block bored .045.
H Beam rods.
Stud kit on mains and head.
Engle KV1 cam.
Modified oil pump with oiling hole drilled from pressure side of pump to behind the gear
Rollmaster Double roller timing chain, with cam stop button installed
Ported and polished head with engnblr valves, double springs and teflon seals,
Standard NOS rockers
Chrome moly push rods.
Clifford HP intake
Carter AFB
Clifford headers.

So, this is the damage that I have found. (I will attach photos once I have worked out how to do it).
1. Oil pump gear (melling rebuild kit) was striped quite heavily, and somehow had no clearance between the gear and the oil pump body when removed from the block.
2. Cam gear has an ever-slight amount of feathering on it.
3. Thrust bearing is heavily pitted and appears to be melted in spots.
4. Other bearings both mains and rods show significate wear for limited miles.

Here is the good.
5. Pistons, rings and rods appear to have no abnormal wear
7. Piston bores appear to have no abnormal wear
8. Crank journals are not damaged
9. Cam lobes and lifters have no abnormal wear
10. Head and rocker gear have no abnormal wear

So let's start with number 1,
Is this the reason why my pump gear is striped? Please see attached link, I get similar results of around .080" of cam walk.

https://www.youtube.com/watch?v=_tXj5spK1NE

Number 2.
Can I reuse the cam if it has slight amount of wear on the drive gear?
Number 3.
Is this due to oil starvation or possibly water in the oiling system?
Number 4.
Is this the result of contaminants in the oil, ie worn oil pump gear?

Lots to digest here I will post photos as soon as I can.

Thanks again Adam
Author:  Dart270 [ Wed Aug 07, 2024 5:05 pm ]
Post subject:  Re: Slant 6 meltdown
Hi Adam,

Sounds like a cool car and engine buildup! Sorry to hear about your struggles. Oil pump gear failure is quite common with new pumps (made after about 1995). Please try to post pics of the cam gear so we can see how much it is damaged. Most likely this just happened because of the new/crappy/soft oil pump gear, and you can just replace bearings and oil pump, and maybe the cam if too much gear damage.

THE BEST thing you can do is find an OLD USED pump with a good gear and just clean up and run that pump. You can pull the side cover and see if there is much scoring on the pump surfaces, but 90% of the time these pumps will go 200k+ miles. I have been reusing old pumps on all my new engine builds for many years now and it has worked perfectly. Some members (including me) on this site should have spare good used pumps.

Slant on,
Lou
Author:  mcnoople [ Thu Aug 08, 2024 6:38 am ]
Post subject:  Re: Slant 6 meltdown
Quote:
Hi Adam,

Sounds like a cool car and engine buildup! Sorry to hear about your struggles. Oil pump gear failure is quite common with new pumps (made after about 1995). Please try to post pics of the cam gear so we can see how much it is damaged. Most likely this just happened because of the new/crappy/soft oil pump gear, and you can just replace bearings and oil pump, and maybe the cam if too much gear damage.

THE BEST thing you can do is find an OLD USED pump with a good gear and just clean up and run that pump. You can pull the side cover and see if there is much scoring on the pump surfaces, but 90% of the time these pumps will go 200k+ miles. I have been reusing old pumps on all my new engine builds for many years now and it has worked perfectly. Some members (including me) on this site should have spare good used pumps.

Slant on,
Lou
I find it funny and sad that pump gear failure is still a thing on our engines. I remember my very first post on the "OLD" message board was asking about the MP high volume oil pump and being warned about the gear problem. That was around 1999 or 2000. My question was whether the extra height of the pump would clear the limited space on an early A body. Never did install that pump and still have my original pump in that engine.
Author:  slantzilla [ Thu Aug 08, 2024 9:08 am ]
Post subject:  Re: Slant 6 meltdown
Buddy of mine had me put an MP pump on his Dart motor, even though I begged him not to. Motor didn't make it a week. Pump gear gone, cam gear damaged.

I have an old Autozone pump that Doug blueprinted back in the 90s. I have switched it from motor to motor a few times.

The pump on my old motor from the Buzz was one of the $12 closeout specials from I think O'Reilley's a few years ago.
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