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Once again oil pump gear damage? No it was not.
https://www.slantsix.org/forum/viewtopic.php?t=62134		 Page 1 of 2
Author:  lgu32 [ Sun Mar 25, 2018 5:06 am ]
Post subject:  Once again oil pump gear damage? No it was not.
I feel me a bit stupid just now. I have lost once the oil pump gear at high speed at past. Now I have had it happened twice.

The damage for timing set has been been secondary failure. At least there is damage at distributor gear so I assume this started because of oil pump gear worn out.

Image

Cam and pump were used 15000 km and timing chain was brand new. Only 100kms before timing gear installation this happened.

I am optimistic that I can use this engine once again. Head seem to be fine. Just 4 valves, couple of rockers and pushrods seem to be needed.

I need a new cam. Hughes racing seem to have wide selection for slant. This is 1966 Dart (light) with 4.10 gears and automatic. I am ready for high stall converter. Like to get peak power close to 5000 so which cam could to this? How much I need stall for that cam?
Author:  slantzilla [ Sun Mar 25, 2018 7:02 am ]
Post subject:  Re: Once again oil pump gear damage
WOW! I have never seen a pump gear failure wipe out a timing set like that. Did it completely lock the cam up at high rpm? Normally the gear wears until a couple teeth shear but the engine still runs. :shock:
Author:  lgu32 [ Sun Mar 25, 2018 8:26 am ]
Post subject:  Re: Once again oil pump gear damage
Cam and bottom end of engine are still in the engine compartment. Cam doesnt rotate more than half turn and when rotating ccw direction distributor shaft raises. The cam button kept the shaft in location after the gears distroyed.

In the past the gear failure indicated just from oil pressure light. Now came "big bang" and then car was silent.

I had approximately 6000rpm on it when this happened.
Author:  Rick Covalt [ Sun Mar 25, 2018 9:27 am ]
Post subject:  Re: Once again oil pump gear damage
I will be surprised if the oil pump gear caused this. Unless it failed and then something else broke. That appears more catastrophic. I bet there is more destruction inside. Sorry for the breakage.
Author:  lgu32 [ Sun Mar 25, 2018 10:24 am ]
Post subject:  Re: Once again oil pump gear damage
I have been training today some positive thinking.
Will be sure this one is not polluting for a while.
Author:  sandy in BC [ Sun Mar 25, 2018 11:07 am ]
Post subject:  Re: Once again oil pump gear damage
I wonder if the crank gear failed first.
Author:  lgu32 [ Wed Mar 28, 2018 9:28 am ]
Post subject:  Re: Once again oil pump gear damage
Quote:
I wonder if the crank gear failed first.
It seem gone so. I was looking thru distributor hole. Cam and oil pump are in very good order. Why it was not rotating was the distributor. The stop of the cam has been so fast that upper parts of distributor are not in order. The small piece keeping the upper axle in place (circular part inside the shaft) has been jumped out as well the shaft. As soon I took stuck distributor (plastic gear is in order too!) the cam was rotating freely.

No oil pump damage. Look like the "Melling style" timing set with cast iron wheels has been explosed. Chain was ok. Just the wheels did this.
Author:  Rick Covalt [ Wed Mar 28, 2018 3:49 pm ]
Post subject:  Re: Once again oil pump gear damage
Did the cam gear have the large oblong openings in the gear. They always looked a little odd to me
Author:  lgu32 [ Thu Mar 29, 2018 11:40 am ]
Post subject:  Re: Once again oil pump gear damage
Quote:
Did the cam gear have the large oblong openings in the gear. They always looked a little odd to me
Yes it was with such holes.
Author:  '67 Dart 270 [ Thu Mar 29, 2018 2:04 pm ]
Post subject:  Re: Once again oil pump gear damage
Wow, never seen that before in a slant...

I use Rollmaster, double roller, billet steel, won't fail on you, here's one for $120: https://www.ebay.com/p/Rollmaster-Doubl ... 1017015003

Brian
Author:  Old6rodder [ Thu Mar 29, 2018 6:26 pm ]
Post subject:  Re: Once again oil pump gear damage
Did this twice in one meet, new set each time. Eventually figured out it was a valve hanging up and stopping a piston. This engine's an interference build, but a stocker can be capable of it under some circumstances.
You may want to double check your valves for full range of free movement, and/or your cam for a break.

Image
Author:  lgu32 [ Thu Mar 29, 2018 9:08 pm ]
Post subject:  Re: Once again oil pump gear damage
There is marks in 4 valves and pistons of touch but all valves are so straight that they closed fully. One rocker was totally destroyed as well a pushrod was bent. I have bronze quides, correct springs and the cam has been there more than 15000 km and has been spinning the same (6k) every this and then.

Past I had too weak springs and it gave warnings by rattle at high speeds. It was sticky valve problem because of tight quide - stainless valve/bronze quire need more than steel valve/cast iron - studied now. IIn the past I had individual bent valves but they were totally stuck to quides. have not met it for long while after quides were opened and springs replaced stiffer.

I have tested valve to piston clearance and there was "a lot". I quess the cam stopped and after that pistons came and close valves.

Of course all parts have to inspected.
Author:  lgu32 [ Fri Mar 30, 2018 1:16 am ]
Post subject:  Re: Once again oil pump gear damage
Lifters came out easily. No one was damaged. Cam lobes can be seen thru lifter bores. No visible damage in any of them. Cam rotates freely.

The design of the cam wheel is stupid. Usually they have drilled holes for positioning pin but this is different. It is not difficult to think of when rotating the wheel which kind of cracking power comes over the wheel. The bolt was still in correct order.

Image

Seem that I can use cam and lifters as well pistons for next build up.

Lost valves, rockers, pushrods. And need a quality timing gear. I have one roller set used for 15000 km. Probably I buy just a BBM chain for the wheels as they are "like new".

https://www.rockauto.com/info/583/3-495 ... __ra_p.jpg if someone like to made 2nd test for confirmation. I bought mine from local store.
Author:  DusterIdiot [ Fri Mar 30, 2018 5:39 am ]
Post subject:  Re: Once again oil pump gear damage
Quote:
The design of the cam wheel is stupid. Usually they have drilled holes for positioning pin but this is different. It is not difficult to think of when rotating the wheel which kind of cracking power comes over the wheel. The bolt was still in correct order.
Not really, this gear was designed/engineered for a stock grocery getting motor, they did not engineer it for anything over 4000 rpm or 150 hp at the crank... time to get
one of the Rollmaster units...
Author:  lgu32 [ Fri Mar 30, 2018 12:30 pm ]
Post subject:  Re: Once again oil pump gear damage
Quote:
Quote:
The design of the cam wheel is stupid. Usually they have drilled holes for positioning pin but this is different. It is not difficult to think of when rotating the wheel which kind of cracking power comes over the wheel. The bolt was still in correct order.
Not really, this gear was designed/engineered for a stock grocery getting motor, they did not engineer it for anything over 4000 rpm or 150 hp at the crank... time to get
one of the Rollmaster units...
I have been working for 38 years at product development of many industrial products. No one has never has asked me to make parts weak for any reason. Designer of this has not realized what he is doing when making machined groove for cam pin.

It is possible to see signs there that the cam wheel has been started oscillating just before destroy. The cam pin has made noticeable signs for both sides of the groove. Sure it can last with continuous low speed. But because the design it can't handle forces which can occur at full power.

Stock 170 will run much more than 4000 and this is compatible (fuse).

As well in the package of this low quality timing set was not mentioned not for "tuned" engines.
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