Distributor gear excessive wear - Stroker with 68-231-4 Cam.

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lcolina
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Vehicle Model: CJ7

Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by lcolina »

Hi all,

I am having a recurrent issue with my stroker. It's the third time that my distributor gear fails due to excessive and incorrect wear.

This stroker was build using my previous 68231-4 cam from old stroker, and after first gear failure (Distributor gear broken) I replaced the cam with a new 68-231-4. Internal gears on the Oil pump had to be replaced to (using another oil pump I had) due to metal parts.

After a few months, excessive play on the distributor shaft and uncommon very sharp teeth on the distributor gear made the ignition fail again. I replaced the gear and now, after only 1000 miles, the distributor gear is showing again signs of uncommon excessive wear (sharp on the los side).

Is it possible I am having an issue with the camshaft walking in the block?

I am about to buy my third camshaft (68-231 again).


Any help or ideas guys?

My Setup:
Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom Forged Bulltear Pistons 0.60 20cc
68231-4 camshaft Compcams with stock springs.
0631 head Ported
Mopar/Victor 0.043" head gasket
24 pound injectors
99+ Intake, ODB1 system with MAP sensor from ODB2 and OEM Throttle body.
Standard 98 Block bored to 0.60
9.94 CR
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Cheromaniac
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Re: Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by Cheromaniac »

lcolina wrote: July 31st, 2018, 9:38 pm
Is it possible I am having an issue with the camshaft walking in the block?
Since you're having recurrent premature distributor gear wear, I'd say that cam walk is the most likely reason.
lcolina
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Stroker Displacement: 4.6
Vehicle Year: 1981
Vehicle Make: Jeep
Vehicle Model: CJ7

Re: Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by lcolina »

Thank you my friend!!!!

I am purchasing the spring, bolt,pin kit to make sure the spring rate is the correct.

I guess I will have to replace cam bearings and lifters also.
Russ Pottenger
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Re: Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by Russ Pottenger »

To remedy the problem of camshaft movement, I' make a cam bolt that I've drilled out similar to the stock OEM bolt. But rather than utilizing a pin and spring, I've inserted a Delron bushing that works as a solid thrust button. I think this is a much better way to limit camshaft walk.

Feel free to shoot me an email and I'll forward you a picture and pricing.

Thanks,
Russ Pottenger
Bishop-Buehl Racing Engines
531 N. Lyall Avenue
West Covina, California 91790
Work (626) 967-1000
Cell (626) 673-2203
Email/PayPal: [email protected]
lcolina
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Stroker Displacement: 4.6
Vehicle Year: 1981
Vehicle Make: Jeep
Vehicle Model: CJ7

Re: Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by lcolina »

Problem is getting worse.

The cam is walking as we are able to move it with a screwdriver. It walks a lot, like half inch. We replaced the bolt, pin and spring with new one and it walks the same.

The mechanic is suspecting of the timing chain. He says it could be wrong part number. My surprise is that it's the same part number I used for the old stroker with a different engine block.

Investigating, I realize there are 2 part numbers, one for 98 and older blocks and one for 99 and new blocks. Could that be the problem?

I am checking with the mechanic the year of my engine block but the Timing chain I am using os Cloyes 9-3127. If the part I should be using is Cloyes C3225, could that be causing the cam to walk?

Russ, The thing is that I live in Venezuela and importing things here takes forever, but if I need to use it, can you ship it quickly? Can you advice on the best solution for me and send me the price to [email protected]?
lcolina
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Stroker Displacement: 4.6
Vehicle Year: 1981
Vehicle Make: Jeep
Vehicle Model: CJ7

Re: Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by lcolina »

My engine block is 53020569, its supposed to be 98, so it should be ok right?. So is it possible that the problem is on the engine block?
lcolina
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Stroker Displacement: 4.6
Vehicle Year: 1981
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Vehicle Model: CJ7

Re: Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by lcolina »

Comp camps specs & summitracing applications says the following about the 68-231-4

American Motors 199-258 c.i. 6 CYL. 1964-1997


Is it possible this cam does not work with 98 engine block? should I change the block to an earlier model?


:frustrated:
Russ Pottenger
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Re: Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by Russ Pottenger »

Hi Leonardo,

I just emailed you information and pricing on my cam bolt with built-in trust button.

Russ
lcolina
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Vehicle Model: CJ7

Re: Distributor gear excessive wear - Stroker with 68-231-4 Cam.

Post by lcolina »

We measured the comp cams length and compared to the one cam, it’s 1.2 mm longer, which makes the cam not to be centered with the distributor gear.

So far, the problem doesn’t seem to be the cam walking, it seems to be the contact pattern of the pinions.

We tested with grease the contact pattern of both cams, and with the oem the footprint seems to be good and the aftermarket is not ok, it will destroy the pinion again.

Any ideas guys?
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