Guess the sound

[Chisholmcody]

 https://vimeo.com/128827890

Update pulled the valve cover and 2,4,6 are stuck on exhaust stroke which explains the no compression
But as seen in the video the valves are not moving. Which means it's the cam or the timing chain

Is there any easy way to tell?


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[frotosride]

That is extremely weird. Are you sire you still have spark at all cylinders. If the valves aren't moving then either the can shaft isn't moving due to the chain being broke or the lobes are all those lobes are wiped out..highly unlikely but possible. Take the distributor cap off and turn the engine over again. If the distributor isn't rotating then its either the timing chain, can sprocket or crank sprocket. You could have shared the crank pin or on the sprocket 9r possible the bolt and pin on the can sprocket. Check the dizzy first.

[frotosride]

This would explain the compression results.

[Chisholmcody]

I was reading online and it says the l6 250 had no timing chain is this true?


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[frotosride]

Yes it actually has two helical cut grars... sorry for the miss info on the chain.

[Chisholmcody]

Do you by chance know if those gears are plastic or are they metal


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[frotosride]

Definitely metal gears. Which was likely the noise you initially heard

[Chisholmcody]

Think they stripped?

How hard are they to replace?


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[frotosride]

It's possible that they are worn down or even the key to one gear or the other sheared. Ease is all in the mind of the doer. If it were me I'd answer yes. All of your accessories Wil have to be removed and the balancer/crank pulley pulled. Along with the oil pan if I'm not mistaken the i6 front oil pan seal shares the timing cover just like the v8's. But the good news is this engine has been used since the 60's so finding parts are almost as easy as a 350

[Chisholmcody]

Am I able to remove the oil pan with the motor still in the vehicle or should I pull it


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[Chisholmcody]

And are the gears pressed on or do they unbolt?


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[frotosride]

I've never disassembled one of these but it wouldn't be hard o determine if the oil pan front rail shares a seal with the timing cover. However you may be interested to know that from the '70s up to the mid '80s the cam gear was a special hardened plastic called micarta. Most aftermarket replacement gears are aluminum but the plastics are still out there and I'd avoid them like the plague! The unfortunate part is that you will have to remove the cam to replace the gear successfully. The old on which is likely still plastic can be heated and pressed off. The new one has to be pressed on as well after heating it and it needs .001_.005 clearance between the plate and the gear for proper cam thrust clearance.  Unless the front end of the truck is disassembled you may need to pull the motor to remove the gear. I do not recommend trying to do it in place because you only get one shot. Once the gear cools you either force it off and get a new one or you heat it up and pray you do not damage it on the way out.

[Chisholmcody]

Hmm if I have to pull the motor I might just go get a 350

But if I do pull the motor and do the gear would another a new cam with a gear already installed be the better route due to ease (if that is the issue)


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[frotosride]

I second the 350+ morion... but I'm a power junkie so of course I'd pick more displacement.
If you bc an find a new cam with the gear already installed then I'd certainly go that route especially if I didn't have a press. I know I sky and comp offer cams but I'm not sure if they offer stock replacements or just upgrades.

[Chisholmcody]

Thanks for the help I'm going to look at it more this weekend


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