Is my cam and or my chain shot? with pics

[fordconvert]

This is a 200 out of a 66 mustang. I bought this car last fall and drove it a few thousand miles. After I got a few other things fixed like the carb and exhaust it ran fairly well except it had a nasty vibration at idle and would also vibrate and loose all power at high rpms. Also I could run the base timing at 18 without detonation. My theory was that the timing chain was installed one tooth off but it looks to be correct. Compression was good to great. I dont remember the exact numbers but it was one of the first things I checked. They were all around 180 +/- 5 warm and dry.

Got the pan and covers off today

chain slacked

chain with tension taken up by the tape.

Chain says 'made in usa' on the links. I dont see any wear on the gears. Both keys seem tight and intact.

Is it shot? Another guy told me if all that black stuff is worn off its shot.

If the cam is shot can it be changed without removing the head? I would rather not remove the head if I dont have to because of the rest of the 'might as wells'. It didnt burn oil or foul plugs and the breather stays clean.

 

[Bort62]

Well, I've had a few beers and the pictures are fuzzy (not that many beers) - but the cam looks fine to me.

At least as far as one can tell without a dial gauge.

Not sure about the slack in the chain, i've never had one of these apart ironically.

 

[Anonymous]

Is it shot? Another guy told me if all that black stuff is worn off its shot.

There is no "black stuff" on the lobes of a cam if that's what you're referring to.

A cam "grind" is exactly that. They grind the profile of the cam to make it a super fine surface finish.

I'd definitely change out the timing set - may as well 'up' the cam and springs a bit and rework the head while you're at it.

Good luck.

 

[rbohm]

8) the cam looks ok to me. as for the timing chain goes, you have about 1/2" of freeplay from the looks of it. since you have the engine apart, i would replace the timing chain and gears.

 

[mustang6]

Is it shot? Another guy told me if all that black stuff is worn off its shot.

You've got it a little backwards but there is some truth to this. Cam lobes (at least for non-roller cams) are ground at a slight angle at their peaks. This is what causes the lifters to spin as they ride up and down the cam lobes, they are biting only on one edge of the lobe. As a cam wears it loses this slight angle, eventually wearing the peak of the lobe into a level surface that no longer spins the lifter- greatly increasing friction and overall cam lobe/lifter wear from that point on. At that point it is considered to be worn out.

So what do you look for? The parts of the cam lobe coming in contact with the lifter are worn shiny. So you are looking for a darker part of the cam lobe that is not in regular contact with lifter base- if your cam lobes are shiny all the way across their tops then they are worn out and the cam and lifters need replacement.

In a couple of your pictures I think I can see some dark, non-worn surface left on some of the cam lobes- others look like they are worn all the way across but it is hard to tell for sure in the fuzzy pictures.

So check them out close up and let us know how they look.

 

[Ronbo]

Tell me there was a bolt holding the cam gear on? I'm assuming you took it off but I figured I'd mention it anyways.

Ron

 

[addo]

The motor appears remarkable clean inside. Either it's been well-loved, or it's a reasonable low mileage build.

Chains NEVER skip on these motors (that should flush an incident out the woodwork! ) but they do get horribly sloppy.

The IWIS brand chain such as used in Classic Inlines' timing set may be renewed independently of the sprockets - your initially higher purchase cost therefore becomes cheaper over time.

Cam I am not sure about. Would like to see lifter base radius checked - it's supposed to be a 40 inch radius.

Cheers, Adam.

 

[fordconvert]

I would say that the peaks are worn all the way accross. Some of them have a dull look to them but only at the peak. Many of them look like there is contact all the way around from edge to edge.

The motor does look fairly clean. The covers were very hard to get off and the gaskets still look like cork so I am betting that they are not orignal, most cork gaskets that are 40 years old dont look like cork anymore. Whatever sealer was used was very stickey so Im betting its somewhat modern. The worst oil leak was the front of the pan and front seal. The timing cover was not stuck on as good as the pans so I wonder if someone has messed with the cam or chain in the past. When I first got it running the oil was nasty and black after a hundred or so miles but after 3 or 4 changes it started to look normal. At the least the car had a major choke and carb problem so I think part of the oil problem was due to the extra rich running. The guy I bought it from said it was a 18 year old kids DD and his dad made him sell it because it needed so much work. It had been sitting for 3 years when I got it. The sales guy said the kid drove it to the lot but didnt remember if he had been driving it before that. The kid was for sure not mechanical or electrical, there were a lot of dumb things that were easy to fix.

Can the cam be changed without removing the head? I assume if I am changing the cam due to wear I would be crazy not to change the lifters. If I turn the thing sideways so the lifters wont fall out of their bores can I pull them out the bottom once the cam is out? If I do take off the head what are my chances of getting it to seal again without getting stuff machined? I just spent $4000 building a stock motor for another car and dont want to get heading down the same road with this one yet... the old 'as long as im this far, might as well'

 

[addo]

Leave the head on if you can; pulling your lifters out the motor's bottom would do well.

I agree totally with the idea of not touching more than you have to.

 

[MustangSix]

Leave the head on if you can; pulling your lifters out the motor's bottom would do well.

I agree totally with the idea of not touching more than you have to.

You could do that, but at this point, with the engine out and 90% disassembled, why not pull the last 14 bolts and take the head off? If you accidentally push one in too far from the bottom, you'll be pulling the head anyway.

I would spend the extra 30 minutes and $20 it would take to yank the head and put a new gasket on it. You'll get a good look at the bores and be able to clean the piston tops and chambers too.

I agree totally with the idea of not touching more than you have to.

OTOH, many of us subscribe to the theory of "If it ani't broke, fix it until it is."

 

[fordconvert]

More pics with out the flash so maybe they will be more clear. I have a guy that is going to loan me his degree kit so I can maybe get an idea if the cam timing is at least part of my problem.

IMG]http://i148.photobucket.com/albums/s35/73eldo/Ford/camD.jpg[/IMG]

I have pretty much decided that this cam is not new and is not going to last a lot longer but I would like it to go a few thousand more miles before I rebuild the whole motor. I am down to about $1000 left in the budget to get this car back on the road and I need at least $350 in brake parts and about $100 in the rear end. That doesnt leave me much for the motor so I am hoping that I can just get a new chain with the adjustable slots and get it as close as possible to where it should be. It doesnt look to me like any of the lobes are worn enough to cause a huge problem at the moment. I understand that the wear will occur much faster now so I will need a new cam soon.

 

[addo]

I think there's plenty left in that cam for you. With sensible oil changes and usage, another 20K no worries.

 

[rbohm]

I think there's plenty left in that cam for you. With sensible oil changes and usage, another 20K no worries.

8) i agree with addo. at this point i would put on a new timing chain and gear set, and call it done.