Chain cover question

[Soren Lorenson]

Hi, under a prior username I described some engine trouble and the consensus was a chain tensioner failure (horrible grinding noises and engine died). I've finally gotten around to working on it, had to grind off rusted exhaust bolts etc, but now I'm ready to pull off the covers and take a look. Drained the oil, no metal bits.

Couple of dumb questions not addressed in the books to start with.

Do I need to take out what I've marked with the red arrow?

And, since it has the tensioner upgrades, I'll have to take off the oil lines. Should I go after blue or green? What's easier?
Thanks

[Trackrash]

Red, no, it can stay, but might be easier if you take it out. Its a temp sender.

I would remove both the blue and green before removing the chain cover.

I would be interested in seeing what or how the upgraded tensioner failed.

[Soren Lorenson]

Ok thanks. I'll update as I go and we'll see what happened. Probably all stems from over-revving when a throttle linkage failed.

[HarryD]

Originally Posted by Soren Lorenson

Ok thanks. I'll update as I go and we'll see what happened. Probably all stems from over-revving when a throttle linkage failed.

I hate to say this but... if you had a true over-rev is may not be your tensioners but damaged valves etc. Remove your valve covers and see if you have any broken rockers.

Also, my 1973 has a rev limiting rotor which would prevent this type of over rev (vs the "money shift"). Did your rotor fail or did you have the wrong rotor?

[Mark Salvetti]

SCs have a rev limiter relay that cuts out the fuel pump. They don't use the rotors.

Mark

[HarryD]

Originally Posted by Mark Salvetti

SCs have a rev limiter relay that cuts out the fuel pump. They don't use the rotors.

Mark

OK, I stand corrected. The OP still needs to verify that the rev limiter function is indeed functional.

[kent olsen]

Harry have you ever had that rotor short out on you??

I did once at an autox in Florida and replaced it with one from a VW without the rev limiter to get home.

[Soren Lorenson]

Yep it could be valve damage but right after it happened I pulled the valve covers off. At that time the only thing I saw was that the clearances were all out of whack and 3 of the adjusting nuts were stuck / stripped. I replaced those rockers (no other obvious damage) and she drove fine for 2 trips around town. The 3rd trip ended with grinding and various loud noises followed by a flat bed home after just cruising along the road, not hard driving.

I'll get it pulled off tomorrow night (xmas concert for the kiddies tonight)

[DRACO A5OG]

Ouch, I suspect buddy's 76 of the same, his #6 exhaust valve was really out of wack, like 5.0MM, yes 5 not 0.5. I am hoping for him it is just carbon but that is allot.

Break a Leg OP!

[HarryD]

Originally Posted by kent olsen

Harry have you ever had that rotor short out on you??

I did once at an autox in Florida and replaced it with one from a VW without the rev limiter to get home.

Kent ;

Fortunately not, but I did have my throttle stick open.

[Soren Lorenson]

That's a great photo. Scary but great.

[HarryD]

Originally Posted by Soren Lorenson

That's a great photo. Scary but great.

Uh... ummm Thanks I think!

As it turned out I had a passenger on this run as well.

FWIW, I finished my run without a cone penalty or a DNF!

[Soren Lorenson]

Uggg. Got time to pull off the driver's side today and had my fears confirmed....





Rebuild time eh?
What's that red soft plastic broken / smashed band? The metal was sitting in the lowest portion of the chain housing and the red rubber was tucked up under the chain but not really stuck into it, I swept it out with a screwdriver.

Guesses on what happened?

[Trackrash]

Is there still tension on the chain from the tensioner, or is it soft or spongy?

Have you pulled all the valve covers?

That red piece looks like sealant. Not sure about the metal bits.

[ed mayo]

Looks like broken oil control ring

[Soren Lorenson]

Yes, I pulled the valve covers a while ago and everything looked ok as far as I could tell, but the engine's in the car.

The tensioner feels pretty solid. The car had the Carrera upgrades so they aren't original. The lower chain is movable but not the upper part, is that normal?

At this point I'm struggling with the idea of dropping the motor and trying to tackle it myself v sending her off. In theory I like the idea of doing the work, but I'm afraid I'll get in way over my head pretty quickly.

[DRACO A5OG]

Originally Posted by ed mayo

Looks like broken oil control ring

Oh damn Brother, that is both the part of lower oil seal and piston ring.

It is time to take the engine apart.

That orange thing looks like #8 Bearing Seal or it could be the Cam end orings. Again engine dismantle will reveal the culprits.

How many miles do you have on her?

[Soren Lorenson]

89k. All part of over-rev damage I guess. From a 20c piece of plastic bushing. Sweet

[DRACO A5OG]

Well, if you can find ALL the other parts on the top end on tear down then you can bypass the engine case split, but it must be all parts of ALL broken pieces.

Check the oil drain pan too.

Your bearings should be fine with that mileage if you regularly changed the oil but an oil analysis can hep verify if bearings are still good short of an engine case split.

I feel for you Brother :-(

[Soren Lorenson]

Time for a trip to Harbor Freight for that atv jack...