C7ZE A Balancer and Timing Chain and Gears on GT350 with A/C

[Road Reptile]

Hi Again,
Just to get a point across. The C7 restamped harmonic balancer was only stepped to allow for pulley
Offset-this does not affect balance or change the distance/clearances involved with the hatchet.
Much like machining a flywheel when replacing a clutch,will not require a rebalance. I have chased 67 A/C K cars for over 40 years and have learned a lot of mis-understandings/rumors Facts are
They are rare, as the total was 132 cars. Most books say A/C was not available with a K engine.....
This is because most people have not seen one. Ford/Shelby first equipped cars with A/C in 1966 when they finished the year with 4 Convertibles.We have documents showing the special request for K engines with A/C. For 1967 Ford used the same setup for the crank pulley and it was given a new part number to show the change.The C8 part is different and became a common replacement.A K engine will have EXTREME imbalance if the hatchet is removed and the engine is not rebalanced. It is actually 30.2 ounces with a K engine because of the hatchet,heaver rods and different flywheel/harmonic balancer ....A standard 289 is 28 ounces.The best way to check out your engine is remove the oil pan and inspect/verify what you find. And a car built in the 1200 range is not considered "Early" to be precise it would have to be in the first few hundred and finished by Shelby before Jan 1967.
Hope this clears up any rumors/myths that you may have. Jim Cowles (r.i.p.)is the only other person that seemed to understand K cars with A/C and we really miss him.
R.R.

[localzero]

There are plenty of excellent insights above and tend to agree with all of them. Given that, to the best of my recollection, the engine didn't seem to present any abnormal vibration before the removal of the drive belts, crank pulley and timing cover, etc., I'm inclined to go with 67350#1242's assessment.

I've now also concluded that the hatchet counterweight was removed to accommodate the wider chain and am reasonably confident that the engine was rebalanced thereafter. Quite possibly this was the result of excessive wear to the original narrow chain and gears and the wider set may have seemed like the logical choice at the time. An interesting side-note: it's entirely possible that 67350#1242's A/C-equipped car was the example assembled right before mine.

I've ordered a new wider chain and gears timing set and will reassemble the front of the engine in the next week or two. Thereafter, the proof will be in the running, so to speak. I'll make it a point to update the thread regarding the outcome.

On a related note, I genuinely appreciate the input of every participant thus far and I'm grateful for your having pointed me in the right direction in this situation.

Tom

[67350#1242]

I may be too late, but I might suggest getting a roller type chain as long as you are in there?

 I also own a 67 C code coupe with AC, and the only differences I see between it and the Shelby other than the damper modification, is the lack of A/C compressor brace between compressor and intake manifold, and the routing of the heater hoses, as the Shelby does not have a thermostatic choke - the one hose doesn't run through a clip on choke housing.   The dampers used on C and A code engines did not have the wide outer ring and the wider A/C pully fits no problem.  There is no boss on the cobra intake to mount the compressor brace and apparently it isn't needed.

I have also seen two differing 3-sheave A/C pulleys on these cars;  one with larger and one with smaller diameter A/C pulleys. (the most forward sheave )    I believe the smaller diameter was used on the hipos to slow the compressor speed, but I have also seen them on non K code setups, maybe some sort of power option?   If anyone has more info on this I would be curious to learn.

[localzero]

Thanks to R.R. for clarifying some of the details related to the hardware associated with the installation of A/C on the K engines. To be honest, I was unaware that the four '66 convertibles were so equipped. I was under the mistaken impression that this combination first occurred for the '67 model year. Furthermore, I wasn't certain that the A/C option was even available from the outset of production.

The over-stamped number on my harmonic dampener or balancer also contributed to the confusion and left me under the impression that this part and the associated pulley were part of a rather hastily implemented A/C fix. It obviously didn't affect the overall balance of the K engine, but did serve to alter slightly the weight of the rotating assembly and this concerned me.

Additionally, I've learned that the term "early" applies specifically to the cars assembled prior to January 1967. I used the term casually, as my example falls roughly into the first third of the production run for the '67 model year and this was indeed an error on my part.

67350#1242's subsequent suggestion of substituting a roller chain hadn't occurred to me actually, but this is an excellent idea. My paradigm has always been to err on the side of originality and this is probably what got me into trouble initially regarding the missing counterweight. I'll give the roller chain option some serious consideration and will likely order one. In many respects, the OEM timing components ship has already sailed and the lesson has been learned.

Given that there were only 132 350s assembled in the A/C configuration for '67, it's understandable that there's a not a massive brain trust relative to their specifics. I suspect that I was very fortunate indeed that all of you took the time to educate me and broaden the knowledge base somewhat in the process.

Tom