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New healey 100 owner start up Q'S . Valve train

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jeff clunn

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Just got my first Healey,a 100, 1954,and am sorting it out after a long storage. Right now the gas tank is being boiled and coated. I was going to adj the valves prior to startup but have noticed some concerns. First the head bolts seem to have lock washers under them that have opened up under the torque of the nuts.I d like to replace them with the propper washer , I assume the propper washer is a sort of flat washer? can I do this one at a time without damage to the head or the headgaskit? Next, the rocker pedistals are shimmed up with washers, maybe 1/8" why would this be done? My thought was that the head may have been shaved? What should the compression be in each cyl? Thanks in advance for your reply, Jeff
 
Welcome Jeff;

I haven't done a lot of work on 100s, but here's some thoughts: You can probably get away with swapping one washer at a time on that engine...it's cast iron and short, so warping is less likely. But it makes me wonder about the person who did this in the first place....hope the moving, internal parts, such as rod bolts are assembled correctly. If it were mine, and I was keeping the car, I'd drop the oil pan and have a look around inside the engine.

As for the rocker pedestal being shimmed....it's anyone's guess, but also sounds "creative" in an improper manner. If you don't already have a workshop manual, get one and use it to reassemble properly. To see if the head has been shaved, you'd have to compare to the standard dimension unit...workshop manual might have this info....or you could join your local chapter of the AH club (link on this forum) and see if you can get a measurment on an unmolested car. Good luck!
 
Jeff

The rocker pedistal would need to be shimmed if the head was shaved, because the pushrods are a fixed length and you don't want to disturb the rocker geometry to minimize valve train wear. .125 (1/8) is a lot to shave a head! That's serious racing territory!

The compression ratio is somewhere around 7.5:1 on a factory assembled engine. In an ideal world the compression would be 7.5x14.7 = 110 pounds, however many factors affect this number, including the temperature of the inlet air and the temperature at the end of the compression cycle. This can change the measured pressure by 15 pounds easily and minimizes the ability to guesitmate the real compression ratio using cylinder pressure. For instance the compression on my 3000 is 9:1 on paper, but the measured pressure is between 155 and 165 pounds which would indicate 10.8:1

The important thing when checking cylinder compression is consistency between cylinders; +- 10 pound variation is OK.

I agree win aeronca; There are several clues here that suggest you sould look deeper prior to firing that engine of yours up. After all, a day worth of checking and $90.00 worth of gaskets will give you a much better idea of what you have for an engine and may save you an engine rebuild.

Whatever you do with the headbolts, be sure to retorque them to the factory specification after you've replaced those dodgy split washers.

Good luck and have fun doing it.
Thom
 
Thanks for your thoughts,It did run,not to well, and I did make it around the block once, seemed to run a bit hot, and leaked lots of oil out the valvecover gaskit, thats what got me under that. I assumed the hot running was crud gas and bad tune. All plugs looked black cruddy but no water.Wish I could remember who borrowed my comp. gage, Santa?Thinking that taking the head and pan off is a good plan. Can the rod bearings and mains be changed from the under the oily side? I have a tr-6 and have done this a few times. The book lists this as an engine out operation but it looks workable. The thrust washer arangement looks better than the tr's, are they trouble on these engines? Thanks for your info, great to have somebody who knows so available. Your lucky im not a faster typer or I might become a pest with a milliom and one questions. Jeff
 
Jeff:

Yes, rod bearings and mains can be changed with difficulty with the engine in place. It is not clear why to do this, though. If the car needs new bearings, the crank should be ground as well -- unless you have an unusual situation with bad bearings with good journals. Not likely. And once the crank has to come out, well, you may as well pull the engine.

You can certainly look and even plastigage the bearings you have to assess their state and let you know if more work is needed. This can be done with the engine in place. For an engine that has sat a lot, this would not be a bad idea, you can clean up the inside of the oil pan while you're at it. Removing the head will allow you to look at the bores and mic the cylinders. If all that info suggests rebuild, then it is time to pull the engine and get the job done.

Are we having fun yet? Don't worry, you'll be on the road later than you think! But spring is a long time off, and Healey's are miserable in the winter.....

Bill.
 
Your car sounds like it's been seriously fooled with. Mine was similar. Eventually I found out it had longer chevy valves in it that fouled up the rocker geometry pretty bad. I was able to make it more or less whole again, but it took some time. Parts swapping was common in the 60's and 70's when parts availability for 100's was pretty bad.

Why do you want to start the engine? Is this a car in good condition that has just sat for 10 years from good running condition? Or is it a beater? If it's the latter, I suggest you pull the head and check out what's going on with it. A decent valve job is not too expensive, and then you'll know it's right.

If you still want to start it, I don't see where the valve or headbolt issues you describe would do much damage to the engine -- though they may make it very hard to start and it probably won't run well. Make sure the shims on the rocker stanchions don't block the oil passage to the rocker shaft. Seems to me that passage runs through one of the stanchions, I don't recall which one.

Good luck, your gonna love that 100! Watch out for the acceleration, can cause whiplash or wheelies....

Bill
Albuquerque, NM
 
I see no reason why you could not remove and replace the head nuts one at a time--try doing it in the sequence for tightening the head that is shown in the Service Manual. A copper head gaskt is normally not reusable, but I don't think that r & r'ing the nuts one at a time would constitute a "removal".

Best--Michael
 
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