Here's #2:

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doesn't he have a website? I was just thinking about a post either in a add of his on E-bay or on some forum that sounded like someone was making new SOHC heads but couldn't remember where this morning.

Where up here on east coast?

Check out www.rockerarms.com

You might find all that you need right there.

http://fomoco.com/index.asp?Dept=5&Page=SelectArea

n/m

n/m

I have built a 390. It barely ran 20 psi at an idle. I also have an old 360 in my truck. After many miles, it still barely runs 20 psi. Looking at my chiltons, the book said that I was OK as long as the psi jumped as rpm's went up. I would not be concerned unless you have a high volume pump.

I have a friend with a '70 428CJ/Auto that I have the "honor" of working on time to time. His will knock badly on 93 octane gas. He mixes some race gas in with each tank. The CJ compression is too high for modern gas. Things you might try:
Combustion chamber cleaner
Retard timing (watch for overheating)
Run mixture a little rich (re-jet)
Cooler thermostat
However, all are band-aids for the high compression :(

There are two sources for vacuum advance. 1-Ported vacuum and; 2-Manifold vacuum.

Ported vacuum is a tap below the carburetor's venturi and above the throttle blades. Vacuum here is nil at idle and inreases with throttle opening and diminishes with load. In other words, no vacuum advance at idle, a lot of vacuum advance under light cruise load, and little to no vacuum advance under engine load.

Manifold vacuum advance is a tap below the throttle blades and responds directly to manifold pressure...It rises and falls as does manifold pressure.

The factory used ported vacuum and in your particular case, thermostatically controlled ported vacuum. In almost all cases, it's best to leave the vacuum source as ported vacuum.

But it gets more complex since vacuum advance is only one of the three timing components. You have your initial, your centrifugal, and your vacuum advance. All three of these timing advance elements work together with the intent of giving you the highest cylinder pressure possible consistent with the engine design and available fuel. Well, the fuel that your engine was designed to run on is not readily available anymore so you're going to have to make some adjustments to reduce cylinder pressure. You do that through mechanical modification like cam and/or pistons or by tuning your advance.

You want to run as much initial advance as possible and work on your centrifugal and vacuum advance tuning. In almost all cases, the only difference in a factory performance distributor and the one they put in a station wagon is in the centrifugal advance curve. In the day your engine was made, you had a lot of centrifugal advance that came in very early in the rpm curve. The wagon's distributor had less centrifugal and it came in at higher rpm. In many cases, the wagon had nothing until over 2,000 rpm and full centrifugal advance at well over 4,000 rpm. Most vacuum advance cans contribute from 15 to 20 degrees of advance but isn't referenced in the total advance you often see written in car magazines. The only way you're going to understand what your centrifugal advance is doing is to have a fully-degreed balancer or use a dial-back timing light. If you feel comfortable enough with removing and disassembling the distributor, you can tune your centrifugal advance yourself, otherwise you'll need the help of a professional tuner. Essentially you want to slow down the centrifual advance and in many cases, limit it as well. Remember, you want as much initial advance as you can run so if your optimal advance curve puts your total advance at 36-degrees and you're running 12-degrees initial, your centrifugal limit is 24-degrees. Vacuum advance is, again, not part of the picture.

You can tune your advance curve to accomodate your engine on today's fuels, but it will not perform up to factory power figures. The ultimate solution is to use lower compression pistons, update the cam, and tune your advance curve. You'll produce way more power with a complete package, but that's not always practical.

I pulled the distributor apart because I wanted to see which weights were installed before I made my next move. It has a 15l and a 10l. Would that mean that the mechanical advance would account for 25 degrees? Would it be beneficial to put two 10l's in so I could run more initial before pre-detonation? Again, original, un-rebuilt CJ. I run straight 92 octane because I think that octane boosts are a waist of money. I would blend with race gas, but that's horribly inconvientient. I know I'll have to back the timing down to eliminate pinging.

and what is it used for?

Well...all the old specs for forged pistons for "performance" engines are in the ball park of what you've found, however it is imperative to go with what the piston manufacturer reccomends. My TRW forged pistons call for only 0.0015 " clearance, but if you read the fine print, it says to allow an additional 0.001" for high performance applications. So, that would be 0.0025" That goes against any Ford spec I ever saw for forged pistons. Now, most machine shops actually bore/hone to the nominal size. For example, a 4" piston that's for a 0.010 overbore is enlarged to 4.010 and the clearance is whatever you get when you measure it after the work is done. Also, used pistons measure loose as the piston skirts get banged up and "bent in" a bit after they are intially used, so an additional thou of clearance is normal when you measure them. I'd say your clearances would be fine for a high rpm strip motor with original forged pistons, but a little loose on the street.

or a rebuilt. Do you have the tools to measure everything? Is there any surface rust or grit/dust in the bores? I would start by checking the deck height on all cylinders if its a short block. If its a fully dreesed long block, I would take a cooking baster and shoot just a little Marvel Mystery oil in the spark plug holes while turning it over very slowly. After a couple of days I would put fresh oil in it and spin the oil pump with the valve covers off and watch for the delivery of oil to ALL rocker arm oil spit holes. If that checks out, I would then pull off the fuel pump and bench test it. After that, well its up to you depending what you want to do to it.

Yep, strip it down and start over. Dried out gaskets, rust and you name it could be there. Why ruin a potentially good motor by running it up after all that storage time.