|
By 63 alaskan - 16 Years Ago
|
I just installed an MSD Ready to Run distributor, MSD coil and re-tuned the Edelbrock 500 carb. After quite a bit of tuning and trial and error, I thought I would post what worked changes for my engine in the hopes it might help someone else.
Engine: 292, compression is 150-165 psi in all cylinders, Clay Smith, 245 hp cam, stock valve train, rams horn exhaust with H pipe. Pretty stock, but mechanically healthy engine. Vehicle is a 1956 F-100 with 3.73 gears, and 3-speed manual.
The old distributor had a Pertronix unit in it, but the advance mechanism was worn, and very loose allowing the advance to come on much too soon. The gear was worn causing what I think was spark scatter with the old gear type oil pump I'm using. The rough idle was very noticeable when the engine was hot.
The best combo for timing with the MSD seems to be using blue springs, and the silver 25 degree bushing with 12 degrees initial. I changed the MSD supplied vacuum pot which after some research at NAPA was found to begin pulling at 5-7 Hg and all in by 11-13 Hg, with a total of 12 distributor degrees of advance. I changed the vacuum pot to a Echlin VC680 which begins pulling at 8 to 11 Hg and is all in by 16 Hg with a total of 8 distributor degrees. My mild cam allows the engine to generate a lot of vacuum so the stiffer pot works better (connected to the timed port on the carb), and I think it solved a light throttle surge condition with less timing (8 degrees at the crank).
For the carb I went to one stage leaner on the primary circuit (rod change only) and went one stage stiffer (pink) on the rod springs to solve a mid-throttle bog. I ended with one stage richer (.098 jets) on the secondary circuit which solved high speed ping (mid-grade 89 octane gas).
The now idles perfectly at all temps, and is not a quirky as before when the vacuum pot was connected to the manifold port. Drivability is right on with just a little lean stumble when cold, but only for the first couple of minutes. Full throttle pulls up the local freeway grade is noticeably stronger and smoother. Plugs look good too.
Now if the MSD will prove as reliable as the old Pertronics unit, I'll be very happy. ( I am keeping the old distributor and coil under the seat just in case though....)
Steve B
Oakland, California
|
|
By Ted - 16 Years Ago
|
|
Steve. Thanks for the detailed info. Past experience with the MSD distributors has been good so any problems are going to be rare.
|
|
By mctim64 - 16 Years Ago
|
Hey Steve, Good to see you on the site. Sounds like you've got the truck running good. 
|
|
By 63 alaskan - 16 Years Ago
|
Ted-
Thanks for the encouraging word regarding the MSD reliability. I have read on the MSD tech site about some problems with corrosion (rust!) of the internals as well as bad oxidation of the cap contacts. My thinking is that these cases are related mostly to applications using the amplifier boxes and the tremendous energy that is being passed. Time will tell whether the MSD parts are better suited for racing applications where the engine only runs for a few hours each year...
Tim-
Hey small world! The advance curve I have now is actually better for load hauling than it was before. I was having pinging at low rpms before, and that is now cured. We really will have to meet out at Spencer sometime!
Steve
|
|
By Unibodyguy - 16 Years Ago
|
|
Steve that is great info. you shared, down the road I'd like to try the same combo on my truck. I wish I had more cam though before anything else. Michael
|
|