Tall T wrote:Hey Uncle,
I sent Jim of this site an email and he found this info that he said he really had to dig for.
<https://oldihc.wordpress.com/category/frequently-asked-questions/engine/>https://oldihc.wordpress.com/category/frequently-asked-questions/engine/
"GRD" is indeed Green Diamond and they were the FLATHEADS of the 30's and 40's.
SD-220 Engine Tune-Up
The gross HP of the SD-220 is 100, and the net HP is 90, both figures measured at 3600 rpm…which is also the maximum recommended rpm.
Original spark plug recommendations were AC 45 Commercial, Champion J-8, or Autolite N-7, gapped at .028″-.032″. Ignition point gap is .018″-.024″, dwell angle 31-37 degrees, with initial timing set at 2 degrees BTDC. recommended valve clearance setting is .018-.020 HOT. These specs are from the CTS-11 factory technical service manual for L-series trucks.
My '54 3-ton is now 12 volt, alt equiped.
Thanks,
Terry
I would like to clarify some of the information from Tall T and from a link,
https://oldihc.wordpress.com/2013/01/13 ... cations-2/, supplied by Dean446.
I need to do work on my L130 with a SD220. I had the carb rebuilt and after installing was able to make the motor run fairly well but not great. Starting the cold engine became much harder and after the rebuilt carb was done the motor developed a new symptom of a rare backfire and limited power off a start, almost stalling. I drove the truck around for a few days and it functioned well once warmed and rolling at 35mph. The truck then sat for a few weeks and when I drove it the next time it had NO POWER. On flat ground 30mph was almost impossible with a lot more backfiring sputtering. 1st gear was all I could use to get uphill and back home. Seems odd for there to be such a big change in performance between drives.
I want to check the timing, dwell and adjust as needed but some info provided buy Tall T and Dean446 conflict, specifically the dwell angle range. The link has 28-35 and Tall T stats 31-37. I know it's not much of a difference but I want to make sure I have it correct. I have never done any timing or dwell work before so this will be a learning experience for me. I read through the IH manual and could not find any info on how setting timing or dwell is properly done. I know dwell is set by adjusting the gap on the points but I do not know what the scale located under the distributor is for or how I use it to adjust engine performance.
More questions:
What is the rest .016'' for?
What does 4b. BTDC mean regarding timing?
Overall I know why timing and dwell are important and the rough steps to go through when checking and adjusting both, but for this particular motor I do not know the specifics. Any help is appreciated.
Thanks