|
ChadS
10-21-2004 08:26:02
|
|
Re: Chad im trying to tune my S M in reply to Buckmaster, 10-20-2004 16:21:47
|
|
| |
Buck, need a bit more info,,, When you rejetted the carb, with the throttle wide open, (running) can you back out the mail fuel adjustment out, and make it run rich? you should be able to make it smoke black pretty good. that says it is getting fuel flow into the cyl. setting the main jet is not hard, but really, a load should be put on the engine and set it to where it barely smokes out the exhaust. (under a load) no load settings, wide open, and turn the screw out till it smokes, then back in till it just smooths out. it should give some smoke out the pipe when you crack the throttle. What fuel are you running? Hope it is not much over 100 octane. Engine like that should only need 94 octane on the high side of the scale. Run a compression test, If you want me to tell you what this engines potential is,, that compression test will tell me how good it is, and lets me know what I am dealing with. A 264, with 100-130 psi, is relitivly stock,, looking at around 55-60 hp, 130-160psi range, 60-68hp, 160-200 68-73hp. that is a close estimate on some of the M's that have came into the shop and with different compression pressures with stock cubic inches. Ok, lets move on,, the valve lash, .017 is the book specs. But you are not running in the fields,, you are looking for performance. I have found that valve lash is crutial to utilizing the camshaft profiles. Problem is,, how does one know if the cam they have is giving them the full potential. I use a compression guage to set lash. By setting them with the guage, it is checking your work. with the engine warm, remove the spark plugs, pick one cyl and work with it. run a compression test, and record the reading. now, what you are gonna do is find the proper lash setting that will give you the highest pressure reading on the compression guage, on stock cams, you will find that a tighter lash will boost compression. do one valve at a time, record the readings from the guage, and the lash setting it ends up with. you will find that the cyl pressure will increase, for me to decribe what this does, is dials in the camshaft profile to the peak performance for that grind. only way I know how to know if it is right, is if the compression goes up. dont overtighten the valves, and keep the engine warmed up. Now, lets say your compression goes up after this adjustment, so now you need to give it more fuel, to feed the extra compression you have found. If the pressure goes up 10 psi,across the cyls, thats 5 hp off the bat,(on an IH) tune the carb to that 10psi, and could be 7hp more at 540 pto rpm. Lets move on again,,, the Distributor. You said the mechanical advance was stuck, did you replace the springs in it? those old stock springs in the IH and delco distributors are so stiff, it takes 5000rpms to activate them! replace the springs with ones from a chevrolet recurve kit. they are lighter in spring tension, and will help with throttle response upon acceleration. Now, where is your base timing set at? At an idle,, does it sounds like a car idling in gear?? labored?? if so, you can give some of the timing back to it, for full power the timing on the engines on the dyno range from 25-30 degrees advance, but that varies from engine to engine. for lite duty pulling, I set them on the dyno, and make a scratch on the distributor housing, then back it back off to where it runs like a sewing machine, and tell the customer, that for more pulling power, just move the distributor to that mark. That way, for when they are using it on the farm, or whatever,, it does not have to run on the ragged edge all the time,,, You are going to break your governor spring, eventually it will stretch and break, so keep an eye on it. the governor, from what you said you found, that will help tremendously!! now the carb is opening up with the governor. rite there, was a big problem with your set up,,, most of the IH that come in here,, to get tuned up, they get a governor spring change, and solves the half open half shut carb problems at full load rpms. Does your Super M have the 2 weight, or 4 weight governor? more later,, hope this helps a bit,, ChadS
|
|
|
