Hey everyone i was wonderin is the number one cylinder of the firing order up front by the radiator or back by the firewall. Also when timing a 235 can i just roll it over to tdc on the firing stoke and put the dizzy in pointing at the number one terminal on the cap and time it to my ear. Also whats a good trick for putting dizzys back it i cant get it to go all the way into the oil pump groove. Any help would be appreceated and thanks in advance. jake
Hey Jake - #1's up front ahead of the other five. You could probably get her close to firing up with your timing method, but it would be 50/50 on getting the spark to #1 or #6 on TDC. Lots of folks here have posted their timing techniques and you pull them up quickly with a search on "timing" in the archives. Can't help you on getting that dizzy back where it belongs other than to tell you that patience will have a better outcome than a BFH. Pretend it's your girl friend... talk sweet, be patient and gentle and you should be able to get it back in. Mike M '27 Chevy '41 John Deere B '49 GMC FC-150
RE: Dizzy Install Jake ; The helical drive gear makes the shaft turn a little bit as you slide it into place , this means you must needs position the oil pump drive slot so it'll line up as the shaft begns to turn . it can be tricky . I'd avoid timing by ear since that usually results in too much advance , if you don't like using a dynamic timing light , get a vacuum gauge and connect it to the intake manifold ans advance the timing to get the highest _steady_ vacuum reading , if the needle jumps , it's not right or you have tight valves , 99 % of the engines i work on have tight valves so I never touch the timing untill thay're adjusted first . -Nate
RE: Dizzy Install Hey, Nate.... old hand that you are... can you shed a little light on what you mean by "tight valves"? I could sure use a pointer here.
RE: Dizzy Install Nate - Don't forget to tell Jake about your "ping" test. That's worked great as the final timing adjustment for me. Mike M '27 Chevy '41 John Deere B '49 GMC FC-150
RE: Valve Adjust & Ping Test As normal wear occurs in any engine , the working clearances between the valve stem and the rocker arm decreases untill eventually there is no gap at all , this is called a ' tight ' valve . In our old tech engines , accuracy is ensured by adjusting the valves while the engine is @ operating temperature . you can make the 1st. adjustment with the engine cold but they should be checked with the engine warmed up , don't worry about it cooling off as you labor to get them done , just _DO_ a valve adjustment before attempting to do any other tune up or carby work . The ' Throttle Ping Test ' is where you set the timing by advancing it then running the truck @ 35 MPH in top gear and stamping the throttle to the floor ~ if it pings , pull over and retard the timing a -tiny- bit , try again , if it _doesn't_ ping , pull over and advance it and try again , repeat untill it pings when you stamp on the gas pedal in top gear @ 35 MPH then retard it only the tinest amout necessary to stop the ping . This is GM's factory approved method of timing that's _far_ more accurate than any timing light could ever be as it sets the correct maximum timing advance for your particular engine at the elevation you're using it at . Remember ; every time you go to work on running issues , follow the proper sequence 1st. , adjust the valves . 2nd. adjust the points gap / dwell . 3rd. adjust the ignition timing . last thing , adjust the carby as needed . I hope this helps.... -Nate
