So in trying to tune - get more vacuum out of my build 462 -10:1 288-94h I decided to run more initial this time at 18 deg and keep the black bushing 18 degrees in my msd ready to run for 36 degrees total advance - running no vacuum advance ....the problem is up around 3800-4000 rpm today I recorded 45-47 degrees total advance a full 9-11 degrees over what my 18+18 cap should be ???? Remember I AM NOT running vacuum advance at this time...the distributor has less than 1000 miles on it , new double roller timing chain etc. - all new components. Are these msd's usually spot on for total timing or can they vary in the amount of total advance ? Is it possible my dialback timing light is crap ? Any ideas ? I have one blue and one silver spring in there can they stretch ? I would think its the bushings job to stop things from going over 18 ...anybody else seen this ? Thanks , John Ps besides this total advance issue - the additional 2 degrees got me approximately 1/2 to 1 full inch more vacuum at idle.
The only time I've seen the MSD cause goofy timing was with the adjustable timing retard. Besides that, I've never seen it change my timing. -Bob Cunningham
If the wiring to the magnetic pick up is reversed in polarity, the engine will run with advanced timing. With a ready to run distributor, I don't see how you could have done that though. Try another light, or use a 30* mark on your balancer.
Mike at Automotive Machine & Performance told me not to use a dial back timing light with my MSD system. I have also been told by other long time drag racers not to use one. Just my (there) two cents worth.
Ok easiest first I am borrowing my buddys timing light tomorrow night....hopefully thats it .....I will double check the wiring polarity out of the dist - just in case. So Larry help me understand if its wired reversed you are actually retarded from what the timing light says your advanced ? Non dialback : I just remembered buried somewhere I have a fixed - non dialback ancient timing light somewhere I will dig it out and put a 30 degree mark on my balancer and check it that way ,,,thanks for the advice. J
Back when guys were using their old stinger distributors to trigger MSD boxes, if you reversed the polarity, the timing would be advanced.
As usual Larrys the man ...I switched over to my ancient (havent used in 10+ years ) non dialback timing light- put Larrys 1.75 inch - 30 degree mark on my balancer and my total timing all in is around 32-34 right now- so the jumping was due to the dialback light (ACTRON with an MSD ready to run dist combo) ...it started to rain so no further road tests today . I am also chasing a few things...I only have a moroso 2 inch filter on the motor with a closed top for hood clearance - after taking it apart I noticed it only has about a 1/2 inch total open space above the carbs neck for the motor to suck air through- direct shot .... the other 1.5 inches of filter are below the carb neck / drop base ? Thinking I am under"aired" I borrowed a K+N filter top from a friend and put it on there and then put clay on the front and sides of the air cleaner to check for clearances between the filter crown where the wing nut goes and it is only 1/8" inch from the hood. The filters sloping sides luckily are possibly 1" to 3/4 to 1/2 for sure clearance from the top of the hood......I have a suspicion this may have been adding to the running like it was choked issue. Remember I went to the taller Sp-1 this time out up from an Ebrock- Perfomer . Its raining so I cant go out and try to see but 1/2 space above the neck to feed a 462 cant be good I am thinking. Thanks again Larry on the timing. J
So I ran my 65 in between rain storms last night WITHOUT THE AIR CLEANER for a 2 mile cruise and it ran -felt great for the first time ever since the rebuild . I couldnt get into it - nail it as it was wet out but I believe the choking under acceleration was due to my NEW sp-1,drop base air cleaner and lack of the carb neck spacer I ran with the same filter last time but with the Edelbrock Performer (shorter intake). I had to hastily pull the carb spacer off weeks ago because the hood was crushing the element down with the taller SP-1. The 850 carb venturis are so close to the inside of the air cleaner lid-top there is hardly any air gap to pull air from. Without the spacer I used last time lid is .5" closer to the carb opening...I had an open element top to try BUT its pyramid peaked-shaped and sits higher so it gets crushed down by the hood even more and the center plastic button where the wingnut goes is a 2" solid plastic circle and partially blocks all of the venturis even worse - so that top will not work at all. I think what I will need in the end is a 2."5" filter and a "flat top open element lid" opposed to a pyramid shaped open element top with no carb spacer ...that combo should clear. If anybody has a p/n for a 14 " flat top lid / open element let me know please. Picture angles on Summit Racing dont show if the open elements are flat or pyramid shaped. This acceleration problem was a tremendously basic problem in the end..always check the basics frist ... I feel really stupid . A p/n for that style top would be a great help...... EDIT : COMBO THAT FINALLY FIXED IT ALL Final air cleaner solution in "my" 65,455,SP-1,850 DP was Moroso 14 inch solid top and drop base Moroso p/n 65903 2.5" K+N 14" high flow red filter p/n E-3735 no carb neck spacer thanks to all - JFK
The only thing that works with my SP-1 is that triangular Edelbrock filter (the foam one.) One of these days I am going to have to put on a VNF hood with a scoop.
Found this old thread, and it may have something ot do with an issue I'm having.... my 73 has a Stinger S-4 ignition, and I cant get the car to run without less than 40 degrees initial timing! I have the instructions from way back when, and it appears to be installed correctly with the proper color wires from the module going to the harness correctly. Should I pull the terminals out of the harness and switch them just to try it? I checked TDC, thats OK and the distributor is dropped correctly. It actually makes OK power, but runs choppy at idle and I'm scared to burn a hole in a piston before I get it squared away... anything else I should check?
