Have a 72 Ford 302, basically stock with headers in a car that weighs about 2000 lbs with a 5 speed manual trans...picked up a used MSD distributor and coil...car runs great but feels a little sluggish, 35 deg all in on timing, no vac advance...thinking of installing the vacuum advance and with a car this light I was wondering what advance springs and stop should I use as a starting point...runs good, starts good but not as snappy as it should be...any help from the ford guys would be appreciated, and Merry Christmas to ya'll.
I use the blue (light) and silver (light) springs with the 18 degree black bushing, which is the largest of them. Full advance at 2300 rpm. Initial timing on mine is 16 degrees.
If it’s a stock 72, those were about the low point for the 302’s. What I remember (always doubtful) is a lower compression 2 barrel motor, really tuned down for emissions stuff. Doesn’t mean it can’t be tuned better, but there might be some upgrades in order. Depends what you’re looking for.
MSD has the information online, it’s just a matter of buying the spring/bushing kit and experimenting.
@Ron Brown Is this a first time out , or a distributor swap to an existing car? Try and rule out the obvious by re-installing the old distributor and seeing if the issue stays of goes away.
the old distributor is a worn out Mallory that has issues...this engine is in a Sunbeam Tiger that originally had a 260 v8...has a 650 Holly and long tube headers...I do believe the MSD is factory settings, but will know more tomorrow when I pull the cap off...it does not currently have a vacuum advance but we are going to install the one that came with the dist.
Vacuum advance only affects "off throttle" cruising /economy As soon as you floor it [even slightly] the vacuum drops off. Check the TDC on your marker is actually at true TDC then use MSD timing tape on the balancer. I've always used the "controversial" Ported vacuum because I've always set up engines with no vacuum advance. [race cars] If the advance curve and timing is correct vacuum advance shouldn't make any difference [except backing out of the gas while cruising] Before you throw $$$ at it, why don't you advance it to about 38°+ [which increases the static advance] Go out and try it , but keep the RPM below 3000 so it doesn't reach full advance. See if it pulls better. If it is more responsive ,you will benefit from lighter springs and shorter advance stops [re-curve] I am a big believer in trying / diagnosing things instead of throwing $$$ at it
Going out on a limb here but a "used MSD" might not be much better or as good as a Known to be worn out Mallory. I used to work for the go to guy to set up distributors in Central Texas in the 70's and guys would show up with used Mallorys that they had bought off some dirt track racer that were plum worn out. Some times the same distributor that JT had told the racer that it was worn out. Simply meaning that a USED performance distributor is still a used distributor. Stilll I have fought the timing mark location thing on a couple of engines and would be brining that one up on TDC and checking to make sure that it is right. Simple things first then go to the complicated things. Side note, my Uncle sold Sunbeam Alpines in Cali in the 60's but I think he was down around Riverside at the time.
I used to know a guy (lost touch with him 10/15 years ago) who had a Tiger with a stock 2bbl mid 70’s 302. That thing scooted along. I know you think it’s ignition related, but maybe investing in an O2 sensor set up and see what’s up with the AF ratio, might be in order and see what’s happening during the sluggish times.
yeah...checked TDC ( several times) and it is dead on...I think im gonna try to set it up all in at about 3000/3200 rpm...it acts sluggish, like it wants more advance so I may change to lighter springs...
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