JoeMustang

Does anyone else have a 68 302 that installed a roller cam? I found out thats what I have, and want to know how to set the timing at. I have an MSD ignition, so I don't have a vac adv to disconnect while setting it. Is there anything else i need to do?? And what should it be set at, because now it's at about 13, and when I rev it up, it goes to 30.

mat11089

U could pul another degree or two but thats all id do.your total timing seems a lil lower but ur ina good place.

67mustang302

Timing requirements depend on the engine build, and vary from engine to engine and climate to climate. Mine is around 10-12 at idle and about 32 total for instance. Generally speaking though, bigger cams with bigger heads and bigger intake want more ignition. A rule of thumb that some go by, is give it as much ignition as you can without detonating, or going overboard, yet still providing the best performance.

rmodel65

in my 5.0 ive got mine set at 14 degs

JoeMustang

As far as build, it has a performer intake, edelbrock 600 carb, gt40 heads and headers. I run 93 oct gas. Any idea if I have to disconnect anything on my MSD ign, when I set the timing? And should I be reving it to 2-3000 rpm and setting the total timing to 34 or to 14-15 at idle??

rmodel65

14 at idle but dependeing on your gear rratio tranny type etc u might want to bump it a few more degrees some 5.0 guys rng 18degs etc just depends on the cars tune bumping it up gives a nice kick in the pants for accerleration but it might lose a mph or 2 on the top end

Starfury

12-14* advance at idle is probably going to be good. Basically as high as you can get it without getting pinging under heavy load at low rpm's.

SBF's like total timing to come in early. 32-34 total by3k should be good. The MSD has an adjustable mechanical advance, so you have to replace a bushing to change the max mechanical advance, and springs to change the curve. Check on the MSD website for instructions.

67mustang302

Also if you have an MSD box your idle timing prolly won't be accurate with the gun because of the multiple sparks. Most guns can't pick up the timing right, so you'll have to set it based of total advance, over 3,000rpm where the box is only firing 1 single spark. If you don't have an msd box, and just the dizzy then n/m. If it's vacuum advance then unhook it and plug the vacuum line when you set the idle timing.

Colorado_Mustang

Dang, I run 10* at 1k rpm, and 34* at 2700 rpm (with good gas in the tank, -4* for typical pump gas). Any more and it bucks the starter.

JoeMustang

Yes, I have an MSD box, and no vac advance. So if I set the total advance with the timing light, am I look ing for 32-34 total at 2500-3000 rpm, amd then just call the idle timing done??