I wanted to ask,whats the deal with people running locked timing?do you benefit by it?i notice alot of guys have there distributors locked around here in my area? Thanks
Plain and simple...they just don't know enough about how to correctly set up a distributor to get it to work right. Racers do it because it's one less part to go wrong in a race.
I would want to send out my distributor to re-curve it one day,but all the chevy guys around here all have and recommend locked timing,i tell them they`re whack. Thanks
George, Locked out timing is usually a race only modification. On a street vehicle, you are better off with the mechanical, and vacuum advance operating. With locked out timing, the engine runs with a constant amount of advance. This can give you starting problems unless you have a start retard. The Chevy racing engine requires a constant amount of advance above 1500 RPM, according to Smokey Yunick's "Power Secrets" book. I don't know if that applies to Buicks. In his book, he states that the advance mechanisms in the distributor are the primary cause of timing irregularities, and you get a more accurate spark delivery to each cylinder without them.
Well if you run wide open ALL the time you might want to lock it out , other than that Don't. BTW my friend runs a mustang with a 5 speed in the 10's and its not locked on his car and it is a street car. Drives real nice at 2k or less on the street. Just my opion though.....
Years ago I worked on a SB Ford in a Super Comp dragster. We started out with standard weights, springs, etc. The motor would rev so quick that when the weights would come back in they would slam together and get stuck, making the timing erratic. We locked the distributor and it made a world of difference. It actually makes the lower RPM's crisper. Also, with the new digital ignition boxes you can lock out the curve on the distributor and use the computer to set the curve right on the laptop screen. You can make the "curve" any shape you want. Imagine the possibilities.
But lets say you are to lock a distributor out,where or what degrees do you lock it out to?you cannot run for instance 32* at all times or 34* could you? Thanks
Take Jeff Kitchen's example as one to look at, that Super Comp engine ran a cam with very late intake valve closing, which knocked the lower rpm compression (DCR) out of the equasion, severely less cylinder pressure (which is starter motor resistance). In his case, two different issues were addressed and dealt with, the issue of compression resistance at starter motor turining the engine, and big cam issues the under catch low rpm had. Since the big cam knocked out the cyl,inder's ability to "catch" and hold mixture, which lessened the comp ratio, the locked out timing was beneficial in crutching the low rpm loss from the cam. His engine also idles and leaves the line way above a reasonable idle rpm for a regularly daily driven engine, probably right at or very near what the street/mild strip setups would be at the end of their curves vs. rpms. For street and moderate performance, leave the mechanical and vacuum advance curves in, set them up right, and enjoy the performance. Besides, Chevy engines have very different combustion chambers and can rtolerate locked out with bigger cams much better than mostg Buick heads can in similar situations on the street and mild strip.
George, That is what locked timing is. The mechanical and vacuum advance mechanisms are brazed in position, and you set the timing at what you want to run. 32-34* for a Buick. Your initial and total would be whatever you have the distributor adjusted to. Like I said, the only problem you would have would be starter motor kickback, unless you had a start retard feature. My MSD Digital 6+ has a selectable 20* start retard. If I wanted to lock my timing out(I don't), I could run my 32* and the engine would crank at 12*, and as soon as the engine reached 500 RPM, the MSD box would advance up to 32*, and the engine would run at 32* all the time. With a racing setup, the engine spends most of it's time at high RPM, so locked out timing gives more stabile, accurate timing. But a street car is at low to midrange RPM most of the time, and benefits from different timing.
George, Try to find someone who knows about Buicks that has a distributor machine and send it to them.
