Has anyone tried the screw in the plate method? I have a $500 ignition system but it won't be ready for this weekends test n tune. I am gaining timing at 4000 rpm, 36 at 3000 under that.
Easy way to limit the HEI mechanical advance?
- Thread starter olds307 and 403
- Start date
- Status
olds307 and 403 said:
Would you please restate this? I think you mean that you're getting 36 degrees of total advance at 3,000 RPM and more above 4,000 RPM, but I want to make sure I understand. What sort of recurve kit and springs are you using?
Great info here on HEI conversions/tuning.....
http://www.442.com/oldsfaq/ofign.htm#IGN PointsHEIIgnitionConversion
http://www.442.com/oldsfaq/ofign.htm#IGN PointsHEIIgnitionConversion
Stock weights, light springs. It stays at 36 total, in by 3000 rpm. Then at 4000+ it gains additional timing, supposedly a common problem with the HEI. I spent $500 on an ignition system, has not worked from day one. I just may have missed the delivery guy who had my parts, didn't think they would come in time. I have 16 mechanical adjusted in that distributor, about perfect. I bought 3 months ago. Blew up my rear end, wasn't in a hurry but the rear is fixed and the test n tune is tomorrow.
Why does it always seem you wait until the last minute to get your car up and running right for your one time a year only racing?
Anyway, how much additional timing are you getting after 3000? Maybe it's not even worth worrying about for now? $500 seems an awful lot for a simple HEI setup which is all you really need. What do you have exactly? Have you contacted the manufacturer/dealer of what you bought and asked them what they recomend?
As far as trying to cobble something up last minute before race day, I don't think that would be a good idea. Worse case scenario, you turn you base timing down a couple degrees until you figure out how to get it the way you want it without boogering anything up.
P.S. Did you ask your question on ROP? If anyone would know, it would be those guys ( assuming it doesn't turn into a argument/pissing contest ).
Anyway, how much additional timing are you getting after 3000? Maybe it's not even worth worrying about for now? $500 seems an awful lot for a simple HEI setup which is all you really need. What do you have exactly? Have you contacted the manufacturer/dealer of what you bought and asked them what they recomend?
As far as trying to cobble something up last minute before race day, I don't think that would be a good idea. Worse case scenario, you turn you base timing down a couple degrees until you figure out how to get it the way you want it without boogering anything up.
P.S. Did you ask your question on ROP? If anyone would know, it would be those guys ( assuming it doesn't turn into a argument/pissing contest ).
I bought this off a well known Olds dealer, missed the parts unfortunately today. It is a fancy set up, I thought not cheaping out was the right way. I actually have 4 race days this year. Well a blown rear 3 days before the first test and tune sucked. Then phone tag for the diff parts and emailing for the ignition parts have really taken the interest out doing anything with my car. My car will run 36 degrees at idle no problem. I am getting at least 3 extra degrees. I also rejetted the carb to match the factory 403 primary jet and rod combo. Same rods, up 2 jet sizes. I have multiple hanger and secondary rods. I am hoping for some improvement but who knows.
Im trying to understand why anyone would have there timing set at 36 degrees at idle....makes no sense to me.....unless your idle is 1500rpms.....Most Olds motors like about 36 degrees TOTAL advance timing....at most, your idle timing should be around 6-10 degrees at 600 rpms.olds307 and 403 said:
bill said:
I'm guessing the plan is to run 36 degrees initial and lock out mechanical advance for racing...? I've never tried physically limiting it, the screw method might work. I would have offered other suggestions if there was time, but it looks like race day is here. If by cheap you mean factory parts, sometimes cheap and effective is better than the alternative. I spent quite a bit of trial-and-error time getting my factory distributor just right, but it's possible to do. Good luck at the track.
bill said:
This is true. You get a cookie
OK, you might have to return that cookie I gave you. Olds engines ran 20* base timing ( @1100 rpm's ) stock with the HEI's. I don't think there's any mechanical advance in yet at 1100 RPM's because the factory curves are so lazy.
Now run a high compression Olds engine and you will want to reduce the base timing a bit or it'll be hard to crank and/or ping at light throttle, but then you'd want to recurve the distributor to still give you your 36ish total.
Olds 307 and 403, I wouldn't worry about a 3* creep. Just run what you got and see what you do. Reduce your base timing by 1-2 and/or run higher octane just to be on the safe side if you're really concerned about it, but I think you should be OK.
Your correct...I didnt factor in the fact that hes running a lower compression engine than I am. Really wanted that cookie....DoubleV said:
- Status
