Box Stock

Whats your timing?

1fasttiller

1fasttiller

Member
I know to some this may be a secret, but to those of you that can share, what is your preferred IGN timing for Plate motors and unrestricted? I've been backyard building for many years, all the way back to flatheads and I just recently heard something from a Very well known builder that took me off guard...

I was always told that on a plate motor you want high(er) timing due to the excess fuel/rich carb. It helps burn the fuel and make the plate motor more responsive. My go to timing on small plate motors has always been 37-39*. I run 33-36* on unrestricted stuff. My motors aren't national caliber by any means but they win local shows and run well.

My recent conversation with a very well respected national builder has changed my mind, he told me to back off to 32* on my sons plate motor and see what it does. I did exactly this, put a straight up key in with the 6619 ARC and timed to 32*. The motor ran wonderful this past weekend against some of the best in the state. I don't have a dyno to prove anything and validate this but I'd love to see some info from those of you that will share.
 
Trouble with GX200 is they have a crappy coil that retards ignition more at high RPM

Try using the latest coil from the UT2 GX160......it's a far better animal. From 5000 rpm onwards the power curve holds on stronger. This coil has a smooth flowing ramp top and bottom profile on the steel lamination stacks, near the 2 bolts.

The coils to avoid are the ones with the angular / jagged top and bottom near the bolts.
 
Good info Knighty... do you know if this coil is legal? It doesn't retard timing as RPM increases? I thought basically ALL small engine coils of this type did this?

Do you happen to have a Honda PN for this coil? I'd like to do some more research.
 
I was always 34-35 on unrestricted and 38-40 on plates..(thinking I needed to). I got a piece of advice that changed my mind. Nothing is higher than 35 unrestricted or plate for me now.
 
No.....when I starting building clones I talked to different people who said the timing needed jacked up to help burn all the fuel due to the plate.. I’ve found that’s not the case and using the butt dyno it doesn’t fall off up top like they would with 40 degrees in em.
 
Wow, thank you guys. Definitely helps solidify what I'm being told. Goes against everything I've ever thought or been told but it works. Heck out purple plate motor turned 6300 this past weekend and was turning faster laps than the leaders but we ran outta laps!
 
Can we revisit this a bit. So what started the high timing theory and with all the big name builders doing this it had to be for a reason? Im sure a lot of monkey see monkey do but usually these guys have dynos and can compare data accurately. How and why did this change?
 
jsf74 said:
Can we revisit this a bit. So what started the high timing theory and with all the big name builders doing this it had to be for a reason? Im sure a lot of monkey see monkey do but usually these guys have dynos and can compare data accurately. How and why did this change?
Click to expand...
Would love to know this myself. I'm sure more than one big builder has dyno'd high and low timing on an identical engine and found what works. Note the info I got was direct from the man himself- Dr Fast (Rudy Wade)
 
I’ve always built my plate stuff around 37 to 39 but that was only because of what I researched. Wish i had a dyno I would be nonstop trying different things just for the hell of it.
 
Cams, heads and a Dyno determine today’s timing. Back in the day of only a few cams to choose from and not permitted to port high timing was where it was at. The Dyno and flow bench allows discovery. Oh and by the way guys, I am retired.
 
How I thunk bout it.
Think about a capital V.
At lower rpm the coil can charge during the time the magnet travels across the top of the V.
When speed increases the top of the V gets closer together because there is less time to charge the coil.
To compensate for it, the now narrower V needs leaned over some so you can start charging the coil at the same time. But you still will have less time to charge the coil.
What else can help are either have a coil with less resistance making it easier to charge up or use a stronger magnet.
 
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