timing issue slant 6

hi to everyone i hope someone can help me here

i will try to explain this the best way i can

i run a slant 6 engine in HA/GR class best time so far is a break out finals run of 14.397 sec and the best MPH is 96 + MPH in a 1700 LB HAMBster

but i have a major tuning issue
PART A i run a gear drive set up (see picture) in this picture it shows the timing dots on the gear drives line up when the #1 piston is at TDC, and the distributor rotor button is aligned in the cap to fire on #6 lead

when i turn the engine 1 revolution the distributor rotor is now ready to fire on # 1 lead BUT the timings dots are now 180 degrees apart

PART B at TDC on # 1 the timing mark on the harmonic balancer (see picture 10 degrees AFTER 0 (the rotor is on # 1 and the timing dots are 180 degrees apart (the rotor is actual past # 1 buy 1/4 inch )

PART C when i fire the engine and hit the timing light the timing mark shows up at approx 12-14 degrees before 0

it is not a spun harmonic balancer as i have just purchased a pro-street balancer and when i put it on it was at 10 degrees AFTER 0 as well

if you are confused about my explanation, so am I
something is wrong , i am going thru the traps at approx 4800 -5000 rpm
(plz dont post what is wrong is that i am using a slant 6 LOL )

or did we consume to many wild turkeys when we screwed the engine together


hot head work * race cam * triple SU carbs * ceramic button clutch* borg warner 3 speed * 4:11 gears and a locker diff

 

G'day Fully Six, to suggest a few possible fixes...

for 'A'...sounds like you need to re-index the distributor or change the order of the plug wires on the cap. PM Old6rodder, he has been through some similar things on the Barn Job.

for 'B'...if the timing marks show ten degrees after when it is actually at TDC, make new timing marks for 0 degrees when at 0 degrees.

for 'C'...if it runs good at where you set it, just use the settings that work. Sounds like the car runs pretty quick as is, but if it weighs 1700 pounds...think about putting the car on a weight loss program. Pounds per horsepower has always been the name of the game.

Perhaps some Bundy OP instead of the Wild Turkey would help.

Like the high tech gear drive, but as another possibility you could try fitting a stock chain and sprocket drive and see if it all comes out the same just on the outside chance the gear drive is marked wrong.

 

Howdy,

This can be really annoying, eh?

"A" is correct. The buttons line'er up for overlap on #1, and firing on #6.

"B" & "C" I suspect is your problem. Yeah, there were a couple different scale plate/damper wheel combos and it's sounding like you have a mis-match here.

10* past on the wheel and 1/4" past on the rotor are roughly the same, suggesting that you're actually pretty close to proper no matter what the scale says.
In addition, 10* off plus your stated 12*/14* total adds up to 22*/24* actual total (assuming you're more right than your scale plate). That's much closer to what a slant likes and runs well on. That fact that you're running at least decently would seem to bear this out.

I'd recommend re-certifying TDC mechanically, as suggested, then putting a temporary new mark on the wheel next to the 0* mark on the scale and trying it that way for a bit. If it works out as I suspect it will you can then make the new mark permanent.

Lastly (and just for the hell of it), I also don't care for the scale plate set-up. I always grind it down to just a pointer and scale mark the wheel itself, advance only, in 5* or 10* increments from 0* to 30*.
"Just the facts, Ma'm.", as it were.
Don't forget that the wheel marks go the opposite direction from the scale. I did that wrong once, many years ago.