Kat

iTrader: (4)

Be the best to to use in this suitation

It is a 383 10.5:1 comp, ported TFS heads, Lunati cam grind # RRA1-224-232-6 (specs are exhuast closes at 0* atdc opens at 52* bbdc, intake opens at 4* btdc and closes at 40* abdc, lobe sep is 112, center line is 108* lift is .504 intake .514 exhuast, duration at .050* 224* intake 232 exhuast, advertised duration is 280* intake 290* exhuast)

Yes he has the 1.6 RR on it stock converter, rebuilt tranny with shift kit and 4.11 gears

The weights that are in there now have a 60 stamped into them

Base timing is set to 12*

Ummm Sooo what would be a good advance weight to put in there?

Thanks

Kat

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90 RS 305 TBI A4
Dumb ***/**** poor/orginating memeber of the infamous NE Crew
Time to see, believe this in me,This pain that i feel deep inside

Jester

Get a set of aftermarket advance wieghts. They're only like $10, and come with 3 sets of springs usually to experiment with. Don't trust whatever came in there stock..god only knows what kind of curve it's actually giving you by now.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

Kat

iTrader: (4)

I know Jester thats what we have now. I figure that I post up something about it see if anyone has any insight of what weight would be good to start out with.

Kat

AlkyIROC

The numbers don't mean anything.

Your base timing is 12 degrees. What's the total timing? Remove and plug the vacuum line and bring the rpms up until the spark curve stops advancing. You'll need an advance timing light or a balancer with degree marks on it. Your total timing should be all in before 3000 rpm and total timing should be 36-38 degrees. When you advance your base timing, you're also advancing the total the same amount. If the base was originally 10 and you went to 12, the total could have been 38 and is now at 40. Recurve the distributor back to 38 total (or whatever your engine likes best).

The weights will determine how much mechanical advance there is. The springs limit the rate of advance. You can mix and match the springs (one light, one heavy) to fine tune the rate at which it advances.

Those recurve kits they sell are tuning aids. You can't put in any weight or spring without knowing what it's doing. You can also go to the junkyard and pull different weights out of HEI distrubutors to try and get different total mechanical advances. The center cam lobe will also change the curve. Like the springs you can also mix and match the weights to get different mechanical advance totals.

Your best bet is to take the distributor (or another one) to someone who has a recurve machine. When they have all the specs for your engine and car, they can recurve the distributor to exactly what you need.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block

Best ET on a time slip: 11.242 altitude corrected to 10.89
Best MPH on a time slip: 121.52 altitude corrected to 125.89
Altitude corrected rear wheel HP: 497.9
Best 60 foot: 1.546

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

Jester

Most any standard aftermarket wieght set has a 20 degree total advance. Changing the springs changes the rate at which that comes in. Most sets also come with a graph showing what curve different springs will result in.

use the middle springs to start.

IF it knocks before 3500, put in heaver ones. IF it knocks after, Retard the base timing and/or vacuum advance canister if you have an adjustable.



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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
JSP Motorsports
ICON Motorsports

Kat

iTrader: (4)

Thanks guys I appericate it!!

One good thing is that the ballencer does have timing marks all the way arround it!

Looks like I know what I'll be doing sometime this week

Kat