Ok the shop that installed my motor(they insisted they install it was on warrenty work cause a rod bearing let go after a month) susposedly set the timing curve checked it total timing was at 24 degrees at 3000 rpm shouldn't it be at more like 38 deg. Inital timing was at 10 deg.

The vacumun advance is not hooked up they said engine did not have enough vacumun to opperate it unless I got an adjustable one. So I have to run about 20 deg intial timing to get 38deg total timing. This is with the moroso recurve kit with the lightest springs.

Does this soud right to u guys or is there something wrong with my igintion system? Also with motor in sig. would I have enough vac to use vac advance I have a feeling the shop isn't being exactly truthful with me about this. Have to what to tommorow to test it cause I don't have an extra vacumun line.

------------------
406SBC
-DART SPORTSMAN 2 HEADS
-RPM INTAKE
-750 SPEED DEMON MECH SEC. CARB
-HEDMAN HEADERS
-COMP CAM EXtreme energy #284 .507/.510
-1.6 roller rockers
-th350 tranny
-posi rear disc

 

That setup sounds kind of hairy, low rpm vacuum wise. Try a Crane adjustable vacuum advance kit. They are not expensive ($20) and might help.

------------------
1986 Camaro Sports Coupe
T-tops, variable wiper, power hatch, rear defrost, third brake light
LG4 305 V8, Hooker Shorty headers, 3" pipe into Walker Quiet Flow dual exhaust
Edelbrock Performer intake, "Damonized" Q-Jet 4bbl, K&N filter, Crane ignition kit
TH700R4 transmission and Derale cooler
Air conditioning, power windows, power door locks, power brakes, power steering, tilt wheel
Kenwood cassette, Pioneer 6x4 component front speakers
Rockford Fosgate 6x9 Punch rear speakers
Z-28 front and rear sway bars
Aluminum slots and Goodyear 225x60R15 Eagle HP tires
243 horsepower and 326 foot pounds of torque at the flywheel
_ _ _ _ _ __ _ _ _ _ _
Yea verily, and he smote the smog heathens from his small block Chevy, even from the air pump to the converter ...
Todd 1:1

 

Thanks I think I will try that. Why are the weights in the moroso kit so differant from the stock ones? The stock ones were bigger wouldn't they offer more advance over the little moroso ones?
Think I will put the old weights back in and try that b/c the car seems to be running hotter since I put the recurve kit in.

Is it possible to get timing tape to stick to a chrome balancer or am I going to have to get one of those timing lights with the dial on it?

 

Can't tell you all about the springs, only know that the Crane kit comes with 3 sets and good explanation of which to use. You definitely want your ignition curve to be complete by 3000 rpm, may be even earlier. Just try the different sets and see which make the 406 happiest

It might even be easier to take your car to a place that can pull your distributor and spin it up on a special machine. Then they can dial it in perfectly. Any speed shop should be able to direct you to one.

 

most factory distributors are limited to about 18 to 20 degrees internally. Even with springs, the slot does not allow it to go further. You might want to check to see if there is a nylon bushing on the advance pin. Remove that and you can get about 3 more degrees.

 

Are u talking about the pin that the weights sit on or the ones that the center bar sit on?
The distributor is an accel hei. The kit claims 24degrees advance total with the lightest springs. On back of the kit it says with the light springs u don't reach full advance till 5000 rpm.
1500 6deg
2000 8
2500 14
3000 16
3500 18
4000 20
4500 22
5000 24

The med springs reach full advance at 7000(22 deg) rpm and the heavy at 8000(20 deg)
Did I buy a bunk recurve kit or is this normal?


------------------
406SBC
-DART SPORTSMAN 2 HEADS
-RPM INTAKE
-750 SPEED DEMON MECH SEC. CARB
-HEDMAN HEADERS
-COMP CAM EXtreme energy #284 .507/.510
-1.6 roller rockers
-th350 tranny
-posi rear disc

 

normally it's a slot on the main shaft that mates up with a pin on the cam for the weights. But on an accel i don't know. I have never heard of springs that stiff. Factory springs are normally that stiff even. Is this a moroso kit?

 

Forget the Moroso kit- it's junk. Put the stock weights and centerplate back in the distributor (you can still buy stock replacements at most auto parts stores if your originals are trashed or lost).

Stock weights and centerplate along with the blue and silver spring from the Crane kit will get you a lot closer to what you need timing curve wise than what you have now. 20* of centrifugal advance, all in by 3000 RPMs and then NO MORE beyond that point. Perfect for street performance.

The Crane kit even comes with an adjustable vacuum advance can that will work well with even the wildest cams.

THere is an article in the tech section of this board about tuning the HEI for performance which can tell you more.

 

SB406,

Damon has helped me out on a lot of my carb and ignition work and he is always right. Go to the HEI atricle on this site--he wrote it and it WORKS!

You definitely want to get the Crane kit AND FOLLOW ITS INSTRUCTIONS. It is obscenely cheap and will make your car jump like it's been hit with an electric cattle prod! No kidding.

 

I've alredy put the stock weights back in and I'm going to get the crane kit on monday.
I'll be sure to check the tech article on hei dist.
Thanks.