Tryin to get a handle on tuning this little 305. It's producing alot more torque after a cam swap but its power is lacking beyond 3600rpm.

Specs.

Accel 59107 distributor.
Base timing at 16*
Total at idle 30*
1 step lighter on the springs

Edel 2103 Camshaft
Duration at 0.006" Lift:Intake: 288° Exhaust: 288°
Duration at 0.050" Lift:Intake: 214°Exhaust: 214°
Lift at Cam:Intake: 0.295"Exhaust: 0.295"
Lift at Valve:Intake: 0.442"Exhaust: 0.442"
Timing at 0.050" lift: Open Close
Intake: 0° ATDC 34° ABDC
Exhaust: 44° BBDC 10° BTDC
Centerlines: Lobe Separation - 112° Intake Centerline - 107°

Edel 2701 Performer EPS Intake

Edel 1405 Carb
Stock jetting.
7" hg step up springs.

Heads Gen I Ported.
Compression running around 150 psi across the board.
Vacuum holds strong at 18" at idle 15" in gear and 20"cruising.

Forged flat tops
Hardened valves
Hardened push rods 5/16th x 7.794in length
104lbs valve springs

Headman Shorties
1 5/8 in. primaries
3in collectors
2 1/2 ypipe back.

Hope thats enough information to help.

This is where it sits at this time. I'm thinking go back to the original distributor springs and bring the timing up some more. The more I pull it back the more torque on the low end but the top end falls off alot sooner.

I love the low end power but... Any tips on tuning to get that power band up a little higher or a good timing curve to set for this cam? Startin to get nervous about pushing it beyond 16 or 17* btdc at WOT. When it detonates I can't hear the knock without a stethescope. The downside to stronger thicker parts i guess.

I'm accustomed to stock but this new setup is startin to drive me nuts

 

Welp a quick update having it at 17* instead of 14* like the cam card calls for has shifted the power from 1500-3500 to 2500-4500 but it isn't pulling in the same manner as before. Seems 15-16* is the hot spot for it.

Now for the real kicker. Runs outstanding when the engine is around 160-170 once it gets up to about 190 and settles there power goes to hell and it runs seemingly rich.

So my money is on mixture now. Gonna be looking at a wideband O2 this weekend to get that RIGHT.

But if anyone has a good suggestion for dist springs base and total advance to squeeze a little more power out that would be great.

 

#1 Cam cards list crank degrees, NOT degrees of spark advance.
#2 You need to use a dial-back timing light to determine what your mechanical advance is and your total advance.
#3 Your vacuum advance line needs to go to manifold vacuum and not ported vacuum.
#4 Springs do not change the AMOUNT of mechanical advance that is added, only the rate at which it is added.


15* should be pretty good for initial advance. Vacuum advance will be adding about another 15* like you said and that's normal, but a bit irrelevant to this situation of power loss.

You want your mechanical advance to be adding around 18* - 20* so your total advance will be 33* - 35*. Mechanical advance is measured using a dial-back light with the vacuum advance unhooked and plugged on the vacuum side. Mechanical advance is adjusted by swapping bushings on the mechanical advance mechanism - where the springs go. Mechanical advance can also be limited by adding metal or with screws if the right bushings aren't available to you.

Once this is done and you have about 35* total advance at WOT, then you can just adjust intial advance up or down 2* or so to find your best power at WOT. You can also change springs until your bottom end torque and throttle response are to your liking but still staying out of spark knock. One light spring and one medium spring is a common combination if you want somewhere to start from.


Good plan on the WBO2! You may indeed be running too rich. An engine running to rich will seem to want extra spark advance. If you lean it back down you may find the engine only wants 32*-34* total advance and makes more power that way.

Edit: If you have any trouble starting your engine hot with 15* initial then lower the initial and add some to the mechanical advance to make up for it. If you have an adjustable vacuum advance you may want to loosen it up so it adds a little more at idle.

 

Thanks a bunch gonna go through it here in a little bit to get the total timing on it. I haven't pulled it off of 17* yet but going to here shortly. Then I can come out with the full mechanical timing curve. Right now the timing on the vac is sitting around 30-32* and it starts up great hot or cold. A little more stubborn when hot but a little throttle fires it right up. Will have more information here in a little bit.

Once again thank you.

 

RPM DEG
700 15
1000 30
1500 32
2000 35
2500 36
3000 37
3500 38
4000 41

Vacuum pulls in about 15deg as it stands now.

 

A quick update:

Edit: Checked the plugs this evening. No fouling. In fact they look perfect. Even burn across the plug no splotches no dark carbon only a small layer of suit. It's idling smooth again as well. On the plus side I noticed some fuel hose needs replacing between the steel tank lines and the fuel pump. Both spongy and cracked. Willing to bet a piece flaked off and made its way to the carb. Would explain one or 2 things.


Put my order in for a wideband kit today should be in tuesday. $236 guage 0-5v sensor and lc-1 module all included. Seems fair considering what the sensors go for by themselves.

The way the timing is throwing way out at off idle without the vacuum advance has me thinking the springs are definitely too light. Gonna toss one of the originals against one of the lightweights and see if that pulls it back enough.

Can't wait to have this thing running the way it was meant to. Alot of hard years working to restore it and finally coming down to the home stretch.

 

Switched one of the light springs for one of the originals and the timing perfect. Power now stretches evenly from 1500-4000.

Base 15*
Mech +20*
Vac +18*

Runs SMOOOOOOTH.



Now I'm down to mixture. And that will be a project later in the week.