barnett468

Put tape over it before proceeding.



Is this a 351 windsor?

If it's a 289 or 302 you do not have enough compression with 61 cc heads.

That cam has an intake valve closing time of approximately 61 degrees.

Make sure your gas is 91 – 93 octane and less than 3 months old if it’s corn gas.

Install exact factory recommended heat range plugs.

Set idle speed to 850.

Set idle timing to 12 deg btdc.

Set fuel mix screws until highest rpm is barely reached.

Set idle speed to 850.

Drive car for 10 minutes to get eng warm.

Turn it off and let it sit 10 minutes then restart taking notice how fast it
turns over.

Turn dist until it just barely reaches peak rpm. Once it is reached the rpm will
barely increase as you turn the dist or it will stumble.

Lock it in 2 degrees before peak rpm or stumble.

Turn it off and let it sit 10 minutes then restart taking notice how fast it turns over.

If it turns over noticeably slower then reduce timing by 3 deg.

You are done with idle timing.

Set max timing to 34 deg btdc using dist stops.

Drive it.

If it pings upon acceleration then it is likely advancing too soon.

See what rpm it reaches max advance it.

If it is below 2800 rpm then change the springs until it reaches max timing at around 400 degrees more than where it currently is.

Drive it, if it still pings then change springs again.

If it still pings once you reach max timing at 2800 rpm or slightly higher you likely have one or more of the following problems:

too lean

your gears or too tall

your stall convertor is too low

your engine is running over 205 degrees.



You should have a 6.5 power valve.

From a stop, depress gas pedal quickly to 1/2 or 2/3 throttle. Do not floor it.

If it burbles/stutters and hesitates for a second, the mains are too large.

If it hesitates with no burble/stutter like it is out of gas, the main jets are too small.

Change jets 2 sizes at a time.

Gun Jam

Thanks for the excellent write up.

I went to go try it out got to this step "Turn dist until it just barely reaches peak rpm. Once it is reached the rpm will barely increase as you turn the dist or it will stumble"

and ran into an anomaly.

at 850rpm rolling in advance from 12 deg caused engine rpm to increase rapidly after passing 20 deg it was still increasing at a fair rate but it appeared to be tapering off. according to the timing light I was well past 30 deg initial. The engine was still running smooth and rpm had come up to 1400.

The timing light is an innova digital 3568+ and says it is compatible with MSD ignitions I am running and MSD A6. I dont know if the readings are bogus or not at this point. I was using the adv button to roll in timing light advance until the TDC 0 mark was on the indicator and it would tell me the adv on the LCD. the RPM display on the light works well and the light pulse looks fine. MSD has confirmed that the innova 3568 will not work with MSD ignitions and suggested and MSD timing light. The specs on summit for the innova 3568 says it does work with Mulit spark ignitions....

I will look into this before I continue...any thoughts on this?

thanks

-Gun

67mustang302

I use a simple timing light that's just a light, not anything else, no adjustor etc.

CD boxes can get pissy with anything other than basic timing lights.

barnett468

OK,

The "rapid" engine rpm is most likely caused by the advance inside the distributor advancing.

If it rapidly advanced at around 1100 rpm or less, it is definitely due to the springs on the advance weights being WAY to light.

If you do not have springs you can get them from Summit or any speed shop.

If you reread my previous post, you will now hopefully understand what I was referring to regarding the distributor springs and max timing rpm.

If you have really low compression you can often turn the dist until you have high initial timing and not notice a stumble etc. in your driveway but you really can't drive it this way.


I still have no idea exactly what engine or rear gear I am trying to help you with.








sThis is cause byHE ENGINE

barnett468

Unfortunately, I am unfamiliar with the compatibility of timing lites with multi spark ignitions.

Do you have flat top pistons or dished pistons?

barnett468

what size are your carb jets?

is there an edit button somewhere?

Gun Jam

I'll check the adv weights but Im pretty sure they are set for "all in @ 3k" I dont remember the color combo.

pistons are flat top.

engine is 302

Gears are 3:80s

main jets are 70 but being compensated at higher speed using a larger than stock high speed air bleed. I really do need to go back to base line after see how much timing changed things.

You probably dont have enough post yet to edit stuff.

thanks

-Gun

Gun Jam

its occurring to me that I should be running a distributor that has vac advance...The dizzy I have now does not and it is scheduled for a rebuild..so rather than rebuild perhaps I should replace it with a vac advance dizzy for improved street performance...

That brings up the issue of the vac advance module. Most take 15 deg vac to be fully advanced. My vac is never 15 at idle and will typically fluctuate between 13.5 and 12 inhg...so now I would have to track down a module that would be 10 inhg to stop advance from surging.

Any ideas on this?

Thanks

-Gun

barnett468

ok thanks for the info.

sorry tgis will be short.

you are at around 9:1 static comp.

your cykinbder cranking comp is around 140 psi theoretical.

you need around 160 psi to optimize your perf on 93 octane.

if you run e85 junk corn gas you can bump it a little miore than that.

you will possibly get a lot of "facts" about the vacuum advance. in general, in my experience it will give you no real hp gain. it is mainly to increase mileage etc.

others experiences may be different.

shelby's and ac cobras are road race cars that are not operated at peak rpm all the time like john forces funny car is and i have never seen one on one of those.

if you have a surge i need more details.

i would put the stock air and ifr jets back in it.




get any perf out of it.

r70dynamic is ariundcompn says that cam is fo

barnett468

don't believe your dist advance weight chart, only the real world matters.

your advance sounds like it is too much too soon by your description.

i would yank those heads and mill aroiund .028" off of them.

what gears ans stall or trans?