cam vs timing

[scotiascrapiron]

the ford guy at the dealership in my home town said that on a 302 stock motor,timing should be set at 12* it's a 1978 ltd motor.i have basically rebuilt the motor from the pan up.the cam that went in has 231 duration at .050,110 lobe separation and .512 valve lift int/ex. and at 12* it's a dog (spits and sputters until about 25/28 hundred rpm) then it's a beast.what do you fellas think I should do,go up or down on my advance or what,any ideas would be appreciated. mud season about to get into full swing and I need help.

 

[v-8power]

I would say with that duration your not going to make power until at least 2000RPM.
What else you have to go with it? What kind of carb, size headers?
Did you degree in your cam?

 

[scotiascrapiron]

it's a 650 holley dp with edelbrock rpm intake and edelbrock heads and yes the cam was degreed and came in at spec(intake open @ 9* btc-close @ 42* abc,ex open @49* bbc close @2* atc). like I said the motor will scream at 2500 up but getting to that point is not very pretty. I'm starting to think i'm over cammed. no headers i ported the stock manifolds and ran straight pipe to just behind the transmission (c4 with racing guts and shift kit).

 

[COPPERHEAD85]

are you running any kinda stall in the t-converter?

 

[bobbywalter]

thats uh...well you made your bed

 

[scotiascrapiron]

2600 stall and in a couple of weeks i'll be changing to d35/8.8 with 4.56 gears. won't that help?? i'm running stock b2 axles now- 3.73

 

[scotiascrapiron]

well bobbywalter, i've had chance to lay in the bed i've made but still haven't come with a plan. if you or anybody else can come up with some ideas as to what i can try, to at least get my motor running at it's best (all things considered),my deepest appreciation would be extended to you.

 

[88mudder]

What color are your spark plugs burnin? Im thinkin it could be carb adjustment.

 

[COPPERHEAD85]

i was running the same stall,3.73 gears with a larger duration cam and 2 650's and didnt have a flat spot like your having.2k and you stab it and it would roll.
i think it was at 10*timing.ill have to find the spec sheet on the cam. this has been 5 yrs off and on trial and error.now ive changed heads and intake + went up tire size since then.

 

[scotiascrapiron]

well, i put the timing light back on the shelf and pulled out the vacuum gauge.I timed it with that and got a lot better results.no more poppin and spittin but still takes a second or two to get rpm's built up. the 4.56's will help lessen that and would a higher stall make it even better.

 

[D'cheat]

It sounds like you need to play with the jets on your carb. I had the same problem with my 71 stepside. I changed the jets and BAM power is back.

 

[baddad457]

I think you need to play with the tuning first. With that cam/intake/carb, it should pull from idle on up. Look at the vacuum advance first. Is it working? Or do you even have it and/or is it hooked up correctly? Also might need a different powervalve too or switch to a vacuum sec. carb.