Hello again...I have the carb figured out...now...how do you determine if you need vacum or mechanical...electric choke or no choke?
354 hemi...dur= .050 230 230
adv 300 300
lift 480 480
lobe 108
30 over...mallory dist
vac at idle 10......
thanks....mike
vacum or mechanical? choke or no choke?Hello
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Re: vacum or mechanical? choke or no choke?Hello
vacum or mechanical what?
Re: vacum or mechanical? choke or no choke?Hello
If yours is a street car, where you have all kinds of different loads and conditions i think you'll find better driveability with an electric choke and vacuum secondaries.
While its true you could adjust opening time on mechanical secondaries you know you're going to put your foot all the way in it every time so the adjustment might not mean much. Adjusting the opening of secondaries is a kind of fail safe option. Once tuned right, they will never open until the extra flow is demanded by the motor... no bog. You wanna enjoy driving it, right?
While its true you could adjust opening time on mechanical secondaries you know you're going to put your foot all the way in it every time so the adjustment might not mean much. Adjusting the opening of secondaries is a kind of fail safe option. Once tuned right, they will never open until the extra flow is demanded by the motor... no bog. You wanna enjoy driving it, right?
Re: vacum or mechanical? choke or no choke?Hello
>Adjusting the opening of secondaries is a kind of fail safe option.
here I meant VACUUM secondaries.
here I meant VACUUM secondaries.
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- Joined: Sat Nov 30, 2002 2:16 pm
Re: vacum or mechanical? choke or no choke?Hello
secondaries!polyspheric wrote:vacum or mechanical what?
Owner of the Poor Man's Hemi Cuda
Re: vacum or mechanical? choke or no choke?Hello
Thanks..I went with a all aluminum street avenger 650, vac 2nds,electric choke...bolt it on monday...bought from Holleytv.com
should have checked Jegs first....much better deal ohwel!!!
thanks for all the info guys...will post pics soon.....
should have checked Jegs first....much better deal ohwel!!!
thanks for all the info guys...will post pics soon.....
Re: vacum or mechanical? choke or no choke?Hello
mrossbach wrote:Hello again...I have the carb figured out...now...how do you determine if you need vacum or mechanical...electric choke or no choke?
354 hemi...dur= .050 230 230
adv 300 300
lift 480 480
lobe 108
30 over...mallory dist
vac at idle 10......
thanks....mike
you definitely should run a vacuum advance AND a mechanical advance together, because vacuum goes away and mechanical takes over at RPM WOT
if you run vac advance, it will pick up your idle and help tame that big cam
run as much initial timing as you can without making the engine hard to crank over, and run as much total timing as you can at high rpm without pinging- timing tames a big cam for the street
to be honest, that's a big cam for a 354- let me relate this story
I ran a 308/320 advertised duration, 230/240 @ .050", .520" lift cam in a "brand x" 406 motor- it took some work to tune it, had to use 1 step richer metering rod, and also a weaker metering rod spring, to get it to idle and not be lean
I took that same cam, put it in a 350, and it was a BEAR to tune- it was so lean it blew flames out of the carb when it was cold
I'd recommend a smaller cam for a 354 for a street car, say 200 degrees @ 050"
basically look at what other 350 engines run for cams, and choose a cam with those specs and performance level- such as a 340/360 Mopar cam specs- if I was building a 354 I would not put a 230 @ .050" cam in it, unless it was a stick with 4.33 gears, or an automatic with 3000 stall converter. My 230 duration cams were dead below 3000 rpm, they hit like a sledgehammer right at 3000 rpm, and pulled to 5500
Re: vacum or mechanical? choke or no choke?Hello
Hello thanks for the info. I was just going to sell the engine afterI built it. However I found a nice 46 studebaker p/u. I have a 700r4 w o/d trans, dana 61 with 456 gears, 33 15s rr tires...airbag susp....I just put a Holley, aluminum, 650 ,vac secds, electric choke.oldngood wrote:mrossbach wrote:Hello again...I have the carb figured out...now...how do you determine if you need vacum or mechanical...electric choke or no choke?
354 hemi...dur= .050 230 230
adv 300 300
lift 480 480
lobe 108
30 over...mallory dist
vac at idle 10......
thanks....mike
you definitely should run a vacuum advance AND a mechanical advance together, because vacuum goes away and mechanical takes over at RPM WOT
if you run vac advance, it will pick up your idle and help tame that big cam
run as much initial timing as you can without making the engine hard to crank over, and run as much total timing as you can at high rpm without pinging- timing tames a big cam for the street
to be honest, that's a big cam for a 354- let me relate this story
I ran a 308/320 advertised duration, 230/240 @ .050", .520" lift cam in a "brand x" 406 motor- it took some work to tune it, had to use 1 step richer metering rod, and also a weaker metering rod spring, to get it to idle and not be lean
I took that same cam, put it in a 350, and it was a BEAR to tune- it was so lean it blew flames out of the carb when it was cold
I'd recommend a smaller cam for a 354 for a street car, say 200 degrees @ 050"
basically look at what other 350 engines run for cams, and choose a cam with those specs and performance level- such as a 340/360 Mopar cam specs- if I was building a 354 I would not put a 230 @ .050" cam in it, unless it was a stick with 4.33 gears, or an automatic with 3000 stall converter. My 230 duration cams were dead below 3000 rpm, they hit like a sledgehammer right at 3000 rpm, and pulled to 5500
It runs much better now. The carb I had was used for 1/4 mile...it was not really set up for street use..ok thanks again...mike r. mich