383 combo

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cab0154
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Re: 383 combo

Post by cab0154 » Thu Apr 19, 2018 10:55 pm

Sounds like a very solid 10 second combo with the right converter
"Anyone who thinks the low RPM engine will be faster just does not have as much experience as the rest of us" -The late, great Joe Sherman.

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Re: 383 combo

Post by tcb3274 » Fri Apr 20, 2018 8:42 am

Thanks kirkwoodken for that information. Harold was very big on this cam!

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Re: 383 combo

Post by tcb3274 » Fri Apr 20, 2018 8:43 am

cab0154

That would be great! Thanks for chiming in!

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Re: 383 combo

Post by tcb3274 » Fri Apr 20, 2018 10:58 am

Any ideas of what the rpm band will be in a 383?

Im thinking anywhere from 6300 to 6800

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Re: 383 combo

Post by cab0154 » Fri Apr 20, 2018 2:01 pm

tcb3274 wrote:
Fri Apr 20, 2018 10:58 am
Any ideas of what the rpm band will be in a 383?

Im thinking anywhere from 6300 to 6800
I would think the shift point would be between 6700-7k depending on what the top end allows it to do. at 6800 I came up with cylinder demand of 266 cfm at 100% VE.
"Anyone who thinks the low RPM engine will be faster just does not have as much experience as the rest of us" -The late, great Joe Sherman.

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Re: 383 combo

Post by tcb3274 » Fri Apr 20, 2018 2:41 pm

The engine was on the dyno before with a ICL of 108 and it clocked out at 6700 making max power. I re degreed it bring the power in sooner and to not leave anything on the table, but it has not been dynoed at that degree.

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Re: 383 combo

Post by steve cowan » Fri Apr 20, 2018 7:11 pm

My opinion is if you are serious you have to turn engine 500-1000 rpm past peak power on the gearshift, I have not dynoed any of my engines because I can't afford it but I use the track to test and try different ideas and what I found over a dozen passes in one day was changing the gear shift rpm in 100rpm increasements netted me faster et and slower mph, the cam I was recently using was my comp billet N20 cam as at the time it was the only small base circle cam I had,I am using scat 8740 i-beam conrods, my 5.7 scat H-beams will clear a standard base circle cam.
Anyway,
254-260 @ 0.050"
680 lift with 1.6 rockers
112 lsa in at 106-108 tried both made no difference.
I ran car from 6600 on the shift and over a dozen or so passes up to 7500 on the shift it ran it's quickest, the car traps at 6800
I will try a set of 4.3:1 rear gear eventually as I believe it should trap at 7000 plus
I am giving engine freshen up at the moment, I have a choice of a small base circle cam -Howard's 257-263 @ 0.050
680 lift
106 lsa in at 102 icl
Comp roller
262-270 @ 0.050
680 lift
106 lsa in at 102-104 icl
Can use H-beams but need to resize and bolts so always at a cost
I am running psi springs 230-600 nose
Ti valves and retainers
Heads are out of the box 215 dart pro 1
I have run 830 annular holley 11.4 s
I am using a 950 hp carb at the moment
I am using a 850 speed demon with 1 3/4
Throttle bore on my stockish 327
At the moment, it ran 107 mph last weekend with the 830 annular but driving on the street it seems a lot more responsive and I believe I can get it to run 110 plus
Next weekend,
Hopefully some of the information might give you some ideas on your own build
Thanks
Steve C
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Re: 383 combo

Post by tcb3274 » Sat Apr 21, 2018 10:41 am

Steve

What is the poundage of the car and the rear gear?

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Re: 383 combo

Post by steve cowan » Sat Apr 21, 2018 4:49 pm

3400 with me
4.1:1 rear gear
255/60/15
Turbo 400 8 inch 5600 rpm converter
I have a 9 inch 4000 rpm converter which I feel is a bit tight
Foot brake only no trans brake
Is your 750 holley stock out of the box??
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Re: 383 combo

Post by tcb3274 » Sat Apr 21, 2018 8:03 pm

Steve

I don't remember at this time what jets are in it, but it is a stock Holley 750 with the choke horn milled off and has some emulsion air than stock as well. I'm sure a bigger carb would benefit me as well.

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Re: 383 combo

Post by Carnut1 » Sat Apr 21, 2018 8:20 pm

steve cowan wrote:
Fri Apr 20, 2018 7:11 pm
My opinion is if you are serious you have to turn engine 500-1000 rpm past peak power on the gearshift, I have not dynoed any of my engines because I can't afford it but I use the track to test and try different ideas and what I found over a dozen passes in one day was changing the gear shift rpm in 100rpm increasements netted me faster et and slower mph, the cam I was recently using was my comp billet N20 cam as at the time it was the only small base circle cam I had,I am using scat 8740 i-beam conrods, my 5.7 scat H-beams will clear a standard base circle cam.
Anyway,
254-260 @ 0.050"
680 lift with 1.6 rockers
112 lsa in at 106-108 tried both made no difference.
I ran car from 6600 on the shift and over a dozen or so passes up to 7500 on the shift it ran it's quickest, the car traps at 6800
I will try a set of 4.3:1 rear gear eventually as I believe it should trap at 7000 plus
I am giving engine freshen up at the moment, I have a choice of a small base circle cam -Howard's 257-263 @ 0.050
680 lift
106 lsa in at 102 icl
Comp roller
262-270 @ 0.050
680 lift
106 lsa in at 102-104 icl
Can use H-beams but need to resize and bolts so always at a cost
I am running psi springs 230-600 nose
Ti valves and retainers
Heads are out of the box 215 dart pro 1
I have run 830 annular holley 11.4 s
I am using a 950 hp carb at the moment
I am using a 850 speed demon with 1 3/4
Throttle bore on my stockish 327
At the moment, it ran 107 mph last weekend with the 830 annular but driving on the street it seems a lot more responsive and I believe I can get it to run 110 plus
Next weekend,
Hopefully some of the information might give you some ideas on your own build
Thanks
Steve C
Steve, friends don't let friends drive stock. Hit thise heads with a die grinder! Even a quicky job will add 30cfm intake flow. The exhaust is a bit tougher. Thanks, Charlie
Servedio Cylinder Head Development
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9:00am - 9:00pm EST

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Re: 383 combo

Post by steve cowan » Sat Apr 21, 2018 11:51 pm

Hi Charlie and thanks for the response,
I am actually picking up the dart pro 1 s from my machine shop tomorrow, they had a check over and clean up, guides are still good and getting a decent valve job, I have not had them on my flowbench yet, I am going to disassemble the heads and take some measurements, I did cc the runners and combustion chambers and fluff and buff them with 60 grit roll when I first purchased, I kept the chambers as cast,
At the moment I think the engine making approx 500-510 hp and the heads are probably holding the engine back, I don't want to pay someone to port the heads for me as I enjoy doing as much of the work as possible but to be honest I don't know where to start and I am worried I will mess up a good set of heads, I have some basic porting and measuring tools, I was also thinking of sending a cylinder head to Tony knight and pay him to port one intake and exhaust and chamber for me to copy the rest but I have not talked to Tony about this as it was just a thought, I have my bench up and running and has performance trends software but again I am left scratching my head most of the time,
There are a lot of guys here that get awesome results from a 10.5:1 comp 383 sbc and I would like to be one of those guys

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Re: 383 combo

Post by Carnut1 » Sun Apr 22, 2018 2:27 am

Tony does killer work. I like the idea sending them to him and copying the rest. That would be a nice project.
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Re: 383 combo

Post by MadBill » Sun Apr 22, 2018 12:43 pm

steve cowan wrote:
Sat Apr 21, 2018 11:51 pm
... I don't want to pay someone to port the heads for me as I enjoy doing as much of the work as possible but to be honest I don't know where to start and I am worried I will mess up a good set of heads, I have some basic porting and measuring tools...
With the will to learn and a few tools, some guidance from a book or books such as this one by David Vizard: https://www.amazon.com/David-Vizards-Cy ... 1934709646 you will be well on your way to better performance and a sense of accomplishment.
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

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Re: 383 combo

Post by steve cowan » Sun Apr 22, 2018 4:45 pm

MadBill wrote:
Sun Apr 22, 2018 12:43 pm
steve cowan wrote:
Sat Apr 21, 2018 11:51 pm
... I don't want to pay someone to port the heads for me as I enjoy doing as much of the work as possible but to be honest I don't know where to start and I am worried I will mess up a good set of heads, I have some basic porting and measuring tools...
With the will to learn and a few tools, some guidance from a book or books such as this one by David Vizard: https://www.amazon.com/David-Vizards-Cy ... 1934709646 you will be well on your way to better performance and a sense of accomplishment.
bill,
funny you should say that as i am reading davids book at the moment
how to build horsepower carbs and intakes,i have most of DV books plus a lot more in my library,and of course you are 100% correct (as usual lol)i do have the desire to learn but i spose the fear of failure is what holds me back,i purchased a bare cast dart 170cc head a while back to use as a test head and have modified a intake and exhaust port and bought a couple of different shape valves as well,i have not had it back on the bench as of yet as this thing called going to work 60-70 hrs a week gets in the way of having fun,thanks for kicking me up the backside bill it is much appreciated and i apologize for hijacking the OP thread that was not my intention

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