Output guess of SBC build.
#1
Thread Starter
Joined: Jan 2007
Posts: 11,939
Likes: 32
From: Conroe, Texas
Output guess of SBC build.
Alright fellas, this is what i wanna do:
383 crank in a 4 bolt 87+ SBC.
DART 230cc heads(pro 1)
Roller cam, 242/248 @.050 542/564 lift on a 112 LSA
Flat tps with 11.1 compression.
RPM air gap intake.
1 3/4 hooker headers.
Holley 750(pro form) carb.
Scat 6 inch rods.
I am hoping this will make over 500 fwhp, think it will go on 93 octane?
Thanks for any input fellas, this is not a gaurontee but it is what id like to build if i get the $$$.
Zane
383 crank in a 4 bolt 87+ SBC.
DART 230cc heads(pro 1)
Roller cam, 242/248 @.050 542/564 lift on a 112 LSA
Flat tps with 11.1 compression.
RPM air gap intake.
1 3/4 hooker headers.
Holley 750(pro form) carb.
Scat 6 inch rods.
I am hoping this will make over 500 fwhp, think it will go on 93 octane?
Thanks for any input fellas, this is not a gaurontee but it is what id like to build if i get the $$$.
Zane
#4
i build a 383 thats real close to that,flattops,damn near same cam with brodix ik200 heads,pro products crosswind and a holley 770,it makes 550hp at 6200 rpm's also makes around 525 ft lbs at 4000 on 93 octane
#5
Thread Starter
Joined: Jan 2007
Posts: 11,939
Likes: 32
From: Conroe, Texas
So im good then, i am wanting the 230s because they will be going on a 400 build later so i would rather buy one set of heads than two ya know? So 93 octane is no problem then, i guess im gonna say a 6500 shift point is the possiblility?
#7
Heads, cam, headers, ect ect.
The guy that built the motor in my car told me that its better to go with a cam thats to small then one thats to big.
If you ask me, heads that are to big for your motor will kill the air flow velocity holding the motor back.
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#8
Yeah most people get hung up on flow #'s at max lift, its not about port volume and max airflow its more about port velocity. Thats the main reason Vortec heads are so effective w/ their small runner volume. So IF it were mine I would run a 200-210cc w/ 2.05 valves max on anything under 410" and 7500prm, otherwise you'll end up with a VERY lazy engine that you need to rev the **** out of to make any power. I would run a min of around .590-620" lift and 242*-254* camshaft, you also must remember that cubes will eat up duration and make the same camshaft have a different power band from a small to a larger mill.......
#10
Thread Starter
Joined: Jan 2007
Posts: 11,939
Likes: 32
From: Conroe, Texas
Well, i will be running a solid roller on the 408, i even have the possibility of stroking the 400 past 408 but i heard it is hard to squeeze 434 cubes outta a stock 400 block.
#11
I'm going to say that the heads and large duration are going to kill any low end power this motor could make, especially with your air-gap dual plane intake. And then the dual plane will choke your top-end. I bet that combo won't make 500hp. A single plane intake might get it closer. And go with smaller heads. The 230s might make 5 more horsepower at peak but at the cost of 5 or more horsepower throughout the whole rev range(especially down low). Look at more around a 210cc head with that cam and a single plane intake and 500hp will be close.
#12
like i said before the heads are too big,but dont mess with the rest of the combo and you will have a great street combo.
1 thing i have learned over the years is buy the right parts for the engine you are building not one you want to build down the road.Usually down the road takes alot longer than you originally thought and then your stuck with a bad combo longer.Build the motor the way it should be,when your ready to upgrade,sell the old engine and build a new one,if your going bigger and badder no parts should work from one to another-if something does it isnt correct for one or the other.
1 thing i have learned over the years is buy the right parts for the engine you are building not one you want to build down the road.Usually down the road takes alot longer than you originally thought and then your stuck with a bad combo longer.Build the motor the way it should be,when your ready to upgrade,sell the old engine and build a new one,if your going bigger and badder no parts should work from one to another-if something does it isnt correct for one or the other.
#16
I am going to build my motor with an aftermarket block but wil lmore then likley keep the smaller heada to go with the smaller headers and all.
Then when I tear into the motor again I can if need be bump up the CUI and throw on some larger heads and headers.
I am going for big power with heads that were made untill the early 90's and are small to most peoples standards.
On the old 468 the car made insaine power on the motor from near idle all the way to 7k RPM and had compression a little lower then what the cam recomends. Thats with a single plain intake.
In all honesty it looks like you will be stuck with a top end power car with a bottom end to mid range power intake..
#17
I say do it but use at least a victor jr., Preferably a Super Victor. With those heads ported and a super vic with a little plenum work that thing will make insane power and probably go some 6.60's at 103mph when dialed in, in a 3200lb car.
#18
Thread Starter
Joined: Jan 2007
Posts: 11,939
Likes: 32
From: Conroe, Texas
No ****? I have a RPM air gap already but if i can score a used vic JR i will deffinatly tdo so but funds are running to a close pretty quikly and i want the dana 44 and T56 installed by next month too. I will let you guys know what happens. I am deffinatly going to buy the LS7 lifters.
#20
I wouldn't recommend running a single plain intake or the 230 cc intake runner heads with the cubic inches and compression that you are running. Hell, my circle track race motors that are 383/406's with 14:1+ compression & methanol, I still don't recommend the 230cc heads. You can watch the guy's out at the track with heads that are too big get passed by the ones that use an appropriate sized head for the cubes at hand. I would start with a 200cc intake runner head and port them to around 207-212cc, then you will have a set of heads that will work very well with your 408 as well.