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Old 11-30-2012, 08:43 PM
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Sooooo anyone who read what i typed and didnt add their own "what they want for xmas" to the build have an opinion for an all track car with listed parts cam selection?

Im thinking i might be maxed out with the assault cam i linked previously.

Last edited by kentactic; 11-30-2012 at 08:51 PM.
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Old 11-30-2012, 08:52 PM
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then use race parts
ok ill go buy some "race parts" thanks.
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Old 11-30-2012, 08:54 PM
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Originally Posted by kentactic View Post
Ok thanks for the input. Ill add this car wont be driven to the track. always trailered.
Ok so that makes a big difference cause the next larger cams will still be bumping at 2k rpm. You can go with the largest flat solid magnum or xtreme.

The largest magnum is about as large as i would go. Xtreme from comp is in the same range for the largest cam. Xs290s is flat solid as well

Magnum 306S
12-225-4 - Magnum

What type of trans?
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Old 11-30-2012, 08:57 PM
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RR-652 3800-7400 .650 .024 286 256 106
ROLLER .645 .028 298 264
victor junior intake,850 HP,227 cc heads,
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Old 11-30-2012, 08:57 PM
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Originally Posted by hcompton View Post
Ok so that makes a big difference cause the next larger cams will still be bumping at 2k rpm. You can go with the largest flat solid magnum or xtreme.

The largest magnum is about as large as i would go. Xtreme from comp is in the same range for the largest cam. Xs290s is flat solid as well

Magnum 306S
12-225-4 - Magnum

What type of trans?

Now were cookin! Im really not as far as the trans. Ive heard turbo 350 a lot. It says the springs must be modified. The assault heads dual springs are good to go for that right? It also says the heads must be machined. The assault heads are good to .650" lift so theyll work as is correct?

Last edited by kentactic; 11-30-2012 at 09:10 PM.
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Old 11-30-2012, 09:12 PM
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shaft rockers. 1.6 on the intake side/ 1.5 exhaust side, power glide transmission with 5,000 stall, 4.88 gears. trans brake,get a blanket just in case.
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Old 11-30-2012, 09:51 PM
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Cam selection

If you are building a racetrack only engine why is the compression so low. The 383 rotating assembly I see is for a 1986-up Chevy street engine. They don't give you the flow rate of the heads you have listed. If I was building a cheap 383 engine I would at least buy big enough heads for it to breath. Like these SBC Chevy Aluminum Heads Assembled 210cc 2.02 Angle - KMJ Performance. Since you have a cast crank I wouldn't spin it any more than 6000 rpm. The wimpy hyd. flat tappet cam is about correct for it. You might be in the 400 hp range. Bump the compression up to 11.0-11.5 and get a Comp Cams XR300HR 12-444-8[10]. .562/.580 lift and 248/254 duration. 110 LSA and 106 ICL. Super Victor Intake and a 850 cfm carburetor. This will at least get you up to 450-480 hp and 482 lbs. of torque Then you will need a 3000 lb car with a 3500-4000 stall and some gears.
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Old 11-30-2012, 10:54 PM
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If you are building a racetrack only engine why is the compression so low. The 383 rotating assembly I see is for a 1986-up Chevy street engine. They don't give you the flow rate of the heads you have listed. If I was building a cheap 383 engine I would at least buy big enough heads for it to breath. Like these SBC Chevy Aluminum Heads Assembled 210cc 2.02 Angle - KMJ Performance. Since you have a cast crank I wouldn't spin it any more than 6000 rpm. The wimpy hyd. flat tappet cam is about correct for it. You might be in the 400 hp range. Bump the compression up to 11.0-11.5 and get a Comp Cams XR300HR 12-444-8[10]. .562/.580 lift and 248/254 duration. 110 LSA and 106 ICL. Super Victor Intake and a 850 cfm carburetor. This will at least get you up to 450-480 hp and 482 lbs. of torque Then you will need a 3000 lb car with a 3500-4000 stall and some gears.
I like that head 50 more bucks aint bad. The rotating assembly i went with is going to have to be the limiting factor. I decided to go low budget. Im just going to have to build the motor to what that setup can handle. Ill get it all put together, Get a car together and run it and see how it is. If its dog slow then i can let everyone i know run it with confidence atleast.
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Old 11-30-2012, 11:46 PM
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Also that rotating assembly is optional 1 peice or 2 piece seal.
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Old 12-01-2012, 12:17 AM
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Cam selection

It says the springs must be modified. The assault heads dual springs are good to go for that right? It also says the heads must be machined. The assault heads are good to .650" lift so theyll work as is correct?[/QUOTE] You will need to purchase valve springs that the cam manufacturer recommend for the camshaft. The springs that come installed on the heads are for hyd. flat tappet camshafts.
K12-444-8 XR300HR uses 987-16 valve springs, best roller rockers 19001-16, and push rods 7809-16.
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Old 12-01-2012, 12:34 AM
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the valves are for a hydraulic flat tappet.
I use heavy duty or severe duty valves
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Old 12-01-2012, 08:41 AM
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It looks to me like the eassult heads are procomps and the assult rotating assembly is scat. And its exteranlly balanced. So its really not great for 7k+ rpm redline. h beam rods and forged crank/pistons would be better. It will still work but might not be as good if your going for max power na. But this will easily take 500hp. I would focus on that level of performance.

With those heads and rotating assembly. I would stay with the 12-225-4 magnum. I got a feeling those heads arent going to flow real well.

Pro built powerglide like vinnie said is what you want for straight race car. Th350 is heavier and has more power loss. Its popular because it can be built cheaply and is really much better on the street than a 2 speed power glide.

Is this your first race car. If so i would focus on the rotating assemblies 500hp range. Its going to come apart at 800 hp. Also 500hp will take you down the track very fast. You will have your hands full getting it in a car and going down the track straight. Also at 500 the weak stuff will start breaking and you will start apending your racing budget on saftey equipment.

Sorry not trying to confuse you just want to help you get something together that will last a few race seasons and provide the punch needed to move you down the track. 1/8 and 1/4 mile cars usally are set up a little different. Might want to make a choice on what ypur going to run. Gears are usally different for 1/8 mile.

Did i hear a "mud racing" in there.... Mud drag racing usally requires a pro to build the engine cause you will be bouncing around and engine will hit the rev limiter and fall on its face. So they build the motors to "cam out" and not over rev or invest thousands in electronics.
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Old 12-01-2012, 11:16 AM
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Cam selection

A quick reply about the valve springs before you decide what head you are going to use. Here is a cheaper alterate to spending $1000 on Hyd Roller kit. This is the 306S K12-225-4 solid flat tappet complete with cam, lifters, valve springs, locks, retainers and timing chain for $434.95 or $409.88 from Amazon.com + free s&h. Pushrods part# is 7372-16 or 7972-16. Roller Rockers part# 19001-16 recommended for high lift cams. Here is another 210cc set of heads for you to checkout, same brand as KMJ is selling but with upgraded stainless steel valves. White Performance Detail Description. Sounds like a better head than what KMJ was selling. Call them with your cam info.
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Old 12-01-2012, 05:21 PM
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Originally Posted by hcompton View Post
It looks to me like the eassult heads are procomps and the assult rotating assembly is scat. And its exteranlly balanced. So its really not great for 7k+ rpm redline. h beam rods and forged crank/pistons would be better. It will still work but might not be as good if your going for max power na. But this will easily take 500hp. I would focus on that level of performance.

With those heads and rotating assembly. I would stay with the 12-225-4 magnum. I got a feeling those heads arent going to flow real well.

Pro built powerglide like vinnie said is what you want for straight race car. Th350 is heavier and has more power loss. Its popular because it can be built cheaply and is really much better on the street than a 2 speed power glide.

Is this your first race car. If so i would focus on the rotating assemblies 500hp range. Its going to come apart at 800 hp. Also 500hp will take you down the track very fast. You will have your hands full getting it in a car and going down the track straight. Also at 500 the weak stuff will start breaking and you will start apending your racing budget on saftey equipment.

Sorry not trying to confuse you just want to help you get something together that will last a few race seasons and provide the punch needed to move you down the track. 1/8 and 1/4 mile cars usally are set up a little different. Might want to make a choice on what ypur going to run. Gears are usally different for 1/8 mile.

Did i hear a "mud racing" in there.... Mud drag racing usally requires a pro to build the engine cause you will be bouncing around and engine will hit the rev limiter and fall on its face. So they build the motors to "cam out" and not over rev or invest thousands in electronics.

Ya if i can make 500hp NA im stoked. I will go with the 12-225-4 magnum as recommended. Im pretty much set at gearing this car for 1/8 mile. And no mud racing the other thing i said was sand drags. Its a 300ft race on something similar to beach sand. Its not very bumpy as top fuel cars often slap paddle tires on and run as is. Beleive it or not they hook better in the sand then they do on asphault. 100ft tall rooster is pretty cool too.
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Old 12-01-2012, 05:22 PM
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A quick reply about the valve springs before you decide what head you are going to use. Here is a cheaper alterate to spending $1000 on Hyd Roller kit. This is the 306S K12-225-4 solid flat tappet complete with cam, lifters, valve springs, locks, retainers and timing chain for $434.95 or $409.88 from Amazon.com + free s&h. Pushrods part# is 7372-16 or 7972-16. Roller Rockers part# 19001-16 recommended for high lift cams. Here is another 210cc set of heads for you to checkout, same brand as KMJ is selling but with upgraded stainless steel valves. White Performance Detail Description. Sounds like a better head than what KMJ was selling. Call them with your cam info.
Thanks i will deffinatly look into these.
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