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Topic Review (Newest First)
12-02-2012 04:40 AM
Choctaw Bob
Quote:
Originally Posted by kentactic View Post
Ok thanks for the input. Ill add this car wont be driven to the track. always trailered.
I ran 5.90 in the 1/8th with a 410 cu in Windsor in a 92 Mustang. This car had 12 to 1, heads that flowed 360 cfm intake, a solid roller .700 lift cam and a 500 shot of 2 stage fogger nitrous throu a JW powerglide and 4.10 gears.
This is just to give you an idea where you have to go to run 5s in the 1/8th.
Get a copy of desktop dyno so you can run the combinations of compression, cam, power adders so you don't waste money on components that won't get you where you want to go.
Set a goal of how quick you can afford to go, then build it! Have fun.
12-02-2012 03:22 AM
kentactic
Quote:
Originally Posted by hcompton View Post
That cam does not guaRantee 500 hp. More like 450 with a good intake like victor jr or victor. Heads may also be an issue if you want to make 500 exactly. look like more around 400-450 with less than 210cc heads. (brodix, dart) 210 or larger would be better for max effort racing but i would go cheap for now and plan to rering in two years with a few upgrades.

You will have lot of fun just getting to the track every week with clean runs fast or slow. Best not to blow the budget before you hit the track.


I agree 100%. Get the car built for not too much money, and play with it. Once it gets boring start upgrading parts. Good stuff.
12-01-2012 09:13 PM
hcompton That cam does not guaRantee 500 hp. More like 450 with a good intake like victor jr or victor. Heads may also be an issue if you want to make 500 exactly. look like more around 400-450 with less than 210cc heads. (brodix, dart) 210 or larger would be better for max effort racing but i would go cheap for now and plan to rering in two years with a few upgrades.

You will have lot of fun just getting to the track every week with clean runs fast or slow. Best not to blow the budget before you hit the track.
12-01-2012 05:22 PM
kentactic
Quote:
Originally Posted by cdminter59 View Post
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.
12-01-2012 05:21 PM
kentactic
Quote:
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.
12-01-2012 11:16 AM
cdminter59
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.
12-01-2012 08:41 AM
hcompton 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.
12-01-2012 12:34 AM
vinniekq2 the valves are for a hydraulic flat tappet.
I use heavy duty or severe duty valves
12-01-2012 12:17 AM
cdminter59
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.
11-30-2012 11:46 PM
kentactic Also that rotating assembly is optional 1 peice or 2 piece seal.
11-30-2012 10:54 PM
kentactic
Quote:
Originally Posted by cdminter59 View Post
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.
11-30-2012 09:51 PM
cdminter59
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.
11-30-2012 09:12 PM
vinniekq2 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.
11-30-2012 08:57 PM
kentactic
Quote:
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?
11-30-2012 08:57 PM
vinniekq2 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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