lets see 72 duster 4 speed, 391s. would like to use scat bottom end kit.. forged pistons and h beam rods. forged crank. holley carb 750 or larger , trickflow heads. unsure about piston type . hydraulic roller cam... recommendations on this, street duty occasional track run.would like to run pump gas 500 hp. this is my last build.. i want to do it right.Begin here giving us the info we need.
making that attempt...Just an observation: This is the way many questions get asked on Facebook, “what’s everyone running”, and all too many will start throwing their .02 in with what their combo is or tell you what you should do, then it typically turns into pure nonsense. Here, you have to give specifics. And then you’ll get some good advice from many helpful knowledgeable people.
On my 360 based stroker I used a Blueprint short block (9.8ish CR) mildly worked over EQ heads with the stock 1.92” intake valves, 750 DP w/no choke on an Air Gap, a 280 advertised, [email protected]” .517 lift hydraulic flat tappet cam (yielded a rock solid racy idle and pulled to 6000rpm) 1-5/8” headers w/3” exhaust, a 10” 3500 converter and 4.10 rear. Nothing trick or special, 100% street able manners and ran high 11’s in the 1/4. Pump gas is all I ran, I could have taken long trips in it if I wanted. It would be considered a mild build, but was optimized. Make sure everything is matched and then optimized by working on tuning (engine/drivetrain/chassis) If you called various cam companies for a recommendation I’d bet they’d spec something with the duration @050” of low/mid 230’s maybe even up to low 240’s, some depending on who you call would spec a faster rate lobe with higher lift for the heads, and grind it on a 110 LSA. Seems to be the default specs many give in many cases when calling , especially as soon as you mention “street”......lets see 72 duster 4 speed, 391s. would like to use scat bottom end kit.. forged pistons and h beam rods. forged crank. holley carb 750 or larger , trickflow heads. unsure about piston type . hydraulic roller cam... recommendations on this, street duty occasional track run.would like to run pump gas 500 hp. this is my last build.. i want to do it right.
Do you mean use HR cam with solid roller lifters ?Skip the hydraulic roller. You can use HR a lobes, just run solid rollers on it. Lash it at .002 cold and send it.
It’s best to figure out what you want out of your car. Street/strip or canyon carving/auto cross. Due to what you want out of your car the cam selection will be a little different, depending on power brakes, carb selection, DP or vacuum second. What heads and valve size, intake and such.
Currently my 72 duster set up for canyon carving / auto cross
340 .30 over
4-speed 3.91
Comp EX285HL, 241/247 at .050 110LSA
2.02 J heads,
Air Gap,
Holly 750
Vac brakes
The motor pushed 390hp on the dyno, but is not happy with a 4 speed setup.
I’m changing my heads to a set of Eddy RPM heads that are fully ported with 2.05 valves, ported Airgap, removing Vac Brakes. New cam solid flat 234/234 at 50 on 107+2.
I’m really tempted to drag the motor to Cali and run it on my brothers 901 superflow and see how these changes to the motor change the power / power band...
Don’t worry about valve lift. It’s not something to worry about unless you have a cam already with huge lift!yes..looking for recommendations on lift etc... for a street some strip 408
was the carb a DP or vac sec? Just an old 750 type or the newer ones with adjustable throttle plates, etc like Quick Fuel, BG, etc ?
My 416 has a step down cam from yours (comp 274-solid). I have a BG Silver Claw DP. And we have to play the throttle plate stops and other stuff to tune it. I’ve got a tight converter and it will get an off idle stumble it not tuned right.
Which make you wonder about the quality of the build....Almost cheaper that you can build one..
Mopar 408CI Stroker Crate Engine | Small Block Chrysler | Longblock | Roller Cam
I fixed your sentence to clarify what you meant to sayWhich makes me wonder about the quality of the build....
I know you and I are discussing this on a private thread. Would it be worth it to have a custom cam ground for my application? I'm will to pay extra, to a point, for the right cam for my car. Do you have a list of custom cam grinders you like? Time's coming up for me. Thanks , Rumble.Don’t worry about valve lift. It’s not something to worry about unless you have a cam already with huge lift!
The pistons in the kits (or separate) have valve reliefs ready for .600+ lifts. You just have to make sure your properly timed in order to make sure the valves clear the piston during there cycle.
A combo is what you need like what 12many to James Clews left behind.
The way to choose a cam general basics.
I say this because the way a cam can be cut an show a huge difference. So below is “In General” & what you’ll find with off the shelf cams.
Duration; is going to be the operating rpm range. The cam companies give you a general RPM band range there cam will operate in. It’s not in stone but close enough for the most part.
Lift; Use as much as you can get as long as the head flows at the valve lift for the cam. Is this important? Not really huge but the more you can take advantage of the heads flow capability the better. But it is not a huge deal. Don’t sweat it.
Rate of lift; Of the valve is the quicker is better but taxing on the valve train which shortens longevity of the valve spring. It’s a catch 22 that is met in the middle with the cam grinders on there shelf cams.
LSA; Everyone loves that muscle car chop at idle. It’s the least of your worries. For a street & street strip ride, a 110 has that sound and works great with automatic transmission cars. I’d go 2*’s narrower for a manual.
Going with a 112+ often requires a rise in compression to offset a lower lack of torque and the idle starts to smooth out.
Error on the small side; This is something you have read over and over which is sometimes ignored and later regretted. Think of it this way, if you error on the smaller side, it’s added torque & probably only a few HP short of the goal. Error on the bigger side, the engine/car feels crappy down low.
Camshafts are like socks. There often changed and there are lots of verities out there to choose from. Search out lots of combinations. It’ll help in the game plan. And make a game plan and stick to it. Not sticking to it gets expensive.