When good is not enough, Camshaft time again.

[Kent mosby]

So it is time to install a new camshaft in my Scamp. My previous one was designed for a nitrous application and that notion is gone. Now I am at a point where I am considering just replacing the solid flat tappet with a hydraulic roller, solid roller or even a hydraulic flat tappet. The more I read, the more confused I get. The car is very street friendly and has gone 11.46 at 118, but mostly 11.7-11.9 no prep. The reason for the change is the urge to get the most out of the motor with the last cam change in my life. At 65 yo, I don't know if I will want to do it later.

What considerations are used for your buying decisions regarding cam type first?
My heads and springs will handle the roller pressure. I will be replacing the aluminum rockers with 1.5 RR steel, probably 440 source, Bushed Stainless Adjustable Rocker Arm System - 1.5 Ratio.

Solid, hydraulic, flat tappet or roller? Street friendly, yet fast at the track is my goal.

I will be talking to Dwayne at @PRH this week for his recommendations for specs.



RB 512ci, 440 source stroker kit with lightweight crankshaft, forged pistons, 10.83 CR. Trick Flow 240 heads, 440 source aluminum rockers 1.6RR, Trick flow single-plane intake. Holley Super Sniper EFI, HyperSpark ignition, coil and distributor. TTI 2 inch headers. Hughes 3000 stall TQ(yet stalls at 4500 according to andyF). 727 transmission with transgo TF2 valve body mods. B&M Quicksilver shifter. Gear vendors overdrive to 8 3/4 rear end with 3.91 gears, braced in back. SS leaf springs. Viking dual adjustable shocks. Pypes Exhaust 3" into 2.5 inch. RacePro mufflers. Cooper Cobra 275/60-15 28.2 inch diameter tires, with drag radials for track. Current cam specs 244°/252° @ .050”, 282°/290° adv, .516”/.537” lift (1.5:1 rocker), 112° LSA, .016”/.018” lash, Solid lifter from Oregon Cams.

 

[George Jets]

You don't have to over think it, Ma Mopar got it right the first time around.

Put in the "Roadrunner" flat tapet hydraulic cam and enjoy your car.

Unfortunately a lot of people over cam their engines, then are unhappy with the driveability of the cars.

Just like the small blocks > 340 cam, Big Blocks > Roadrunner cam... they run nice, sound nice and perform nice when you want to getup and go.

☆☆☆☆☆

 

[496 polara]

I would think a different solid lifter profile will give you what you want without changing much else. That said Dwayne has seen and done it all so I would give his opinion considerable weight.

 

[BSB67]

It seems unlikely that your springs will work on a solid roller.

Also seems like there is more to be gained with a cam. But cam swaps are usually a compromise, particularly on a street car.

Do you want similar idle and street manners that you have now? Or you okay with more radical?

 

[BSB67]

I would think a different solid lifter profile will give you what you want without changing much else….

Unless you are really wanting the most power, this is likely a better and more cost friendly approach.

 

[RustyRatRod]

Kent, I don't think those springs will work with a roller, hydraulic or solid. Since that's the case, I advocate for a solid roller. But since it's a street car, I would run a street solid lobe. That's one that's a little less aggressive and won't beat the valve train to death driven regularly. I would call Schneider Cams. Tell them what you have and you want a street solid roller. See what they recommend.

 

[junkyardhero]

You don't have to over think it, Ma Mopar got it right the first time around.

Put in the "Roadrunner" flat tapet hydraulic cam and enjoy your car.

Unfortunately a lot of people over cam their engines, then are unhappy with the driveability of the cars.

Just like the small blocks > 340 cam, Big Blocks > Roadrunner cam... they run nice, sound nice and perform nice when you want to getup and go.

serious question, did you even read the assignment? he clearly states that he wants to get the most out of the motor.

did you not notice that he's bumping 512 cubes with trick flow heads, almost 11:1 compression and is backed up by a 4500 stall converter and 3.91 gears? of course you didn't, because you didn't read what he wrote!

yeah a RR cam runs great in a stock application but that 431/431 268 {330hp) or 450/458 268/284 (power pack) cam in a big cube stroker is going to be akin to a 360 2bbl cam.

terrible advice, george.

 

[TT5.9mag]

If it’s very streetable, and you’re happy with how it runs now, leave it alone. You aren’t going to pick up .5 second at your level with just a cam swap. The decision NOT to run nitrous doesn’t change what the cam does in the engine, every cam is a nitrous cam, and therefore every cam is not a nitrous cam. There’s not much to gain unless you make a very large change in camshaft. Leave it alone, go drive it.

 

[TT5.9mag]

You don't have to over think it, Ma Mopar got it right the first time around.

Put in the "Roadrunner" flat tapet hydraulic cam and enjoy your car.

Unfortunately a lot of people over cam their engines, then are unhappy with the driveability of the cars.

Just like the small blocks > 340 cam, Big Blocks > Roadrunner cam... they run nice, sound nice and perform nice when you want to getup and go.

View attachment 1716466044


☆☆☆☆☆

Holy crap.






WHAT?!?

 

[TT5.9mag]

serious question, did you even read the assignment? he clearly states that he wants to get the most out of the motor.

did you not notice that he's bumping 512 cubes with trick flow heads, almost 11:1 compression and is backed up by a 4500 stall converter and 3.91 gears? of course you didn't, because you didn't read what he wrote!

yeah a RR cam runs great in a stock application but that 431/431 268 {330hp) or 450/458 268/284 (power pack) cam in a big cube stroker is going to be akin to a 360 2bbl cam.

terrible advice, george.

11:1 512 with a 268 cam. That’ll have 300psi of cranking pressure. It’ll need nitromethane to idle.

 

[Kent mosby]

If it’s very streetable, and you’re happy with how it runs now, leave it alone. You aren’t going to pick up .5 second at your level with just a cam swap. The decision NOT to run nitrous doesn’t change what the cam does in the engine, every cam is a nitrous cam, and therefore every cam is not a nitrous cam. There’s not much to gain unless you make a very large change in camshaft. Leave it alone, go drive it.

I was thinking somewhere in the .600-630 lift range. not too crazy. What other mods do you suggest?

 

[TT5.9mag]

I was thinking somewhere in the .600-630 lift range. not too crazy. What other mods do you suggest?

I won’t suggest any without knowing your goals. You’ll need to define what you’d like out of it first. “The most” is not clear.

 

[Kent mosby]

Only low 11s consistently. so about 1/2 second. Still be able to idle at 950 rpms and have enough vacuum for the EFI. no other vacuum accessories..
Same good street manners

 

[junkyardhero]

Holy crap.






WHAT?!?

shown: a visual representation of Turbo Mike's reaction

 

[TT5.9mag]

I think if you’d like to pick up 1/2 second you’ll need to jump up pretty far. Like 10-15 degrees at 050 and maybe a few more degrees of split, and as much lift as the lobe will tolerate. If you’d can afford it a solid roller will be the best. I’d keep the lobe sep pretty wide and let it run hard up top, (like 114 degrees) it won’t be lacking torque with 512 cubes. AND I would send your intake to Wilson and have it professionally ported at the same time. That’ll get you a good deal and those cooper cobras will have no chance.

 

[TT5.9mag]

shown: a visual representation of Turbo Mike's reaction

View attachment 1716466079

Fuckin NAILED IT!!

 

[RustyRatRod]

I think if you’d like to pick up 1/2 second you’ll need to jump up pretty far. Like 10-15 degrees at 050 and maybe a few more degrees of split, and as much lift as the lobe will tolerate. If you’d can afford it a solid roller will be the best. I’d keep the lobe sep pretty wide and let it run hard up top, (like 114 degrees) it won’t be lacking torque with 512 cubes. AND I would send your intake to Wilson and have it professionally ported at the same time. That’ll get you a good deal and those cooper cobras will have no chance.

That's why went straight to a solid roller recommendation. I got the impression he wanted to make a pretty big difference. With EFI involved, he definitely needs to make a call and talk to someone.

 

[junkyardhero]

.... and those cooper cobras will have no chance.

[narrator: dear reader, the cooper cobras had no chance from the beginning]

 

[TT5.9mag]

That's why went straight to a solid roller recommendation. I got the impression he wanted to make a pretty big difference. With EFI involved, he definitely needs to make a call and talk to someone.

Dwayne will be able to give him a good recommendation. Likely much better than I ever could.

 

[RustyRatRod]

Dwayne will be able to give him a good recommendation. Likely much better than I ever could.

You and me both!

 

[Newbomb Turk]

You have a box way too small to play in.

You either need to change some expectations or leave it alone.

A cam change isn’t a half second. I don’t care if it’s a nitrous cam or not.

If I were you I’d go back to the nitrous idea. You can do a hundred shot and easily get where you want to go.

And when you’re off the hose it will be exactly what it is now.

Put it on the hose.

 

[Kent mosby]

You have a box way too small to play in.

You either need to change some expectations or leave it alone.

A cam change isn’t a half second. I don’t care if it’s a nitrous cam or not.

If I were you I’d go back to the nitrous idea. You can do a hundred shot and easily get where you want to go.

And when you’re off the hose it will be exactly what it is now.

Put it on the hose.

That is the easy route. My Sniper could do all the nitrous control. I know that is an option. But if I go there, now I need a roll cage and suit and all the safety stuff. Then how do my grandkids ride in the back? I say this with tongue in cheek as this makes the most sense. But options? Thanks for the differing notion.

 

[TT5.9mag]

That is the easy route. My Sniper could do all the nitrous control. I know that is an option. But if I go there, now I need a roll cage and suit and all the safety stuff. Then how do my grandkids ride in the back? I say this with tongue in cheek as this makes the most sense. But options? Thanks for the differing notion.

Wether you pick up a 1/2 second with n20 or N/A power you should still have all the saftey equipment

 

[crackedback]

Solid roller with same dur and lift into the .650 area should get you another 30+ cfm of port window, not including everything under the curve..

Say you add 45-50hp there , car should run 11.00 at 123ish.

Idle quality shouldn't change much with the same duration/lsa.

 

[Bewy]

I am not sure if Ma did get it right the first time.....
Looking just at FT cams, the limiting factor to max lobe lift & area under the curve....is lifter diam. The 904 Mopar lifter allows for more of both.
A friend has the MP Hemi book & he was looking at the MP cam, 296 adv dur SFT for his Hemi. Using the supplied 0.850 constant, duration is 251 @ 050. Lash is 028/032. So a lot of lift is lost due to lash. I found an Ultradyne 904 lobe that has the same 251 @ 050. Adv duration isa much shorter, 278*. The big kicker is the NET lobe lift. The UD cam uses 0.016" lash. There is 0.036" more lobe lift [ after lash ] with the UD lobe.