Putting together a 421 here are the details. Shp block, dragonslayer crank, crower stroker rods, ross pistons -6cc flat tops 11.1 comp. Afr 235 heads. Miniram intake. Whole block is going together as we speak. I most likly will be running a shaft system and on AFRs recomendation lighter springs with the titanium retainers and morel lifters. Basically a full bore as far as I would run this setup with a hydralic roller. Its a street car and I dont want to run solid. Yes i know I am leaving alot of power on the table but I have made up my mind to run hydralic and decided to go all out with the lightest valvetrain to get the job done. Spring will be a bit stiffer at 168lbs on the seat recommended by AFR for valvletrain stability. Will be using morel lifters. Intake is a miniram. I have narrowed it down to one cam from crane. Was going to use a 236/242 from comp based off the xfi lobes but they screwed up the grind and sent it out without the step nose leaving me to use a cam button which I did not want to. Want it set up with the retainer plate. And basically they wont take it back, as It was custom ground billet with cast iron gear , so its up for sale for anyone interested. So instead of spending any more money with comp I decided on a crane unit #109651. A little more agressive, 240/244 302/306 its ground on a 110 lobe but we will be changing it to 112 .558 I .558 e with 1.5 . With a 1.6 well be right around .595. And with the shaft system any ratio is available 1.6, 1.65, 1.7. So we can set it up any way we want. Its a street strip car. And I think its a good choice with a bullet proof bottom end to handle the intended 6500 rpm and rock solid valvetrain for long life. Let me know your opinions. Thanks and take care.

 

1.65-1.7 on intake, 1.6 exhaust, may need more spring

 

A stronger workable build Sir.I bow down to you.

 

Orr you must have read my mind. Thats what I was going to run. Afr is putting on duel springs that are not as wide as the 1.550s. Plus they recommended the morel limited travel hydralic lifters. Any exp with morel?

 

Thank you. Im looking for a max effort hydro roller motor. I really didnt want to get the dragonslayer crank and had opted for the compstar, but apparently callies discontinued the 3.875 stroke 1 piece cranks. Idk . All in all im hoping for at least 550 crank hp. Think it may be doable.. Thanks again and take care..

 

Like i said before i have 246/252 in my 400. Runs fine. .640" with morels, but not the limited travel ones. Seems to be fine. Granted i had geometry issues with my offset intake rockers which ruined the intake guides in no time and suffered abit of instability over 6200 on low boost and 6000 on 15 psi. My springs are 180 seat 450 open. I want to run 200/500 if i could find a suitable spring but my cam guy believes it will be fine once geometry is right. I may do a shaft rocker this time but i dont want to spend more on this car. Trying to turbo or cam my other ride

If you dont make 600hp with this build i would be disappointed. Should not have an issue doin that. You could run another 5-8 deg duration like mine and still be fine, as 421 will eat up cam and airflow but what you have with 1.7 rocker will do well with those heads

 

My builder said the same thing about the offsets. He had them and didnt like them. Uses the Crower shaft system which I will be using with the ss rockers. We had discussed the duration but since its mainly a street car and will be running a 3000 stall. I opted for the shorter duration. Dont want to run a 3400 stall and dont feel comfortable buzzing the motor to 7000 to get max hp. This cam with a 1.7 on the intake is .632. With a 1.6 on exhaust its .595 and a 1.65 its .613. So Im kinda glad comp screwed up.

 

Yeah that cam should do very well. Streetable and enough lift to keep that motor fed

 

We found out the hard way with our 565 you have to check/size/hone the lifter bores for the correct clearances.We broke a bunch of parts while we figured that out.Then when we got the 632 we knew what to do.

Given your parts choices I would guess you know this already.For me I would think you are a tad heavy(.5 point) in the SCR and would want to find a cam with a DCR for pump gas.DCR of 8.5 and SCR around 10.5.You could run a squish/quench at .040 which would help some.

 

Could stay with the 110 lsa to help. Dcr will be alittle higher but AFR chambers are pretty tolerant of compression. It definately will take less timing than most sbc. Probably 30-34 deg with a heat range 7 plug. 6 may work but 7's are not a bad idea

 

Well I got the cam but hae one reground with a 112 lobe seperation vs the 110 it had off the shelf. Apparently it changes the duration 2°+ on both intake and exhaust. So the cam will be a 242/246. Think it will work out fine.