I know they are expensive as hell, but I am intrigued.. what is so great about them? How would they work on the street? I could use them on the street by using a milder cam, right? Could I still run hydrolic lifters with them or does it have to be solid? Where do you get the offset lifters and offset rockers? Is it possible to machine an LT4 manifold to make it work for the raised runner? What exactly is the raised runner? Also, would these heads with a machined LT4 intake kick *** on the street? I have a stroker now... I am saving my pennies as AFR wants a mint, but are they worth it?
thanks in advance...
Cody

 

anyone?

 

How many questions you got Cody?

The Raised Runner means that the port is located higher above the deck surface which gives you a longer gradual short side radius which is needed for high RPM HP.

Fine, they are just suited really well for higher RPM applications.

Yes you can run a mild cam with them without problems.

Yes you can run a hyd with them it's just tricky.

Here is a example of a hyd roller 215RR motor
http://popularhotrodding.com/enginem...208PHRSherman/

I've talked with Joe about what he did to run that and it's not that hard at all.

Comp, Crane, Isky, Crower all have the lifters if you go solid. Isky has a offset stud Rocker that will work

Or you can do shaft mounts.

Yes with a lot of weld or adapter plates could work, but the real question is why? A Sheetmetal or single plane would make more power and do the heads justice.

If you wanna spin lots of RPM, yep they sure are!

Bret

 

HA!! Sorry Cody I forgot about the offset rockers, when you say lots of rpm, how many is alot, I have a stock bottom end with an 847 and stock heads and looking to upgrade. Might freshen up the bottom end when I get heads.

 

damn dude, you know your stuff. So basically for the street it is big time overkill? I want a street friendly setup, and don't plan on spinnin the crap out of it every other minute...

 

Hey if ya got the money, why not? It is overkill because you can make power without them.

Basically they can make power over 8000rpm if they are on the right motor, even higher raised runner stuff is needed for more RPM than that.

Bret

 

Joe says in that article that he expects it to peak at 6400? That doesn't seem to high to me. Would it be better to run a solid lifter on the 847 or just get a new solid cam or would the 847 with a rev kit work with the off set rockers? Joe said he used a rev kit with a hyd. over 6k but I have heard you say you don't need it under 7k?

 

Rotors,

I've had hyd rollers run to 7500rpm without issue without a rev-kit. You gotta understand that his setup used dual springs comparable to Comp 977's and the rev-kit and it peaked at 6600rpm.

To make things stable it takes a few things, the right combination of valve spring, component mass, lobe profile and stiff rockers, studs and pushrods.

That 2002 EMC motor that's profiled in that article is a good example of what you can do with a street motor when things are done right, that motor could easily make over 500 at the tires.

Bret

 

300CFM is 300 cfm whether it comes out of a 215 or a 210 CFM runner.
Ya can get that from heads ya don't have to spend 8-1000 dollars for shaft rockers. A sheet metal intake is 2500+ and other ones will do the job for a lot less like a Holley Stealth Ram but won't fit the 215's.
If ya got a big stroker get the 227's and no shaft rockers or special intake and make the same power.

 

do you think the engine can survive a year with the 227 and stock crank/pistons if it only has 58k miles?

 

Just as well as it could survive a set of ported stockers.

 

Yeah they are awesome race heads IMO. For a street car you can go just as fast and spend less money. Money that could be used other places in the combo. I have guys going bottom 10's with AFR 210cc heads. How fast do you want to go?

 

Hell we are doing that with a 383 and ported stock heads. 10.30@126@3416lbs.
Why spend your money on aftermarket when ya are just in the 10's.

 

Because 10.01-10.1 @ 130-136 > 10.3@126. Plus the fact your casting is maxed out at this point and the AFR's are out of the box

 

What the hell difference does it make if it's maxed out it's 1500-2000 dollars cheaper. If I had aftermarket and wasn't running any better than that I would be ashamed to admit it.