jeff1000man

Go to a bigger cam and switch to solid roller. They are not as much trouble as people say. Actually they are very simple.

Those Merlin heads are holding you back.

You need an AFR or Dart pro 1 aluminum, or similar quality, CNC'd head at about the same runner as you are using now.

Those 2 things will wake those little engines up. Then you can move to the super chiller and the bigger boost or blower if you want.

That top end set up is holding you way back.

Like everyone else said, Those engines should make mid 700's with no blowers.

THLWL

John - Guy is running a solid roller cam set up. He goes to set the valve clearance about every 6 months and finds they don't need adjusting. So they appear to be low maintenance.

Dueclaws

Tommy-
Guy's engines make some serious power. Solids rollers don't scare me and I've used them previously, but would need to pull the engines to install them and was hoping to avoid that this year...maybe cam and heads next year?

Note: I posted the wrong Crane cam previously in this thread
(#139681/Crane HR-240-365-2S-12-IG was from my previous N/A engines) I believe the cams in the current S/C engines are #13HR00153.

I've found a fair deal on two 14-71's and intercoolers: will probably do that now.
Thanks
John

Panther

If you do big blowers but not the heads I think you'll still be near the same place.... You might be able to run 1-2 points higher on boost without hitting detonation with the bigger blowers but you need the heads and intercooler to complete the package.

I have almost an identical package as you and with a solid roller cam it made a tick under 840 hp. My comp. ratio was 8.3 and boost was 7 lbs... @ 5lbs boost HP was even at 800... 6 lbs was 825 and 7lbs was 840...all around 5800-6000 rpms...

The engines idle perfectly, the cam isn't radical and IMHO it's set up rather conservative....which is what I wanted...

http://media.putfile.com/JC-Performance-Dyno

Panther

Cam is a Crane 138631... no rocket science...just the right amount of lift and duration so that it's not hard on parts.

Panther

741 is to small for a 572 blower motor.. It'll work up to 540 but that's about it, then you're limited... This is also probably why his power peaks at 5500 rpms. He needs more duration with those cubes.

WildWarrior

If it were me I would sell your heads to a street rod guy and grab a set of CNCd AFRs or Dart heads and add a high end dual pass cupro nickel inner cooler,not a super chiller.
Your cam will still work fine especially with a killer head .With good heads, your 8-71s and inner coolers you will make more hp than by adding 14-71s to those heads.
As far as going with a solid roller, I guess it all depends on how much 30 or so hp is worth @ 6200rpms vs replacing lifters and valve train components every 75hrs or so.
We run our Hydraulics to 6500rpms or more every run on 1300+hp Marine applications and don't need to touch our valve train for hundreds of hrs .Three times longer than a solid,just add another half lb of boost if you need a few more ponies..
Good Luck!

heavyhauler

The 13HR00153 has 254/258 @.050 with .680" lift on both valves, and on 112 degree lobe centers. That's more cam than the other one you thought you had, but I would think you would want somewhere around 280 degrees @ .050 with a blower setup and the size carburetors you already have if you are looking for optimum horsepower with current combination. Again if you go with larger blowers you're going to need more stick.

Dueclaws

Warrier- I know that (ideally) the engines need better heads plus cupro intercoolers, and larger blowers.
Which heads, blowers, cams, and valve springs are you running? PM me if you wish.
Thanks for the info.
Due

Panther

Depends what cam you're running...

250 hrs on a solid roller setup is common place these days and at that time you'll probably need to rebuild the engines at this power level anyway.

It depends what he's looking for... 700 lift solid roller, yeah you'll have to keep up with it a lot... 630-650 lift solid with soft ramps and you lash every 50 hrs and replace rollers @ 200-250 for 1/4 the price.