Why 5400 and down for max rpm? Im not against adding duration, I just don't like big lift with short duration, and nearly solid roller ramps on a pleasure hydraulic camshaft.

SB

I am thinking about a 6000 rpm redline. Given the parts that I have I don't think that is excessive, likely get away with another 1000 with no issues other than the need for a stud girdle, but that is a standard BBC issue when you start to rev them.

I am not adverse to running a tunnel ram but I am becoming concerned about total port volume/cross section area and the resulting decrease in flow velocity.

I have found a few threads dating as far back as 2003 using the 335s on 540s and they seem to make more power than I am looking for... This is with high rise rather than tunnel ram intakes. I realize that I can make a ton of very reliable power with this combination, but I am putting it through a bravo XR, so in the interest of not building myself a drive breaking monster I want to keep the power in the 600-650 range with out completely neutering it... I know that Mild Thunder has been involved in a couple of similar builds so I look forward to the input.

I have seen a couple of setups with the EZ-EFI 2.0 and that has impressed me with its self-tuning capabilities. The application was BBC again but in cross country race trucks.

Keep the ideas coming !! I appreciate the input!!

What exhaust system you going to be running MTR?

A properly tuned tunnel ram will increase air speed not slow it down.

That's where it sounded like you guys where going.

By the OP's last post, I guess not.

Well, that said.....would a 242/248 with .650" or so be out of touch " ?

I think we are close SB. Something like this would work nicely

http://crane.carshopinc.com/product_.../140173/139681

The 741 crane works good too. I had a flat top piston 540ci with 741 crane , stock crappy merlin iron heads , made right at 600hp at 5800 with a dart single plane.

Here's a look at comp's master lobe profiles they grind from. Page 16 is their marine grinds. They aren't offering anything in .650 lift with a 1.7 rocker, until the duration gets up to 254 range. In the 240* range, their "High lift" profile, is a .360 lobe/.612 valve lift. Seems like them and crane, are generally on the same page with lobe sizes for basic bbc marine/endurance stuff. Maybe the independent cam guys know some things they don't about duration vs lobe size, spring life, and so on. Possibly having in house spintrons, and grinding machines, might be a benefit to designing cams for all different applications, I would assume.

http://www.compcams.com/Technical/Ca...obeCatalog.pdf

CMIs from the HP500EFI

Comp and Crane stuff are older lobes.Up until recently we didn't have hydraulic lifters that would support the higher lift cams. Now we do. About a year and a half ago I called everyone and there brother trying to find .700 + lift hydraulic lobe profiles. The only ones that had them were Bullet and Cam Motion. I highly doubt the larger companies are going to get into more exotic hydraulic cams for BBC I really don't think there is a big market for it. From what I've been told the LS market is really starting to pick up. And when you only need 1 cam core on the shelf to make whatever cam you want (instead of a gazillion) it's a no brainer (business wise) what to focus on.

if you don't have Inconel the "might be for sale valves" BETTER be for sale or your gonna have some issues soon....