632 boat motor. I don't want to get into clearancing rods so I'd rather stay with a small base circle camshaft... But is there anyone out there with big hydraulic profiles? LSM?

yep,them babies really move some air,almost enough to blow a match out.

You don't need that much duration. But, if you use the right rod, a 55mm standard height cam and a 4.75 stroke only requires minor clearancing on 4 rods, or sometimes none at all. Depends on the cam profile and rod. If you are planning to turn the rpm's to take adavantage of that duration, I would definitely step up to the stronger core to help deal with the spring pressures you're running, and a .904 lifter. Also, .700 lift isn't much for a cam that size, with the heads you'd need to take advantage of those cubes and rpm's you'd probably be better off with lift in the .800's.. You'll need a Ti intake for sure, but the biggest problem will be controlling the heavy Inconel exhaust valve past 7000rpm. I think you may want to step up to a solid to run that rpm..

I already have the rods and I know they will need clearancing with a larger core. Not so much worried about the lift as the duration. I already have the combination worked out and know what works just trying to duplicate it with a hydraulic lifter rather than a solid.

With those duration #s and lift getting into the 800-860 lift with the big cubes, it's looking like some of the older Tractor Pull motors we played with spinning the $hit out of them. Black Baja sounds like a real nice project going together! I'm sure the boys around Memphis can hook you up, along with Bob M. keep us posted.

we have 280 680 lift Ron 504-616-6005

Cam companies such as COMP have a large choice of custom profiles that are not in their "normal" catalog. Of course I am not looking at one of their custom lobe catalogs, but the odds are pretty good what you are looking for is available in a custom grind.

But my 31 pitch prop won't let me get the high! Hahaha

Paul,

It requires a bit of an explanation as to why these courts are so difficult to source. A cam core has three basic parameters under which it’s manufactured.

The first is range of duration, the second is the range of lobe separation angle, and the third is range of lobe lift. To put a specific cam profile on any particular core the range of the core must fit on all three dimensions the range of the profile desired. If any of the ranges in these three parameters are exceeded you risk broaching the heat treat in the core.

As an example, let’s examine the range of these parameters on the OP’s inquiry as the finished cam might look like.
Let’s say it’s a 280º intake duration 290º exhaust duration, with a .714” valve lift on the intake and .705” valve lift on the exhaust, ground on 115º lobe separation that angle, advanced 4°. You may be able to source a number of cam cores with two of the three parameters, i.e. lobe separation angle and duration, but not with the proper lobe lift. Until recently there was virtually no demand for 280º/290º duration cams, on a 115º lobe separation angle, that had a lobe lift as small as .415”.

Now that Morel has developed a .903” inch diameter hydraulic roller lifter we have had manufactured a number of core selections to accommodate high lift, long-duration hydraulic roller profiles in a range needed in H/R applications.

The next critical aspect you would need to examine would be finished cam journal and lifter (.842’ vs. .903” .935”) diameter. There are a number of choices available with these dimensions also.
Std BBC______1.948”
50mm________1.968”
55mm________2.165”
60mm________2.362”

We have collaborated with Alex @ Haxby Speed on two of these Hydraulic roller applications, varying in output from 1250 HP to 1340 HP at 6500+. The data shows conclusively, moving up from a standard diameter BBC journal with a .842” lifter (.750” wheel) to a 55 mm journal, and .903” diameter lifter, with a .810” wheel, has made a measurable decrease in core deflection and decidedly enhanced our ability to stabilize the valve train.
Bob

Is that the lift and duration you're running in a solid roller 280 290 @050 ?