performance cam for 4.6

[MotoBando]

Hello,

I am getting conflicting reports about a Crower 50229 cam not working in 4.0 / 4.6 blocks due to the end of the shaft being different. Can anyone validate this, or point me in the right direction of a similar spec cam that will work in a 4.6? I am in the midst of rebuilding a 4.6 to stick in my D1.

Thanks!

 

[D Chapman]

The Crower 50229 fits the motor, just not the Rover front cover from 1995+. Basically, in "stock form", it's made to be used with a dizzy. But, the dizzy gear can be machined off and a new hole bored and tapped for the timing gear.

D&D Auto in MI can do this for you. In addition to the cam, you need a new timing set with the cam sensor ring attached. You also need a cam sensor spacer.

The whole lot will run you about 450.00+-. It's all or nothing.

Only downfall with the set-up is you loose the thrust washer. Because there is no thrust washer, the cam will "walk" and you get a knock at start up and sometimes at idel.

Depending on your use, you may also look at a stiffer valve spring. There are no (known to me) "drop in" springs. There is a Chevy spring that fits the bill, but the spring seat needs to be machined a little. I would highly recommend this, but you can get by without it. With that cam, you get a little spring bind at higher RPM's. The Chevy springs will correct this. In a Rover, you will probably never notice, but over 3,500 RPM's, you're basically floating the valves. Again, not a big deal in a 200-250hp engine.

 

[MotoBando]

Thanks for the reply, and advice. The only thing I am not fond of is the thought of that Crower cam walking...unless it can be further machined to fit the thrust washer. I did one more thing - I checked with a local company (Schneider race cams) here in San Diego and they said they could regrind my existing cam to a more radical profile that would boost performance. This would be achieved by grinding slightly off the heel of the cam as well in order to give it a different profile on the lobe. Has anyone tried this? The concept seems to decent enough and I would not have to worry about springs binding from too high of a lift. Any thoughts?

 

[D Chapman]

I don't understand how you are going to get a higher lift if they re-grind your cam.

But yes, the walking is shitty. It's just the price you have to pay for a hotter cam right now.

 

[MotoBando]

Yeah, I don't know either. They told me to come by and they'd give it a look and let me know what they could do. I'll let ya know what I find out...

 

[ptschram]

I can't believe I'm gonna say this.

Don't start trying to reinvent the wheel with your camshaft profile!

The Crower 229 and 230 are both time-tested and proven by many of us (I've put a bunch in trucks, Muskyman has the 229, I believe Dan has the 230 , AFIRover has a 230 in his truggy and we'll be putting one in his supercharged hot rod engines and I have one to put in my 4.2).

I haven't had even a hint of a problem with the lack of the thrust washer.

These trucks eat camshafts from poor crankcase venting, excessive blowby/crankcase pressures, low oil change frequency in many cases and not being run to full operating temps resulting in corrosive combustion by-products condensing on the steel cam as the engine cools. To even consider grinding the lobes smaller to achieve a beneficial profile is folly, would certainly be more expensive than a new mass-produced (?) Crower and of questionable longevity/reliability-regardless of who is doing the work. I don't like having cams for 60 year-old vehicles polished, much less re-ground in an attempt to achieve improved performance, specially when there are alternatives available.

FWIW-when I was picking a camshaft for my engine (no, it's not just a rumor or my fantasy, it really does exist) I ran computer simulations on all of the currently available Rover engines for which profile data was available. In a very surprising revelation, I found that all other things remaining the same, the 230 has the most power and torque, under all conditions.

Dan-Mark has two or three different options in valve springs, however, my machinist and I both agree that the 65# of seat pressure of the Rover springs is probably enough for the engine speeds most of us will see in normal on or off-road use. That said, Mark is pretty insistent that the 90# springs are the way to go. Maybe for the supercharged engine.

Cheers,
PT

 

[MotoBando]

Thanks for the testimony - sometimes that's all one needs to make a good decision I guess... I'll probably give D&D a call later today. Not sure I'll go with a 230 - maybe something milder. I'm also trying to avoid a possible hassle of spring issues. On my last rover which had the 3.5 in it, after a rebuild I put in a Piper cam (forget which profile - maybe 260?). I failed to check clearances before reassembly and every other day or so while driving I would snap a rocker arm off the shaft. Once I replaced all the original rocker arms everything was fine.

Thank you all again for the feedback - good stuff.