Crane HIT-290-2-NC
 

I installed an older Crane cam in a 455 that I just put in one of my drivers. The back of the cam was marked HIT-290-2-NC. The specs on it are supposed to be: (234 244 .485 .505 112). I got it broke in last week and it idles smooth and sounds nearly stock. Not that I'm unhappy, but I was expecting a somewhat choppy idle. I attached a picture of the back of the camshaft that I took before I installed it that references the part number. Am I missing something here? Has anyone else used this camshaft in a 455 and had it idle smooth?

My engine specs are:

.030 455 with pop up pistons, 9.75:1 compression, 197 round port heads, stock 1.5 rockers, stock round port exhaust manifolds into 2 1/2" exhaust, performer rpm intake.

What do you have for idle vacuum?

Another detail is how much over lap does the Cam have?

If you stuffed in the Cam without doing a degree check then it may be advanced and not straight up.

Running exh manifolds tends to tame the sound of a Cam a bit.

If you find you have too much bottom end then go in and retard it 2 degrees.

If the idle is like stock it can't be as big as your numbers.

Pretty common cam back in the 80s.

Here is what that cam sounds like on my 455 ... no balance tube or x pipe.

https://youtu.be/jy2-6x7sJR8

A Performer intake even when gasket matched as needed to match the intake ports in those 191 heads is not a good pick for that motor.

It really needs a 1” spacer.

Also the stock valve spring installed height on those heads will not take the lift of that Cam.

Thanks for the replies. I have not measured vacuum yet. The intake is a performer rpm and not a performer. The valves are 5.10 length and the correct pushrods were installed to compensate for the taller install height of the valves. So, there was plenty of retainer to seal/guide clearance. Thanks for the video, neighbors complaint. Mine doesn’t have the same sound at idle as yours. I am starting to wonder if my cam was mis marked or something.

I tried to load a video of the idle so hopefully this works.

https://m.youtube.com/watch?v=bu7zyTVTUTM

Your idle sounds faster which has an effect. Are you running an X or H pipe? That tends to cancel out exhaust pulses and make the idle sound smoother.
Mine definitely sounds like it has more “hair” than yours. My cam is Part# HIT 284281. 234/242 & 296/304 advertised duration, lift .473/.488. The cam centerline is ground 6 degrees advanced.

I’m unfamiliar with your part number but the duration(s) at .050 are close to mine. Yours may be the earlier version which had more lift.

Is it possible you used Crane Hi-intensity lifters?

I agree, yours does seem like it has more loap to it. It sounds hotter than mine. I couldn't find the 284281 numbers on the cam, only the one listed in my picture. It does currently run an H pipe.

I suppose it is possible that it might have had Hi-intensity lifters? I can't recall if the lifters had a wire clip or the tru-arc style clip. This cam and lifter set was in the engine when I bought it. The engine had sit for many years after rebuild. So, I took it all apart to check everything, had the block honed for the forged pop up pistons I wanted to use and reassembled it. The lifters seem very quiet at idle. Do the Crane Hi intensity lifters make noise similar to Rhodes lifters?

Retainer clips are the same on the Cranes and a relatively quiet. Only way to identify them is they have the part numbers laser etched in the oil band.


Rhoades are noisier and use a snap ring

What idle speed? Sounds like 950+

I had decided I had to have an H pipe so I had a local shop hole saw the exhaust extensions and weld in an H pipe. When I fired it up my idle lope was gone.

I dealt with it for a while and finally had individual extensions bent and reinstalled by the same shop. They thought I was nuts until they started it up and heard the difference.

You might have the Crane variable lifters. They will tame the idle quite a bit with no ticking. Their effect on shortening the duration at low rpm is not as dramatic as Rhodes lifters, but will smooth the idle some.

Before I pulled a lifter, I’d cut and cap the H pipe and put on chambered mufflers. They both accentuate the idle note.

I've run that cam before, it's basically just a touch larger than a RA IV cam. Which in a 455 would be more tame.

In a 455, it works with less gear than a 400, but it a great running cam.

It does sound like your idle is a little higher, which is fine for a manual. For an auto, as long as it doesn't slam going into gear or try to creep you're fine.

Crane used to make a '308' cam, which is a solid step up from that grind, which worked real well in 455s, and retained the 114 LSA. Can't recall the specific specs but it was like a 240s/250s @ .050 cam. I ran that a couple times and liked it.

Many here used to tell me it was way too big, but IMO it wasn't.



.

Back in the day, a general rule of thumb was, what worked well in a 400, add 10 degrees duration for a 455 to be similar.

That general rule worked well for me...

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Thanks for the replies, everyone. I didn't think to look and see if these were the bleed down style Crane lifters, but it is certainly possible. Idle is around 850 rpm, currently. I agree, it sounds like it probably needs to be a little less. At this point, I probably won't open it back up to check the lifters and will just drive and enjoy the car. I was hoping for more loap at idle but will live with the results. The good news is the cam broke in fine and everything else seems to be fine otherwise.

sounds like it idling at 1000 rpm...