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#1
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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. |
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#2
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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.
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#3
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If the idle is like stock it can't be as big as your numbers.
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1967 Firechicken, 499", Edl heads, 262/[email protected]" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. [email protected] mph with a 1.45 60'. Still WAY under the rollbar rule. |
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#4
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Pretty common cam back in the 80s.
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Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune [email protected] 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs 1964 Corvette Coupe 327 4 speed |
| The Following User Says Thank You to Skip Fix For This Useful Post: | ||
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#5
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Here is what that cam sounds like on my 455 ... no balance tube or x pipe.
https://youtu.be/jy2-6x7sJR8
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Triple Black 1971 GTO |
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#6
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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.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#7
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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.
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#8
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I tried to load a video of the idle so hopefully this works.
https://m.youtube.com/watch?v=bu7zyTVTUTM |
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#9
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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.
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Triple Black 1971 GTO Last edited by NeighborsComplaint; 04-01-2026 at 05:42 PM. |
| The Following User Says Thank You to NeighborsComplaint For This Useful Post: | ||
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#10
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Is it possible you used Crane Hi-intensity lifters?
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#11
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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? |
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#12
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Quote:
Rhoades are noisier and use a snap ring |
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#13
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Quote:
__________________
Will Rivera '69 Firebird, 400/461, 290 Eddy D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears '69 LeMans Vert, XS 350, #47 heads, TH400, 10 Bolt 3.23 gears, work in progress ‘66 Lemans, 455, 310 KRE D-Ports, HR 236/245, TH400, GV OD, 12 bolt 3.73 gears - see it here: https://youtu.be/RP_s1wJKm_Y?si=K0NZxoTyaGcj8Dcb |
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#14
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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.
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Triple Black 1971 GTO |
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#15
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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. .
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. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
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#16
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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... .
__________________
. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
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#17
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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.
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#18
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