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What Hydraulic Roller Cam in 467
I know there have been many posts on here regarding what Hydraulic Roller Cam to use. Old Faithful, Stump Puller ETC.
My car is 1964 Pontiac Grand Prix 4 speed manual, 4.10 gears ( Probably switching to 3.64 ) Motor will be 467 CI KRE 310CFM Heads, 11:1 Compression Torker 2 with 950HP 1 inch spacer. Will be using Long Branch Manifolds instead of 4 tube headers so I'm sure this will affect cam choice Overlap etc. Thanks, Rich |
I would go no smaller than the OF grind and install it at 109-110ICL. Same basic combo I have, mine is closer to 11.3 to 1 compression and using the OF cam on a 112LSA. It's been flawless now since 2009 on a steady diet of pump gas, even runs OK on 87 octane w/o pinging but it will "run-on" once in a while on a really hot summer day fully heat soaked so I typically keep 91-93 octane in it. The ICL came in at 109.5 so I just left it there and glad I did. Idles nearly dead smooth with just a hint or "attitude". Makes 13.5" vacuum at 700rpm's with only 10 degrees initial timing.
Compression is your friend with these things and allows for bigger cams with less negatives. However a small cam and high compression can get you into trouble in a hurry and little cams aren't going to take advantage of 310cfm head flow either......FWIW......Cliff |
x2 on the OF in my 467 e-head 10:7 motor. runs great on the street on pump gas & does consistent low 11's. great cam.
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The OP didn't really say if the cam needed to be stop 'n' go traffic friendly. Just 4 speed with a possible rear gear swap. Clay |
The last 467 I recently built I went with a custom ground camshaft from Paul using voodoo lobes that is very close to Old Faithful specs. 239/243 @ .050 and a pinch over .600 lift and on a 112 LSA. I installed it at a 106.25 ICL. Engine is 9.98:1 compression with iron heads. Dyno'd with 91 pump gas.
Stock intake, carb, and exhaust manifolds and it made 507/571 on the dyno and idles with only a slight attitude and makes 13 inches of vacuum up here at 5,000 feet elevation. Car has working AC and is an automatic with a custom converter through Cliff that drives fantastic. Easily a daily driven car if one wanted to, behaves nicely. I'd lean on what others said, with an engine this size I really wouldn't even look at a camshaft any smaller than 230's @ .050 intake duration. The 455's gobble that up like it's not even there. I don't even consider a cam rambunctious in these engines until you start getting up closer to 250 @ .050. |
My thoughts mirror the other guys thoughts on cam size. But rather than compcams we are using “3823” hyd roller profiles from Bullet. I believe they are basically Ultradyne profiles converted to computerize profiles. I think the smallest one is 236 @.050 and the largest ones are 260s as .050 and they all have .3823 lobe lift. Makes for a range of .573-.631 for lift depending on the rocker arm ratio.
FWIW, I like the lift range, and I like the way the 3823 cams are designed for the lash ramp coming off the base circle. A kind of example of the difference between the design like a comp Magnum HR and the Bullets is running a solid roller hybrid on one of the Magnums, to quiet the noise down most guys lash them to .005-.008. Compared to the Bullet is .008-.011. It is a difference in how the profile comes off the base circle. The XE and XE FI are more aggressive yet. Not trying to bash a compcam or Old faithful what so ever. The comps like the OF are great cams. Imo, if you are running plenty of compression, on pump gas, on the street, that slower ramp won’t hurt you at all. Plus to lift as shut the valve a little slower will likely make it little quieter, maybe even more dependable. |
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Three similar hydraulic roller intake lobes....
Comp Magnum High Lift #3122B (Old Faithful) 289 236 160 .3800" 0.570" UltraDyne #HR12 288 234 155 .3533" 0.530" Comp QXI #13451 289 237 158 .3950" 0.593" The QXI Series lobe profiles are designed to provide the highest available valve lift for modern cylinder head ports, along with excellent stability and the broadest possible power range in hydraulic roller applications. . |
To reinforce what Cliff says keep in mind that in motors like the 455 who's stroke is bigger then it's Bore, cylinder pressure will rise much faster then a over square motor and on pump gas you need to bleed that off with the Cam.
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I forgot to add Comp XE lobe 3196
288 236 162 .3900" 0.585" This is the intake lobe Dave Bisschop uses on his revised Old Faithful cam (OF2). However Dave apparently orders it with a "B" suffix code after the lobe number as he does on the older OF cam. By doing so the duration can vary slightly by 1-2 degrees. And the lobe lift increases by 0.001". Keep in mind a 2-valve ported cylinder head responds to valve lift without a sacrifice of idle and low speed qualities. Bottom line, the engine wants all the lift it can and thrives on it so run as much as mechanically achievable or unless prohibitive because of cost limitations. . |
Only when the Intake tract as a whole can provide increasing air flow levels when adding more valve lift, in regards to your last paragraph.
Other wise once port velocity drops off too low from porting the head and increasing the heads minimum port area Torque output levels at low speed will fall off a cliff! |
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OK. But note the OP will be using ported KRE heads that flow well above .600" lift and have less intake runner volume than a similar ported Edelbrock head. . |
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I have been using this cam with 1.65 rockers in my 467. Been happy so far.
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head flow vs cam lift?
https://www.yellowbullet.com/threads...m-lift.394221/ Cam lift vs. cylinder head flow http://nastyz28.com/threads/cam-lift...ad-flow.37265/ . |
Thank You for all the suggestions. The car will be 95% street driven with occasional trip to the track.
I like all the characteristics mentioned about the OF cam. I had a Crower 255/261 @.050 with 108LSA Solid Cam in a 421 that was in the car previously Ran great but had a lot of overlap and as a result always smelled like exhaust fumes after driving it. Thanks Again for the input Rich |
You will love the cam. The street manners will surprise you once you get the tune dialed in. You can lull your passengers to sleep or scare the living crap out of them! Best of both worlds!
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Both of those links have great info Stevo, but they don't touch on the big plus of having good swirl rates at low rpms and low flow rates.
This contributes greatly to combustion efficiency at any rpm, but especially to Torque numbers made at low rpms and air to fuel ratio numbers. And yes, if the op is running ported Kaufman D port heads then he will be better off for his needs then starting off with Edelbrock round port heads. |
243/251 voodoo
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