This is a completely theoretical question being asked by a smallblock Buick guy. (Yes Virginia, sometimes small IS good.) Anyway, I'm awed by the engine output numbers from 400-455+ engines that I see discussed in this section of the site. It gets me to wondering if there are thresholds of cam lift/duration/lobe separation that coincide with the use of dual plane, single plane and sheet metal intake manifolds. Obviously, head/port design and valve size are crucial considerations. But, is there a direct relationship with different header sizes and collector designs at different output levels? When you set out to build Buickiller engine what are the tried and true packages at each threshold. Do you always go by your application first, or build from the ground up and keep going? I'd be interested in learning from your experience as I've recently acquired a plain jane '66 Special with a much beloved 300. But it keeps whispering "feed me a big block" when I walk through the garage.
It,s my feeling that most cars,Not just Buicks are running cams that are to big. Ive run 11.80,s with .496 lift and 225 duration at .50 Just food for thought. Hope that helps ? Wayne 70 GS STG 1 Conv 70 STG 3
BBB cams Thanks Wayne, I was hoping to get a response like yours to the thread. Those times are impressive. Let me ask you this, when you selected your cam did you consider the design of your intake manifold, heads and exhaust system or did you go by the cam grinders description? What kind of intake, heads and exhaust are you using? Mark
At that time (1988) the heads were ported STG 1s & Intake was a B4B. as for cam selection, It was installed when the engine was stock and as i modified the engine i left the same cam in untill the engine became very modified at which time it was changed, so no real thought was given. But if this is a street car & will be running full exhaust i would stay with a cam with not a lot of duration I.E. 230-240 at .50. FYI that cam was a Schnieder 290H also compression must go up as duration gets longer.
BBB cams Thanks again. It appears that you took a fairly systematic approach to building more power. Out of curiosity, what would you estimate the horsepower and torque levels to be on that engine?
How much cam? I have a daily driven (in the summer) 462 in a '67 riv. I have run several cams and have two favorites. The first was the TA 308S solid lifter cam. Admittidly too big for my combo, it killed enough bottom end that I could hook the car up on the street fairly well and it pulled like crazy up on top. My problem was that it liked to be shifted at 6200-6300 rpm, and I spun #2. I think that was due to oil starvation from my center sump oil pan though. My other favorite cam is the one that's in the car now and it is a 240/246 comp x-treme energy with .558/.561 lift. 110 seperation, installed at 106 degrees. I have 9.5 to 1, TA sp-1 with a 1050, 1.65 rockers, etc. etc. The heads are fully ported stage-1 with 283 cfm intake and 215 cfm exhaust. The car weighs 4550 with me in it, I run a 3.42 gear with a 26" tall tire and a 10" Coan 4000 rpm converter. So far, the car has run a best ET of 12.07 seconds at 109.49 mph. That's with my home made 1 3/4" primary 3" collector headers. This cam will idle fairly smooth in gear at 800 rpm, but I usually let it idle higher, I feel that it's better for the cam to idle at 900 in gear and 1000-1100 in neutral because of splash lubrication. My whole point is that you have to match the cam to your whole combo, but sometimes overkill works better on the street if you can't hook the massive torque. A smaller cam is easier to tune around because they are less fussy and they will definately give better milage (if you care).
