I should have been posting this from the get go but I was lazy, so my apologies. My 462 came up with a valvetrain noise in early december, when we ran a leakdown we found the #8 Intake valve was bad so we pulled and tore it down. Yes, the valve guide was bad but I also found that I was slowly losing a few cam lobes. So that explained why this engine was down on power all fall, although it was still running 12.70's@104-105 up until November (but down from a prior best of 12.47). So the build/rebuild specs are: -70 SF block, full oil mods inc. main saddle 10/2 back oiling -Buick rods +.010 Clevite P's -Stock stroke +.020 Clevite P's -TA 6 qt pan -AMP pickup screen -AMP crank scraper -TA/Speed Pro 1621A's, .030, .007 in the hole 10:1 -Hastings Moly 1/16,1/16,3/16 rings -661 Heads, 71 CC gasket matched at intake -Light bowl/throat work, flowed 260/170 -TA Orange Crush .038 head gaskets -TA stainless 11/32nd valves, brass guides -TA 1125 springs -67 430 1.59 rockers/shafts -TA 1559 dual feed cam bearings -TA/Crower 288-94H cam - 228/239@.050 114, installed at 108.5 ICL -Delphi hyd.flat tappet lifters -Smith Bros. adj. pushrods, hybrid 5/16-3/8 tips -70 intake, open plenum with center divider intact -71 540 carb 76/44 mains/rods B hanger, CC secondary rods -71 077 distributor 15 initial /20 mechanical -Pertronix III ignition / FAST PS50 coil -AC R44TS plugs .035 -TA .032 intake gaskets -AMP valley pan - Jim Roger's 67 430 manifolds Ran it on an old inertia dyno to break in the cam and find optimal timing, best pull 441 HP /544 TQ at 35 degrees total. We did not try to fine tune as the dyno operator was squeezing us in as a favor. Dropped it in the car, drove 100 miles to track (literally) and ran a best of 12.67@106.4. Carb is still on the lean side (thanks to JW for the needle/seat tip), I think with a little more time and tuning this motor could dip into the 11's on 91 octane. There ya go!
By having no plan at all. The 12.67 run was on a 1.87 60 ft, old motor could pull 1.77 and had 30lbs less torque. Both the car and motor have it in 'em, I just got to hit that magic mineshaft tailwind run.
Great post! What's your car weigh? Mine 462 has ran 12.55@112mph with a few additional "upgrades", but crippled by my ability to run a stick shift. 1.9 60ft and slow shifting.
My car is 3850-3900 lbs coming off the track. That mph is why I think it should be high-11 capable if it were an automatic or launch/shifted better.
and yet, my car generally seems to ET like a car maybe 2 mph faster. Punches out of it's weight class I guess.
3.73, 26 " tire. It has no MPH, never has. Crosses the line at 5500, which is right where I wanted to . Might cross at 5600-5700 with this new motor, to soon to tell..
I've had several of those combos...run hard but won't mph for squat....pull clean..nose up..just kinda level out at the 1k ft and coast....
Yep- given that I’m racing stock classes that’s what I’m working with. And I know enough to work with its strengths as opposed to try and turn it into something it’s not. It can be done buts it’s expensive and fragile.
I've got 3.89 gears, no converter slip and crossing around 5500-5600 rpm too. I shift at 6k, so geared it to cap out around 118-120mph when aiming for 500hp. Came up a little short, but its really a daily driver so alright.
I dont know if 5% converter slip is accurate for my brand new super shiny Tri Shield unit, but thats what I used to calculate that at 5500 my speed should be 110, and that doesnt quite match up with my time slips. My prediction is when all is settled and dialed in, this car will be a repeatable 12.3 car at 107-108. There, I put my money down. I get that trap speed is dynamic anddifferent than static stripe speed, so time will tell and maybe that 110 isnt so far off after all. Funny cause the guys that run my ET's generally run 5-6 mph more than me, this engine is proving to be more of the same.
I’m planning a similar build to yours with a few minor differences for a 67GS 400 , retaining the switch pitch and 2.93 rear. With the 288 94h on 106 my dcr is 7.40 , my question , how does this cam behave as a daily driver , I was considering the 284 88h but I thinking I can go a little more aggressive . I like your build I’m impressed by the output for such a modest combination. Cheers and well done
It's atually great for a daily - My dynamic is 7.50, I can drive it on 87 octane, and race it on 92. (Mind your quench, mine is .042) I get 13.5 mpg, no annoying valvetrain noise, 16 inches of vacuum and idles at 750 no problem. If anything, it's a little too stealthy. :
