wow 401 nailhead in hemmings 500-lbs torque at 2900 rpms 329 hp at 3800 rpms, 461-471 lift on cam on a 110 lsa cast pistons. get be a 206 duration at .050 for the high torque at low rpms same with hp very low rpms. I would guess 206 -212 duration at .050 that I can find in there cam lobe specs with .461 lift.
they used stock valves, they say any bigger valves will not fit. it didn't say about any head work. they used shorty headers. rope rear main seal. get this a melling high volume oil pump. never heard of a high volume pump? they didn't do there home work.
Checked my mailbox on the way out and there it was!:TU: Neat article, has some mistakes but some stuff I didn't know... -Engine was designed to minimize oil leaks. -They pointed out the forged rods are lighter than a comparable BBC rod, 690 vs 832 grams. -Crank has rolled fillets and weight is comparable to a SBC forged crank. -Bottom end is said to be good to 6500 rpm with cast pistons! Misses: -Melling Hi-volume pump (no such thing for a NH) -Valve seals used on 'exhaust' side in '66 (nope, they were on the intakes) -small ports 'enable rapid cylinder pressure rise during combustion'. (maybe they mean the 'fast burn' pentroof chamber design?) -the Comp cam part number they give is just the cam core....without the lobes ground to size. -and finally, they claim the later 400/430/455 is a 'superior' design!uzzled: (okay, they flow better, but the bottom end and oiling systems suck!) Questionable: -rope rear main seal -'Rebuilders Choice' pistons varied by 0.003 to 0.004" in diameter. (I won't be buying any of those!) Yeah, I was surprised the hp peaked at 329 hp @ 3800 rpm but dropped to 311 hp @ 4600. Why did it drop??? Curious what the cam specs are.... Joe, I did see the 0.461" lobe (#5440) with 206 duration, but I'm not seeing 0.471" lobe. With a stock cam having about 209* duration, maybe their cam is too small. And the 500 cfm carbs will give less performance than a Q-jet.... at least it does on my blue car. The '66 Q-jet gave me 2 tenths, or maybe 20 hp. it's very noticeable at higher rpm's :grin: Overall, it's a neat article, and that 500 ft-lbs of torque makes for a great street cruiser!
I agree. am thinking with 2 600cfm carbs and 216-224 cam they would have way more hp and not drop off as much and long tube headers would help hp and keep tq still around 500 ft-lbs even with the bigger cam. then the part about no bigger valves will not fit . I shouldn't say anything, seeing a nailhead build any time is a great thing.
Nice TQ....HP not bad. I bet this engine HP falls off " The cliff" at around 4400 hundred.Nice to see something other than a sbc build.
Yup, just when I let my subscription expire they come out with a Buick article. I was a subscriber since #1 but got tired of hearing Hemi and Shelby. PONCH
From the article: RPM- Torque...HP 2500- 474......229 2600- 482......238 2700- 492......253 2800- 498......266 2900- 500......277 3000- 499......285 3100- 496......293 3200- 495......302 3300- 494......310 3400- 490......318 3500- 485......323 3600- 475......326 3700- 465......327 3800- 455......329 3900- 439......326 4000- 420......320 4100- 408......319 4200- 399......319 4300- 392......321 4400- 387......324 4500- 379......326 4600- 355......311 Now I see the peak at 3800 (329 hp) is nearly the same at 4500 (326 hp), then starts dropping off. Most stock and mild builds usually peak around 4600-4800 rpm, so this one fits the trend. I'd guess the hp dip between 3900 and 4400 is a tuning issue. Comparing this to Greg's build, Greg's makes more power from 3900 rpm-up, and peaks at 4700 rpm....his bigger cam and head work definitely help.
Funny that little is ever spoken of the nailhead but when you talk to old school muscle car guys i find the nailhead was quite respected. Most of these guys prefer SBC or BBC but they rarely have anything bad to say about the nailhead other than the heads limited the engine. Around here i believe i have the only one for at least a 100 mile radius.
Chuck,,,,it is so simple,,,, :Brow::laugh: The reason that chebbies are so popular, is that you can get anything you want for them, chrome plated, fur lined,,,, for way less money than other brands..... In reality what has fascinated me about the nailheads was the high quality, the unique design, and the toughness that was engineered into them.... the nickle/iron block material,, the forged crank and rods,,, the forged rocker arms,,,, big,thick, beefy mains and bolts.... 3/8 rod bolts.... and a oiling system and cooling system that was good to go as is, not needing a bunch of work .....the only 2 things that I have found that are problem areas are the factory cast pistons, that have high mileage on them, fracturing, and the harmonic balancer hub that will crack down thru the keyway.... and that seldom happens.....
i get alot of people that dont really know about anything but bbc or sbc. i guess thats just the fact that they dont build all those old great engines anymore or that alot of trucks are around here.
Crower has some similar grinds (lift & LSA) with duration of 212*/218* at .050. Seems like plausible values to me.
I have long felt that the fairest and best way to evaluate the design of just about anything, is to see how well it achieves it's design objectives. Using that approach, you can reasonably compare a VW Beetle with a Rolls-Royce Silver Ghost. The Nailhead was designed to be a durable low-rpm torque-monster that would move a heavy car well. I think that it accomplished that goal brilliantly. A bonus feature is that it will move a light car even better. Some criticize the design for the small valves, but the engine was not designed to be a 6,000 rpm winder. As long as we are able to accept the fact that it's a torquer and not a high-rpm engine, even today, there are few better motors.
