Nailhead engine's the reason why

Hey heres a thinker I was wondering if anyone in here knows why nailheads are called exactly that I have asked people who even own one and they arent even sure so if anyone even has somewhere I could find out why they are called that would be great thanks all
Owen

 

the consensus seems to be that when the valve covers are off it looks like a bunch nails stuck in a board. or at least that's what the old-timers keep telling me.

 

I guess that makes since but I have never seen a nailhead with out valve covers so that maybe would be a good idea I guess thanks man if any body eles has an idea though please post it

 

The '53 - '65 Buick engines were called Nailheads, because of the valve configuration. If you look at a cross-sectional view of the cylinder head layout, the valves sit vertical instead of on an angle like most every other V-8 engine ever made. The valves, sitting vertical like they do, resemble nails, thus the engines were named "Nailheads".

 

TAGMAN is half right. another of the reasons and [probably the MAIN reason is because of the small size of the valves compaired to most V8s. another name that they used to be called before the word "nailhead" caught on was the "nailvalve". i suspect that fans of these torquey Buick beasts switched it "nailhead" because it sounded less like a slam on the engine than "nailvalve" which is much less flatering of a name. it leads one to think it ca't perform as well as others because of the small valves. but we all know that is not the case. the unique angle of the valves and the intake runner configuration lend quite well to very high numbers in low end torque. 445 ft/lbs from a STOCK 401ci V8!! NOT BAD!!!

 

Whoa thanks man I guess that answerd my question sorry if I sounded like an idiot but I was just curious about knowing and thats really cool the fact that it pulls that much tourqe of the line Im really surprised about that

 

From what i know..they are called nailheads, because buicks have distinct looking valves. They were much smaller than the other v8's of the era, so they looked more like a "nail". The valve covers being upright isn't a reason, that i have been told, but more so of the previous reason.

 

Does anyone know why Buick made this change to smaller valves? Just to try something new or what? They must have seen some sort of advantage (unlike the slant 6 which I know wasnt made by buick but still a POS and a horrible design)

 

i don't know...we put a boatload of miles on a slant six...before we knew about things like checking oil and stuff....


nailheads are good looking motors

 

I happen to have a 401 nailhead. Still hangin in the garage waiting to get a home, but non the less I have one. I did a ton of research on these engines and decided to hunt one down becuase they are factory HotRod engines. The 1961 401ci nailhead has 345horse and 445ft/lb of torque. Not bad for a stock motor. The 61 also has the wilder cam grind of the bunch. Later in 63 or 64 they switched to a milder cam grind that leaned out the horse power a bit. The stuffer upper cl*** that were buying the Buicks were going back to the dealers apparently asking why there nice sofa ride was idling so harsh. **** what did they know.

So if you are looking into getting a nailhead I would suggest a 60-62 401 with the wilder cam grind. But that is just my 2cents. What do I know, I am just a young gun.

 

How rare are the old nailheads?How much will one set someone back?

 

The Nailhead like all old iron are getting hard to find. I paid 250 bucks for mine but I practically stole mine. You can exspect to pay anywhere from 400-800 for a rebuildable relect to stock smoker.

 

i had a few 425's, the 425's came with a steel crank. the valves were that small because thats all that would fit in the head design (without mods). the BEST carb/intake set-up (for power) was the stock 2x4, the next was a qaud and the last was the stock carter. sadly the offy intakes ****ED on those motors and the factory set-ups were better. but the factory 2x4 set-up is $$$$ (i sold one on ebay for a $1000 and the carbs needed rebuilding). the motors are getting harder to find also (along with factory goodies like finned vavle covers). if you can get a 401 or a 425 i would, there are companies that make hop-up parts for them and with a little mods they are scary!!!!.

 

the big reason for the head design was because these motors were designed to fit into the engine compartments that up until this motor was designed were occupied by the straight 8. the motor needed to be narrow to fit into these engine compartments and running the valves the way they did offered up a very compact package for a V8 engine (at least width wise).

i've had several 401s and never paid too much for any of them. the last two i bought i got in two complete 64 Rivis for $250 for the pair. one was stuck but the other was rebuildable and i got $350 for it on Ebay. thats typicaly about the price i've seen rebuildable 401s going for. 425s are a bit harder to come by and can be a bit more costly. i don't know as much about the value or availability of the older/smaller nailheads but they are out there and can be had for a reasonable sum if you just look.

 

I'm planning to go look at a "running" 425 nailhead today in a supposedly nice more-door sedan. The guy that owns it said the quad carb needs rebuilding, but otherwise the engine runs fine. How difficult is it to rebuild one of these old Buick quads, and does it take an "Nailhead" expert to do a decent job of it, or can a rodder with average mechanical ability and the patience to read directions handle it? Is there literature out there on rebuilding the Nailhead quad carb?

 

Yea I wonder that too and Im also curious about black top and his nailhead that he is trying to get rid of, it would be my first nailhead to work on but I have always liked the fact that thewy were even called nailheads and that Bob Bleed has one in his roadster just makes me that much more interested in it so how much for it and can a newbie like me do the work on it?

 

One of the nice things about the Nailhead is the bullet proof bottom end. All the cranks are forged, all the rods are forged. Pretty stout from the factory. They're low-end torque monsters.

 

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(unlike the slant 6 which I know wasnt made by buick but still a POS and a horrible design)

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Wanna explain that? One of the best engine designs ever. Right up there with the 200-250-300 Ford Six and the SBC.

But I don't know nuthin either.

Jay

 

Sure I had heard from about six different people that the slants were a bad design(never did exactly why though) though when they introduced them in 1960 they had the two versions 101 hp 170cu in or the 145hp 225 so they seem low power and everything it might have been the fact that I was just talking to guys that might have been obsessed with speed or they just had bad experiances with them Im not sure, but I do like the fact that in 1965 they came out with the first preformance four speed for an in-line six so I dont know for sure if they are bad realiabilty or not but hearing from most of you guys I guys they are cool engines

 

So I have a couple o' questions...

if the factory 2x4 is the best set-up,(which I've also heard before)
what would be the 'second' best..??

I have a 425 in my '65 Rivi, and when it was rebuilt 2 years or so ago,
we put a little bit more of a cam in it(from TA Performance)
and it now has an Edelbrock 750 just begging for the headers/exhaust
that TA Performance now offers too...(finally..!!)
That ****er is one bad mofo..!!
It'll annihilate the tires(posi too) at any given time..!!


So, what about extrude-honing the factory intake manifold..??
I've heard that is the hot ticket to boost performance
not only from stock intakes, but also stock exhaust manifolds...

I'm planning on getting the headers from TA eventually this next year,
but would extrude-honing the stock intake be worth it..??

Or should I start another thread on this subject..???

 

there is a stock fourbarrel intake that is claimed to be the best . better then the 2x4 intake even...

some rare option intake or what ever it was one or 2 year only...
in like 64-65 or something

 

psyco is right there is that four set up it is said to be better but I have heard that if you go much bigger then that you lose peformance so yea I guess thats my 2 cents to

 

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if the factory 2x4 is the best set-up,(which I've also heard before)
what would be the 'second' best..??

So, what about extrude-honing the factory intake manifold..??

but would extrude-honing the stock intake be worth it..??


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Actually the Edelbrock B262 Dual Four manifold is the best. But they are very rare. The Nailheads seem to like more carb than most other motors. The Quadrajet 4-barrel manifold is the best of the single four manifolds. Again rare. The Offy's ****, period. Extrude honing is a way to get a little extra flow for the stock intake. Don't take out to much though or you'll lose port velocity, which is oneof the reasons the Nailhead has such good low-end. Port matching the intake to the heads will help. If you don't go headers, extrude honing the exhaust manifolds helps. There is a group that is looking to make a new intake based on the B262, info is available via both the Yahoo Nailhead group and V8Buick.com.

 

anybody know the numbers or a way to identify that
particular better stock 4 barrel intake..??

 

As far as intakes go....
Edelbrock B-262 2x4 (Unobtanium)
Factory 2x4 possible tie with the Weiand 2x4
Factory Q-jet
Factory carter

If you are really interested, check out the Nailhead forum on Yahoo.

 

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......probably the MAIN reason is because of the small size of the valves compaired to most V8s

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kustombuilder: I thought you said size didn't matter
Sorry, I forgot to mention the small size of the valves being the main reason for the engine being called a nailhead.
Here's a cross-sectional drawing of the engine and showing the valve location & relative size, for anyone that cares....

 

My understanding of the reasons leading to Buick's unique head design had more to do with the division's customer base than anything else.

At the time the engine was designed, Buick was only marginally less prestigious than Cadillac -- and only marginally less pricey in their larger models. And they were substantial -- read, heavy.

Given the technology of the time, heavy was a good thing, a selling point in fact, because big heavy cars were equated with quality. A lot of what was going on -- heavier metal gages, reinforcement, more insulation, and size -- had to do with more-favorable sprung/unsprung weight ratios.

In spite if the quest for ride comfort, luxury cars were still expected to perform respectably, and Buick in particular had a reputation for being an exceptional performer, even the best-performaning American production car in the late '30s, early '40s with their Century models.

So, how did Buick achieve superior performance in heavy cars? With a very torquey engine design -- a long-stroke, in-line eight-cylinder. There were other torquey eight-cylinder in-liners on the market at the time, so how was it that the Buick was able to outperform them? The Buick did it with a rather modern OHV cylinder head, whereas most of its compe***ion featured either L-head or F-head designs.

When Buick opted for a more-modern V-8 engine configuration they endeavored to retain performance characteristics that were familiar to their loyal customer base. The problem they faced was how to deliver good old in-liner torque in a configuration that didn't accomodate severly undersquare torque-producing architecture, but still have the engine displacement to keep the their big puppies cruising smartly, reliably, and economically once they were underway. An important detail was that they didn't want their new motor to be annoyingly buzzu and noisy on the road.

Buick's answer was the "nailhead" with its small valve diameters and appropriate runner sizea that produced the desired high intake velocities right from the time the throttle was opened -- creating the instant-response, right-now torque charastertic of all nailhead Buicks.

Anyway, that's my take on the how and why of the nailhead Buick motor.

 

Well I will tell you all one thing Im learning a **** load more then I expected to thanks for the posts everyone!

 

Firstoff, I think Kustombuilder has put the facts straight as to the nailheads. Couple more useless facts.

1. The 401 and 425 have the same crank, the difference ois the 425 has bigger bore.

2. The quadrajet intake is the best single four intake, but rare as they only came out in 1966, the last year for the nailheads. Nailheads ran from 53-66.

3. Nailheads use a skirted block design and the bottom ends are very strong. Forged cranks and forged rods were used in all.

The smaller Buick 215/300 engine is NOT a nailhead. It may have similar appearance with the flat valve covers, and is sometimes called a pinhead, but it shares nothing with the real nailhead engines. Real nailhead has dizzy in the rear, pinhead dizzy is in the front.

The most desireable nailhead would be a 65-66 425 with 2x4. But any 425 is a good engine. For that matter a 401 is plenty for almost anyone's needs. A nailhead is a great looking engine and should be utilized for torque, not high rpm.

I disagree that a 61-62 is the best. These have the dynaslow cranks and will not bolt up to 64-66 T-400 without adapters and extra expense and h***le. The 64-66 T-400 is so much better then the dynaslow. The best T-400 would be a 65-66 version with the switchpitch. The switchpitch is like an dual stall speed, one higher rpm than the other.

A real 401-425 nailhead 4-speed bellhousing, flywheel and clutch set-up is quite hard to find. The early nailhead 264-322 manual set-up is fairly easy to find.

 

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(unlike the slant 6 which I know wasnt made by buick but still a POS and a horrible design)

[/ QUOTE ]


Wanna explain that? One of the best engine designs ever. Right up there with the 200-250-300 Ford Six and the SBC.

But I don't know nuthin either.

Jay

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i agree. i had a friend throw a rod on one once. went right through the block and tore the starter damn near in half on it's way. needless to say there was no oil left in it but he still drove it 20 miles home. it died as he pulled in his driveway. he was a lucky ***** though. always seemed to either break down or run out of gas as he rolled in his driveway