PONTIAC ZONE TECH FORUMS
 

Go Back   PONTIAC ZONE TECH FORUMS >
Engine Tech
> Grape Vine - General Discussion
User Name
Password

Grape Vine - General Discussion Shop Talk - Bench Racing, No political or religious topics are allowed.

Reply
 
Thread Tools
Old 12-31-07, 09:31AM   #1
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default Buick Nailhead-"pentroof" combustion chambers

I have to give Buick credit for the old nailhead design

pentroof combustion chambers
shaft rockers
centrally located spark plug like a hemi

these engines are cool !

the heads are not high-flow wonders, and basically had Pontiac D-port like flow characteristics, i.e. 200-220 cfm intake, 160 exhaust- but pretty damned advanced for an early-1950's engine design.

http://cgi.ebay.com/ebaymotors/1964-...spagenameZWDVW
Attached Thumbnails
Click image for larger version

Name:	660c_1.JPG
Views:	199
Size:	25.1 KB
ID:	14705   Click image for larger version

Name:	6664_1.JPG
Views:	245
Size:	22.9 KB
ID:	14706  
Zedo is offline   Reply With Quote
Old 12-31-07, 01:27PM   #2
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default

whoever removed the edit function from this forum, put it back on already, so I can fix posts, like this one I have to add this picture to, so it can be enlarged.
Attached Thumbnails
Click image for larger version

Name:	65c3_1.JPG
Views:	163
Size:	25.6 KB
ID:	14708  
Zedo is offline   Reply With Quote
Old 12-31-07, 11:54PM   #3
Pontiac Jack
M/T Hemi Guru
 
Pontiac Jack's Avatar
 
Join Date: Mar 2007
Location: Phelps, NY
Posts: 702
Default

I'm not sure why you consider them "advanced". Those huge(!) chambers need correspondingly huge domes on pistons to achieve any compression ratio. The resulting combustion space configuration is the exact opposite of modern chamber design.
Thanks for posting the pictures- I hadn't seen a nailhead chamber in many years.
P.S.- You can edit posts for a while- I think an hour- after you post.
Pontiac Jack is offline   Reply With Quote
Old 01-01-08, 11:08AM   #4
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default

Quote:
Originally Posted by Pontiac Jack View Post
I'm not sure why you consider them "advanced". Those huge(!) chambers need correspondingly huge domes on pistons to achieve any compression ratio. The resulting combustion space configuration is the exact opposite of modern chamber design.
Thanks for posting the pictures- I hadn't seen a nailhead chamber in many years.
P.S.- You can edit posts for a while- I think an hour- after you post.
Jack-here's why I consider them advanced-reread my post "advanced for the 1950's"- i.e. for their time- pentroof chambers with centered plugs are still in production, and used today in many GM cars, and other makes as well.

Buick had a V-8 with shaft rockers and pentroof chambers in 1953, when Pontiac still had a straight 6.. Furthermore, Pontiac never DID get a shaft rocker setup on their V8, ever- and shafts are superior in stability, to ball stud rockers.

The plug location in center is better- the 3.4 liter DOHC in my 1995 Pontiac, uses the same pentroof chambers and centered spark plug- albeit with 4 valves per cylinder and shallower chamber. Ditto for old my Saturn 1.9 liter DOHC engines. Many other engines, used pentroof chambers and centered plug recently. It is the easiest way go get 4 valves per cylinder.

So I stand by my statement- Buick was way ahead of their time. Today, the pentroof/center plug deal is common, in any commuter 4-cylinder engine.

You are correct in stating a huge chamber volume and domed piston are passe' for production passenger cars- that is mainly due to EMISSIONS- these engines polluted a lot, like all other engines of that era.

But not so for racing, where emissions doesn't matter. Every Top Fueler and Pro-Stocker or NASCAR engine runs some sort of domed piston today (look at them). T/F and F/C engines run pistons with huge domes in them.

this is all relative- a bread/butter Pontiac 400 is more modern and has more potential, than any Nailhead- which is why they quit makin' nails ! big airflow they ain't ever had, even ported they only hit around 225/155 cfm i/e- basically stock Pontiac D-port territory, the biggest valves that will fit are SBC 1.94"/1.50"-yet these nailhead fans shell $1000-$1500 to port to this level- the quickest nailhead I've heard of yet street legal is an 11.0 car at 122 mph

Intake Flow at Lift (000=No value listed)
100-200-300-400-500-600
053-110-157-180-190-195 1.87” Nailhead Head (no porting)
059-119-164-179-183-184 1.94” Nailhead Head Conversion by Carmen Faso
062-127-171-197-212-219 1.87” Nailhead Head Ported by Greg Gessler
061-121-172-201-215-223 1.94” Nailhead Head Ported by Steve Magnotti

Exhaust Flow at Lift (000=No value listed)
100-200-300-400-500-600
045-077-099-114-119-120 1.50” Nailhead Head (no porting)
048-082-112-120-124-125 1.50” Nailhead Head w/valve job by Carmen Faso
048-083-108-130-138-141 1.50” Nailhead Head Ported by Greg Gessler
052-093-126-141-150-153 1.50” Nailhead Head Ported by Steve Magnotti
Zedo is offline   Reply With Quote
Old 01-01-08, 11:17AM   #5
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default

Quote:
Originally Posted by Fireball View Post
Wait until you have to buy some of those advanced main bearings.
cost is a moot point in this hobby anymore-
big picture- what's $145 for main bearings, when everyone is spending $100 a week on gas for their commuters- to get burned fumes that blow away in return ?

Pontiac mains are banging on $100 now anyway-at least you get to keep the bearings, and run them for a while !

besides, nailheads look cool, and sound even cooler:

http://www.youtube.com/watch?v=tkxVkT7vRnc&NR=1

http://www.youtube.com/watch?v=eFjgU4IlbjA
Zedo is offline   Reply With Quote
Old 01-01-08, 01:45PM   #6
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default

Quote:
Originally Posted by Fireball View Post
They wanted over $300.00 for the main bearings 10 years ago. I think Kanter has the best price on them, they bought up all the old stock. I talked to a few people who owned GS cars. I was told a good running Chevy 327 was a match for the 401 Buick.


Well that's a given- a good running 327 could actually walk on a Pontiac, or any other brand-x engine, for that matter. They buzz those SBC's to the moon like a motorcycle, and make big HP with them.

Nailhead bearings are $145 now, Kanter is overpriced

http://www.speedwaymotors.com/p/4594...-Bearings.html

perhaps someone started making them again ?
Zedo is offline   Reply With Quote
Old 01-01-08, 02:26PM   #7
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default

I had one of those switch pitch TH400 trannies- but had it converted back to non-switch pitch, by changing input shaft and converter. It had the standard TH300-350-400 bellhousing pattern. The later nailheads will accept any of these.

I wonder if those bearings are made "overseas" ??

Fireball, did you run a nailhead ?
Zedo is offline   Reply With Quote
Old 01-02-08, 08:23AM   #8
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default

Quote:
Originally Posted by Fireball View Post
I had a 65 Skylark GS. I started to do the car but got tired of it and ended up selling it. I found the right Turbo 400 in a junkyard for $50.00. The guy I bought the car from rebuilt the engine in a class at the Jr college. He bought the pistons right from Buick. There was water in the oil and he thought it was a blown head gasket, the heads were removed and never put back on and the car sat for years like that. The leak was the timing cover. The guy I sold the car to had a machine shop freshen up the engine. I rode in the car after it was done. It ran good but it was not real impressive. The Turbo 400 was never installed, it had the ST300 transmission in it. I might still have the articles on how to hot rod the Nailhead.

I ran a TH300 trans for a short time, in a '72 Olds Cutlass with a 350-4bbl Rocket Olds engine- it was my parts chaser and daily commuter all through the 1980's. That tranny is a horsepower sponge. Later I switched it out to a TH350 and it accelerated noticeably better. The TH300 tranny on a nailhead Buick that already has smallish ports, would no doubt, be unimpressive.

IMHO, if one was to build a nailhead, the 425 is the only one to bother with, if available. It needs the extra cubes to make torque, because it lacks the airflow to make high RPM HP. The nail isn't a premier "musclecar" engine, it's a rod/retro engine, like a Ford flathead or early Rocket or early Hemi. The chamber/piston dome/valvetrain design is really unique, pushrods outboard of valve stems- along with the flat valvecovers, makes for a airplane-like engine appearance. They are a great looking, and great sounding engine.
Zedo is offline   Reply With Quote
Old 01-12-08, 08:37AM   #9
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default

check out the intake port angle and pushrod location on the nailhead

intake is a straight shot in- to build more runner volume, just add spacers to intake mounting surface to raise it up

pretty cool !
Attached Thumbnails
Click image for larger version

Name:	p135219_image_large.jpg
Views:	158
Size:	46.5 KB
ID:	14809  
Zedo is offline   Reply With Quote
Old 01-12-08, 04:39PM   #10
JEFF W
Drag Racer
 
JEFF W's Avatar
 
Join Date: Apr 2005
Location: Hazen ND
Posts: 191
Default

I bet the exhaust flow was not to impressive with the near U-turn that it takes though.
__________________
North Dakota's fastest REAL GTO.
JEFF W is offline   Reply With Quote
Old 01-12-08, 07:44PM   #11
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default

yep, same bent port as a Pontiac has

if you look at previous posted flow numbers, you'll find the nailhead heads flow almost identical numbers to Pontiac D-port heads, with a little more on the intake

The pushrod outboard of the rocker arms, and shaft rockers, is more reliable and upscale than a Pontiac ball stud rocker.

and the Buick nail came with forged steel cranks and forged steel rods across the board, from 1953 to 1966- years after Pontiac had gone to cast cranks and cast rods

it wasn't a cheap engine !
Attached Thumbnails
Click image for larger version

Name:	p37744_image_large.jpg
Views:	93
Size:	27.3 KB
ID:	14819  
Zedo is offline   Reply With Quote
Old 01-13-08, 01:16PM   #12
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default nailhead chest tattoo

these engines have a dedicated following, no ?

I guess this guy has no intention of running anything else but a nailhead in his lifetime !
Attached Thumbnails
Click image for larger version

Name:	chestyy0.jpg
Views:	96
Size:	83.3 KB
ID:	14820  
Zedo is offline   Reply With Quote
Old 01-25-08, 03:21PM   #13
Zedo
oh no portzilla
 
Zedo's Avatar
 
Join Date: Apr 2006
Location: USA
Posts: 3,212
Default 2-4's with 1250 cfm

anything with 2 carbs each with 625 cfm, direct from GM in 1966, has to be good

I believe this is the last factory 2-4 option GM ever offered on a V-8 from the factory or dealer

http://cgi.ebay.com/ebaymotors/ws/eB...NA:MOTORS:1123
Attached Thumbnails
Click image for larger version

Name:	0db2_3.JPG
Views:	73
Size:	58.4 KB
ID:	14887  
Zedo is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 2 (0 members and 2 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Detonation/Preignition You need to know! Bruce Wilkie Forced Induction 5 11-18-10 12:08AM


All times are GMT -3. The time now is 05:23AM.

Featured Ads
Ken's Speed & Machine
Mayhem Turbocharging

Carter Cryogenics.  What can we freeze for you?

Pacific Performance Racing

Central Virginia Machine Service.  Home of the Injun Engine!

All Pontiac Engine Kits

Larry's Auto Machine.  Full serivce auto, marine machine shop, domestic and foreign.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
2001 - 2007 PontiacZone.com
Page generated in 0.09532 seconds with 11 queries