Archive for the ‘Buick Tech’ Category

Story by Phil

You know when it happens, a loud bang then the oil light is on…”

Here is some technical information that some owners of older Buicks might find helpful. Being in a Buick only dealership you get to see common problems related to only one car manufacture. The items below are things we saw a lot of and sometimes could be prevented with proper maintenance. Again this is done from memory and I am sure I have forgot some things.

The “Nailhead engine” 1953-1966

Lifter Noise

The rocker arms would cut there way into the rocker arm shaft. This changes lifter piston position and creates excessive clearance between camshaft and valve causing the noise. Shaft replacement is necessary along with a few rockers. This was caused by lack of oil changes. About 1965 we did at least one a day.

Water Pump Failure

Early failure is caused by drive belt tension being too tight. A V-belt grips on the sides and as it wears it get narrow and drops down into pulley. It then becomes necessary to over tighten to eliminate slippage. This puts too much pressure on the water pump bearing and causes failure. The belt should be flush with the top of pulley. A/C cars use a dual drive on the compressor. This was done because the A5 and A6 compressor uses 15 horsepower to drive it. With two belts less tension was needed. It is important to purchase these belts as a matched set and always replace in pairs. For the correct tension a belt tension gauge is nice but a good mechanic can do it by the finger test. We saw a lot of pumps fail around 35000 miles because the belts were just too tight.

Broken Piston Skirt

This is caused by over revving. Don’t wind a nail head up too high, they don’t like it. They are a high torque, low rpm engine. I pulled the head off a 63 Riviera (401) and one piston was missing. I was looking at a connecting rod and wrist pin but the entire piston was in pieces laying in the oil pan.

Broken Oil Pump

This happens in real high mileage engines only. The shafts the oil pump gears both the drive and idler wear down. This causes the gears to bind up and explode the housing. You know when it happens, a loud bang then the oil light is on. If the engine is shut down right away a new oil pump is all that is needed.


The main reason we saw was a plugged up radiator. The main cause was over age coolant. Radiators plug up from the bottom to the top. Looking thru the fill hole is not a good indication of condition. Of course old hoses and water pump failure caused a lot of it too.

Coolant In Motor Oil

From lack of coolant changes a small hole will develop in timing chain cover behind water pump. These can be welded up if a new cover cannot be found. Change coolant every 2 years.

Blown head gasket from being driven in an overheated condition.

The temp light goes off at 280 degrees. There is no safety zone at that temperature. Shut off engine immediately and you will save the head gasket. Other than 1962-63 215 cu. in. aluminum V-8 and the 1964 300 V-8 I have never seen a head gasket go bad for any other reason than an overheat.

Throttle won’t return after being floored

Broken left (driver) engine mount. Rod type throttle linkage binds under air cleaner housing when engine rolls up due to broken left mount. This was the first federally mandated recall I can remember. We installed a cable around the upper suspension control arm and attached it to two head bolts with brackets. Starting in 1968 cable throttle controls solved this problem. Later models have hooks built into engine mounts. I have had this happen to me several times. It’s most unpleasant. Remember go for the ignition switch not the shift lever if you want to save the engine.

Binding Throttle With AFB Carburetor

Metal plate under carburetor has holes in it where it covers exhaust passage. This has allowed wet exhaust to eat thru the aluminum casting of carburetor binding primary throttle shaft. If not too bad the carburetor can be repaired. A stiff throttle spring is not the fix.

High Oil Consumption

Other then the usual worn piston rings common to all engines the nail head likes to wear down the valve guides. This allows oil to be sucked in around the intake valve. Also the 1959 thru 1965 used a stem seal that did a poor job. In 1966 the top of the guide was cut down to accept a positive seal. The nail head is the only GM engine I know of that has replaceable guides. They merely drive in and out with a hammer. The 1966 guides and seals will work with the earlier models. Valve grinding was common with the older engines because of poor gas additives, conservative driving and low spark voltage. It all but disappeared in 1967 and returned in 1975 and left permanently in 1977.

Crankcase Full Of Gasoline

The internal seal would fail in the fuel pump. This allows gas to be pumped into crankcase via the pump actuator arm. Yes the engine will still run when this happens.

Constance velocity universal joint 1962 thru 1970

Because of the long wheelbase of most Buicks and the desire for a smooth vibration free car the CV joint was used in the long drive shafts. The Rivera uses two. It is a ball and socket between two u-joints tensioned by a very stiff spring. Lubrication is done thru a small hole in the part between the u-joints. This requires a needle type grease gun. Also high-pressure grease is necessary. We were replacing three to four of these a week in the old days. The problem was one of two, they weren’t getting lubed or regular chassis grease was being used. When they go bad you will feel a shutter on take off. I had one customer ask for a tune up because he thought it was an engine miss.


Excessive brake pedal effort or brake pull. During the drum brake era thru 1970 we had a lot of this. Mostly the cars had a brake job done elsewhere before coming to us. GM used only new riveted brake shoes. The aftermarket brands were generally bonded rebuilt shoes. Bonded lining is hard and rebuilt shoes won’t re-arch themselves to the contour of the drum. Simply replacing the shoes solved the problem 90% of the time. Bendix still makes new riveted shoes for older models.

The 1956 models with power brakes left the assembly line with what was called a displacement master cylinder. Instead of an internal piston it used simply a large rod going thru a seal that displaced the fluid in the sealed reservoir. The failure rate was high. Most were converted to the piston type master but there still may be a few left out there.

In 1967 and 68 the disc brake system was made by Bendix. It used a 4-piston caliper. One of the pistons would become stiff and cause uneven pad wear. Also the piston seals would leak. This ended in 1969 with the Delco Moraine single piston floating caliper.

Front Suspension 1957 & 1958

The 1957 models came out with A-arm front suspension unlike the king pin used in 1956. The arms were made from cast iron. Iron is a brittle metal and when exposed to a lot of pressure it will snap like a pretzel. At the same time power steering was becoming popular. If you curbed the wheels and turned them into the curb the upper A-arm would snap. This could also happen if a large hole was hit in the road. The 1958 model had the same problem. The fix came in 1959 with stamped steel control arms. There was many a Monday morning we came to work and saw a 57 or 58 in the service yard listing like a sinking ship due to a broken A-arm.

Rivera Engine Size

All 1963s had a 401. All 1964s had a 425 and yes dual quads were available in 64. 1965 single 4 barrel was a 401, dual quads were a 425. All 1966s had a 425. In 1966 the 425 was painted red.


455 Stage 3 In CaseBuick wasn’t shy when it came to research and development in the late 60’s. What follows is the story of an extremely rare 455 cubic inch 4 bolt Buick V8 factory experimental block which up until recently was owned by John Fritz. John was kind enough to allow most of an article which he wrote for to be reproduced here along with a few new facts which confirm the blocks authenticity. Did you know there is another famous Buick which also runs a 1970 Stage III 4 bolt motor? The Buick Blackhawk Concept Car uses one which produces 463 @ 4600 rpm and 510 lb-ft @4200 rpm … “Its powertrain is a 1970-vintage 455-cubic-inch Buick GS Stage III V-8 engine…” read more…

This 4 bolt block is an important part of Buick Performance history and John has included some extra photos which have never been seen before (a exclusive!) which add to the fascinating story of this Big Bad Buick Block which obviously should have been standard equipment in every Stage ‘x’ Buick in 1970. Read on…


4 Bolt 455 Stage III Block

The Missing Link

Story by John Fritz

“That is our Experimental Work Order number, You’ve got a very rare piece there, we only made a handful of those, take care of it…”

This is one of two Buick 455 blocks with 4 bolt main caps. There were two blocks cast as experimental designs for Research and Development purposes. The picture of the factory “X” cast into the block designates it as an experimental design item.

In the photo I’m pointing to one of the first castings I saw on the block which hinted at it’s historical significance. According to Mr. Dennis Manner (who was the project engineer for Buick during this time and Headed up the Stage Program) The “X” designated Experimental. To the left and up in the 11 o’clock position, is a cast number “4”, which again according to Dennis Manner was the code for the 4 bolt main caps.

I’ve referred to it as ‘the missing link’ over the years, because a lot of folks believe the weakest link in the Buicks, has been the 2 bolt bottom end. I mean face it, the production GS bottom end was no different than Grandma’s Electra (! – ed). When I contacted Kenne-Bell about it, he said Buick also called it the “Pro-Stock Block” All the other manufacturers had the big 4 bolt main “bullet proof” bottom ends. Even though a Buick would stomp most of them straight off the showroom floor, and gives years of dependable service, this particular motor was no “regular motor”. It was officially called the “Stage III” by the Buick Engineers who built it!

When this beast was complete, it was a force to be reckoned with. It was hand delivered one sunny day by a group of Buick Research and Development men to the racer I purchased it from (he had an “IN” with them for some serious assistance on the old Dynaflow trans. (mis-pronounced Dynaslush). This was at one time a complete and running motor! It was a zenith for the 1970 Buick 455 motor. When delivered to the only other person than myself, and Buick to own it, it was “Loaded for bear”. The motor was filled with oil , ready to install, and RUN, and run it did, with the tire technology at the time, it was still able to run in the mid 10’s according to the man who ran it.

The motor had a custom sheet metal tunnel ram intake, equally rare Stage 3 cylinder heads, Stage 3 cam, Stage 3 pistons (13 or 13 1/2 to 1)a Gilmore oiling system, and of course,the foundation of it all ,the Stage 3 4 bolt main block. This block has solid webbing (production models were cored out for weight savings) and thicker mains (in addition to the 4 bolts main caps) to endure the flex and strain of this powerful mill. The webbing in the lifter area has also been fortified to endure flex in serious applications.

Hot Rod Cover

History: I discovered this block by total luck back in the late 80’s. I had advertised a fiberglass Skylark hood for $125 in a local paper, when the ad came out it said $25. Needless to say I had a flurry of calls. I had always grown up around GS’s, and spoke with Richard Lassiter at the very beginning of his starting the GS Club in the early 80’s, so I was more than happy to talk to any, and all, the Buick guys who called about the mispriced hood.

One of the callers, after a long talk of sharing GS information, gave me a phone number to call. He said the “Old Man” had Stage 1, Stage2, Stage 3 parts. I probably paused too long after he said that, but I was thinking “OH NO, not another one!” Another person you think knows Buicks until they say something like “Yeah, my “Grand” Sport had a 454 with four bolt mains, vinyl top and was actually a real GSX”. Uh Huh. Not to be rude and say “There is no Stage III” I took down the number. I almost didn’t call then I just decided to go for it, maybe he had something I needed.

This guy KNEW his stuff. When I sheepishly said I’d never heard of a Stage III, he about hung up on me for second guessing him. He blasted out every part that was on it, the Buick engineers who delivered and identified it, and topped it all off by telling me “it even had oil in it, and was ready to run”.

I was standing in his shop the next morning! Getting into “The inner tomb” of his shop reminded me of the people who explored the pyramids but on a car level. I lost count of the gates, doors, twists and turns, and attention grabbing carnage of Buick parts that were scattered everywhere, leading to the Experimental Block.

Finally under the buzz of a single flickering fluorescent bulb, I stood over the block and focused my light on a puddle of water resting in the transmission area of the block which stood on it’s end toward the wall. I focused my flashlight on the puddle of water, from the leaking roof, that had been there for a good while. I made some small talk about the roof leak before he finally told me to “spin it around”.

There they were. Factory four bolt main caps. I stirred up the water when I moved the block, as I reached down to scoop the water out, I saw a large “X” cast into the area, Buicks sign for Experimental products. I believe these were on the Proto-type Detroit Auto show 1970 GSX ,which gave away it’s history. I was literally shaking, I was so excited about finding this incredibly rare, and forgotten part of Buicks “Stage Program”.

455 Stage 3 Block with Owner John Fritz

455 Stage 3 Block with Owner John Fritz

I bought it on the spot, and started the process of trying to document it. Many of my calls were extremely frustrating, with people “enduring” talking to me thinking I was some wacko wasting there time with something that doesn’t exist. I had my first break through when Kenne-Bell acknowledged that they had heard of it. There was a dry spell of information until I got a call out of the blue from one of the Head men in Buicks Stage Program. An engineer I had been speaking with told me he was friends with him, and he’d try and have him call me. Then one day out of the blue he actually called me! I went through several minutes of questions on experimental casting marks, date codes (1970) codes designating the four bolt mains etc.

Finally came the “Coup De Graus” John he said “Are there ANY other STAMPINGS on the motor”. I said “yes, but couldn’t those just be done by anyone like you see at machine shops when you get an item back?” He asked again for the stampings, and the location of them. I read them off, told him the location, he told me to wait a moment, and then I listened to him sifting through several papers. It was finally identified by the Head of the Stage program as one of there original R&D pieces. He said ” That is our Experimental Work Order number, You’ve got a very rare piece there, we only made a handful of those, take care of it.” He asked me if there was anything else he could answer but since he called me, caught me off guard, and floored me with the confirmation, all I could do was say “No Sir, and Thank You!”.

Hope everyone enjoys the info. Before anyone asks, all the scattered parts the original owner had are gone. Someone went in and cleared him out shortly after I plucked the Experimental block out. Today it sits safely in a special display case, being treated with the respect it deserves. I hope one day to be able to show it at the GS Nationals. It would definitely give us something new and different to look at and think about, “What if this whole package had made it to production before the 70’s gas crunch?” That’s one GS I’d love to drive!

John Fritz

John, thanks for allowing me to document this rare piece of Buick history. The block may change hands in the future but this story will be here for every one to enjoy. It’s a real privilege to be able to tell the story here at BuickStreet.


Note: August 2002 – This block has now been sold. It is in the hands of the Buick Performance Group who will ensure that it gets displayed for all to see at their upcoming events.

Carter Quadrajet Model QJ-9089 Installation Instructions

Carter Quadrajet Model QJ-9089 Installation Instructions

Carter Quadrajet Model QJ-9089 Image Gallery

14 Sep, 2010

Nailhead Blueprinting

Posted by admin under Buick Tech, Nailhead Blueprinting

Nailhead Blueprinting – Article Reprinted with Permission

This is an article which appeared in the April 1966 edition of Hot Rod magazine. I am posting it for historical reasons and to help Nailhead enthusiasts with information which will hopefully assist them in the rebuilding their 401/425 Nailheads. The article was written by the well known, widely read and respected automotive journalist Eric Dahlquist.

Links to Full Size Pages – Nailhead Blueprinting Article

Article Page Gallery (For Full Sized Pages See Links Above)

This is an article which appeared in the April 1966 edition of Hot Rod magazine. I am posting it for historical reasons and to help Nailhead enthusiasts with information which will hopefully assist them in the rebuilding their 401/425 Nailheads. The article was written by the well known, widely read and respected automotive journalist Eric Dahlquist.

Build a Better Nailhead – 10 Page Article Reprinted with Permission

This article was written by Jeff Tan with photography by Michael Breeding.
It appeared in the June 1999 issue of Rod and Custom Magazine.

Links to Full Size Pages – Build a Better Nailhead Article

Article Page Gallery (For Full Sized Pages See Links Above)

Note: For Full Sized “Build a Better Nailhead” Pages See Links at Top of Page

This article was written by Jeff Tan with photography by Michael Breeding.
It appeared in the June 1999 issue of Rod and Custom Magazine.