KyleDallas

For those interested in the development and history of the 427 Big Block
... there is a nice write up on the 427 Mystery Motor in Drag Racer Magazine. Details include the Mystery Motors use in Drag Racing and in
Junior Johnsons NASCAR Impala.
The article also details some of the similarities and differences of the
Mystery Motor with the 409 and the production Big Block Chevy 396-427.
The article does not mention its use in Corvette racing aplications but
does mention it was used in Johnsons 1963 Impala Stock Car. Johnson
won 7 races and captured 10 pole positions in the 1963 #3 427 powered
Chevrolet Impala.

KyleDallas

DZAUTO

Kyle,
I haven't seen the article (and I don't subscribe to that magazine), so I cannot thoroughly comment on the text of the article.
BUT, unbeknownst to MANY people, Chevrolet built TWO 427 engines in 1963. One was an RPO (Regular Procuction Option) and the427 "Mystery" engine. Both were COMPLETELY different engines. Dimensionally, they shared some commonality, but that was it! Period!
The RPO was Z11, which was NOT just an engine, it was a COMPLETE pkg which was ONLY on an Impala 2dr hardtop (NOT an SS). This pkg included a stroked 409 (to 427) with totally different heads and a 2x4 intake that was different from the regular 409 intake. This was primarily a drag race specific engine. There is a lot of debate about the total of Z11 cars sold (the range is from about 50 ot 57 cars). About 12 DOCUMENTED survivors exist.
The 427 "Mystery" engine was essentially the forerunner to today's BB family. The Mystery 427 was NOT available through ANY normal, or even special channels such as a COPO. It was "secretly" provided to a VERY select few for NASCAR racing, clandestinly out the back door of Chev engineering.

The picture that you have posted of Jr Johnson's #3 car MAY NOT be the real deal. A number of years ago, Floyd Garrett cloned a 63 (and VERY probably that is the car he cloned) like JJ's car, complete with a 427 Mystery engine that he had previously bought from Smokey. I went to Floyds Museum in Tenn about 3yrs ago, SPECIFICALLY to see that car (JJ's #3) and a REAL Z11 car that he had. HE HAD SOLD BOTH!!!!!!!!!! I was heart broken! That's why I think that maybe the picture posted here MAY be the Floyd clone (which, by the was was supposed to be a VERY, VERY correct clone, even by JJ's personal approval). Floyd DOES still have (at least 3yrs ago) a complete Z11 engine on a display stand in the museum.

richbopp

Can you unravel the difference between the 427 ci and the 427 HP. The picture shows a 427 "HP" car, does that imply a 427 ci. Could that 2 door Impala have a 396/409 in it that was 427 HP rated?

KyleDallas

I've done no research on the pic... I can't comment on the car's authenticity... I merely posted it as eye candy.
Tom, the Drag Racer Magazine article is at home, where I'm not, currently... and it bears out what you have stated... the article is about the Mystery engine (almost quasi BBC) and not the Z11/409/427 variant...
From memory, I believe the article stated that the "Mystery" motor had a little thinner casting than the BBC.... the valve covers on the Mystery engine were also thinner and shorter ( I believe) than the BBC.
I do remember seeing a pic of the Mystery Motor in my copy of
Smokey Yunick's book "Power Secrets"... and I remember feeling that it looked very similar to the Big Block Chevy.
I would not give to much credence to the horsepower ratings on any
of the vintage NASCAR hoods (per sandbagging).... although cubic inch displacement rules were in effect and could be trusted. Junior's stock car was said to be running the Mystery Motor at Daytona in 1963... where he qualified #1 at 8mph faster than the previous years record. I do not believe Junior ran the 409 variant in 63 at all.

If I rember correctly, I will check when I get home, the article said
the Mystery Motors were cast betweeen August-1962 and January 1963.

Here's an authentic Junior pic


for the sake of keeping it straight... there are 3 chevy 427's we are talking about here.

1. the Z11 409 Variant 427
2. the Mystery Motor 427 "special backdoor" racing non production (Junior's-1963)
3. the Standard Big Block Chevy.. in 427 cubic inch trim

DZAUTO

Rich,
Back in the early NASCAR days, the rules were MUCH more "interpretable" by the teams (many even made up their own rules and they got accepted by NASCAR). Not so today! Teams are now frequently broken by "bent" rules. Horsepower ratings did not necessarly imply displacement. As you probably know, the top 63-64 409s were rated at 425hp, so it only stands to reason that the Mystery 427 was likely a little higher than 427hp(). You suppose? (Jr himself even admitted in an interview that they were making about 500hp with the Mystery 427!!!)

Kyle,
From all accounts and looking back at the 63 Mystery engine, it definitely did have some weaknesses. They had some bearing problems for one thing. The Mystery engine retained the same journal sizes as the 409 design (today's BBs have bigger jorunals as a result).
Appearance wise, the Mystery engine definitely looks like the 65-later MKIV BBs, but as you mention the heads had enough differences that they will not even come clost to fitting on a MKIV BB. They even have a different bolt pattern. And you're right about the valve covers, they're smaller. But, as you can see from any of the Mystery pictures, its the daddy of the 65-later BBs.
Dick Keineth, who is THE Chev engineer behind the design of the Mystery engine, impressed Smokey with it's revolutionary design. By the way, the 348-409-(Z11 427) family has become known as the MKI, the Mystery 427 as the MKII, the MKIII engine was ONLY on paper (never porduced) and now we have the MKIV, V and VI (or if you prefer Gen 4, Gen 5, Gen 6) BBs.

Jr DID whip the field at Daytona in 63, very impressively, with the Mystery engine. But, because of failures, he didn't finish well. But you can be sure (as they say, the rest is now history) many, many people stood up and took notice. Even Ford FORCED NASCAR to require that GM provide them with a couple of the Mystery engines (do you suppose Ford did any R&D when they got their hands on them?).
Oh well, things are different now. I miss the fights! AND NASCAR IS WRONG, WRONG, WRONG FOR NOT ALLOWING THEM!!!!!!!!!!!!

JohnZ

Here's an original '63 427 "Mystery Motor" in the Powertrain display at the new GM Heritage Center.

JohnZ

The Z-11 was a stroked 409 "W"-block, in an Impala with aluminum front sheet metal and bumpers; here's the Ronnie Sox/Larry Wilson Z-11 at this year's Meadow Brook Concours d'Elegance, fresh out of a complete restoration by Hank Gabbert, who lives just down the road from me.

hdvettes

JJ ran a 1963 Corvette ZO6 with the Mystery 427 in it, I believe at Daytona. The car qualified #1 or #2. It was a rainy day and the heat inside caused the windows to fog up so bad that they parked the car. Something about the steam made it unbearable to drive.

This car with a complete Mystery Motor was on display at the Bloomington Special Collection in the early 90's.

The car is allive and well in So. Cal., it appears at the Monterey Historics every once in a while.

The motor with the car came from Smokie's shop. It was bought for the car at the big garage sale.

I believe it is the only Corvette to qualify on the front row at a Nascar race.

I delivered the car and the motor to the Special Collection.

Mike

KyleDallas

Looks like Mopar copied GM's tactics of building a New Big Block in the
off season for house cleaning at Daytona..... it was 1964, a year later,
that Chrysler took 1,2,3 at Daytona with the Hemi...
Junior led the most laps of the 1963 Daytona 500,with the Mystery Motor, before retiring..... and, um..ahhemm... Junior was in a Hemi car at Daytona in 64. The Ford SOHC "Cammer" 427 was built in 64.... but NASCAR's Bill France took one look at the 427 SOHC and said NO!!...... outlawed before it ever saw a race..it made 658hp with dual carbs,and was offered by FoMoCo in crate motor form... it had hemi chambers with single camshafts over each head driven by a chain..


Valvetrain of the Ford 427 SOHC "Cammer"... built to "one up" the Mystery
Motor and 426 Hemi.

If France had allowed the "Cammer" to compete..... I believe Chevrolet would have answered the
challenge and we would have Chevrolet Hemi's in pushrod or overhead cam arrangements today...
Nick Arias and Sonny Leonard have built Hemi heads for the BBC..... Sonny's heads can be bought
Today.... for a measely $14,900 a pair... (see the link below)
**
**
http://www.sonnysracingengines.com/p...eads/hemi.html

*****

Sonny Leonard GM Hemi

63Corvette

Here is another "REAL" Mystery 427 Engine. This one belongs to Tom McIntyre.

DZAUTO

Kyle,
Don't feel bad at all about no research and lack of authenticity.
These kinds of previous historical engineering exercises (and that is about what they amounted to) are frequently very difficult to document, and sometimes impossible to document. With some of this stuff being 40+-50+yrs old, and when you talk to the individuals who were specifically involved in the design and development, they often can't remember for sure exactly what and when things occured. Back 40-50yrs ago it never occured to them that this sort of stuff would some day become very historically significant. They were just doing a job--------------sometimes for fun, but most of the time for a paycheck.
For example, I'm 63 now, and back in my childhood/teenage days, there were MANY, MANY things which are long gone now and today absolutely nothing exists that would indicate what or where they were! Never occured to me 40-50yrs ago to take notes and pictures of Santa Fe or Frisco steam locomotives pulling trains through Okla City, or TWA Super Connies out at the airport or B-29s coming and going at Tinker AFB.
Nor, did it ever occur to me to go out and take pictures 30+yrs ago of the GM assembly plant being built in OKC which was permanently shut down a few months ago.
I'm sure the same existed with folks back in the 50s-60s, in what I consider to be the hayday of GM (particularly Chev) developments. Thus, a lot of things like the Z11, 427 Mystery engine, Small block hemi heads, etc, etc, are at best sketchy.
So don't feel bad that you don't know some of this stuff. Just start documenting all of today's cookie cutter, monochromatic, lookalike cars ( ) so that you can show the pictures to your grandkids 40-50-60yrs from now!

KyleDallas

When I was watching the Barrett Jackson auction on Speed the other
night... I thought I saw the rear section of the Junior Johnson Holly
Farms 1963 Impala..... I just did a quick search and found this...
**
**
http://www.barrett-jackson.com/aucti....asp?id=150725

It's a little hard to tell from the page if Junior's 63 Stockcar is fixing to go to auction... or if it has
already gone through..

joe58

Smokey Yunick ran one of his famous black and gold #13 cars at Daytona 1963 with a 427 Mystery Engine and on top of the controversies with the engine he hires a Sprint car driver who never ran a NASCAR race.

It was Johnny Rutherford and he ends up winning his first NASCAR race which was one of the 100-miler qualifiers for the 1963 Daytona 500
Jr Johnson won the other.
I have read in many articles that both 427s blew up in the race but the Daytona results show Rutherford finished 9th
Jr blew up and is listed as 42nd

rahzip

This sound like a good topic for vettefinder Jim Gessner.
There is another member with knowledge of the mystery motor. Maybe he will share some of his knowledge with us.

63 340HP

The rumor at the time was that Ford pushed Bill France very hard to allow the SOHC 427 in NASCAR competition. He was ready to let Ford in when Chrysler sent down a represenative that provided photos (or engineering drawings) of a four valve per cylinder varient of the 426 hemi. Reportably the information presented related to an engine that Chrysler had in development. The implication was if Ford was allowed to run the SOHC, Chrysler would immediately step up the competition another level. The result would be a competition engine development race, one that would leave privately owned teams undergunned (and underfunded). In an effort to maintain the spirit of a low cost NASCAR competition series Bill France decided to tell Ford no SOHC in NASCAR.

For Chevrolet to step up (and into) a competition engine development program, to complement the fairly new MKIV engine, would have demanded much from GM management (they did not have the ego of Ford, or sales tied to competition success as much as Ford).

MikeM

These two cars are both replicas. The picture was taken in the last two years but I can't remember where or when. I'm thinking Charlotte, last Summer.

I doubt GM was "forced" by NASCAR to give FORD a couple engines for their review as GM was not officially involved in racing in February of '63 and that policy was reitierated to the divisions in January of that year.

The '63 Daytona Sportsman race that the Mystery engined Corvette was entered in was won by Paul Goldsmith in a 421 Super Duty powered '63 Tempest owned by Ray Nichels.

The Z-11 was first a "package", released in Summer of '62. It was available over the counter as aluminum front fenders, hood, bumpers and braces and the special engine components as some have described. It was also available as a complete car in late '62. Only in the Impala, not the bubble top Bel Air, with all the special parts. The cars were about .5-.6 seconds quicker in the quarter mile than a tuned standard 409.

A story that I heard in 1963 from someone who was there: In the late Fall of '62, a van box truck rolled into Indianapolis Raceway Park drag strip pits during the course of one of the last events of the year. Back doors come open and out rolls a solid white '63 Impala. The owner requested permission to make an exhibition pass down the track with the fastest RamCharger (MoPar) at the track. He would not open the hood for inspection. Permission granted and the race was on. The Impala blew the Mopar away which was no small feat, rolled it back up in the truck and left. Nobody knew who the guy was. He wouldn't say.

Was this one of the "mystery engined" cars going down South to get ready for Daytona? I've always thought so.

I think there were four teams that started the season with those engines. Ray Fox (Junior) and Smokey and two more. I believe Ray Fox was the only one that kept the engine running the whole season as parts weren't available from GM. As a matter of fact, I believe I heard that GM demanded the Mystery Engines be returned before the racing season even started but evidently nobody complied. I think I heard Junior tell that story about hiding one engine in a barn.

DZAUTO

[QUOTE=MikeM]
I doubt GM was "forced" by NASCAR to give FORD a couple engine for their review as GM was not officially involved in racing in February of '63and that policy was reitierated to the divisions in January of that year. QUOTE]

Mike,
This a quote from Smokey himself.
From FAST CHEVYS by Alex Gabbard, bottom pg 30-top pg 31.
Direct instruction given to Smokey Yunick by Bunkie Knudsen,

"Knudsen calls and said,'Smokey, listen. I don't want you to say a thing 'til I get through. I've been up all night with this thing, arguing back and forth with France. Number 1, we are going to race the cars. Number 2, we are going to take two engines down to the Chevy dealer for Ford to pick up, and they are to be there at eight o'clock in the morning. You are to keep the thing going, and try as hard as you can to win. Now, we've talked about this many times. I'm not asking you, I'm telling you'".

I've also read this elsewhere---------------------it seems as if it was in Smokey's book.

joe58

This is the story told in many NASCAR history articles.
Only production engines were allowed to race and Chevy said it was a production engine and anyone can buy one. So one of the Ford teams said OK I'll take two and Chevy said OK and sold two to the Ford team.
The engine was allowed to run.
Bill France played dumb as he was doing whatever he can to get all the car co. run in NASCAR.

from my notes
The 1963 Daytona Speed week was a wild year. The normal road race was the Three-Hour Continental race was held February 17, 1963
In addition to the Continental race some one has big idea to run a race with stock cars and sports cars together on the oval. This was called the American Challenge Cup race and I believe was only run that one time on February 16, 1963. The American Challenge Cup race was won by a 421 Pontiac Tempest. It rained during the race but they didn’t stop it.
1st owner Ray Nichels driver Paul Goldsmith Super Duty 421 Pontiac Tempest by over 5 miles.
2nd: owner Nickey Chevrolet driver A.J. Foyt in a 1963 Z06 Corvette.
3rd: owner Mickey Thompson driver Billy Krause in a 1963 427 Corvette

KyleDallas

This has turned into a very nice discussion with many good contributions..... here are a few factoids from the Drag Racer article on the 427 Mystery Motor...

The Mystery Motor that was photographed for the article (there are
pics of the casting numbers) caries a casting number of
0-217199.... the "0" denotes a pre production casting.
Also cast in the block is 9-13-62... the date of Sept 13, 1962 in standard short abreviated form.... which is the date the block was cast.

Each head is 25 lbs lighter than it's Big Block Mark IV
brother.

In a pre Daytona dyno test.. the 427 Myster Motor made 620 hp
with a single Holley on a 180 degree high rise aluminum manifold.

The Valves on the Mystery Motors heads were 2.19 Int and 1.72 Ex.
Chambers were very similar to the 65 to 70 Mark IV closed wedge
type heads. The heads were dubbed by early writers as "Porcupine"
heads but were officially called "Canted Valve" heads. Pop up pistons
gave the Mystery Motor a 12.4:1 compression ratio before milling.

The stroke was 3.65 inches and the rocker ratio was 1.75:1.

The Mystery Motor was said to be GM's test bed for screw in rocker
studs.

It is believed by Mystery Motor experts that 18 engines were produced by GM.

There were 4 different intake manifolds developed for the engine..
all were 180 degree design. Smokey Yunick stated the best of the
4 designs was casting number 0-232166.

The 12.4:1 pistons are listed as part # 0-233239

Here are the head flow cfm numbers provided by Valley Head Service
tested a 28 inches.
LIFT..........INT..........EXH
.100..........73.2.........73.2
.200..........122.4.......122.4
.300..........234.0.......147.5
.400..........277.8.......177.4
.500..........300.8.......196.2
.600..........328.0.......210.3
.700..........341.2.......221.0

The Exhaust ports were round... cast iron exahaust manifolds had
2inch primaries and were 33 inches long... they dumped into a
4 inch diameter 26 inch long collector.

All information listed above came from Drag Racer Magazine-
July of 2006.. Volume 10, No.4 pp 60-67... web address is
http://www.dragracermag.com