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Mk II vs Mk III detail differences?

General engine tech -- Drag Racing to Circle Track

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SchmidtMotorWorks
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Re: Mk II vs Mk III detail differences?

Post by SchmidtMotorWorks » Sun Jul 07, 2019 12:35 am

I would like to know how the head bolt and intake port design decisions were made.

It is probably the most slapped together mess in all of that era of engine design, but people figured out how to make power with them.
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Re: Mk II vs Mk III detail differences?

Post by PackardV8 » Sun Jul 07, 2019 1:16 am

Yes, but remember in the first few years, they had a reputation as hand grenades. I even knew small dealerships who wouldn't sell the high-performance versions. They knew they'd be getting too many problems.
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Re: Mk II vs Mk III detail differences?

Post by GLHS60 » Sun Jul 07, 2019 1:43 am

ProPower engines wrote:
Sun Jul 07, 2019 12:17 am
After seeing the valve train layout and how the push rod guides were made inline is it possible they used a 409 block
with the canted valve head.
Never had thought about it till now or had two side by side but some guys did run a 409 block and used the at the time new 454 crank in them. While the Z11 is said to have used a 6.135 long rod the 396-454 did also but the 409 block with the canted valve head would explain how the 396 and 427 heads came to be.

Is it possible that GM had the later 396 BBC on the drawing board and had some stuff made at that time and they adapted
the canted valve 396 heads to the larger bore 409 block?

Back then the back doors of the car manufactures had cool parts leaving to be run in nascar this may have been one
of those times when someone said hey why not try this and kick ass in february.
Close, Dick Keineth created the top end and needed a proven Engine to run them on.

That's why he modified a stock Z-11 short to mount his radical new heads on.

The Mystery retained the Z-11's big bore, short stroke, crank, rods, inline lifters and main saddles.

The Mystery even kept the odd W style water pump on the Mystery block only with a 90 deg deck.

Early 1963 GM placed a no racing edict on all divisions, Pontiac and Chevy were hurt the most.

Keineth had 42 sets of parts to test but didn't have time due to the corporate edict.

Instead he shipped them out to Smokey and others for the upcoming Daytona etc.

The proved very fast but with little to no testing many failed, "junk oil system and shaky rods?.

Thanks
Randy
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Re: Mk II vs Mk III detail differences?

Post by GLHS60 » Mon Jul 08, 2019 4:25 pm

Good question and I don't yet know the exact answer.

Dick Keinath was a fine Chevy Engineer who worked on many projects including the W Engines.

The W Engines featured a cylinder head compromise dictated by higher ups.

The order was to use one head casting for car and truck Engines regardless of compression ratio.

This was best accomplished by placing the combustion chamber in the block.

In order to have a wedge shaped chamber the deck was cut at a 16 deg angle.

While this has proven to be not ideal the W Engines sure were pretty.

Understanding the W Engines shortcomings Mr Keinath designed the splayed valve head.

Unfortunately there never was was any testing to speak of, this is where Smokey came in page.127

'I really liked my new job at Chevy...to work on the development of the Chevy "Mystery Engine".

Doubly unfortunately, the project got cancelled and he was banished to Opel in Germany page.145

"Or like Dick Keinath who ended up at Opel in Germany. Maybe best Engine man GM had.

What did he do to get banished? He fought to save a good Engine design."

Thanks
Randy


SchmidtMotorWorks wrote:
Sun Jul 07, 2019 12:35 am
I would like to know how the head bolt and intake port design decisions were made.

It is probably the most slapped together mess in all of that era of engine design, but people figured out how to make power with them.
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Re: Mk II vs Mk III detail differences?

Post by GLHS60 » Tue Sep 10, 2019 2:13 pm

INTERESTING UPDATE

Recently I bought a book containing a Dick Keinath interview, lots of info from the man himself.

Here is a link to his 1964 canted valve patent: https://patents.google.com/patent/US3276438

I'm going to re post and correct or verify previous posts based on what Mr Keinath stated.

There are also interviews of others involved in the MK II /MK IV project and a MK III clarification.

Mr Keinath started at GM in 1950 working on all of GM's automatic transmissions.

He joined Chevrolet Engineering in 1952 and assisted Ed Cole and others on a new Turbo Fire V8.

There was already an Ed Kelly V8 but it was mostly or entirely discarded.

The new Turbo Fire (SBC) proved very successful and work continued on making it better.

Mr Keinath was a proponent of big bore short stroke Engines and he had a 302 running by 1957.

Casting issues delayed the big bore until the 1962 327 but his 302 became part of the 1967 Z28.

He also worked on the Turbo Thrust W engines and was responsible for the passenger car 409.

Until then Engines were designed for passenger car, truck, marine and sports car usage.

Probably how the 348 W got its reputation as a truck Engine as its design was all encompassing.

He was solely responsible for the 153 4 cyl and 230/292 6 cyl using Turbo Fire design philosophy.

His work on the passenger car( and racing) 409 made him aware of its combustion chamber issues.

Racing at the time meant stock car racing, EG: NASCAR and the 409 wasn't up to the job.

Fortunately, Mr Semon (Bunkie or boss) Knudsen became Chevrolet GM and was a racing fan.

His prior job as Pontiac GM allowed him to promote Pontiac on the stock car tracks.

With Smokey Yunicks help Pontiac won many races and this gave Pontiac much needed prestige.

GM was out of racing but the GM 14th floor executives weren't racing fans so they never noticed.

Once Knudsen came to Chevy he wanted Chevy to become a force on the high speed ovals.

Knudsen gave the go ahead for Chevy to build a racing Engine and Mr Keinath got the assignment.

The engineering work Order stated:" Please design an Engine per instructions of RL Keinath"

First and probably an order free of any constraints was issued!!

Work began on what became known as the MK II Mystery Engine ( he never used the word motor)

Thanks
Randy

numboltz wrote:
Fri Jan 19, 2018 11:52 pm
Interesting that in spite of multiple statements in the articles of the day stating it was entirely a racing
engine, the cylinder heads have heat crossovers in their castings and it appears that the intakes
have those provisions, too.

Other trivia I have seen includes the fact that they used the same basic rod forging as the 409, with
the pin hole moved a small amount. I would assume that the block went down the same line as the
409s did, even though the decks were at a different angle. With the cranks being interchangeable,
the rods similar and the bore spacing the same I wonder just how much detail difference there was
in the basic block castings? Be fascinating to compare the two blocks.

Finally, I have read that Chevy was forced to sell 2 engines to Ford to prove the engines were
available in the market place and thus NASCAR legal. Apparently late in the season Junior
Johnson was plumb out of engines and by some form of shenanigans was able to acquire one
of the two from Holman & Moody. I suspect the other one is the grandfather of the 385 series not
too mention the Cleveland family.

There must be at least one patent for the canted valve idea, but so far I haven't found it.
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Re: Mk II vs Mk III detail differences?

Post by Schurkey » Tue Sep 10, 2019 3:49 pm

GLHS60 wrote:
Tue Sep 10, 2019 2:13 pm
Recently I bought a book containing a Dick Keinath interview, lots of info from the man himself.
What book? Link?

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Re: Mk II vs Mk III detail differences?

Post by GLHS60 » Tue Sep 10, 2019 7:41 pm

http://www.alexgabbard.com/fast-chevys.html

Thanks
Randy

Schurkey wrote:
Tue Sep 10, 2019 3:49 pm
GLHS60 wrote:
Tue Sep 10, 2019 2:13 pm
Recently I bought a book containing a Dick Keinath interview, lots of info from the man himself.
What book? Link?
Sherwood Park
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Re: Mk II vs Mk III detail differences?

Post by Schurkey » Wed Sep 11, 2019 11:49 am

GLHS60 wrote:
Tue Sep 10, 2019 7:41 pm
http://www.alexgabbard.com/fast-chevys.html

Thanks
Randy
So I go to the Amazon web site for that book, thinking it sounds interesting and maybe one I should buy.
https://www.amazon.com/Fast-Chevys-Alex ... ef=sr_1_1?

Amazon tells me I bought it in 2012.

That's when I went down to my library and found it parked on a shelf.

Senility approaches.

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Re: Mk II vs Mk III detail differences?

Post by GLHS60 » Wed Sep 11, 2019 12:36 pm

Thais too funny!!

I have an extensive library also but no other Richard Keinath interviews.

The book doesn't look like anything special but the interviews are priceless!!

Thanks
Randy
Sherwood Park
Alberta,Canada

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