History the 427 Mystery, mystery

.....and then beat you with experience......LOL

 

Clearly a Magnum Cum Laude graduate from the Donald Trump Academy of Debating Skills... when confronted with factual information, resort to name calling...

 

yep forgot that part.

 

Popcorn anyone? Stop the bullshit and address the OP question/comments!!!!!!!!!!!!!!!

 

Two wrongs don't make a right; but two wrights made an airplane!

 

Jeez, it looks like thats what I was doing???

 

Sorry PB more reading

 

Wolf
I'm not an expert, they may have looked the same on the outside but I seriously doubt they were metered the same internally.

 

Dick Keinath also designed the 348, 409, and Z-11 427 engines so it is certain the Mystery Motor 427 and the Mark IV big blocks evolved from those W engines. Rex White drove race cars with all the above engines (except Z-11) and worked closely with Keinath in improving them.

 

Really, there isnt any room for doubt, all you have to do is look at the specs on the two motors and its obvious.

 

I recall getting confused about the differences in deck angles/block deck height; expressly between 348 and 409. Never having the two in any one place at one time, it was rumored that the 409 intake would NOT bolt onto a 348, as the manifold was 'wider' (or narrower!)
This was after I retired my 409, so that remained an argument. (some said same, others said "NO!")
What say you, my HAMB brethren?
Man, like Benno says: An Elephant sized bite of information on these engines!

 

I thought it was more an issue with the port sizes?

 

The 348 and low horse 409 intake are interchangeable. The high horse 409 aluminum intake takes special heads with higher ports.

 

Engine design is oftentimes not done without taking into consideration total program cost of bringing the product to production.

Things like bore spacing and other machining reference points are considered so that expensive highly tooled transfer lines can be salvaged for even a "clean slate "design.

That explains why things like bore centers and cam locations would carry over from the 348/409 to the later porcupine big block engines.

I recall seeing the GM Performance display at the Woodward Dream Cruiser a few years ago. they had 409/427 Z11/427 mystery and the later 396/427/454 Rat engines in the same display.

The 427 Mystery motor was neither a 409/427 Z11 nor a production 427 Rat, although it shared the later production engines design concept features. It is sort of an early proof of concept prototype.

 

Thats what I thought.

 

I also looked at the head gaskets for Mark IV's and 409's it looks like they only moved 2 head bolts in the top row per bank, it looks like the rest of the head bolts even line up...

 

Over lay the gaskets and I think you will find at least two more, end cylinders bottom outsides..What did those heads use for alignment dowels, like SBF bushings at couple head bolts or separate location? Lotta holes ....

 

yes, the two larger holes at the ends of the upper row use alignment dowels that the head bolts pass through. I always liked that deal on BBC's. As far as the alignment, you could be right, i dont have any 409 head gaskets here to compare, was just looking at the photos. Regardless, the majority of the head bolts look to be in the the same place.

 

There's about this much difference. You can port match the low performance heads to the high performance 2 X 4 intake. The heads won't still won't flow like the QA/QB heads, but ...................................... And I've seen folks just bolt them on and do OK. You do have to eliminate the intake bolt between the ports and fill the bolt hole in the head, but if ya gotta have a stock high performance intake on small port heads just dive in and do it.

BTW, this is a junk head I ground on to see if it could be done without breaking through the port roof.

 

Seb, you figure these two? (orange arrows)

Could be right, the Mark IV looks closer to the bore centerline??? But its hard to say, the photo of the 409 head gasket was taken at a slight angle from the bottom, the Mark IV gasket photo looks dead center. Would be interesting to lay the two gaskets on top of each other.

 

Egocentric. Destroys threads w/out one shred of modesty. Ever.

 

it's a lot to do with that Z-11 crank.....and the other stuff/parts....

 

That Mickey Thompson Corvette pictured above is one of the most valuable Corvettes in existence and has a very interesting history. It was one of two Corvettes that introduced the Mystery Motor to racing at Daytona in 1963 a week before the Impalas did.
Chevrolet had given Thompson both Corvettes along with two Mystery Motors to run in the American Challenge at Daytona. Smokey Yunick was hired to make sure the engine transplants were done properly. Yunick was also preparing an Impala for Johnny Rutherford to drive in the Daytona 500. Junior Johnson and Rex White were hired by Thompson to drive the Corvettes probably because both were racing Mystery Motor Impalas at Daytona. In the qualifying race Johnson won and White was on his bumper trying to pass. When the race started it was raining and the powerful Vettes could not compete with the less powerful race cars. Chevrolet announced to the Chevy racers there would be no funding after the Daytona race. The two Mystery Motors were pulled at Yunicks shop and Thompson sold the Vettes. In 1976 Tom McIntyre bought the car Junior Johnson drove. He knew the history and it was beat up from years of racing so he bought it to race himself. In 1986 Smokey Yunick had one of the greatest auctions I have ever been too. He was selling all the experimental engines he had saved over the last 40 years. There were many different brands of engine going back to the Hudson Hornet. He kept everything. It was a day I will never forget. One of those engines was a complete Mystery Motor. McIntyre came to buy that engine and unknown to him GM had an agent there to buy it. The bidding quickly surpassed what the GM agent was authorized and while he was trying to get permission to bid more the hammer fell on McIntyre's bid. It could be the very engine that was in the car two decades earlier.
McIntyre was in no hurry to mate the engine to the car. But when he completely restored the car recently the engine was installed.. Now you know why it is one of Corvettes most valuable cars.

 

I'm pretty sure a lot of the Z-11 go fast parts (heads, cam, different intake) ended up on 409s that ran in competition. They were different (and better) than the high performance 409 stuff.

 

I think Hayden Proffit's car was one that had the Z-11 stuff added.

 

This is it, right?

 

The Z-11 heads and induction were introduced along with aluminum front ends in late '62 to factory racers to install on their '62 A/FX cars used in match racing. Some of the block assemblies those heads and induction systems went on were way bigger than 427. It gave the racers time to test and tune before most of them received their '63 Z-11 Impalas several months later.

 

It could be. It had 25 years of dust on it.

 

In high school I ran with some twins that always had Chebbys with W motors. They actually pulled a high winding 283 from a '59 post car ( and sold it to me for a dollar) and dropped a tri power 348 in it. Alas I digress but just for background I guess. They always said that the 409 intake would bolt up and the low horse 409 intake was actually a fair match, but the problem was with the port size, the 348 ports didn't line up with the 409 runners well and you actually would lose on the performance end of it.

I suppose if you were industrious enough you could do some port matching, but take the dremmel to the heads instead of the intake.

 

Just me eye-balling them --> the 409 head gasket and the Mark IV head gasket are definitively different. I don't think much of anything is an exact match, except they are both Chevrolets.