12 replies to this topic

[ZL1Johnny]

I have, what I've been told, is a 1969 Chevrolet ZL-1 Aluminum prototype block...sent to Mclaren in 69 with 34 other blocks, and was in a test mule Mclaren called THE DOME. Info on the block is as follows:

427 CID (.040 Over)
Casting: 0-294550
Stamp Pad: 70065 53 W
Sleeved
NOT siamese cylinders
Mech fuel pump provision
Dry Sump
No date code

Additional info and photos available. Any info on this block, or the others delivered to Mclaren , or the DOME would be GREATLY appreciated. Also looking for 67-69 Parts for it. Thanks.
PS: I've discovered some names of what MAY have been Mclaren mechanics / Engineers...perhaps one of them knows?
Cary Taylor
Colin Beanland
Chris Charles
David Kimble
Wally Wilmott
Peter Bruin
Gary Knudson
Al Bartz
Lee Muir
George Bolthoff
Frank Zimmerman
Tom Anderson
Haig Altoonian

GREAT site!

ZL1Johnny@yahoo.com

[Jerry Entin]

George Bolthoff at the McLaren engine Dyno in Detroit

Johnny: Whomever told you McLaren's recieved 34 blocks is wrong. In 1969 Mclaren had 4 engines in England and when the shop moved to Detroit they recieved another 6. They had 10 engines total, nowhere near over 30. George Bolthoff was the head engine builder in 1969.

He will now explain what engines they used:
"I don't have any way to ID a particular engine, however McLaren didn't use the 427 engine in 1969. A few left-overs from the 1968 season were used in testing and development but in early 1969, I started assembling engines using the 4.440 bore blocks in England. This block with the 3.76 stroke crank gave an engine size of 465 CID. This was the engine used until mid 1970 when we used the 4.00 stroke crank for a 495 CID engine."

Above information: George Bolthoff
Photo: George Bolthoff collection

Edited by Jerry Entin, 12 November 2009 - 02:46.

[S A Dunbar]

Al Bartz was a Van Nuys, California engine builder. We used his motors in our Camaro in the mid-seventies....

This is from Wikipedia.....

McLaren cars were specially designed race cars. The Can-Am cars were developments of the sports cars which were introduced in 1964 for the North American sports car races. The development variants M1A and M1B were raced as factory cars in the 1966 with Bruce McLaren and Chris Amon as drivers. In 1967, specifically for the Can-Am series, the McLaren team introduced a new model, the M6A. The McLaren M6A also introduced what was to become the trademark orange color for the team. The McLaren team was considered very "multi national" for the times and consisted of team owner and leader Bruce McLaren, fellow New Zealander Chris Amon and another "Kiwi" and the 1967 Formula One World Champion,Denny Hulme, Team Manager Teddy Mayer, Mechanics Tyler Alexander, Gary Knutson, Lee Muir, George Bolthoff, Gary Knutson, Frank Zimmerman, Tom Anderson and Haig Altoonian & (USA), Don Beresford & Alec Greaves(UK),Cary Taylor, Jimmy Stone, Chris Charles, Colin Beanland, Alan McCall and Alistair Caldwell(NZ). The M6 series were a full aluminum monocoque design with no uncommon features but, for the times, there was an uncommon attention to detail in preparation by the team members. The M6 series of cars were powered by smallblock Chevy engines built by Al Bartz Engines in Van Nuys, CA., They were the model of reliability. This was followed in 1968 by the M8A, a new design based around the Chevy Mark IV "big block" engine as a stressed member of the chassis. McLaren went "in house" with their engine shop in 1969. The M8B, M8C, M8D and M20C were developments of that aluminum monocoque chassis. McLaren so dominated the 1967-1971 seasons that Can-Am was often called the "Bruce and Denny Show" after the drivers who very often finished 1-2. In fact there waseven a 1-2-3 finish at the Michigan International Speedway on September 28, 1969. McLaren 1st, Hulme 2nd, Gurney 3rd. Sadly, 9 months later, Bruce McLaren lost his life on June 2, 1970 at Goodwood when the rear bodywork of his prototype M8D detached during testing resulting in a totally uncontrollable car and a fatal highspeed crash. McLaren continued to succeed in Can-Am after Bruce's death with a number of other drivers, but the works Porsche effort with turbocharged flat-12 engines and a high development budget meant that they could not keep up with the 917. Although private McLarens continued in the series, the works team withdrew to concentrate on Formula One (and USAC, for several years). Team McLaren went on to become a several time F1 champion and is still very much a part of F1.

[Jerry Entin]

Al Bartz and Gary Knutson and Bruce McLaren
This was taken at the Champion Dyno in Long Beach, California.

photo- Tyler Alexander
scanned for site Phil Henny

[S A Dunbar]

Al Bartz and Gary Knutson and Bruce McLaren
This was taken at the Champion Dyno in Long Beach, California.

photo- Tyler Alexander
scanned for site Phil Henny

That is a very young Al Bartz. I wonder what year the photo was taken? Sadly, Al passed away from cancer a few years ago... A truely great guy....

[ZL1Johnny]

Mr Entin / Mr Dunbar,
GREAT info and photos! I KNEW something wasn't right about the "34 other blocks" the seller stated, especially after I talked to the likes of Bill Howell.
It's just that he had a LOT of specific info, of which, I'll include some below. All arrows point to it being a '68 block. So maybe the guy was HALF right, by saying it was in the "Test Mule" called the Dome. Of which, NO one knows anything about...any clues? The fact that it was a 68 block (relative to casting number and bore)...gives a hint, as George said, that it COULD have been a "Development" car, ie, in a "Test Mule". As it was probably NOT in one of the 1968 ACTIVE cars....and therefore, probably never get a chassis number for it, I'll just be glad knowing that Mclaren HAD the block at one time. Although it was mentioned by Mr Bolthoff that it wasn't used in '69, and they had "4 engines in 69"...I wonder how many engines they received in 68, as this is probably when my block was sent....and did they receive that number of partial engines, or just blocks. Just curious...where did the George Bolthoff statement come from..explaining 'what engines they used'? "Sellers info is below":

1)" The block came straight from G/M race division to Mclaren, and did not see any GM car at all.

2) It arrived in England in 1969 with 34 other blocks.

3) It was shipped Standard bore, then bored .030" by Maclaren and fitted with a 4" crank.

4) There's no Chassis number on this car. THe car was called the Dome, but was referred to as a code Number. The block you have was a test mule engine, used before the full spec race engine was ready. In this case, it was the CAN-AM Block (All Aluminum with no cast iron liners). The project was dropped by Maclaren.

5) The mains caps are original but a stud kit was fitted by Mclaren. This involved drilling and threading the original holes to take longer threaded studs for more bottom end bearing size control. The number 24 before the cap number means its the 24th engine block through the machine shop.

6) The Crank,Rods,Pistons,Rings,Damper and Aluminum fly-wheel where sent over by GM to test the 460cid combo in this block. No intake was ever sent, as all the engines where Injected.

7) They sent heads for flow tests. The heads for your block were welded on the exhauste ports to raise the hole port up by .750" to improve the flow characteristics. They got 55hp and 40 Ft Pds of torque from this combo." (END)

Thanks again gentleman...you've answered a LOT of questions.

[Peter Morley]

This is pure guesswork but could the Dome have been the closed version e.g. M6GT?

Have you asked Eoin Young? http://www.eoinyoung.com/

[ZL1Johnny]

This is pure guesswork but could the Dome have been the closed version e.g. M6GT?

Have you asked Eoin Young? http://www.eoinyoung.com/

I did a little research on the M6GT, and didn't see anything with the 7 litre...only smaller engines.
Unless one of the prototypes had it...but I think they still have their engines...but thanks.
Not sure who Eoin Young is...but I'll try it. Thanks also.

[GreenMachine]

That '34', could it have been meant to read '3-4'?

[FlatOverCrest]

If you guys have not seen this.... have a watch...



I watched Gary test this thing a number of times when I was living in SF, the noise is simply stunning!! Nice guy too.

Edited by FlatOverCrest, 12 November 2009 - 11:52.

[ZL1Johnny]

That '34', could it have been meant to read '3-4'?

I've thought of that, and in retrospect, probably...as a GM engineer told me, they didn't send more than a MAX of 10 a year, to anybody.
So, I THINK I can deduce that my block was one probably one of the "leftover blocks" from '68 used in "Testing and development".

[Peter Morley]

I did a little research on the M6GT, and didn't see anything with the 7 litre...only smaller engines.
Unless one of the prototypes had it...but I think they still have their engines...but thanks.
Not sure who Eoin Young is...but I'll try it. Thanks also.

As I said I was just guessing, the time frame fits and you can imagine mechanics referring to the roof as a dome...

Eoin Young is a very well known motoring journalist and author, who came to Europe with Bruce McLaren and helped setup the team.
He is very approachable, knowledgable and was there at the time - if there's anything to the story he should know.

[ZL1Johnny]

So, getting by "With a little help from my friends"...I've had a LOT of questions answered. My remaining 2 questions would be:

1) How many engines did Mclaren receive in 1968...and was MY block one of them (or was
my '68 spec (4.25 Bore) block possibly sent in '69)?

2) Can it be tracked to a specific chassis...to include testing and development?