MAICO Pre-60 Alloy Oval Barrel Blizzard Project.

[Mick D]

Any of that you would like to highlight for the benefit of this thread Paul?

[firko]

Dear old Jim McCabe.....I was in fairly regular email contact with him until his death in 2009. Nobody knew oval and square Maicos more than McCabe.

I recieved the below email from American Maico guru Jim McCabe a number of years ago and only just found it while cleaning up my hard drive files. It's an interesting read, even if you don't totally agree with his theories.

MAICO 326 THEORY
I built a 326cc oval barrel in 1967 using 250 -70mm stroke crank
under a 360 oval barrel cylinder for Enduro work. The 360 oval barrel
with a 76 mm stroke vibrated a lot at higher rpm and the 70 mm stroke
326cc I came up with was much smoother. I was using a tucked in
silencer from a Bultaco Madador on the 360 oval barrel at that point
and it and the 30 mm carb carried right over to the 326cc version
with no change. Compared to my buddies 360 oval barrel I lost a bit
of torque but had another 12-1500 rpm on top and actually the bike
became faster in the woods and definitely had a much faster usuable
cruise speed for Enduros. I recently got my original 326 chassis(62-
65 single loop frame) back after 40 years complete with the engine
etc. to restore.
I purchased a factory made 326cc radial top end a few years ago, with
the 70mm stroke, but with a 250 pattern rear boost port inconjunction
with 77 mm bore. I've done a bit of research on various combinations
of 400,440 and 501 engines. Incidently the original 360 oval barrel
cylinder required decking the top of the cylinder and also the top of
the crank case by 1/2 the stroke decrease (3mm off each) to get the
proper degrees of timing. The key to any of these mods is measurement
of the port locations in the cylinder castings to see if the finished
port timings are close to optimum. Perhaps the most interesting swap
is conversion of a 501 back to approximately 460cc via a 250 stroke
crank. Yamaha rods with longer center distance can be employed to
reduce the machining required in some cases, and late model cranks
can be destroked to provide the advanges of 3 row primarys.
Incidently I dropped off a 80+ pound block of aluminum for my brother
to start machining on a 760cc. McCabe top end. 108mm bore planned.


Within limits, I believe bore and stroke relationships are less
important as far as power characteristics/max power than the port
timing and the exhaust expansion chamber of the engine being built.
The biggest advantage of the short stroke versions is they usually
have larger transfer passages (in proportion to displacement) than
the original smaller cylinders and are capable of breathing better on
top end in addition to the increased displacement. Power output is
controlled really by how many cfm can be flowed per minute and the
shorter strokes will allow higher rpm thus more strokes/minute within
which to flow fuel and air.(and many of the destroked engines have
wilder port timing than the original cylinders had) In the past 50
years the biggest change in Maico engines is in increased vertical
transfer port areas. The difference in actual exhaust port areas
between a 68 250 square barrel and a 2000 water cooled power valve
250 is actually not that much but the transfer ports have doubled in
area during that period. My long term rule is to optimise the
transfer port areas for better breathing and more top end power.
(440's in particularlar need increased area as the increase in bore
dia. is obtained by a reduction in transfer port area) All that said,
a longer stroke combined with a shorter (percentage rod
length/stroke) rod will provide better low speed punch than a short
stroke version of the same displacement in my limited experience.
Nothing beats porting cylinders area wise and degree wise for the
rpm/power characterists desired using data available to us today.
Expansion chambers are another matter however and I'm planning on an
inertia type dyno to facilitate tuning of my engines more accurately.


Some of the 370 Suzuki Savages had very violent power characteristics as
well. I believe there was eventually found a solution to some of the
violence thru the use of an altered ignition advance cure. The best
example of over square under square engines power output I'm
experienced with, is the 125 thru 350 Bultacos where the 125 despite
it's long stroke was a very sucessful high out put engine while the
350 short stroke Astro's are also very very competitive. And the 350
singles went very well on Road racing as well. I firmly believe it's
port timing/expansion chamber design that's the predominant
contolling factor, although most 250 motocross 2 stokes became
slighter under square (strokes became longer) in recent years. I have
to admit that my 499 has grown to be some what of a light switch
engine as far as how it hits compared to power delivery of a stock
400/440/490. as I've strived for more top end output.---

[firko]

While it's a tad too modified for our pre 60 class (and pre 65) I still love Karl Landrus's 1957 250 oval Maico
                                                                          

[paul]

Any of that you would like to highlight for the benefit of this thread Paul?

nah i just found it on the net   did i do something wrong !

[Mick D]

While it's a tad too modified for our pre 60 class (and pre 65) I still love Karl Landrus's 1957 250 oval Maico
                                                                          

The spirit of legitimate vintage competition and show-casing an era must be way different in the US than here. Thank fug for Aussie rules.

That Creation of Karl's is an absolutely beautiful work of art and a testament to his skills base and engineering ability to go outside the square, but I doubt a search of Oz would find any moron Stooopid enough to even consider entering that bike in PRE-70,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, let alone pre 65 or pre 60.

[Mick D]

Any of that you would like to highlight for the benefit of this thread Paul?

nah i just found it on the net   did i do something wrong !

No, not at all mate.

I will try to find the time to explain latter, at the moment I am ready to level this box of crap and the new multi-function center with me granddaddies plumb axe

Time to resort to the camera me thinks

[Mick D]

OK, this is one of the coffee table additions.


These are some pages from it





Also this mag I bought


With this date on the front cover


Featuring this article

[Mick D]

That's too cool for school Paul, looks to be a mid fifties Blizzard or GS250 but it's hard to guess as there's no photo reference in Frank Ronicke's or Mick Walker's books.

Yes, I reckon your dead right about that little beauty being a genuine GS M250B(Blizzard), civilian model.

Maico produced more of this model motorcycle than any other model that it ever produced in its entire range. They added a map box to the tank, rear panier racks etc, etc, painted them dark army green all over, including in the end the hubs spokes, rims, tank badges,etc, even dark green matching vinyl on the seats and continued to sell them to German military long after they became unavailable to the general public.


Maico finally phased out the Blizzard"s supply as a military model and replaced it with this


In early days it was a contract to supply the GS Blizzard as a military mount That saved Maico from impending bankruptcy, bought on by the financially failed attempt of becoming a main-stream automobile player.

Saying all that, it is not cheap to get any bike shipped here from Germany and half decent Blizzards there still pull good amounts of EUROs in their homeland. Just like old rare old Holdens do here, I Guess.

[Mick D]

Watto HVA sent me these great photos of his dad Bills 1960 Maico Blizzard 250 motocrosser...photographed when new in 1960. Bill didn't like the forks so he manufactured a set of leading link items similar in design to a Greeves of the period. The last three photos show the bike as it is today, still in Bill Watsons shed on the western side of the island. It looks to be in remarkably original condition although the frame appears to have been modified or changed at some stage in its life...Whatever has happened it looks good enough to just put the tank back on and enter the pre 60 class at this years Nats. . The bottom photo shows Bill in action (inside line) on the Maico at Herne Hill, WA circa 1960.
                                                                    
                                                                    

That is one nicest and best prepared M250B(Blizzard) GS ROUND IRON BARREL machines the web has ever shown me

[Brian Watson]

It should be Mick...the pic is from 1960..the bike is brand new..

[paul]

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=200920260404

[firko]

The spirit of legitimate vintage competition and show-casing an era must be way different in the US than here. Thank fug for Aussie rules. 

That Creation of Karl's is an absolutely beautiful work of art and a testament to his skills base and engineering ability to go outside the square, but I doubt a search of Oz would find any moron Stooopid enough to even consider entering that bike in PRE-70,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, let alone pre 65 or pre 60.

Here's another USA based oval that wouldn't pass our scrutineering muster.....check out the rear suspension, forks and wheels. It's got the correct tank however .
                                                                                 

[Mick D]

Yeah Firko, all-though I admire hot rods and intend a couple for the dirt track scene, I am pretty much coming to the opinion that we need to play a roll as VMX custodians of history. I intend to keep my bikes as aesthetically original as reasonably possible and legal to the Aussie vmx rules even if I do think they need updating every now and then as new facts come to light. Mind you I will always have optimisations like two finger Maico brakes and clutches as I have had since a 1973 whipper-snapper.

But, hey,,,,,,,,,,,,,,,,

Ola Martin got me reconsidering my approach, when he put his 175 up and his comments in another threadhttp://ozvmx.com/community/index.php?topic=27958.0

Both these bikes are the 175M GS models, with the 21" frontwheel and more powerful engine, for flat out racing A lot rarer than the more common M model.
Mine also has a extra damper for the fork, from the fenderbrace to the upper yoke, between the forklegs.
+ it runs....

This is one of the images I have of what Maico's early production IRON BARREL motocrossers looks like.

Note; the lighter smaller front hub, of which I have one these laced to a 21" muddy.

The more I have looked at this,



      the harder I get,,,,,,,,,,,,,,

It has got me thinking that I will probably get these new fenders painted as well.



   

[Mick D]

If I had of known how to and thought shipping might be reasonable? I probably would have just tryed to buy Ola's bike. Would have beeen a buzz just to service add fuel and mud I reckon.

[firko]

Yeah Firko, all-though I admire hot rods and intend a couple for the dirt track scene, I am pretty much coming to the opinion that we need to play a roll as VMX custodians of history. I intend to keep my bikes as aesthetically original as reasonably possible and legal to the Aussie vmx rules even if I do think they need updating every now and then as new facts come to light. Mind you I will always have optimisations like two finger Maico brakes and clutches as I have had since a 1973 whipper-snapper.

I'm a bit opposite to you in my old Maico endevours Mick. I'll build the Maico Metisse hot rod for motocross....mainly because it's something I've wanted to build for years. For Dirt track however because its so rare I'll do my little KR250 strictly by the book, hence me needing a genuine tank and a pipe to copy. What's the score with the rims on my KR by the way? They're alloy (Akront???) and appear to be the originals, The little hubs appear to be off the 175 or early 250 Blizzard.

 I ran into Blair Harley the other day and we started talking about oval and square Maicos. He remembered seeing some motoball bikes destined for America at the factory in the late 60's, the odds are high that one was probably mine. Old Blair's getting on but he's still got a lot of Maico memories. He reckons the 350 was the best square barrel by far. He probably says that because they wouldn't have existed without his great influence at the factory but I agree with him. He was stoked to hear that I was converting my 360 to 350 as he hates 360 "shakers".

I'm going to prepare my 350 squarie for him to ride at CD10.