400 to 440 head & barrell interchange

[Rosco400]

Can anyone advise if AW400 head & barrell is interchangeable with AW440 head and barrell. Currently on last oversize on 400 and 440 is available on ebay on standard bore
Cheers in advance

[husky61]

Rossco

ring Les

[bigk]

Should interchange, but 440 is a fair bit harder to ride. Not "nasty", but has a lively mid range surge. The 400 is much nicer & easier to ride faster for longer, IMO.
Cheers,
K

[FDR]

Rosco,
Not sure if relevant to 77 model but here goes
My 73 400 Maico had the casings machined around 5mm bigger in diameter to suit the larger outside diameter of the 440 barrel sleeve.

[Rosco400]

I only caught the nickasil thread last night and this looks the way to go without using the 440 head and barrell and stay with the 400. Will wait till this bores screwed and give it a go. Have to take your advice on this one Lozza. The 400 is a nice even power right through and wouldnt like to lose that ,
Thanks Rosco

[paul]

john cadwell from canadian maico said you can get a aw out to 500cc theres one on his restoration page
http://www.maicomotorcycles.com/1977%20AW%20500.htm

john whats in volved with the 500 conversion

paul thought you would never ask. I use a 1980 440 barrel and remove the liner, I have a few 504 liners that match up with the later porting. I remove the head studs and weld them up. I open up the ports and open up the barrel and install the 504 liner and bore it out to take a std 490 mahle piston. I replace the head with a 490 one and install new studs. the 1980 barrel is a bolt on to any case down to 72 so this conversion will work on a 4 speed or a 5 speed. I also flycut the cases to accept the bigger barrel. There is a guy who does this but he uses a 490 liner and cuts it down so it fits the mouth of the case. Thats ok but it does not allow for many over bores. I believe this could be bored to about 525cc. I also port the new cylinder and blend the transfer ports and use a 40 mm Bing carb. My next step is to install a reed.
Cheers,
John

[Rosco400]

Thats very interesting but i dont think i could bring myself to machine my cases

[Maicojames]

Intersting too, since Caldwell races with us in AHRMA-and for Historic class ( PRE-78) the CC limit is stated as 460cc on two stokes for Historic 500 class. Still, if it came through tech, I would never know.

[maicomc490t]

Slightly off thread but I just measured the cases on my 501 engines and the case mouth to accept the cylinder sleeve is 100.1mm. Knowledge is power, so now you are all the more powerful after reading this highly informative trivia LOL 

For my money I wouldn't machine the original cases if your bike is ridgy didge - 400 cases are not hard to find and the machining is dead easy.

Dave Mac

[paul]

james i bet  thats not the only trick up his sleeves (so to speak)  only recencly i watched someone machine and sleeve up a 490 4 speeder thats allot off grunt for short travell suspension
and ive got some more from canada but i canrt find the emails at present