need some help from the gurus: 80mm/83mm cylinders

[motorlou]

hey guys i am working on a project which you can see at the link below

https://www.thesamba.com/vw/forum/viewtopic.php?t=686293&highlight=crazy+vw+vtwin+engine+project

if you go to the last page of the thread you will see i took a little detour from the original plan which used vw cylinder heads. With the new plan, it limits the cylinder size i can use with the new heads. i am looking at using 80mm or 83mm cylinders and pistons (whichever i can fit). i can bore out the head spigot to a max of 90mm. does anybody know for sure what size the 80mm and 83mm cylinders offered by AA performance measure at the top? i have messaged them but they have not replied. any help appreciated. thanks

[motorlou]

ok another question: is there a difference in the VW 1500 83mm piston & cylinders and in the 1385cc 40hp 83mm big bore kit for a 1200? Are the cylinders the same size at the top? same height? i found this picture, is this correct?

[gimmesomeshelter]

80mm cylinders have the following size spigots:

Head OD: 90mm
Case OD: 86mm

Cheers,

Paul
_________________
"I would rather have questions that can't be answered than answers that can't be questioned."

Richard Feynman

[motorlou]

thanks buddy, i will put that info into my notepad where i keep dimensions from different cylinders and such. anybody have any dimensions for the 83mm big bore and the 83mm 1500 cylinders? thanks again

[gimmesomeshelter]

Dwayne Spencer (RIP) made some very nice Dura-Bar cylinders. His website is still up, but I have no idea if they're still available.

http://shastadesign.net/pistonandcylinders.htm

Cheers,

Paul
_________________
"I would rather have questions that can't be answered than answers that can't be questioned."

Richard Feynman

[motorlou]

theoretically if 83mm cylinders have 3.5mm then at the top they should be 90mm. i think they have the extra lip up top like the 77mm cylinders i have laying around. i can throw them on the lath and possibly turn them down to 90mm diameter? what would help me out alot is if i could find or have made, a set of barrels that are "long barrels". that way, my engine which has an 86mm stroke can be bumped up another bit for a longer stroke.