I have a stock 40hp 1200. Right now it has single port heads. I know I could swap out to a 1600 block, but I want to see what I can do with this engine so please forgive me.
I found a set of dual port heads, 113 101 375A, and I'm wondering if these could be made to work with my engine?
I'm particularly confused about what the "Barrel Opening" actually is and how it impacts fitment...I understand the piston barrel needs to fit to the heads on one end, and fit to the case on the other, but I'm unclear on what measurements are acceptable or needed for head to barrel fitment. I measured the OD of my barrels on the header end, and it reads very roughly at around 90.xx mm.
This makes me wonder how they could possibly fit...If I just bolt them on, wont they just slide around? Seems ungood. Could I can spacer machined to centre the barrel to the header maybe?
I asked the owner if he thought they would fit. Here is his reply:
yout barrel opening is 90.5mm, mine is 94mm
it will work you got to use 40 hp rockers and push rods and push rod tubes...the head will bolt up and work fine, just keep in mind the 40 hp is 20 mm shorter so you got to use all 40 hp top end rocker arms, push rods and push rod tubes