Mastermind Meets The MS661 Again

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Lynn, I'm thinking you may have a lot of good things to input here.
No, not a lot, maybe a little. What I'm seeing is a whole lot of hot exhaust up there high when the piston is opening the ex port. That's where the fresh charge needs to go. So, those finger ports aiming straight up seems right. I don't like the transfer ports blowing straight across the piston top.
 
chrysler in the early 90's on their 4cyl engines went from a large oval shaped chamber to an almost heart shaped chamber to improve mixing but none of that applies here. the mixing of air and fuel comes from pushing the mix up through the transfers and the natural turbulence of the intake and crankcase? then its a matter of the fresh fuel/air pushing out the burned fuel with as little dilution as possible. does that mean that transfers need to flow across, up, or toward the intake to push the exhaust gasses out? looking at all the junk jugs i have laying around they all appear to have flat ceilings to the transfers and be aimed toward the intake. so flow is across the piston and toward the intake.

tryin to learn a bit while im on here instead of doing the mountain of work sitting in front of my bench
 
The dual transfer jugs.....well, they are antiques.

Look at a quad ported jug. The two nearest the intake are normally angled upward......and the two on the exhaust side are flat.

Mull that over in the ol' mush melon awhile. :laugh:
So r 2 of them for scavenging exhaust and 2 for charging the chamber with fresh fuel?
 
The dual transfer jugs.....well, they are antiques.

Look at a quad ported jug. The two nearest the intake are normally angled upward......and the two on the exhaust side are flat.

Mull that over in the ol' mush melon awhile. :laugh:
Do the 2 ports nearest the intake side open a tad sooner than the exhaust side transfers?
 
Hey Randy, you figured out how you want to finger port that 088 yet?
Same recipe as smaller saws or a little different?

Oh yeah.......I've got that one done. (in my head anyway) lol

Do the 2 ports nearest the intake side open a tad sooner than the exhaust side transfers?

Sometimes.
 

Latest posts

Back
Top