Finger ports, how to find where to put them

[Fast Fred]

be talkin about finger ports, how to find where they go, port on the piston, and any other important measurement that you would need to know to install them with a good outcome.:cool:

[Fast Fred]

ok see how this looks

[Fast Fred]

ok, the intake side, no matter who's looper you are runnin, this is more or less the intake ports you are runnin

[Fast Fred]

so boost in the center and two side tranfurs, on a used cyl wall some times you can see where the ring gaps run, if not or fresh, you will need to mark the pins to the crown and reinstall ( you don't need the rings on) makin shots of said marks .............

[Fast Fred]

mark the piston pin with pencil up the side then to the crown

[Fast Fred]

then install, no rings, with bearin, snug is good, at TDC transfer the marks from the crown to the deck of the block.....

[Freddie Webb]

Do you have a dyno or access to one?

[quty06]

love to see

[Fast Fred]

on a Stinger, or Yamaha 70 or a SST60 , it's about 10, 10hp total . on a 30hp be less. on a 90hp Yam be more.

[sharpeye Mike]

Is this part of your 56er six pack build thread Fast? Or is that thread dead
Never liked where the ring pins line up, after marking the pistons and cylinder walls I always shied away from cutting into it .

[Freddie Webb]

Which dyno software are you using? Are you set up to dyno at the propshaft or the crankshaft? In what rpm range did you see the 10hp gain? Are you set up to dyno other motors as well or just the three bangers?

[Freddie Webb]

Could you please print and post a dyno spread sheet on this? I would love to see the the torque curves as well as the horsepower. Thanks in advance.

[Fast Fred]

the 56er, far from dead, like all horse power projects it waits on a fat cash injection, witch is slated for it and on it's way. costs a fare amount of cash to run a dyno a day. you can dance around it, talk to it, pour beer on it, mess with the tuna, rejet it, none of those things make horse power. a turbo, super charger, move more volume of mix into the cyl , like more gun powder in the round the bullet goes farther and faster, thats what finger ports do. when done right the rings don't know the finger ports are there. you can move the ring gap but adds cost.

[Freddie Webb]

I understand finger ports and how they work. I have seen dyno results on a v6 I was just wondering how the 3 cylinder responded in comparison. I guess there are no dyno results from your response. Not trying to be a jerk I just was curious for comparison no big deal. I'm sure it will run well.

[LittleCharger]

I understand finger ports and how they work. I have seen dyno results on a v6 I was just wondering how the 3 cylinder responded in comparison. I guess there are no dyno results from your response. Not trying to be a jerk I just was curious for comparison no big deal. I'm sure it will run well.

What were the results on the V6?

Thanks,

[Freddie Webb]

60039

[LittleCharger]

Attachment didn't come through. You can email it to me at pcoulter81@gmail.com

[Powerabout]

60039
was that a std port engine just with the fingers added?
can you repost attachment
cheers

[Fast Fred]

the smaller triples don't quite get the hit the V6's get from fingers. it's a volume thing. don't take things so hard Freddie, it not there. i don't have stock numbers. so why do all the extra work to find where the ring gap runs, cuzz they are most likely not centered, thats just production made, if you don't center up the ring gap, the pin can get worked lose, then she will just come apart. for the most part a V6 150hp with finger ports is a 190- 200hp.

[Freddie Webb]

Sorry the attachment didn't come through. I am not upset Fast Fred I am just trying to figure out where you are getting all these horsepower numbers if you don't have access to a dyno. It's not a big deal I just like data that's all. I wish you well with your project.

[Mumat]

A buddie of mine has a Monty preped loop 6 johnrude and Monty put the ring end gap wright in his finger ports. I would have swore it would snap rings but it does not I wish I would have taken pics when it was apart.

[Fast Fred]

see if this works...........

[Mumat]

From what I read those are mbre sleeves for a 3.0 evinrude

[Fast Fred]

bout time for an installment hear.......

[Coastal 60 LO]

Any more news to share on this Fast Fred?

[Powerabout]

Where are the ring end gaps in those sleeves?

[Fast Fred]

you want the end gap to run in the center of the finger port. it can be a bit off center , but not by much. you can have the end gap pins moved, so the end gap is always on the cyl wall ,adds cost. thats why it's beat to know ware the end gap runns before you start cuttin the cyl

[Frank73]

Hi Fast Fred,

What is the different between build up port on the piston compare the original one. Thanks

[Frank73]

Hi Fast Red,

What is the perfect dimension cut/sized (wide and long) of port suitable for Yamaha 50hp 3 strokes model 6h4?
Another question is why my engine always overheat during the race and damage my Wiseco piston (P4 size), is it cooling system fail or 2t add to fuel not enough?
Thanks sir

[Powerabout]

Post some photos of the piston from all sides..
Do you run extra piston to bore clearance to allow for the forged piston

[Fast Fred]

it may be jacked up to high on the hull and it's runnin out of water at speed. a water pressure gauge would help.
you could strap the hull to the trailer and back it in the water and go at full throttle, keep her in deep see if she gets hot.
not sure what you are asking on first question, wiesco's are forged, they will grow about .004thou when they get to running temp. so when bored you need to add that .004 in, so the piston size and .008 to .010 thou is bore size, if you bore like stock pistons the wiescos will stick at runnin temp.:cool:

[Frank73]

Post some photos of the piston from all sides..
Do you run extra piston to bore clearance to allow for the forged piston



Yes sir, i run extra piston (Wiseco 3130P4) and bore clearance is 2.678in, and my problem is my engine always overheat after run for 300-500mtrs, and i burned 6 Wiseco piston in 1 year time. Until now I cna't solves this problem. Thanks

[Frank73]

Hi sir,

What portion size need to cut (lenght & wide) for Yamaha 50hp 3cylinder at cylinder wall or linear?
Thanks

[Frank73]

it may be jacked up to high on the hull and it's runnin out of water at speed. a water pressure gauge would help.
you could strap the hull to the trailer and back it in the water and go at full throttle, keep her in deep see if she gets hot.
not sure what you are asking on first question, wiesco's are forged, they will grow about .004thou when they get to running temp. so when bored you need to add that .004 in, so the piston size and .008 to .010 thou is bore size, if you bore like stock pistons the wiescos will stick at runnin temp.:cool:

Ya I think I jacked up my hull too high, the hull boom same level with bottom hull of my tunnel, i will try lower it down a bit.
What you mean is I need to bored more wide on linear wall than Wiseco piston factory suggest, Boredsized = 2.678in STD = .040in

Thanks