461 with a bit of modding

[brshephard]

How to cut fast:
Step 1. Grow a mustache

 

[Wonkydonkey]

Ok,, I will do that.

 

[MustangMike]

With the new AM piston, after you check the intake, you can also check if the exhaust will make any difference milling the top front of the piston down a bit. Be sure to use good rings (like Cabers) on the piston.

 

[Wonkydonkey]

Yeh like @tree monkey did in his 461 woods port race thread

 

[Wonkydonkey]

Postie person came the other day,

Jungle muff,
And also a aftermarket piston and cylinder.

I got the kit cos it seemed not that much more, than buying a am piston from the UK, and huztl post quickly.

And I can have a cheap play another day.

So I done a few measurements of the new piston, the wristpin was slightly shorter than the Stihl. So I had to use the heavier a.m. pin.

So a quick timing with the am piston for an intake of 80*
But while I was there I took some numbers of the farmatec cylinder, I was surprised they were close 105-125-70 to the oem.

Now too cut about 2mm off the intake skirt. I did that, an cleaned it up, popped it in and 80/81 squish 21 thou.
I slapped it back together with the jungle muff. The carb needed the LA adjusting as it was now ticking over at 2.9/3k. I set it at 2.5k and let it run for 5 mins
I gave it a few little blips. Then wot, it sat at 12.8k. So I turned in the H till it went 13.8/14k.

Now it was time to show the dog the bone my bone was small but still the same bone from before.

Well it seemed to hold better revs in the cut, and the time was shorter

I'll up the the vid and post the link

 

[Wonkydonkey]

 

[Wonkydonkey]

 

[smokey7]

Was there a reason why you changed the piston? If your oem is good i would go back to if after all of your gains are found. One thing ive noticed is a intake modded for duration runs different then a port opened up for duration. Im suspecting that is has something to do with velocity. Discuss lol

 

[Wonkydonkey]

Yeh I did think the same, that time vs size to get the same numbers. I was just taking it slow/step by step approach, also to see where the gains are coming from.

I think I will learn more this way,

I will be putting the oem piston back in

Cheers