Not So Pro 3

[Mastermind]

@Slumberjack

My memory is muddled.

Here's the cam card.

Looks like with 1.7 rockers it will have .476 on the intake, and .501" on the exhaust.

 

[p61 western]

Sun showed up.
View attachment 266839

GFY

 

[p61 western]

Like.....never.

Sled puller only slightly different lol.

 

[Czed]

I was lucky enough to get a 272xp and a 346xp here locally but my 357xp parts/builder came from a fine fella in MI wink

Have that 272 ported it was originally a 60cc chassis that's why they're so compact for a 70cc saw.

Each porter has specific recipes.
I can recommend steve he did a 266 and a 268
Very strong runner's.
I've had 28" on them for hardwood
But usually run 24" for balance.
I brought this 261 out because of all the overhead cutting I thought it was much lighter
I hadn't run it in year's.
Honestly the 268 is just a tad heavier
Than the 261
I'm going to put a 20" on the 268 and weigh it
They'll be close.

I've built a few of them.

 

[Slumberjack]

@Slumberjack

My memory is muddled.

Here's the cam card.

Looks like with 1.7 rockers it will have .476 on the intake, and .501" on the exhaust.

View attachment 266842

With that much lift and so little duration on the intake. I’d be tempted to retard the cam timing 4 degrees and see what it can do wink wink. You can always go back, with those pistons you probably need that retarding a little. You would be pinging unloaded with the vacuum advance and not able to get full timing at peak load. Especially if it’s got a 6 degree advance ground into it like most, “RV” cams. Heheh if those are 10 to 1 pistons and you didn’t retard the cam timing I’d be willing to bet if you pressure checked it after a break in you would be over 190psi. Food for thought shrugs. Of course I could have it all wrong too in my head movies. Lol just fun to talk about options! Smiles wink

 

[Slumberjack]

Have that 272 ported it was originally a 60cc chassis that's why they're so compact for a 70cc saw.

Each porter has specific recipes.
I can recommend steve he did a 266 and a 268
Very strong runner's.
I've had 28" on them for hardwood
But usually run 24" for balance.
I brought this 261 out because of all the overhead cutting I thought it was much lighter
I hadn't run it in year's.
Honestly the 268 is just a tad heavier
Than the 261
I'm going to put a 20" on theView attachment 266840 268 and weigh it
They'll be close.
View attachment 266844
I've built a few of them.

I ported my 272xp and it’s no wimp wink

 

[redline4]

GFY

Thanks Mike.
GFY too.

 

[cuinrearview]

@Czed did something happen to the Bastard and I missed it?

 

[Czed]

@Czed did something happen to the Bastard and I missed it?

No he evisorated something on my outdoor bench yesterday
No idea what it was just mangled
Intestine's.
*b-word got run over by some piece of *s-word at night a few months ago.She almost made it to 20 year's.

 

[dall]

Kinda the same here.
Not a lot of pro saws to be had.
The shops dont want to let go of any of the Stihls and Huskys that I want to play with.
I know where a complete 046 and an 064 are. Just sitting gathering dirt and crud.
Guy thinks they are gold.

They are

Boss eye ain't had much problem putting my boring bit in a blind hole.........[emoji1787]

Cant say I ever avoided it either [emoji6]

they meant boring as it made them tired and sleepy

 

[ucm931]

Boss eye ain't had much problem putting my boring bit in a blind hole.........[emoji1787]

Cant say I ever avoided it either [emoji6]

Welp.....can't blame you. Kinda hard to ruin one when you can't touch the sides or bottom of those blind holes even when you want to!

 

[Stump Shot]

@Slumberjack

My memory is muddled.

Here's the cam card.

Looks like with 1.7 rockers it will have .476 on the intake, and .501" on the exhaust.

View attachment 266842

Could save some of the bottom end with a variable lift lifter set and keep the let er rip top end, no?
https://www.rhoadslifters.com/Pages/index.html

 

[Slumberjack]

Could save some of the bottom end with a variable lift lifter set and keep the let er rip top end, no?
https://www.rhoadslifters.com/Pages/index.html

He gonna have plenty of bottom end with a dual plain intake and those pistons and that little bit of duration. His compression isn’t getting blead off. It’s not the lift that’s going to kill his bottom end. Not with less than .500. Wink

 

[Slumberjack]

Duration is like raising an exhaust port

 

[Slumberjack]

That’s why you lose vacuum with aggressive cams, it’s bleeding off compression into the intake a little but at the right rpm the volumetric efficiency and scavenging will suck more air through the engine then calculated. He’s not going to run into those issues

 

[Egg Shooter]

View attachment 266832 View attachment 266833 View attachment 266834

Now we are talking performance I get.

 

[redline4]

Rambo time bishes

 

[Egg Shooter]

No sir.

The heads won't be here till the 20th. Then they will have to be port matched, and sent to the machine shop to be printed, and have studs and guide plates installed.

Gonna get em extrude honed too?

 

[Slumberjack]

So instead of bleeding it off On the exhaust port like on a saw when raising exhaust, on race engines, 4 strokes bleed it off into the intake

 

[Slumberjack]

Has to do with the over lap of the intake duration carrying over into the compression stroke.