MillerModSaws plays with 440R/046D Hybrid

[Outlaw5.0]

Also with racing engines a large efficient intake port works better with shorter intake duration and higher lift with a later intake opening point, this is called lobe area. Same principal, its all about managing the airflow at the correct time. Instead of lift we deal with port width, and port height is duration, and valve open and close event is just port open and close events.

 

[cuttinties]

I think about the case volume, intake tract size, carb size, transfer configuration, and bar length.

At this point, experience is my biggest asset. There are some saw models that I've done 100 or more of. I've never stopped trying different things so I keep learning.

As of recently I've been looking at piston speed quite a bit. I've found some interesting stuff.

 

[Outlaw5.0]

Also look into piston acceleration, its different from piston speed.

 

[Mastermind]

As of recently I've been looking at piston speed quite a bit. I've found some interesting stuff.

I hear ya........prolly above my pay grade. I'm just a simple hack you know.

 

[cuttinties]

I hear ya........prolly above my pay grade. I'm just a simple hack you know.

I'll call you in a bit if that's ok. Seems more difficult than it is really. I just built my 385 based on it and ended up with numbers I wouldn't have thought of.

 

[Mastermind]

I'm gonna be heading out to a sweat.

Call me tomorrow........very interested.

 

[cuttinties]

I'm gonna be heading out to a sweat.

Call me tomorrow........very interested.

Sounds good what time?

 

[barneyrb]

Don't leave that little thing called Velocity out of the mix. Low velocity and the carb don't get the proper signal.....

 

[Mastermind]

Noonish....

I wanna make sure I've got time to chew the fat.....

 

[Mastermind]

Don't leave that little thing called Velocity out of the mix. Low velocity and the carb don't get the proper signal.....

I think a lot about transfer velocity.........no so much about intake velocity though. I wonder if I'm missing something there.

 

[Outlaw5.0]

Yep port volume and velocity is important in getting a good carb signal.

 

[cuttinties]

I think a lot about transfer velocity.........no so much about intake velocity though. I wonder if I'm missing something there.

One would think that if your intake velocity were high you'd be able to transfer faster.

 

[redfin]

Did I miss what piston is in this saw? I was just looking at my 460apart on the bench and I'm just at the cusp of freeporting with iirc .03-.035 from the base with no gasket.

 

[cuttinties]

Did I miss what piston is in this saw? I was just looking at my 460apart on the bench and I'm just at the cusp of freeporting with iirc .03-.035 from the base with no gasket.

It's a 440 case 460 top end.

 

[redfin]

It's a 440 case 460 top end.

I understand, just wondering what piston is being used if he cut .070 off his base.

 

[cuttinties]

I understand, just wondering what piston is being used if he cut .070 off his base.

I believe he's still using the base gasket and 460 piston

 

[pioneerguy600]

Posts disappearing is the reason that these things never are finished.

Just saying.

They never end any way Randy, you and Brad just drag it along to the next thread concerning porting. It is ok to have differences in opinions, just keep posting what you each do, leave the personal attacks out of it. This personal stuff just mucks up a good thread!

 

[MustangMike]

Lots of good info provided in this thread, the best #s will often depend on your intended use, and sometimes experimentation will provide results you did not expect.

 

[Tractorsaw1]

I understand, just wondering what piston is being used if he cut .070 off his base.

I think in an earlier picture you can see the engraving on top of his piston, my guess is 046 oem piston?

 

[Outlaw5.0]

Also the taller 064 piston could allow more compression without cutting the cylinder base as much(keep the strength), or just allow that much more vs the standard 046 piston. Of course skirt and pin boss machining is needed along with port adjustments.