What should I do now?

[Jakers]

opcorn:
subscribed...

 

[Dennis Cahoon]

OK, finished up the head today....here's a look.

 

[Dennis Cahoon]

......and for those who really want to see.....the combustion chamber!

 

[Dennis Cahoon]

Dennis, how do you come up with your combustion chamber volume? The 2 piece heads I've done have been a pain getting things the way I want.:msp_confused:

Troutfisher......First you have to decide what fuel you're going to run, gas, alkie, or nitro %fuel. Then you do your "research" and come up with the volume you want to use.
Rules of thumb......alkie/high compression, gas/high compression, but less than alkie, and nitro %fuel/less compression than gas. Then you have to decide what shape combustion chamber to use. Hemispherical is good, but there's other shapes that sometimes can work better. This is where the experimenting comes in. Do some homework and come up with a volume and I'll show you how to cut your chamber.

 

[parrisw]

Sweet work Dennis. What kind of lathe bit do you use to cut a hemi chamber?

 

[Dennis Cahoon]

Sweet work Dennis. What kind of lathe bit do you use to cut a hemi chamber?

A ground round mill end cutter.

 

[parrisw]

A ground round mill end cutter.

Just a HSS bit ground to the right shape?

 

[Adirondackstihl]

Just curious.....what grade alum is that?

 

[deye223]

subscribing

 

[Smittysrepair]

Just here for the show. Nice build Dennis! opcorn:

 

[Dennis Cahoon]

Just curious.....what grade alum is that?

Not sure, bought a rough looking 16"x4" piece of round stock at the scrap yard. Might be 6061, but can't say for sure.

 

[Adirondackstihl]

Not sure, bought a rough looking 16"x4" piece of round stock at the scrap yard. Might be 6061, but can't say for sure.

If it was round stock...chances are its 6060 T6.

 

[Dennis Cahoon]

Is there a 6061-T6 also?

 

[Isna]

OK, finished up the head today....here's a look.

Beautiful!!!
Awesome thread!
if I could manage to save up, I'd love to get you to prepare such a chainsaw. Although I work in the logging industry, most people around here don't even know what a Big Bore is! I get free parts from the local Stihl dealer since I let him try my 440/460BB MM! Although we have a few lumbering contest, such saws don't exist around here. I need one of your saws!!!! If ever you have a modded saw for sale (doesn't need to be a fancy bike saw), PM me.
Keep it going, love this thread...

 

[Adirondackstihl]

Is there a 6061-T6 also?

My bad....I meant to type 6061.

 

[Jacob J.]

Beautiful!!!
Awesome thread!
if I could manage to save up, I'd love to get you to prepare such a chainsaw. Although I work in the logging industry, most people around here don't even know what a Big Bore is! I get free parts from the local Stihl dealer since I let him try my 440/460BB MM! Although we have a few lumbering contest, such saws don't exist around here. I need one of your saws!!!! If ever you have a modded saw for sale (doesn't need to be a fancy bike saw), PM me.
Keep it going, love this thread...

Dennis does do beautiful work for sure. He's nearly a perfectionist and it's paid him big dividends with winning saws in the hands of guys like Mikey Forrester.

 

[Adirondackstihl]

My bad....I meant to type 6061.

Other possibilities that it could be;

2011: Screw machine stock is the best for machining. Fine chips mean faster feeds and longer tool life. Machines to an excellent finish, has good strength, average formability.

2017: Machinability approaching 2011. Particularly suitable for deep drilling operations and parts requiring clean, bright finishes. Formability and corrosion resistance are good. Strength is approximately the same as 2011.

2024: Slightly more difficult to machine than 2011 or 2017, but has enough strength for aircraft fittings, bolts, fastening devices.

6061: One of the most versatile screw machine alloys with good strength, workability, corrosion resistance and ease of joining. Less machineable than 2000 series.

6063: extruded for architectural and ornamental applications. Highly corrosion resistant, with good formability, it is one of the most joinable alloys. Most suitable for anodizing.

6262: Screw machine stock in T6511 temper offers more strength and machinability than 6061.

7075: Provides the greatest strength available in aluminum bar. Widely used in aircraft applications where light weight plus strength are required.


Too bad you couldnt have found any QC-7.
Fully heat treated and stress relieved. Outstanding thermal conductivity along with high strength and surface hardness and as such, it is suitable for polishing and texturing.


Anyway........sorry to ramble. :quiet:

 

[Isna]

Dennis does do beautiful work for sure. He's nearly a perfectionist and it's paid him big dividends with winning saws in the hands of guys like Mikey Forrester.

I know such work has a price and I know it's worth it. Need to save up...

 

[troutfisher]

Troutfisher......First you have to decide what fuel you're going to run, gas, alkie, or nitro %fuel. Then you do your "research" and come up with the volume you want to use.
Rules of thumb......alkie/high compression, gas/high compression, but less than alkie, and nitro %fuel/less compression than gas. Then you have to decide what shape combustion chamber to use. Hemispherical is good, but there's other shapes that sometimes can work better. This is where the experimenting comes in. Do some homework and come up with a volume and I'll show you how to cut your chamber.

Thanks Dennis. The first head we did was for a 3120 gas pipe saw. We got WAY too much compression. Real hard to start, gets hot fast, couldn't get good rpm from it. It's back apart now, the head is at the machine shop being re-cut.

 

[Beer Gut]

opcorn: