High Quality Chainsaw Bars Husqvarna Toys

Another Stihl 460 build

thompsoncustom

Well-Known OPE Member
Local time
10:16 AM
User ID
26079
Joined
Feb 8, 2023
Messages
161
Reaction score
149
Location
iowa
Country flag

thompsoncustom

Well-Known OPE Member
Local time
10:16 AM
User ID
26079
Joined
Feb 8, 2023
Messages
161
Reaction score
149
Location
iowa
Country flag
Something I didn't see mentioned was the under side of the piston, I would think that would be just as important to reduce drag when the piston is headed up. Looks like a fun piston mod might have to try it sometime.
 

Wonkydonkey

Plastic member
Local time
3:16 PM
User ID
3189
Joined
May 14, 2017
Messages
4,565
Reaction score
18,085
Location
Sussex, UK.
Country flag
I'm not sure If I’m on the right page or not ? Is this a woods, irons, wedge & putters thread ?

But anyhow I thought the squish is lost fuel in the combustion and there’s something important about it’s velocity as well.

I can’t remember if it was Bell or Jennings :deal:
 

Rich Fife

Sally slap my ass
Local time
11:16 AM
User ID
26245
Joined
Mar 4, 2023
Messages
684
Reaction score
1,000
Location
Central New York
Country flag
I'm not sure If I’m on the right page or not ? Is this a woods, irons, wedge & putters thread ?
Yep, you're 💯% on the wrong page. We don't build saws to cut, we build them to chip. Like golf. I'm assuming your golf game is weak?
I can hit a nasty slice, straight into the other fairway. 🤷‍♂️
 

Rich Fife

Sally slap my ass
Local time
11:16 AM
User ID
26245
Joined
Mar 4, 2023
Messages
684
Reaction score
1,000
Location
Central New York
Country flag
Something I didn't see mentioned was the under side of the piston, I would think that would be just as important to reduce drag when the piston is headed up. Looks like a fun piston mod might have to try it sometime.
Idk... I think there's too many obstructions in that area to put any thought into it.
 

thompsoncustom

Well-Known OPE Member
Local time
10:16 AM
User ID
26079
Joined
Feb 8, 2023
Messages
161
Reaction score
149
Location
iowa
Country flag
Idk... I think there's too many obstructions in that area to put any thought into it.
ya trying to dimple that area sounds terrible but that's where the drag would be kind of like the back of a semi trailer. those weird panels on the back of some trailers improve fuel mileage by 5%
 

Rich Fife

Sally slap my ass
Local time
11:16 AM
User ID
26245
Joined
Mar 4, 2023
Messages
684
Reaction score
1,000
Location
Central New York
Country flag
ya trying to dimple that area sounds terrible but that's where the drag would be
agreed.
kind of like the back of a semi trailer. those weird panels on the back of some trailers improve fuel mileage by 5%
I figured those panels were for airflow, but, I always wondered if they helped and if so, to what degree. Definitely interesting for sure.
 

srcarr52

Shop rat, backyard slice cutter.
GoldMember
Local time
11:16 AM
User ID
522
Joined
Jan 12, 2016
Messages
3,921
Reaction score
25,888
Location
Iowa City
Country flag
Next up was the cylinder... and jamming out to CCR.


I rarely find a cylinder that has the flange perfectly orthogonal to the bore. Having a dial on the flange is good to get you really close, but like you said in the video, you better check top and bottom of the bore for your final dial in.
 

srcarr52

Shop rat, backyard slice cutter.
GoldMember
Local time
11:16 AM
User ID
522
Joined
Jan 12, 2016
Messages
3,921
Reaction score
25,888
Location
Iowa City
Country flag
ya trying to dimple that area sounds terrible but that's where the drag would be kind of like the back of a semi trailer. those weird panels on the back of some trailers improve fuel mileage by 5%

Those are to smooth the air flow after the trailer to decrease the low pressure region which is where the majority of the drag comes from. Dimples are more like the vortex generators (inverted naca ducts) at the back of the sleeper to keep the flow attached down the trailer. Sometimes you'll see another row of them at the end of the trailer.
 

timg

Supporter of Cat Eating Komatsu Machinery
GoldMember
Local time
11:16 AM
User ID
8928
Joined
Mar 7, 2019
Messages
3,825
Reaction score
19,492
Location
Keystone State West
Country flag
Love it when talented machinist and car chiefs share their thoughts. Keep this thread going guys. In your scenario Shaun both hats fit you well. So on a late model or modified the extended tail sections of the side panels have dual purposes? Both to catch the air into the turn and also reduce the low pressure area on the rear? Interesting.:private::private:
 

srcarr52

Shop rat, backyard slice cutter.
GoldMember
Local time
11:16 AM
User ID
522
Joined
Jan 12, 2016
Messages
3,921
Reaction score
25,888
Location
Iowa City
Country flag
Love it when talented machinist and car chiefs share their thoughts. Keep this thread going guys. In your scenario Shaun both hats fit you well. So on a late model or modified the extended tail sections of the side panels have dual purposes? Both to catch the air into the turn and also reduce the low pressure area on the rear? Interesting.:private::private:

Do you mean the spoiler sides?
 

Rich Fife

Sally slap my ass
Local time
11:16 AM
User ID
26245
Joined
Mar 4, 2023
Messages
684
Reaction score
1,000
Location
Central New York
Country flag
I rarely find a cylinder that has the flange perfectly orthogonal to the bore. Having a dial on the flange is good to get you really close, but like you said in the video, you better check top and bottom of the bore for your final dial in.
The worst cylinder that I came across had to have been made on either an early Monday morning or Late Friday night.... either way, it was F'd... the base to bore reference was insanely out from being perpendicular... it was enough to where I had to use the squishband and 4 point that because Even the squishband was funky.... that was my 1st bad experience with a Chinese 660 cylinder...
 

Rich Fife

Sally slap my ass
Local time
11:16 AM
User ID
26245
Joined
Mar 4, 2023
Messages
684
Reaction score
1,000
Location
Central New York
Country flag
Those are to smooth the air flow after the trailer to decrease the low pressure region which is where the majority of the drag comes from. Dimples are more like the vortex generators (inverted naca ducts) at the back of the sleeper to keep the flow attached down the trailer. Sometimes you'll see another row of them at the end of the trailer.
I love how simple remedies yield positive results.
 

huskihl

Muh fingers look really big
GoldMember
Local time
11:16 AM
User ID
360
Joined
Dec 31, 2015
Messages
22,457
Reaction score
143,011
Location
East Jordan, MI
Country flag
The worst cylinder that I came across had to have been made on either an early Monday morning or Late Friday night.... either way, it was F'd... the base to bore reference was insanely out from being perpendicular... it was enough to where I had to use the squishband and 4 point that because Even the squishband was funky.... that was my 1st bad experience with a Chinese 660 cylinder...
If you’re cutting the base though, the only thing that matters is the X and Y axis on the cylinder wall. If you’re not cutting the squish, there’s nothing you can do about it.
 

Rich Fife

Sally slap my ass
Local time
11:16 AM
User ID
26245
Joined
Mar 4, 2023
Messages
684
Reaction score
1,000
Location
Central New York
Country flag
Do you mean the spoiler sides?
We played around with our spoilers on our race cars... angles, heights and we even angled our spoiler in the sense that the RR spoiler had a lesser degree than left side... in my mind, it changed the downforce on the rear section of the Decking...
 

Rich Fife

Sally slap my ass
Local time
11:16 AM
User ID
26245
Joined
Mar 4, 2023
Messages
684
Reaction score
1,000
Location
Central New York
Country flag
If you’re cutting the base though, the only thing that matters is the X and Y axis on the cylinder wall. If you’re not cutting the squish, there’s nothing you can do about it.
For me, It's the small things that "should be" right, that aren't... that send my OCD though the roof. 🤣🤣🤣 over the years, I've been dialing/throttling that $h!t back but, sometimes... that stupid *s-word flares it up...
 

huskihl

Muh fingers look really big
GoldMember
Local time
11:16 AM
User ID
360
Joined
Dec 31, 2015
Messages
22,457
Reaction score
143,011
Location
East Jordan, MI
Country flag
For me, It's the small things that "should be" right, that aren't... that send my OCD though the roof. 🤣🤣🤣 over the years, I've been dialing/throttling that $h!t back but, sometimes... that stupid *s-word flares it up...
I get that. But if it doesn’t matter because you’re cutting the base anyway…
 

srcarr52

Shop rat, backyard slice cutter.
GoldMember
Local time
11:16 AM
User ID
522
Joined
Jan 12, 2016
Messages
3,921
Reaction score
25,888
Location
Iowa City
Country flag
We played around with our spoilers on our race cars... angles, heights and we even angled our spoiler in the sense that the RR spoiler had a lesser degree than left side... in my mind, it changed the downforce on the rear section of the Decking...

It would have lessened the downforce on the right side of the deck some and maybe decreased the drag.

Here is about the only published cfd results for dirt cars, notice the name on the nose!

 
Top