#1  
Old 06-22-2022, 08:42 AM
Don 79 TA Don 79 TA is offline
Ultimate Warrior
 
Join Date: Sep 2007
Posts: 1,668
Default Cylinder head dimples/golf balls Q

I watched a David Vizard video the other day around head porting and tests he has done. Very interesting stuff indeed.

He said dimpling/golf balling the head while extremely expensive has great benefits but did not elaborate.

I thought i saw some photos of heads that had this type of work done and certainly looked unique.
what's the benefit of it?
would you do it to the intake manifold as well?
anyone ever have it done or know someone that has?
is it something that only works with big cam lifts or large CFM heads?
how complicated is it to do?
and if it's that beneficial why wouldn't aftermarket cylinder heads have that as an option to buy if its something a CNC machine can do?

After seeing Davids video and mentioning of the golf balling, i did a quick youtube search about golf balls and there are many out that explain why they have dimples, however i haven't had a chance to watch them. I'm sure there is a science to that, and is that why its applied to heads?

  #2  
Old 06-22-2022, 09:45 AM
johnta1's Avatar
johnta1 johnta1 is offline
Ultimate Warrior
 
Join Date: Feb 2001
Location: now sunny Florida!
Posts: 21,237
Default

PY has had some discussions on this.
(along with the grooves in the head chamber/deck)

I think more people/porters are using a rough grind now on ports and chambers?


__________________
John Wallace - johnta1
Pontiac Power RULES !!!
www.wallaceracing.com

Winner of Top Class at Pontiac Nationals, 2004 Cordova
Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats

KRE's MR-1 - 1st 5 second Pontiac block ever!


"Every man has a right to his own opinion, but no man has a right to be wrong in his facts."

"People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates
  #3  
Old 06-22-2022, 11:04 AM
hurryinhoosier62 hurryinhoosier62 is offline
Ultimate Warrior
 
Join Date: May 2006
Location: Floyd Co., IN/SE KY
Posts: 3,930
Default

Quote:
Originally Posted by johnta1 View Post
PY has had some discussions on this.
(along with the grooves in the head chamber/deck)

I think more people/porters are using a rough grind now on ports and chambers?

Would defeat the purpose of dimpling to begin with. Polishing the chamber is to prevent carbon buildup. Dimpling on the combustion side of the chamber enhances the swirling of the intake charge. Carbon buildup in the chamber would negate swirling. All the dimpled combustion chambers I seen( ARCA and NASCAR) have polished combustion chambers.

__________________
“It takes considerable knowledge just to realize the extent of your own ignorance.”

Dr. Thomas Sowell
  #4  
Old 06-22-2022, 11:07 AM
hurryinhoosier62 hurryinhoosier62 is offline
Ultimate Warrior
 
Join Date: May 2006
Location: Floyd Co., IN/SE KY
Posts: 3,930
Default

Quote:
Originally Posted by Don 79 TA View Post
I watched a David Vizard video the other day around head porting and tests he has done. Very interesting stuff indeed.

He said dimpling/golf balling the head while extremely expensive has great benefits but did not elaborate.

I thought i saw some photos of heads that had this type of work done and certainly looked unique.
what's the benefit of it?
would you do it to the intake manifold as well?
anyone ever have it done or know someone that has?
is it something that only works with big cam lifts or large CFM heads?
how complicated is it to do?
and if it's that beneficial why wouldn't aftermarket cylinder heads have that as an option to buy if its something a CNC machine can do?

After seeing Davids video and mentioning of the golf balling, i did a quick youtube search about golf balls and there are many out that explain why they have dimples, however i haven't had a chance to watch them. I'm sure there is a science to that, and is that why its applied to heads?
Dimpling enhances the swirling of the intake charge in the combustion chamber. A swirling intake charge combusts more readily and more completely, leading to better performance from the engine. I can’t imagine how much time it takes to properly dimple one combustion chamber.

__________________
“It takes considerable knowledge just to realize the extent of your own ignorance.”

Dr. Thomas Sowell
The Following User Says Thank You to hurryinhoosier62 For This Useful Post:
  #5  
Old 06-22-2022, 11:10 AM
Steve C. Steve C. is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Liberty Hill, Tx. (Austin)
Posts: 10,385
Default

https://www.facebook.com/groups/clio...3040043844660/

Does dimpling intake ports work?

Opinions here:
https://cliosport.net/threads/does-d...ork-no.817453/

A fwiw, Jim McFarland published quite a bit in Circle Track magazine including tech material on dimpling.

https://www.motortrend.com/how-to/en...ixture-motion/

"Of course, and we sometime get a little push-back on this notion, there's always the approach whereby the surface texture of the inlet track (manifold runners, cylinder head ports and combustion space (chambers and piston crowns) can be roughened (or dimpled) to create little eddys or Von Karman rings that energize flow surface boundary layers and improve fuel atomization. In this regard, and as a point of interest, I've heard from some engine builders that have given this approach a chance and were pleased by the results. Might give it some thought. It's not magic."

https://www.motortrend.com/how-to/en...y-faster-burn/





.

__________________
'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 )
Old information here:
http://www.hotrod.com/articles/0712p...tiac-trans-am/

Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine)
5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension
https://www.youtube.com/watch?v=qDoJnIP3HgE

Last edited by Steve C.; 06-22-2022 at 11:19 AM.
The Following User Says Thank You to Steve C. For This Useful Post:
  #6  
Old 06-22-2022, 11:48 AM
Sirrotica's Avatar
Sirrotica Sirrotica is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Catawba Ohio
Posts: 7,194
Default

Mythbusters a few years back covered a Ford Focus in clay, and dimpled the surface for aero, They said it helped more than just a percent point on drag.

26 MPG without dimples, 29.65 MPG with dimples, Here's a clip from that episode:

https://www.youtube.com/watch?v=VUiGhyHC-1A

Car makers say the reason for not making it, is they don't believe it would sell.

__________________
Brad Yost
1973 T/A (SOLD)
2005 GTO
1984 Grand Prix

100% Pontiacs in my driveway!!! What's in your driveway?

If you don't take some of the RACETRACK home with you, Ya got cheated

The Following User Says Thank You to Sirrotica For This Useful Post:
  #7  
Old 06-22-2022, 12:45 PM
J.C.you's Avatar
J.C.you J.C.you is offline
Ultimate Warrior
 
Join Date: Jan 2001
Location: moccasin bayou, Louisiana
Posts: 4,794
Default

I believe Meaux did some back to back dyno tests and the dimpled ports made more power on the application he was testing.
There should be more golf ball experts in cylinder head r&d��

__________________


1963 Cat SD Clone (old school) streeter
1964 GTO post coupe, tripower, 4speed (build)
1965 GTO 389 tripower, 4 speed, driver
1966 GTO dragcar
1966 GTO Ragtop
1969 Tempest ET clone street/strip
1969 GTO Judge RA lll, auto
1969 GTO limelight Conv. 4speed go and show (sold)
1970 GP SSJ
1970 GTO barn find..TLB…390 horse?….yeh, 390
1972 GTO 455 HO, 4 speed, (build)
1973 Grand Safari wagon, 700hp stoplight sleeper
525ci DCI & 609ci LM V head builds

Last edited by J.C.you; 06-22-2022 at 12:50 PM.
The Following 2 Users Say Thank You to J.C.you For This Useful Post:
  #8  
Old 06-22-2022, 01:30 PM
Steve C. Steve C. is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Liberty Hill, Tx. (Austin)
Posts: 10,385
Default

"It works on golf balls because those fly through the air."

Let's talk dimple porting. Effective practice or unnecessary wallet-lightening? Is the juice worth the squeeze?

https://www.facebook.com/EngineLabs/...254091/?type=3

"At the risk of oversimplification, these are similar to the effects of dimples on a spinning golf ball. In the case of the golf ball, they tend to provide flight stability (as opposed to no dimples). In an engine's inlet air/fuel charge path, they can help put fuel that has become separated from the air stream back into some measure of suspension for combustion enhancement, certainly when compared to un-combusted fuel that passes directly out the exhaust system."

From the Jim McFarland Mixture Motion link I posted above.


.

__________________
'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 )
Old information here:
http://www.hotrod.com/articles/0712p...tiac-trans-am/

Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine)
5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension
https://www.youtube.com/watch?v=qDoJnIP3HgE

Last edited by Steve C.; 06-22-2022 at 01:35 PM.
The Following User Says Thank You to Steve C. For This Useful Post:
  #9  
Old 06-22-2022, 01:35 PM
Don 79 TA Don 79 TA is offline
Ultimate Warrior
 
Join Date: Sep 2007
Posts: 1,668
Default

thanks for the info guys, some good replies
and very odd about dimpling a car and actually trying it.... who would have thought that

  #10  
Old 06-22-2022, 07:24 PM
johnta1's Avatar
johnta1 johnta1 is offline
Ultimate Warrior
 
Join Date: Feb 2001
Location: now sunny Florida!
Posts: 21,237
Default

Here is a link to Larry Meaux's thread (not sure if you have to join this one though):

Rough Texture

Some of the pics are missing now. (photobucket)
I think there are some golf ball dimples in there also.


__________________
John Wallace - johnta1
Pontiac Power RULES !!!
www.wallaceracing.com

Winner of Top Class at Pontiac Nationals, 2004 Cordova
Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats

KRE's MR-1 - 1st 5 second Pontiac block ever!


"Every man has a right to his own opinion, but no man has a right to be wrong in his facts."

"People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates
The Following User Says Thank You to johnta1 For This Useful Post:
  #11  
Old 06-22-2022, 07:27 PM
sdbob sdbob is offline
Ultimate Warrior
 
Join Date: Aug 2003
Location: Latrobe,Pa. USA
Posts: 2,538
Default

I talked to Don Johnston about this yrs ago. I saw pictures of this used on heads that supposedly came from Smoky.

The Following User Says Thank You to sdbob For This Useful Post:
  #12  
Old 06-22-2022, 09:33 PM
Brentco's Avatar
Brentco Brentco is offline
Senior Member
 
Join Date: Jan 2020
Location: Orange County, CA
Posts: 147
Default

In theory, dimples would increase the turbulence of the layer of air along the surface of the head. However, it seems that dimples are very sensitive to size and shape, so it would likely take a lot of testing to get the optimum config to make them work, as well as precise manufacturing. As far as aftermarket cylinder heads go, I don’t think that a CNC would be able to make dimples, at least not uniform ones on the inside of a curved surface?

The main benefit of dimples on a golf ball, reducing drag, wouldn’t apply to heads. When the air is flowing around the exterior of an object like a golf ball (or the exterior of the car on Mythbusters) dimples reduce the wake behind the car and reduce total drag. Since the air is flowing through the interior of the head, there is no rear of the object, and no wake for the dimples to reduce. Dimples in a head would actually slightly increase drag, in theory, but also add some possibly helpful turbulence.

https://www.scientificamerican.com/a...es-in-golf-ba/

__________________
1976 Trans Am Buccaneer Red
468ci, 10.5:1 CR, 87 CC RPM CNC e-heads, HR 282/288, 230/236, 561/.573 lift, Johnson Lifters & HS 1.65 Rockers
The Following User Says Thank You to Brentco For This Useful Post:
  #13  
Old 06-23-2022, 10:07 AM
Steve C. Steve C. is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Liberty Hill, Tx. (Austin)
Posts: 10,385
Default

Your comment that it would likely take a lot of testing to get the optimum config to make them work mirrors comments regarding Jim McFarland and his work.... he championed the use of strategically placed dimples in combustion chambers and on piston tops. Further, it may have worked for him using wet flow and computational fluid dynamics to develop. Those foolish enough to place random dimples on their pistons were no doubt disappointed.

Here: https://i.postimg.cc/9MQf7Zxq/Jim-Mcfarland-piston.jpg




.

__________________
'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 )
Old information here:
http://www.hotrod.com/articles/0712p...tiac-trans-am/

Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine)
5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension
https://www.youtube.com/watch?v=qDoJnIP3HgE
The Following User Says Thank You to Steve C. For This Useful Post:
  #14  
Old 06-23-2022, 11:00 AM
sdbob sdbob is offline
Ultimate Warrior
 
Join Date: Aug 2003
Location: Latrobe,Pa. USA
Posts: 2,538
Default

I wonder if all the big gas engine mfgs,International example ever fooled with 'dimples,and other ways ' to improve flow? I never witnessed any.

  #15  
Old 06-23-2022, 11:50 AM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

John, My computer software say that Larry's site has a massive amount of Malware
installed on it. BEWARE BEWARE.

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward.
The Following User Says Thank You to Tom Vaught For This Useful Post:
  #16  
Old 06-23-2022, 01:06 PM
Half-Inch Stud's Avatar
Half-Inch Stud Half-Inch Stud is offline
Ultimate Warrior
 
Join Date: Jul 2000
Location: BlueBell, PA or AL U.S.A.
Posts: 18,457
Default

My dad had a quip-joke: " Golf would become interesting again of they used goldballs without dimples."

So, the ball will knuckleball through the air without the dimples.
So, with dimples, there is a detached layer created that allows the goldball to fly/travel rather straighter. As for slicing/hooking the golf ball, the dimples perform like baseball stitching for the curveball.

Flow for HP: darn sure the inhale tract needs to be straight from fuel intro to intake valvehead. Valve needs a certain angle for best flow past the valvehead. Smooth inhale tract is still best for least CSA, and texture causes an increased boundary layer thickness causing need for more CSA to flow same as smooth& straight.

Combustion chamber: You must go figure that dimpling does ZERO for gaseous fuels like Propane, hydrogen, methane. However, i reserve an open mind to the effect on liquid fuels such as Gasoline and diesel. Dimple away, but oh my, that piston head sure drops liquid fuel no matter whut.

A carefully controller experiment would perfor fine-grain "jetting" adjustments to measure the chamber dimpling advantage. A leaner "jetting" for same HP under load & rpm would reveal the advantage. However small or large the jetting to leaner was, that would be advantage for reduced carbon,wear,and efficiency. Surely ping could remain independent and behaved for same octane...right?

LArry Meau's site was safe, but been awhile since last visit, so good to know not to use a home 'puter to visit.


Last edited by Half-Inch Stud; 06-23-2022 at 01:17 PM.
  #17  
Old 06-23-2022, 01:58 PM
Stan Weiss's Avatar
Stan Weiss Stan Weiss is offline
Ultimate Warrior
 
Join Date: Jul 2013
Location: Philadelphia, PA
Posts: 5,000
Default

Quote:
Originally Posted by Tom Vaught View Post
John, My computer software say that Larry's site has a massive amount of Malware
installed on it. BEWARE BEWARE.

Tom V.
Tom,
What software is giving you this? I was logged into Larry's site this morning using FireFox as my browser and Avast as my AV and got no notice of any problem.

Stan

__________________
Stan Weiss/World Wide Enterprises
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software
http://www.magneticlynx.com/DV
Download FREE 14 Trial IOP / Flow Software
http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php
Pontiac Pump Gas List
http://www.magneticlynx.com/carfor/pont_gas.htm
Using PMD Block and Heads List
http://www.magneticlynx.com/carfor/pont_pmd.htm
  #18  
Old 06-23-2022, 02:58 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,294
Default

I use Firefox and a very good Virus Scanner Tool that gets monthly updates.

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward.
  #19  
Old 06-23-2022, 04:35 PM
Stuart's Avatar
Stuart Stuart is offline
Moderator
 
Join Date: Apr 2003
Location: Minneapolis
Posts: 7,938
Default

There's a BMW shop in the Kansas City area called Metric Mechanic. They have a patented process called Surface Turbulence, where they add concentric grooves inside the ports and on the valves themselves. They claim it increases flow numbers and improves atomization. I think the idea is similar to putting dimples in the surface.

I looked around on their website a bit and didn't find any specific information on how it's done (after all they have a patent on it so I suppose they don't want to give out too much information) but there are pictures of their modified heads and valves out there on the Web.

The Following User Says Thank You to Stuart For This Useful Post:
  #20  
Old 06-23-2022, 05:14 PM
70GS455 70GS455 is offline
Chief Ponti-yacker
 
Join Date: Oct 2002
Posts: 733
Default

The only place dimples make sense in an engine is on any short side radius. The reason a golf ball flies further is that the dimples allow the air to remain attached longer, reducing base drag. On a SSR, dimples will allow air flow to remain attached longer, facilitating an easier turn into the cylinder.

Sent from my SM-T817V using Tapatalk

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:48 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017