Did you heard about the Singh's Grooves??? - Alfa Romeo Bulletin Board & Forums

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 17 (permalink) Old 10-16-2007, 12:06 AM Thread Starter
Registered User
 
AlvaroSeco's Avatar
 
Join Date: Jan 2004
Location: A Coruña, Spain
Posts: 923
Did you heard about the Singh's Grooves???

Hi!

Don't know if this question was discused in this forum, but I think it's intreresting.

Take a look:


http://www.somender-singh.com/
http://www.mazda626.net/index.php?sh...ded&pid=255078
http://www.hotrodders.com/forum/sing...-a-102958.html

What do you think??

Best regards, Alvaro.

subitocorse.com - Digital resource for classic transxale Alfa Romeo cars
AlvaroSeco is offline  
Sponsored Links
Advertisement
 
post #2 of 17 (permalink) Old 10-16-2007, 12:23 AM
Registered User
 
BigSwede's Avatar
 
Join Date: Aug 2003
Location: 58 Deg. North
Posts: 1,898
Heard about them and they show no gains anywhere, only slight loss.
Don't look too them for performance.

Mats Strandberg

GTV 2000 -77
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
<= These are picture links you know...
75 Turbo -87 *sold*
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
<=
BigSwede is offline  
post #3 of 17 (permalink) Old 10-16-2007, 12:37 AM Thread Starter
Registered User
 
AlvaroSeco's Avatar
 
Join Date: Jan 2004
Location: A Coruña, Spain
Posts: 923
Hi!

That's the first thing I thought: "loss of compresion", so i did not understand the trick...

Regards!

subitocorse.com - Digital resource for classic transxale Alfa Romeo cars
AlvaroSeco is offline  
 
post #4 of 17 (permalink) Old 10-16-2007, 04:50 AM
1966-2013
Platinum Subscriber
 
Tifosi's Avatar
 
Join Date: Mar 2006
Location: Northern NY, USA
Posts: 13,741
Technically they work to assist the atomized mixture flow and disburse better, then supposedly help create a more even pressure on the top of the piston during combustion, but it only works on a side valve 4 stroke lawnmower engine and then only if you don't mind changing burnt head gaskets every week.......

Darren
'84 manufacture ~ '85 MY Spider Graduate

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

as hosted by

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Tifosi is offline  
post #5 of 17 (permalink) Old 10-16-2007, 08:53 AM
Registered User
 
Join Date: Jun 2007
Posts: 45
What the grooves do--

First of all, the grooves DO WORK, when properly applied.

AND, it ain't just on 'lawn mower motors'. Lots of work done with 'em on diesels with cylinders you could likely stand up in !!

First thing you have to have for them to work properly is a decent amount of squish/quench area in your chamber. You DO have that incorporated into your piston chamber design already, DON'T you ???

Next, the squish/quench clearance has to be pretty tight for the grooves to do much of anything. As in about .020---.025" on an engine of typical Alfa proportions. If you're not capable of building an engine with this tight a squish clearance that will live, don't bother.

What properly designed grooves do is DIRECT the super to trans sonic flow that comes out of the squish area in a manner so that consistent vortices are created in the roomier part of the chamber--rather than the random turbulence that one gets without such grooves.

Heard the old saw that 'too tight a squish will give you a 'roughness' ' ??
Well, the real translation of that is that random, highly active turbulence in the chamber will give you wildly varying burn rates, and is tantamount to changing the timing on each power stroke !! The consistent vortices that the grooves can give cure this problem.

With the consistent, faster burn rate that tight squish and the grooves yield, first off, the engine will need significantly less ignition advance. Don't take this into consideration, and, yep, head gaskets and other such will have a real short half life.

Benefits--

1. faster burn gives greater detonation resistance on a given fuel.
2. faster burn gives an inherently more efficient cycle, thus lower bsfc (better fuel economy) AND more torque/power.

Greg
bearbvd is offline  
post #6 of 17 (permalink) Old 10-16-2007, 10:03 AM
1966-2013
Platinum Subscriber
 
Tifosi's Avatar
 
Join Date: Mar 2006
Location: Northern NY, USA
Posts: 13,741
This applies to a hemispherical head how?

All I see it reffered for use in is pent roof and wedge heads, (both good for compression, but a bit on the pathetic side AFA burn pattern), and I'll give the benifit of the doubt on diesel (even though they fire as a result of compression and a pocketed piston crown rather than spark......)

I stand by what I said as do the pile of old time racers, engineers, and engineers who race around these parts.


Quote:
Well, the real translation of that is that random, highly active turbulence in the chamber will give you wildly varying burn rates, and is tantamount to changing the timing on each power stroke !! The consistent vortices that the grooves can give cure this problem.
So will a properly atomized A/F mixture coming through proper port work and induction tuning.

Much cheaper than a screwing up a head with grooves if even only from a rebuildable core aspect. :shrug:

Darren
'84 manufacture ~ '85 MY Spider Graduate

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

as hosted by

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Tifosi is offline  
post #7 of 17 (permalink) Old 10-16-2007, 02:39 PM
Registered User
 
Join Date: Jun 2007
Posts: 45
Well--

Glad to see we've sorted out those who might want to learn something from those who like losing to Duckworth and ricer designs !!

First of all, re diesels--a combustion chamber (or the burning air/fuel mix inside it) doesn't give two hoots whether it's located in the head or the piston crown !! In fact, good fuel atomization has another VERY good benefit, but, at least for now, the answer to what that is will be a pop quiz !!

Second---good fuel atomization is a wonderful thing, as are port induced swirl and tumble. BUT--they won't even APPROACH speeding up the burn the way properly directed , squish induced turbulence will.

Third--if you think squish induced swirl is only for pent-roof and wedge type chambers, try taking a peek at the chamber shape in the most advanced two valve true hemi chambers that presently exist--as built by folks with names like Black, Donovan, and Indy (nee Mopar). Clue: they get their shape (and their squish) via educated and effective design of the piston crown.

Recommended reading:

Glassman 'Combustion'

Obert 'The Internal Combustion Engine'

NACA --A WIDE variety of papers written by guys who tested (true hemi headed piston) engines to DESTRUCTION --because many guys lives depended depended on that last bit of performance !!!

Suggest you not refer vaguely to un-named 'engineers' when trying to debate a REAL one !!

Greg
bearbvd is offline  
post #8 of 17 (permalink) Old 10-16-2007, 04:13 PM
1966-2013
Platinum Subscriber
 
Tifosi's Avatar
 
Join Date: Mar 2006
Location: Northern NY, USA
Posts: 13,741
Quote:
Suggest you not refer vaguely to un-named 'engineers' when trying to debate a REAL one !!
You wouldn't know thier names any more than they'd know yours anyway, so what would be the point?

Though I can assure you they're nowhere near as anal as the one who claims to be.

I leave you to the thread, you may call it a 'victory' if it makes you feel better.

Darren
'84 manufacture ~ '85 MY Spider Graduate

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

as hosted by

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Tifosi is offline  
post #9 of 17 (permalink) Old 10-16-2007, 06:42 PM
Registered User
 
Join Date: Jun 2007
Posts: 45
Ahhhh--

What's the point--lemme see--perhaps that in a technical/scientific discussion one references one's sources so that they may be verified ??

Of course, then again, if one has filled one's mouth with not so tasty foot, one might make a petulant excuse for not disclosing one's sources--either because they are imaginary, non-existent, or incompetent ??

And, of course, to distract attention from the above, one might consider making an implied slur of the opponent--'You MEANIE !!! You just wanted to win , and thus FEEL better !'

(Typical debate tactic of the incompetent, uneducated, immoral, and/or traitorous -- attack the messenger when you have a faulty message !!!)

BTW--since you clearly demonstrated that you didn't know the answer to the quiz, I will share it with the others here---

Well atomized (NOT evaporated yet !!!) fuel mixed with air once inside a closed cylinder acts as an interal coolant. It's latent heat of vaporization absorbs some of the heat generated during the compression stroke--thus bringing the compression process toward iso-thermal and away from adiabatic. This lowers the peak pressure in the cylinder, lowers peak temps, reduces bearing and side thrust loadings, and increases detonation resistance. Net effect is positive, even though the lower peak temp reduces cycle efficiency to a small degree.

NOTE: spraying injected fuel on the back of closed intake valves does NOT provide the above benefits, as the fuel is already EVAPORATED before it gets inside the cylinder. You need good carbys--such as DCOE's--to get the above benefits--or injectors that use compressed air atomization and only squirt atomized fuel into the port air stream when it is MOVING, or directly into the chambers. Hence--the fuel economy and power gains from direct injection. Not to mention the bsfc superiority of DCOE's over conventional port injection !!

Bear
bearbvd is offline  
post #10 of 17 (permalink) Old 10-16-2007, 07:18 PM
Registered User
 
Join Date: May 2004
Posts: 4,075
Bearbvd, Can you name one NACA report that talks about these grooves? If so I would like to read it. This thing sort of reminds me of the turbonator, I am not saying it won't work, but I can't see how it would do anything good on an Alfa Nord or and Alfa V6.

Greg Gordon
Greg Gordon is offline  
post #11 of 17 (permalink) Old 10-16-2007, 09:55 PM
Registered User
 
Join Date: Jun 2007
Posts: 45
Sorry, Greg, I can't name (or number) any specific NACA report addressing grooves. There are a LOT of those reports , mostly '30's--'40's vintage !!!! LOTS of fascinating info in them, such as most all one could ever want to know about water injection.

Too bad most of the seriously talented guys involved in that work went off into work on turbines--but, then again, turbines were the 'hot new thing' during that period, so, of course, they skimmed off the best talent !!

Such grooves are pretty common in big diesels--usually in the pistons, NOT the head. And, likewise, I think it would be wiser to put them in the piston on any spark engine, including an Alfa, if one wanted them on an Alfa.

Basically because it's less 'invasive'.

I suspect that the ones pictured were done in the head just so the builder could use off the shelf flat-top pistons without bothering (too lazy ??) to come up with a set-up/tooling to do them on his pistons.

The combustion chamber doesn't care in the slightest whether the grooves are on the piston crown or in the head. The point is to direct the squish turbulence in a consistent manner.

There are some modern (mostly Asian design) spark ignition engines that use various types of groove/texturing on the piston crown, there IS something to it. I've never tried such stuff on an Alfa engine, but may well do so soon.

I AM a FIRM believer in using 'squish' design pistons in Alfas, been doing THAT for about 35 years. The benefits of having squish in an Alfa Nord are striking.

Clearly, if no squish area, no point in grooves !!

Bear (also a Greg)
bearbvd is offline  
post #12 of 17 (permalink) Old 10-16-2007, 11:33 PM Thread Starter
Registered User
 
AlvaroSeco's Avatar
 
Join Date: Jan 2004
Location: A Coruña, Spain
Posts: 923
Quote:
Originally Posted by bearbvd View Post
Clearly, if no squish area, no point in grooves !! Bear (also a Greg)
I've been reading some reports around some websites and all of them refered to heads with squish area design. That's the point, I think.

Anyway I's a wonderfull technical discussion.
Thanks a lot for the posts!

Best regards,
ALvaro

subitocorse.com - Digital resource for classic transxale Alfa Romeo cars
AlvaroSeco is offline  
post #13 of 17 (permalink) Old 10-17-2007, 11:25 AM
Registered User
 
Join Date: Mar 2005
Location: Milpitas CA
Posts: 2,984
The best info on hemispherical heads I found was for race bikes.
As the squish area goes all the way around in a hemi it is not clear how you would do it.
I guess you could add some even spaced all the way around.
but I would see if any of the bikes have done it. I think if the squish is working on the hemi that is as good as it gets. but I think the squish is not effictive many times do to too much clearance.
for it to work right it needs to be very tight almost touching at redline.
who here has even meshered the squish ring? let alone changed it so it is tight all the way around.

1987 black Milano Verde, 1987 (made in 1986)blue $200 gold with ABS and LSD
1972 White spider 2000 Veloce
slyalfa is offline  
post #14 of 17 (permalink) Old 10-17-2007, 01:51 PM
Registered User
 
Join Date: Dec 2006
Location: annapolis, md
Posts: 295
Do you know of any published SAE papers on the subject? I did a search and came up empty handed.

I would think that a gentle slope over the roof of the chamber leading to a final concentrated expulsion of the gases would be more effective.

The company I work for has a in piston design using a gas chamber inside the body of the piston connected to the combustion chamber by a small port that has great result on fuel consumption and emissions. Some of these small changes have great effects on combustion.

83 Spider Veloce
pillowmeto is offline  
post #15 of 17 (permalink) Old 10-17-2007, 02:45 PM
TNT
Registered User
 
Join Date: Apr 2005
Posts: 6
Hi guys , I saw somewere on the Net that it is possible to gain squish area for the Hemispherical heads with special pistons, they are supposed to be domed and too close to the wall of the chamber(the domed crown) within the specific clearance(s) thus creating a '3D' squish area....that 's what they said anyway.I 'll check for the link if u want.
TNT is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
Replace with
For the best viewing experience please update your browser to Google Chrome