The Singh Slash

[turbovanman²]

It has to be the same exact head. So dyno the van, pop the head off, go wolverine style on the combustion chambers, slap it back on, and run it again the same afternoon

I know, hence send me two heads, both the same but one has the grooves. I guess I could do mine but then if it doesn't work and ruins my head, then its junk,

[86Shelby]

So start with a regular old head. Slap it on, do the dyno. Then lift it up, break out the dremel and slap it together again for another dyno run. Practice the lines on a junk casting first. I can get you a deal on the dyno if you do it in Nebraska!

[turbovanman²]

So start with a regular old head. Slap it on, do the dyno. Then lift it up, break out the dremel and slap it together again for another dyno run. Practice the lines on a junk casting first. I can get you a deal on the dyno if you do it in Nebraska!

Mmmmmm, thats along drive,

I don't have any good stock heads, there all cracked.

[BadAssPerformance]

Mmmmmm, thats along drive,

I don't have any good stock heads, there all cracked.

Just the normal cracks between the valves? For the A to B it wouldn't have to be a 'good' head, just be able to hold the same compression on each cylinder.

[86Shelby]

That's what I was thinking JT. As long as it'll hold up for a few runs and no burnt/bent valves it would work.

[ssheen]

Just so happens my spare head that I just grooved is the one I dynoed last. If only I could bring myself to put it on with out the new log header and S70 it would be a back to back.

The is the advice I had from AB about the grooves and the 782 with dished pistons.

"For maximum advantage with the squish ring provided by the piston top,
consider cutting three grooves as shown. All three pointing in the general
direction of the plug. Cut the grooves 1.5 mm wide and wider and deeper into
the chamber cavity. The outlet should be 3 mm wide at the cavity; contour
the bottom of the groove into the roof of the chamber."

[turbovanman²]

Just the normal cracks between the valves? For the A to B it wouldn't have to be a 'good' head, just be able to hold the same compression on each cylinder.

JT, do I have to come out there and smack you. I know what cracks and bad? these are chamber cracks so yeah, head is no good. I figure if the last head works, IE the singh head, might as well leave it on, why take it off again. I also doubt I would get both swapped over and dyno tested the same day. Would probably be a gap of a couple weeks.

[Directconnection]

I'd like to see back to back dyno sheets with teh same head, uncut and cut on anything like this.

I might be able to do this. I showed a pic of one of these modified heads to the headporter at work. He's like "oh yeah...we did that 10 years ago" Seems after numerous tests on SB Chevy Busch series engines they built, it showed absolutely zero gains...and zero losses as well. It was tried on more than just one engine, as well.

If they have the dyno sheets from back then, I'll see if I could post them.

I'll see if I can get more info...

But, no matter what I say... it's certainly great news that turboking's car is running..and running good!

[mpgmike]

Studying the dynamics of detonation, the spark plug fires then sends out a wave of ever increasing pressure and temperature. The back corners of the squish pad receive the highest pressures and temperatures before actually getting caught up in the flame front. This is where the overwhelming majority of detonation occurs. The groove vents this pressure and allows a mini flame front back onto this recess to reduce detonation and improve the homogenizing characteristics of the combustion chamber.

A groove alone might show modest increases in performance and/or mileage, depending on the set-up to begin with. As we boost our engines to the stratusphere, detonation becomes an increasingly important issue. This simple little groove poses no threat as far as cracking thanks to our thick decks. However, it helps prevent piston melt-down and even allows cheaper fuel or higher boost. So far this has been the overall result from the heads I've been doing. I must add that I do many things besides the grooves to better vaporize the fuel then better homogenize it with the air. These all contribute to better detonation control and more power per CFM of flow through the engine (called BSFC on the dyno sheet). I wouldn't want to do just a back-to-back with and without the groove dyno test because the groove is simply an enabler, not the answer in and of itself.

The relationships within the combustion chamber can get complicated when you try to break it down into several phases of combustion, and I won't go into it here. I'll just say that I've researched it thoroughly, I've experimented with it fairly thoroughly, but don't have the dyno numbers to prove anything. I will continue to add the groove to most of the heads I do until I either find a better way, or somebody does what has thus far been impossible...prove to me they're worthless or harmful.

Mike

[Directconnection]

Seems to me that a bunch o different heads modified on a bunch of race motors all on the same dyno showing no gains tells me enough right there that it doesn't do squat, even though I'm still open to discussion.

[Frank]

I just got in and am eating dinner. I need to scan in some stuff tonight, but I found some information that will want to make you poop on grooves! I found teh "eastern passage"!!!! MUHAHAHAHA





Frank

[Frank]

Ok I havent had a chance to scan in the graphs and pictures yet, but I have finally had the epiphany which brought together my thoughts of what was driving me nuts about this guy and his grooves. When I read his stuff, I noticed that it doesnt take into account all of the dynamics that go on inside the chamber. His statements confuse many different principles.

So here we go.

Ok, swirl and turbulent flow is always desired because of the mixing effect it gives to the fuel. Now we have three flow effects in the cylinder which gives an overal swirl/turbulent flow. #1 is the flow from the port into the chamber. This typically starts spinning according to the swirl shape of the head. This typically flows in a downward spiral. This has all be during the injestion stroke. The compression stroke proves the next two contributors to turbulant/swirl flow. So #2 is the piston to cylinder wall interaction. As the piston moves up, air is moved upward. Contrary to popular thought, the highest velocity of air upward is coming from where the air compresses along the chamber wall where the piston meets it. (i have pictures to show this...) This causes the first factor against goorves, but more on that later. As the piston continues to move upward, the closer it gets to TDC, the more we see air jets towards the center of the cylinder and combustion chamber. This is where the next contributor comes in. #3 is the interaction of the flow generated from piston moving up with the residual swirl and on to a reinteraction with the chamber's shape.

Now we get onto the flame propagation properties. This is where MrGroove gets things wrong. He shows laminar flame in his thinking and his diagrams, and ingores swirl. Yes laminar flame is present, however only along the air jet and typically in the direction of the air jet when swirl is present. (I have a picture of this also) Since the air is being squeezed from outside to the inside, flame doesnt propigate per his groove idea. This is why such emphasis is given by "real" engine builders to have the piston's quench area to match combustion chamber's shape. This ensurse that all air/fuel mixtures get squished out into the main chamber, otherwise it doesnt get burned until you are already on the power/down stroke and are not contributing to adding good pwoer.

Hopefully this explains the flaw in this guy's thinking. Flame will not propigate from in to out, so the grooves will be usesless since the air is being "swirled" AND because air is flowing inward and upward away from the cylinder wals. Oh and finally, if swirl is not present, then you will get propigation from in to out, but its still effected by combustion chamber shape.

I am going to try to get you pictures now.


Frank

[Frank]

I will say this. If adding grooves does provide results, I wouldnt mind speculating that it is by stream lining the flow from out to in along the quench area, however I dont think it will assist much at all because of areodynamic effects.


Frank

[mpgmike]

Most arguments can be divided along categorical lines; liberals vs conservatives, creationism vs evolution, etc. In this case, the argument line seems to fall into the camps of those that have tried Somender's Grooves and those who haven't. For years it was concluded scientifically that a bumble bee could not fly, however...

Mike

[Frank]

True that!

[BadAssPerformance]

Most arguments can be divided along categorical lines; liberals vs conservatives, creationism vs evolution, etc. In this case, the argument line seems to fall into the camps of those that have tried Somender's Grooves and those who haven't. For years it was concluded scientifically that a bumble bee could not fly, however...

Mike

Yes, and the world used to be flat too! All myths are fiction until proven as true facts.

I'd like to see back to back dyno sheets with the same exact head, first dyno it uncut and then cut it and re-dyno it with no other changes, swapped on the same day for temp and barometer concerns. Has anyone done this?

[ssheen]

JT, I think you will find those dyno results on speedtalk.com. Do not recall what thread though.

My personal thoughts on no changes back to back dyno is that it will not show the complete story. What about lower EGTs, is that not worth while? Able to run lower octane, less fuel, or higher boost? The cleaner oil reported? Though I understand that seemed to effect the high HP big block guys with the amount of fuel they had to run to idle. The detonation control?

Would anyone throw in +40s and not tune for them before the dyno? Hope not. Why ask for the same from the grooves? Perhaps as baseline, but it should be recognized that properly tuned would be more meaningful.

If part of the grooves is that the C/R should be raised to get the most effect, perhaps, dyno a head with the same higher C/R and then with the grooves at that same higher C/R. In other words, whatever the best state of tune would be with the grooves, try that same state before on a none grooved head, then a grooved one. That, to me, would be more meaningful.

I do have a couple of questions. If the grooves are suppose to speed up combustion, would that be a reason or partial reason for the lower EGTs?

If in fact the grooves do speed up the combustion we should be able to see this. I wonder if I have. I noticed that the engine ran cooler. Which is what I would expect from faster combustion. Less time to transfer heat. Though if it is still trapped in the CC because of the valves?? Also if combustion is faster, would not the best timing be retarded? (good for a dyno test) Would cam timing have to change to take advantage of faster combustion?

[Frank]

Lower EGT's, better mpg, and a speed up combustion are a result of higher compression that these yahoos claim is from the grooves. We know what higher compression does... always have. However they tend to forget that and place claim on the grooves. Guess what else... they also like to clean up the combustion chamber while they are in there.... guess what that does... it gets rid of the detonation issues that are apparent with stock head castings.

Everything they claim has been proven with common mods that they ALL do at the same time. You cannot prove grooves without a back to back test.... no ifs and or buts about it. Sorry to be a jerk, but the theory, the pictures above, the claims, and the results dont agree.


Frank

[BadAssPerformance]

I have yet to see a direct a-to-b... like Frank said, no one just cuts the grooves in.

I agree that if the direct (slashes only) a-to-b does change actual a/f ratio read before (a) and after (b) that it would be fair to modify the fuel delivery slightly enough to match the (b) a/f ratio to the (a) a/f ratio. This all being done of course a-to-b at the same temp and barometer

[ssheen]

Thanks for the pics and info Frank. I had no idea lower EGT's and faster combustion are a product of higher compression.

I understand the position about the back to back dyno.

The results should be the same in the back to back senario I mentioned as well, if the grooves do not do anything.

Here is a dyno of only the grooves being the only change. The compare is the worst after groove against the best before groove.
http://www.revsearch.com/grooves/grooves.html

Discussion starts on page 9 of this thread
http://www.speedtalk.com/forum/viewt...=asc&start=120