Advanced Engineering Tech - cutting a slit in each chamber to relieve quench

my friend did this on his AMC 401 and says it relieves pressure when returning to TDC. anyone hear of this?

http://www.ls2.com/forums/images/smilies/ugh2.gif

haha that's the response i expected. lol

Any effort to LOWER combustion chamber pressures would also lower power i would think.

Sounds like your friend wants to work on his car but not buy any parts.

:confused:WTF!

Hi
Are you talking about the Somander Singh grooves that are either cut into the piston or the chamber?

yea that's it.

Hi
Are you talking about the Somander Singh grooves that are either cut into the piston or the chamber?

+1

somender-singh.com

And the groove is cut in the chamber. Singh provides all the technical data free for the world to use. But, does not allow the design to be used for profit.

It is a simple modification and has been shown to produce decent results.

I've seen it done on an EMC engine or two.

http://members.cox.net/raunch/Scott%20R111.jpg

http://members.cox.net/raunch/scott%20r7_edited.jpg

Here some LS6 heads with that done. Who wants to be the first to try it out and post the results?

I remember something about 'sin-cuts' being on here like 2 years ago where everyone was looking on a honda thread or mazda thread. . . wouldn't that create more hot spots and detonation? I think it was a waste of time.

Found it. . .

http://www.lancerregister.com/showthread.php?t=224101

http://img157.imageshack.us/img157/711/cimg9154nc7.jpg

Video of the car they did this to. . .
notice at 1:40 a piece of the piston or valves popping out onto the floor next to the camera. . .

http://www.youtube.com/watch?v=NSl5zSlZzpM

Enjoy.

BTW, the car cut a 16.83 in the quarter after their work. .

I think that thread just proves that an anyone can take and idea and turn it into pure shit regardless of how good or bad is was originally.

I just spent the last hour going through the 63 pages (over 2 million views) looking for pictures of crap. . . I have a headache!

What exactly is quench and does this modification really make a noticeable improvement on performance?

ya I have to ask what exactly this is supposed to do? Why not just get a proper thickness headgasket IOT dial in your quench pad?

ya I have to ask what exactly this is supposed to do? Why not just get a proper thickness headgasket IOT dial in your quench pad?

I'm sure that would still be important, this is supposed to help get the gas out of the quench area easier and create more turbulence. Enhancing the effect of tight quench.

That went way over my head. Let me see if i got this right. Qhench is kind of like a pocket of air that doesnt get exhausted after combustion? and the slits help with that? Also, whats a quench pad?

A quench pad is just the part of the head that is flush with the deck that is still inside the cylinder. See the photos above how the combustion chamber aren't completely round, the flat part is the quench pad.

A head with a quench pad is designed to force that air out of that area when the piston reaches TDC, that helps create a wave of pressure across the combustion chamber helping the fuel/air mixture to be more dense and more even and it also helps cool hot spots in the chamber. The tighter the quench area then the more the gas gets pushed out of it. Theoretically, you would want zero clearance between the head and the piston at TDC to force all the gas out of that area, but given the fact that real world tolerances would allow for some major engine damage, most try to keep the piston atleast .030'-.040" away from the head. Much more than that and you create an area where fuel gets trapped and won't be burnt evenly.

I think the idea behind the cuts are to help better evacuated the gases trpped int eh quench area and aid in turbulent air flow which makes for a better mixture insid ethe chamber.

I think the idea of doing this is retarded and promotes hotspots in the combustion chamber. . .

IF it had any validity, do you not think the dozens of world wide car manufacturers would have been doing something like this by now???

Ahh, ok. Thanks for info. =)

I think the idea of doing this is retarded and promotes hotspots in the combustion chamber. . .

IF it had any validity, do you not think the dozens of world wide car manufacturers would have been doing something like this by now???

that and when you cut that groove you're adding more quench area rather than tightening it. i have yet to see anyone say how good this idea is.

I'm sure that would still be important, this is supposed to help get the gas out of the quench area easier and create more turbulence. Enhancing the effect of tight quench.


The wedge head(turbulent head)...which has a squish/quench area that allows for turbulence,or cooling of the gases at low RPM's,unlike the open combustion chamber Hemi head which is of the non-turbulent type.The Hemi head is typically more efficient at high RPM's.A head such as the wedge can allow air/fuel to seperate at (high RPM's) due to this turbulence.This is basically the theory of why the Hemi head is efficient.Knowing the facts about a non-turbulent vs turbulent combustion chamber,how would you be getting more turbulence by removing the mixture from the quench area.This quench area is what causes the turbulence.To my understanding,the grooves are too slow this quench at higher RPM's.

If you are going to spend the time and energy and money to remove the head to do this, you're better off just getting a thinner head gasket to cut down the quench distance to better optimize power. It's proven to work, and as long as you don't get stupid with going too thin, it's safe.

So pull the heads, and swap from a stock mls gasket of 0.056" thick to a cometic 0.040" gasket and you be able to run lower octane gas, increase compression a little, and reduce your detonation tendency all for the cost of a new head gasket and some labor.

The wedge head(turbulent head)...which has a squish/quench area that allows for turbulence,or cooling of the gases at low RPM's,unlike the open combustion chamber Hemi head which is of the non-turbulent type.The Hemi head is typically more efficient at high RPM's.A head such as the wedge can allow air/fuel to seperate at (high RPM's) due to this turbulence.This is basically the theory of why the Hemi head is efficient.Knowing the facts about a non-turbulent vs turbulent combustion chamber,how would you be getting more turbulence by removing the mixture from the quench area.This quench area is what causes the turbulence.To my understanding,the grooves are too slow this quench at higher RPM's.

Hemi heads are irrelevant in this discussion. I believe the idea is to give the gases an easier way to escape the quench area, increasing the air speed and introducing more turbulence. Read the article, the whole idea is to increase turbulence. Turbulence makes better air/fuel mixture also helps cool hot spots, which makes more power.

If you are going to spend the time and energy and money to remove the head to do this, you're better off just getting a thinner head gasket to cut down the quench distance to better optimize power. It's proven to work, and as long as you don't get stupid with going too thin, it's safe.

So pull the heads, and swap from a stock mls gasket of 0.056" thick to a cometic 0.040" gasket and you be able to run lower octane gas, increase compression a little, and reduce your detonation tendency all for the cost of a new head gasket and some labor.

I would think the idea is to do both.


Still waiting on a guinea pig.

Hemi heads are irrelevant in this discussion. I believe the idea is to give the gases an easier way to escape the quench area, increasing the air speed and introducing more turbulence. Read the article, the whole idea is to increase turbulence. Turbulence makes better air/fuel mixture also helps cool hot spots, which makes more power.



I would think the idea is to do both.


Still waiting on a guinea pig.

Sounds like the dumbest idea I have ever heard of for improving HP,besides the old TB air foil mod(lol).Obviously you are going to create hotspots in the CC from the sharp edges of the sin grooves.I could see that they could act as air bleeds and create more turbulence...but any gains on the dyno would probably be negligible.

Have not read whole thread. Is of no significance that have ever seen. Also that effort is decreasing effiective quench area. Not adding to it as someone had said earlier. This is nothing trick at all quench is decided on depending on build setup and is then calculated to achieve with decided build specs. Also alot of work is put into chamber design and can't see how that would benefit the chamber. a machininst would not setup his entire build sheet and then cut slits to relieve quench that should have been put into the equation at the beginning. there is just no need i can see power wise or any other reason. and just mentioning this (it all depends on the engine) but could be more prone to leaner areas within the combustion chamber. now im sure it would not make a difference on some street motor making 550. things are not at high enough levels to really see differences, and would say the same on many forced induction engines. But would never see that on a real n/a race engine

I know nothing compared to many. still, all this turbulent talk is all backwards deffinately not correct. want to leave it at that not looking to argue on a computer. dont ever post anything really, just sometimes things catch attention and would want save waste of time for this "guinea pig".

still, all this turbulent talk is all backwards deffinately not correct.

Please correct us then.

I have read that the distance to the quench pad from the top of the piston makes a difference in power. This is proven and dyno numbers can show this. Most books say to set the quench as tight as you can without having the piston crash into the deck. This makes sense, in the moments before TDC DURRING combustion (starts way earlier than TDC) the piston squeezes the volume of mixture from the quench pad and violently into the chamber creating homogeneous mixture or somehow supplementing flame propogation.
We all know air flows the path of least resistance so am i to understand that the volume of air between the quench pad and piston is going to squeeze into a .250" groove instead of a 60cc chamber? And what is this supposed to accomplish that the proper quench set up doesn't already?

I have read that the distance to the quench pad from the top of the piston makes a difference in power. This is proven and dyno numbers can show this. Most books say to set the quench as tight as you can without having the piston crash into the deck. This makes sense, in the moments before TDC DURRING combustion (starts way earlier than TDC) the piston squeezes the volume of mixture from the quench pad and violently into the chamber creating homogeneous mixture or somehow supplementing flame propogation.
We all know air flows the path of least resistance so am i to understand that the volume of air between the quench pad and piston is going to squeeze into a .250" groove instead of a 60cc chamber? And what is this supposed to accomplish that the proper quench set up doesn't already?

Exactly. Valve closing (just to pick number ) 70 degrees abdc. Timing is (also just to pick a number ) 30 degrees btdc. Cylinder pressure extremely high @ tdc although highest optimaly x amount of degrees atdc. Pressure differential occurs in which pressure is always trying to equalize. Cylinder pressure benifitted signicantly as well as in a major part flame propagation

We all know air flows the path of least resistance so am i to understand that the volume of air between the quench pad and piston is going to squeeze into a .250" groove instead of a 60cc chamber? And what is this supposed to accomplish that the proper quench set up doesn't already?

Do we know that airflow takes the path of least resistance? I don't think the idea is to squeeze all that air into the groove. Do they teach "over thinking" at that school?

Exactly. Valve closing (just to pick number ) 70 degrees abdc. Timing is (also just to pick a number ) 30 degrees btdc. Cylinder pressure extremely high @ tdc although highest optimaly x amount of degrees atdc. Pressure differential occurs in which pressure is always trying to equalize. Cylinder pressure benifitted signicantly as well as in a major part flame propagation

Exactly? He didn't say anything and it doesn't look like you said anything either.

Read it again it was said. But if unclear I understand. Not best at translating mind to mouth. This turbulence is talked as if combustion hasn't taken place yet when it has. The quench pad can make for better air fuel Atomization.the shittier the fuel system the more the difference but is not the main point. Air fuel atomization is not key to take place in the Chamber, should happen when the two are first introduced. If the fuel system is good then will not affect it near as much as the pressure gains from the pressure differental created. Resulting in more power that is The real gain. Any attemp to relieve this is not something to do for power

Another thing haven't been a smart ass to you joncr96z. So don't get pissy because you can't understand something. What stripegt is say is that the path of least resistance is not through a .250 thick groove of sharp edges it's to The chamber it's self so air movement would not be high in that area which still brings back to what was originally said.... Is doesn't do anything for power

there are some great minds at S.A.M. With results to prove. So maybe "overthinking" isn't so bad

Acting like a know it all is enough for me. I know what stripe said, I guess you didn't understand what I said. So don't get pissy about it.

My point is that just because you don't learn something at a school doesn't mean it isn't possible. With a quick search I can find a few positive results for these grooves. So how can you say for sure what is going on if you haven't tested it yourself.

And there are great minds outside of S.A.M., with results to prove. So what does that say?

Hemi heads are irrelevant in this discussion. I believe the idea is to give the gases an easier way to escape the quench area, increasing the air speed and introducing more turbulence.

I'm only saying none of the top 5 Engine Masters engines used this idea successfully, I know of zero Pro Stock teams using the idea and I have yet to hear of any Cup engine builder speaking of this idea. While i have heard of textureing, dimples etc. that also isn't used on any winning combinations. I'm not saying the theory isn't possible, but maybe you are the one "over thinking" the whole idea of airflow. If air doesn't take the path of least resistance then tell me why exhaust ports can be merely 2/3the size of intake ports and make power? Is it maybe because the residual pressure in the cylinder is far greater than the pressure inside the header tube? If air didn't take the path of least resistance, then why does air flow through an intake port when the intake valve opens, is it maybe because there is a pressure dop and there is less resistance to flow into the cylinder rather than out of it?

They teach how to think with logic at the School of Automotive Machinists, but if you still think i'm "over thinking" bring that trans am down to Houston with some money in your back pocket :engarde:

Do the heads used on the cars you mentioned have quench pads? And what works on one thing may not work the same way in other applications. That's logic.

Just because air it seems to follow the less resistant path may not be for that reason alone. I'm sure it doesn't go the way of most resistance. However, the grooves in those heads would allow for a lower pressure area at TDC than the surrounding area. Thus causing some of the airflow to follow that path towards the combustion chamber which ultimately has an even lower pressure. So isn't that what you were arguing to begin with? Maybe I confused "over thinking" with "under thinking".

What does my car have to do with anything? Do you have a faster car? Does that mean that you're smarter? There are lots of faster cars than me, that weren't built by SAM alumni. So what?

Dont even know where to begin. Not taking credit away from anyone in any relation school or not. Still missing the entire point this has become more Hassel than worth paying attention to.bash a school that is constantly machining building and testing, not guessing on outcomes. Graduates in all forms of racing .... Constantly getting information in. This is not know It all thing. Am not a know it all. Trying to help on the topic or possibly get help and could still be proven wrong. Has become way out of original purpose of thread. One more thing though, I personaly work and machine on engines/cylinder heads everyday. Have tried to explain my point buy you obviously don't know a damn thing about airflow/ movement from what you have said. determine airflow on the Internet all you want. I'm going to go "overthinking" things and actually machine something

for the racing comment by stripegt not my business. would imagine aggravation getting the best of someone. Proves nothing allthough can understand aggravation for someone with no results mocking a place that has proven results times over

With a quick search I can find a few positive results for these grooves. So how can you say for sure what is going on if you haven't tested it yourself.


on here or google? can you provide us with that? also, have you done these yourself?

Dont even know where to begin. Not taking credit away from anyone in any relation school or not. Still missing the entire point this has become more Hassel than worth paying attention to.bash a school that is constantly machining building and testing, not guessing on outcomes. Graduates in all forms of racing .... Constantly getting information in. This is not know It all thing. Am not a know it all. Trying to help on the topic or possibly get help and could still be proven wrong. Has become way out of original purpose of thread. One more thing though, I personaly work and machine on engines/cylinder heads everyday. Have tried to explain my point buy you obviously don't know a damn thing about airflow/ movement from what you have said. determine airflow on the Internet all you want. I'm going to go "overthinking" things and actually machine something

for the racing comment by stripegt not my business. would imagine aggravation getting the best of someone. Proves nothing allthough can understand aggravation for someone with no results mocking a place that has proven results times over

It's not about your school, but it just so happens that 2 guys from SAM came on are acted like its what they said or nothing. I personally know a guy that went to SAM and he acts the same way, but he really doesn't get it.

Everything that you've said may apply in most cases, but there could be a possibility of something else going here. True it may end up 99% of the time just fucking up a head, but who's to say.

on here or google? can you provide us with that? also, have you done these yourself?

I googled it, seems like most of it was from mpgresearch.com. There were a handful of claims of better low end and MPG, but no real proof or evidence so no real need to post. All that I saw were on small engines (4cyl).

I googled it, seems like most of it was from mpgresearch.com. There were a handful of claims of better low end and MPG, but no real proof or evidence so no real need to post. All that I saw were on small engines (4cyl).

ok so then whats the problem? if those are just claims and you're backing this yet never tried it yourself what proof do you have that this actually works? because, in every other scenario it doesnt. mainly of what everyone else said hot spots and the increase in quench area. those two things are major reasons why this wouldnt work in a internal combustion engine. now maybe this technology applied to a air pump that doesnt produce thousands degrees in exhaust heat i might agree but for us in the auto performance world i wouldnt chance it.

There is no problem. I'm not backing anything. I'm trying to get some one with some time to kill and some spare heads to give this a go.

Yeah, you can read a lot of things that people say on LS1tech, that doesn't make any of it true. It does sound like a goofy idea, and I'm sure that I would never do it myself even if some gains were had.

If it's tested thoroughly and fails, then I'd give major props to whomever tried it. Won't bother me either way.

I want to see a dyno comparison between a head with sin grooves and one without.They would have to be the same cylinder head.Until it has proven a substantial increase in HP/TQ,I am not convinced.

I'll say if it were worth the effort, don't you think the major companies would have done it on their cars already? Ford needs every bit of effort out of the mustang just to whine about being left in the dust. . . GM didn't do it on the LS9 for the ZR1 did they? NO! Don't even consider this crap.

Yeah, you can read a lot of things that people say on LS1tech, that doesn't make any of it true. It does sound like a goofy idea, and I'm sure that I would never do it myself even if some gains were had.

i'm pretty sure that even though ls1tech is the new honda board doesnt mean that all of a sudden tight quench and sharp peaks in quench area will make hot spots is a fallacy. it's going to be true as long as someone with a brain can see the obvious. as long as you're dealing with peaks in a area thats prone to detonation and lots of heat chilling this shit wont work. there shouldnt even be room for debate. im not one to rule out a wild theory but this one sucks. if you in some way decide it's awesome do it and prove people wrong if not this thread should just die because it's a dumbass idea.

I'll say if it were worth the effort, don't you think the major companies would have done it on their cars already? Ford needs every bit of effort out of the mustang just to whine about being left in the dust. . . GM didn't do it on the LS9 for the ZR1 did they? NO! Don't even consider this crap.

thats really a poor argument for anything. gm doesnt use head studs, 6 bolts per cylinder with studs, or arp2000 rod bolts either so that makes them useless i suppose. the reason people dont use it en mass is because its a silly, mostly unproven idea. funny thing is, its silly ideas that usually advance technology. saying cars would be controlled by computers during 60's wouldve had you labeled a crackpot. now... no care is without at least one ecm computer.


concerning the "relieving" quench, wouldnt it be more efficient to port out a slight "cove" instead of creating peaks where hot spots would form? something tells me youll eventually end up with a hemispherical head the further you go with that idea.

No matter what,it is going to create hot spots in the combustion chamber from the sharp edges of the sin grooves.That would in-evitably lead to an engine prone to abnormal combustion/pre-ignition on a high HP/TQ application.I have yet to see an argument worthy of convincing anyone of the positive effects of sin grooves.

If you are going to spend the time and energy and money to remove the head to do this, you're better off just getting a thinner head gasket to cut down the quench distance to better optimize power. It's proven to work, and as long as you don't get stupid with going too thin, it's safe.

So pull the heads, and swap from a stock mls gasket of 0.056" thick to a cometic 0.040" gasket and you be able to run lower octane gas, increase compression a little, and reduce your detonation tendency all for the cost of a new head gasket and some labor.

Actually you have that backwards.An engine with a higher compression ratio typically requires higher octane fuel.In addition,more compression also leads to an engine more prone to detonation because of the increase in combustion temperature.

No matter what,it is going to create hot spots in the combustion chamber from the sharp edges of the sin grooves.That would in-evitably lead to an engine prone to abnormal combustion/pre-ignition on a high HP/TQ application.I have yet to see an argument worthy of convincing anyone of the positive effects of sin grooves.

Not necessarily. There are some sharp edges in lots of combustion champers regardless they could be smoothed somewhat if a hop spot did occur. Also that is one of the benefits of quench is that the turbulence (or pressure wave that it creates helps to cool hot spots. Hence the term "quench". Assuming that the grooves accelerated the velocity out of the quench area that might in it self help alleviate the heat created and stored at those sharp points.

Actually you have that backwards.An engine with a higher compression ratio typically requires higher octane fuel.In addition,more compression also leads to an engine more prone to detonation because of the increase in combustion temperature.

He actually has it right. Tighter quench helps with detonation and often requires less timing to make the same power since the flame front is accelerated by the pressure differential. This is the reason that people that have too high off a compression ratio and try to fix it with thicker gaskets usually make there problems worse.

Here is a link that might justify what I was explaining.http://somender-singh.com/component/option,com_joomlaboard/Itemid,55/func,view/id,55/catid,2/ Coming from a guy who supposively took Singh's guidance.I dont know...I can see where you are coming from also with tighter quench resulting in more turbulance and thearby cooling the gases.

Here is a link that might justify what I was explaining.http://somender-singh.com/component/option,com_joomlaboard/Itemid,55/func,view/id,55/catid,2/ Coming from a guy who supposively took Singh's guidance.I dont know...I can see where you are coming from also with tighter quench resulting in more turbulance and thearby cooling the gases.

There are 10+ post on that link and I don't see any of them that say what you are saying. Be more specific.

Primarily the last post referring to the thicker head gasket with low compression being less prone to detonation.

There is an area between ~.060-~.070 quench height where the air/fuel mixture won't be burnt in the quench area. Of course, lowering compression lowers the risk of detonation but you need to go above that quench. In most cases tightening the quench will over come the added compression factor, unless of course you were already too much to begin with.

On an LS1 the stock gasket is .054 with the piston ~.005-.010 out of the hole. Making the quench right around .045-.055 depending on block growth. This is the norm as it's on the high side for clearance but not loose enough to cause problems. The common problem for compression is running too small of a chamber. Bumping up the gasket .010 will lessen the compression by a few tenths but may actually cause more problems by allowing gas to be trap in the quench area, possibly creating an uneven air/fuel mix and taking away from some of the thermal efficiency. The correct solution would be add to the chamber volume and/or reduce gasket thickness. Also as I said before tightening the quench allows the same location of peak pressure and power potential with less timing, which also reduces detonation tendencies.

That post does suggest that the grooves work better with the looser quench and that there was positive(?) results from the groove even with tight quench.

Jon, I have seen about 6 people try this and none seemed to get any results and they were looking for them and wanted them. Also, as was said by the previous SAM students whom I do not know, the fact is that you do not see this technology really anywhere in all out NA racing basically at all with people who WILL TRY ANYTHING to get more power.

I think it might have some gains in some totally unrelated areas but these grooves don't seem to help good race heads at all although who know that there aren't SOME heads that this might not help? I can't answer that at all but I do know that I haven't seen it do anything on the people's stuff I have seen and I was also interested like you in this deal.

Also if it did work you would be right in that people would probably try and keep it a secret so again maybe it might help a certain style of head a lil but I can't see any major gains but hell who knows unless you do it yourself. FWIW quench area is not necesarily good anyway but if you have it you have to deal with it and on many engines you need it for any compression at all.

It seems the idea behind design is for gas mileage anyway. And what is good for gas mileage doesn't always correlate with performance. I also think that it would have drastic difference in different applications, even if all were negative results.


Still waiting on an LSx guinea pig...

I just read this entire post. I think the die grinder slits cut in heads or pistons is a crappy idea for making more power sorry. I would like to see some one give it a try and send some pictures after trying to make some power with them. A good tricks to lower the compression with out sacrificing horsepower are gas porting the pistons. Removing the area in between the valve reliefs on the piston some cases you have to play around with valve angles to make power when you do this. Deshrouding the valves on some heads. I do agree with not running a thicker head gasket though unless you want to have the head gasket as the weak point for the engine. I use thicker gaskets some times on stock engine turbo cars running pump gas so the gasket goes instead of the pistons. All of these are inexpensive efficient ways to lower compression with out changing pistons and having custom head work preformed.