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Exploration into Somender Groove Theory

you have very basic problems here.
A be-all-end-all test for Somender Groove Theory.

I have realised that my engine is the perfect testbed for a specific engine modification that the TB community has been arguing about for the past decade and a half.
no, it isn't
Will you be milling the head to compensate for the volume the grooves take up? Easy to improve detonation resistance if you're dropping compression.

1. Milling the head would require first CC'ing the current head and then shaving appropriately. I lack the funds and/or means to do so, as die-grinding the head to a certain cc would be significantly more expensive than shaving a specific height from the head. If I can receive support in this venture however, this would be a great addition.
So, you are unwilling to actually do the test that is needed.

wasted time and effort

get two identical heads that are equal on the dyno.

carve one with grooves, measure the vol removed.

remove equal volume from other chamber so test means something.
repeat dyno results.

If this is too much money or effort, don't proceed.
or carve one head up with a control groove:
JmzbIko.jpg



overall, remember that a half assed bad test is just a waste of time
 
I haven't read any of this thread yet, but you can start reading from here in my thread and follow some links if you're curious. It looks like my pictures are down, and I never compiled a conclusion because the results were thrown off(among other things) by the valve adjustment getting changed when trying to leave all things equal.

http://forums.turbobricks.com/showthread.php?t=57077&page=31

I'll come back another time with more information.
 
If this is too much money or effort, don't proceed.

overall, remember that a half assed bad test is just a waste of time

Yes, that is a realisation I am quickly coming to. I'm right now considering how to create a test that is suitable, while sane.

Also; why isn't my engine perfect for this? It's the definition of a stock engine, making stock power, on stock parts, on a stock ECU. Power is where it should be, and is what it should be.

That said, with my current impressions, the modifications I will need will be the type where I will be unable to use my own engine while being able to continue to use my car as a daily driver. Current new idea is to modify an engine to run with per-cylinder knock control and sequential injection, then install a megasquirt to tune it to max HP across the rev range, even at idle. Make similar chart for worst gas quality I can find. Then, remove the head, carve the grooves, shave, and retune for both fuels. Compare timing, power, and fuel curves, and efficiency across the range.

I would also like to add the adendum; shaving will change the size of the quench zone, and that will affect the results.
 
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Yes, that is a realisation I am quickly coming to. I'm right now considering how to create a test that is suitable, while sane.

Also; why isn't my engine perfect for this? It's the definition of a stock engine, making stock power, on stock parts, on a stock ECU. Power is where it should be, and is what it should be.

That said, with my current impressions, the modifications I will need will be the type where I will be unable to use my own engine while being able to continue to use my car as a daily driver. Current new idea is to modify an engine to run with per-cylinder knock control and sequential injection, then install a megasquirt to tune it to max HP across the rev range, even at idle. Make similar chart for worst gas quality I can find. Then, remove the head, carve the grooves, shave, and retune for both fuels. Compare timing, power, and fuel curves, and efficiency across the range.

I would also like to add the adendum; shaving will change the size of the quench zone, and that will affect the results.

you continue to fail to grasp that a shaved head is an inappropriate control for a grooved head.


AGAIN. If you are unwilling/unable to perform appropriate testing with appropriate controls, your test is not worth doing.

where is western NY are you?
 
Combustion development is expensive. Even the OE vehicle & engine manufacturers (car companies) farm this stuff out to specialized 3rd-party companies. Trying to get meaningful results on a hobbyist budget is going to be difficult... not impossible, but difficult.
 
you continue to fail to grasp that a shaved head is an inappropriate control for a grooved head.

My engine is not shaved. My engine is 100% stock, and as of now, has never even been apart to be reshimmed. Belt services and water pumps only. The shave was recommended by other people in this thread, and would be post-groove to compensate for compression loss.

AGAIN. If you are unwilling/unable to perform appropriate testing with appropriate controls, your test is not worth doing.

where is western NY are you?

I am willing, what about what I said indicated I wasn't? Right now I'm trying to come up with a suitable test, trying to find what data and isn't necessary.

Rochester.
 
I would want a full standalone ECU with datalogging and multiple knock sensors, and cylinder pressure monitoring to determine if this is something that is working or not.

Id also think you would want it to be done on an engine dyno with more easily controlled and consistent environment.

And a crank angle sensor which is capable to 0.2 deg accuracy to calculate Heat Release Rate. Cylinder pressure curve and HRR is the hit when doing combustion analysis.
 
My engine is not shaved. My engine is 100% stock, and as of now, has never even been apart to be reshimmed. Belt services and water pumps only. The shave was recommended by other people in this thread, and would be post-groove to compensate for compression loss.



I am willing, what about what I said indicated I wasn't? Right now I'm trying to come up with a suitable test, trying to find what data and isn't necessary.

Rochester.

The shave was recommended by other people in this thread, and would be post-groove to compensate for compression loss.
this is not an appropriate control, you stated yourself many reasons why.


A suitable test involves at least 2 heads

If you have tried grooves, tell what you experienced, and that will be added to the list of tests to see if it can be substantiated and isn't just an anecdote.
having trouble with basic concepts here.
You should bone up on basic theory of testing, such as proper control selection, blindness, sample size etc.

What is your background, fellow Rochesterian?
 
this is not an appropriate control, you stated yourself many reasons why.

A suitable test involves at least 2 heads

having trouble with basic concepts here.
You should bone up on basic theory of testing, such as proper control selection, blindness, sample size etc.

What is your background, fellow Rochesterian?

Yeah, it's not a 100% appropriate control, but all I need is enough evidence that it works. It's what I said before, because each application is different, getting 100% accurate data is impossible. The goal is to gather the kind of data that you can look at it and say "Yep, if this did nothing I would not expect there to be this kind of difference. This is enough of a change that the shave did not affect, and neither did the cam timing". It's about seeing if there will be a significant change that could be considered to be outside the realm of being the result of other changes. Alternatively, the kind of data where you can look at it and say "This is completely normal, and the modification of the increased quench zone caused this, or maybe the cam timing change." That's why one of the tests I think would be good is the Coleman Camping Fuel test, it's the logical conclusion of the Somender Groove testing.

Proper control selection was part of my initial idea of tests, having many many people drive the car before, give their impressions and driving experience, their minimum speed to shift, then doing the modifications and seeing how another population of a similar size feels about the same car after the modification. Separate anecdotes are not data, but when the control factor is the car itself, then it is. The same car, before and after.

I'm attending RIT. Mechanical Engineering Technologies. I'd come by this weekend and show off the car, but my plan is to try to rebuild my rear suspension this weekend. Come on by, I could always use more hands.

Edit: I see where I went wrong. I said "comprehensive analysis", but I seem to have set the standard for "comprehensive" very low for myself.

I will get this testing done one day. That day may not be soon, may not be today, tomorrow, or even in the next year. But I will do it.
 
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The further you get into your schooling, the more you are going to realize the flaws in your thinking. Short of having the engine on an engine dynamometer the data you collect is near useless. In the car you have no control over air temperature/density, cooling temperature, load, ignition timing, fuel flow etc, etc. You need control over all of those parameters in order to gather any useful data.
 
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Yeah, it's not a 100% appropriate control, but all I need is enough evidence that it works.THIS IS NOT HOW SCIRENCE WORKS

It's what I said before, because each application is different, getting 100% accurate data is impossible.
100% accurate data is NEVER possible

The goal is to gather the kind of data that you can look at it and say "Yep, if this did nothing I would not expect there to be this kind of difference. This is enough of a change that the shave did not affect, and neither did the cam timing".

It's about seeing if there will be a significant change that could be considered to be outside the realm of being the result of other changes.
And to do this, you need to test the realm of those change by themselves


Alternatively, the kind of data where you can look at it and say "This is completely normal, and the modification of the increased quench zone caused this, or maybe the cam timing change."

That's why one of the tests I think would be good is the Coleman Camping Fuel test, it's the logical conclusion of the Somender Groove testing. Sorry, but WTF are you talking about?

Proper control selection was part of my initial idea of tests, having many many people drive the car before, give their impressions and driving experience, their minimum speed to shift, then doing the modifications and seeing how another population of a similar size feels about the same car after the modification.
The butt dyno is a poor yardstick


Separate anecdotes are not data, but when the control factor is the car itself, then it is. The same car, before and after.

I'm attending RIT. Mechanical Engineering Technologies.
I'd come by this weekend and show off the car, but my plan is to try to rebuild my rear suspension this weekend.
Come on by, I could always use more hands.

With all possible respect and warmest personal regards, you need to go back to square one and figure out EXACTLY what your question is, then simplify that question as much as possible.
I must assume you are fresh outta High school, and very eager to start your engineering studies.
put down the die grinder, pick up your intro textbooks or pdf or whatever you use now a days and learn the very basic basics of the scientific method.

I commend your enthusiasm, but you really need to get the basics down about control groups, significance, experimental design, and all the basics.
good luck with your studies, and bookmark this thread to reread next year, You'll have a good laugh.

Tell us about your car, do you have a build thread?
 
The further you get into your schooling, the more you are going to realize the flaws in your thinking. Short of have the engine on an engine dynamometer the data you collect is near useless. In the car you have no control over air temperature/density, cooling temperature, load, ignition timing, fuel flow etc, etc. You need control over all of those parameters in order to gather any useful data.

I will do all of this, one day. That day is not today, for many reasons.

I will return to this thread with my results, maybe in one year, maybe in 2, but I will come back and you will learn the data that I have gathered.
 
Proper control selection was part of my initial idea of tests, having many many people drive the car before, give their impressions and driving experience, their minimum speed to shift, then doing the modifications and seeing how another population of a similar size feels about the same car after the modification. Separate anecdotes are not data, but when the control factor is the car itself, then it is. The same car, before and after.

Those results would all be subjective. You will need real engine data from a dyno, with a logging system looking at a big list of different temps and pressures to be able to attribute any net power changes to alteration of combustion chamber geometry.
 
With all possible respect and warmest personal regards, you need to go back to square one and figure out EXACTLY what your question is, then simplify that question as much as possible.
I must assume you are fresh outta High school, and very eager to start your engineering studies.
put down the die grinder, pick up your intro textbooks or pdf or whatever you use now a days and learn the very basic basics of the scientific method.

I commend your enthusiasm, but you really need to get the basics down about control groups, significance, experimental design, and all the basics.
good luck with your studies, and bookmark this thread to reread next year, You'll have a good laugh.

Tell us about your car, do you have a build thread?

"Does this improve low end?"
"Does this enable shifting at lower speeds while avoiding lugging?"
"Does this prevent knock?"
"Does this increase efficiency?"

Those are my questions that I came in with. These are the things that Somender Groove proponents claimed. Each of the tests that I listed in the beginning of the thread was meant to answer one or several of these questions. That is my square one. I have already started there. I have been pondering these questions since I spent a whole day reading Somender Groove threads last March.

And as for "That's not how science works": To some degree, you're right, but the thing about science is that it's about posing a hypothesis and testing for it. If the results of testing show that the results could not have been the result of other modifications, then it works. If not, it doesn't. The scientific method is to establish a hypothesis, and test if it's wrong. If you can't prove it's wrong, it must be right.

The Coleman Camping Fuel test was to run the engine on the dyno on camping fuel (50 octane), and see the power output. If the horsepower was significantly higher when running with the grooves, then they must add knock resistance, or else it would not have run with more power. If it was the same, the grooves did nothing.

I have no die grinder. I have no mill, no lathe, no nothing, only a box of tools, a breaker bar, and a torque wrench. All of this will be very expensive because I lack any and all of the equipment to do this work, besides replacing the head itself.

As for the question of the car:

1986 Volvo 244. Paint and rust repair done last year, paint code 201. It's got an Etak Navigator, 10 Disc CD changer, car phone, and aftermarket tuner. All era appropriate, from the first owner.

Engine is original, never rebuilt. Output 90whp on a Mustang Dyno, with the dyno estimating a crank HP of 115.6bhp. Started with a M46, but replaced it as the front bearing was loose and needed to be rebuilt. Currently has a WC T5, because I wanted 5 gears with a tall 5th for highway cruising. Has cruise control. My next goal is to install a built 531 head, set up for a very wide power band from idle to redline. This is part of what inspired me to do this thread, because I wanted to do tests to see if the modification could be added to my 531 and improve low-end there.

I'm not going to correct you on my age, but your guess is wrong.

Those results would all be subjective. You will need real engine data from a dyno, with a logging system looking at a big list of different temps and pressures to be able to attribute any net power changes to alteration of combustion chamber geometry.

Yes. That's why dyno tests were in the list. The logging is the hard part that I was hoping to avoid.
 
I had a play with this years ago.
Butt dyno showed no high rpm gain but low end and mid range felt better. We run on LPG so the results are likely not the same as what you would see running on petrol.

The amount of gain you get is not going be enough to measure on a chassis dyno as the results could vary that much from one day to the next.

What you can do is see how much timing the engine will take before and after groves. Some will say the change is down to the lower compression.

If you want to prove anything you would need 20 heads. Test every one as is and then grove 10 and test, the other 10 machine out other areas of the combustion chamber to the same CC as the groves and then see how the results compare
 
A stock engine is not going to benefit much from grooves, in my opinion. You likely aren't torque limited by knock and you don't have a noticeably rough idle from an aggressive camshaft. The only thing you MAY improve on is idle and extreme low rpm torque. You can't verify that your detonation threshold is improved because you don't have detonation right now. You don't know that you can't run more ignition timing than stock with increased torque because you did not try that on the dyno.

See the attached image to find what I was curious about in my street car when I tried to document things with facts instead of feelings. I never had a chance to do a direct back to back comparison because the buckets for the shims got mixed up when the head was off(thanks, co-worker! :roll:) and the valve lash changed. Our race car also runs a single groove because I was concerned about detonation being an issue with our compression ratios, but it is not actually a problem. I will try to provide pictures of my two grooved head setups later.

Just an FYI, setting your valves loose will give similar results to the advertised improvement that grooves provide at low rpm and idle(improved combustion efficiency and torque due to reduced camshaft duration). Loose valve lash doesn't reduce detonation threshold, though.

My quick notes are that the grooves may reduce the detonation threshold, and MAY improve idle/low rpm performance, but it was not significant. Immediately after doing the back to back testing on my street car as I meant to document below, the idle and low rpm performance were WORSE!!! I later found out that the main reason for that was because the valve shim buckets got mixed up and I was running tighter valve lash on some than before. Adjusting the valve clearances looser improved my idle and low rpm performance again. Is it better than it was before doing the grooves? I'll never know because the car setup has changed again and so much time has gone by. I might be able to do some more testing with the stock computers, as that's easy enough to go back to, but my custom tuned stuff is different now.

Ps. I never passed emissions testing after the grooves and have moved on to registering the car as a classic vehicle because it doesn't get used much anyway. I will go to a non-race spec catalytic converter at some point in the future, but that car is basically on the back burner indefinitely as I focus on the race car.
 

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A stock engine is not going to benefit much from grooves, in my opinion. You likely aren't torque limited by knock and you don't have a noticeably rough idle from an aggressive camshaft. The only thing you MAY improve on is idle and extreme low rpm torque. You can't verify that your detonation threshold is improved because you don't have detonation right now. You don't know that you can't run more ignition timing than stock with increased torque because you did not try that on the dyno.

Yeah, that's why I was considering the coleman fuel test, to induce knock through fuel quality.

Thank you for the remainder of the comments. If anyone else has anything to say to me, I'm not going to be putting any more responses in this thread for the next year or 2, until I have data. PM me if you want to talk.

Edit: Mods, could you please keep this open in the event that someone, before me, is able to provide the data required to give a response one way or the other?
 
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"Does this improve low end?"
"Does this enable shifting at lower speeds while avoiding lugging?"
"Does this prevent knock?"
"Does this increase efficiency?"


And as for "That's not how science works": To some degree, you're right, but the thing about science is that it's about posing a hypothesis and testing for it. If the results of testing show that the results could not have been the result of other modifications, then it works. If not, it doesn't. The scientific method is to establish a hypothesis, and test if it's wrong. If you can't prove it's wrong, it must be right.





Yes. That's why dyno tests were in the list. The logging is the hard part that I was hoping to avoid.

That is a huge flaw in you thinking process. "If you can't prove it's wrong, it must be right". Wrong to the Nth degree. If someone can't repeat your experiment and get the same results, your experiment is flawed and therefore the results are useless. Keep on the path you are on. You seem to have enough interest I think you will make a good engineer. So many people go into the profession to get a paycheck.
 
I added some massive photos to the above post. You can probably determine which head is the race car head.

You can also find in my previous link to my car’s build thread that another TB user has enjoyed the three grooves he made on his 530 head that was shaved a lot and ran with a K cam. I suspect in a similarly built engine without the grooves but attention still being put towards tight piston/head clearance and no sharp edges may have resulted in the same ability to adjust ignition timing past peak torque without detonation.
 
My experience for whatever it is worth.
1994 940T, 15g, #46 injectors, MBR, 3" MAF, ebay intercooler, exhaust. Sucked the intake gasket in, decided to do head gasket because why not. Before the intake gasket, it pinged audibly on 91 octane. I prepped a non-shaved head with mild porting and SS grooves. It never pinged again on 91 octane.

5JeFTg9l.jpg


Gz31koHl.jpg
 
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