Cutting grooves into heads

I heard about this when I was in India in 1999. I thought it was ghetto back then but its really catching on.

Any thoughts?

http://www.herningg.com/projects/groovyheads.html

http://somender-singh.com/content/view/7/31/

http://somender-singh.com/content/view/68/49/

http://fueleconomytips.com/index.php?option=com_content&task=view&id=73&Itemid=2

http://jeremiahsviolins.com/grooves.htm

It helps burn efficiency(hense power and knock) - when the piston comes to TDC, that groove creates a high pressure surge of air into the quench area that helps ditribute the mixture in the combustion chamber. < - Cliff Notes. You should see the burn pattern in the chambers and piston tops that come out of motors set up that way - looks perfect.

Pretty interesting but wouldn't positioning of the groove be critical for best performance. It just seems to half hazard to me that a guy is breaking out his dremel tool to do this.

I think the groove has to be cut across from the spark plug.

If increasing turbulence is better, why do people port & polish?

Turbulant flow as apposed to a smooth laminar flow will cause air to "stick" to the surface. Thats why on a good port and polish job you actually try to scuff up the intake side a little. Example a golf ball flying through the air.



Maybe i will try this on my jet ski for fun. Head comes off pretty easily and that 2 cycle could def use a better burn pattern

But doesn't turbulent flow slow or lower the amt. of air traveling through a port as opposed to a slick smooth port?

I think most understand this but I'm going to say it anyway for people running out to rip there heads off and perform the surgery.
I hope anyone reading this understands not to go past the inside edge of the head gasket....otherwise you will have issues.

But doesn't turbulent flow slow or lower the amt. of air traveling through a port as opposed to a slick smooth port?

You want turbulance on the intake side so the fuel atomizes better and you polish the hell out of hte exhaust side.

I think most understand this but I'm going to say it anyway for people running out to rip there heads off and perform the surgery.
I hope anyone reading this understands not to go past the inside edge of the head gasket....otherwise you will have issues.

Someone had to say it. I'm sure you saved at least one 16 yr old kid from messing up his car.

If increasing turbulence is better, why do people port & polish?

You completely missed the point, this is done in the chamber for turbulence under compression, not impacting port flow. In theory the turbulence at the top of the compression stroke mixes the air and fuel better and helps the flame front travel.

Far as polishing most of the time that is done it is because the person didn't know what they were doing and mistakenly thought it benificial.
I don't even buy the polish the exhaust port leave it a tad rough so carbon can stick and insulate the head a mlittle from the exhaust gas heat. If the motor is running right the carbon will not accumulate to the point of any restriction.

The groove is to push the fuel mixture out of the quench area into the combustion pocket closer to the plug, for a more complete burn. In tests there have been no HP gains,just fuel mileage gains. It may help detonation but that has not been proven either. Right now it is just an experiment.

Don't know about everybody else but I want the quickest ET not the least amount of fuel burned in a pass. Do they give trophies for that.

There is a guy down here cutting 4 grooves across the quench area. He has also done radial grooves,but their car didn't gain any measurable ET/MPH.

I heard about this when I was in India in 1999. I thought it was ghetto back then but its really catching on.

Any thoughts?

http://www.herningg.com/projects/groovyheads.html

These guys are documenting gains. I have no idea about lowered et's etc...

These guys are documenting gains. I have no idea about lowered et's etc...

They also went from 9.0 to 10.2 compression ratio. I was told sharp edges result in hot spots and possible pinging. Would these grooves not count as such?

Cutting steps into the backside of each valve to help with fuel atomization was a pretty clever idea.

These guys are documenting gains. I have no idea about lowered et's etc...

He did a lot more than grooves in the quench area.

These guys are documenting gains. I have no idea about lowered et's etc...
They got just about what you'd expect from bumping the compression.

I dont see how there would be any gains from that modification.

The rule of thumb is the tighter the quench the better, in my oppinion that would relieve the quench erea therefore giving a less turbulance and hurting mixture and flame travel. That combined with the comp ratio being slightly lowered doesnt sound like a worthwhile effort.

Just my .02

Go back and read my post about how it creates a "jet stream" into the quench area creating turbulence and better distribution of the air/fuel leading to a more efficient burn.

By having the 4v SVT motor, you already have a super efficient chamber - not really any tricks or gimicks to make it better. That is why you can run 10:1+ compression and a blower on a 4v motor and still not detonate.

Go back and read my post about how it creates a "jet stream" into the quench area creating turbulence and better distribution of the air/fuel leading to a more efficient burn.

In theory it sounds great but..

Take a big thick book and slam the book shut, turbulant air will be forced out when its slammed shut. Take that same book and cut a slice out of the middle and slam it shut again, the air will have less force and turbulance due to being slightly relieved by the channel you cut in it. This is why a lot of people run a zero deck hight with the minimum thickness head gasket they can get away with. It is the best combination for enhancing the quench erea and promoting better mixture turbulance and flame travel. Cutting groves or lines in the quench erea would have the same affect as increasing the deck hight or changing to a really thick head gasket. You would lower the comp. ratio by doing this and you would also lessen the benifits of a tight quench.

I am by no means an engine expert but this is my logic.

The problem with your example is that the air is blowing into the room with nothing to stop it, we are talking about a contained cylinder under extreme pressure...totally different situations.;)

That groove is not enough to lower the compression much at all.

The groove may be 1-2CC's.
The groove isn't about anything but squishing the mixture toward the plug for a better and faster burn. If ya clean the quench area then there is not any left over mixture to cause detonation.

There is a guy down here cutting 4 grooves across the quench area. He has also done radial grooves,but their car didn't gain any measurable ET/MPH.

You wouldn't be talking about Johnny Pilcher would you? I asked him about doing some nitrous heads for me and he swore up and down the I should remove all the quench area in the chamber(although I'm not sure how). He said this really worked in Nitrous motors.

You wouldn't be talking about Johnny Pilcher would you? I asked him about doing some nitrous heads for me and he swore up and down the I should remove all the quench area in the chamber(although I'm not sure how). He said this really worked in Nitrous motors.

No.
I wouldn't remove the quench either. Ya need to talk to some of the big guns before ya do anything like that. Shannon Jenkins comes to mind.

Just by looking at the burn pattern you can see that there is a more complete burn. I wouldnt really focus on the performance benefits of this modification but more so on efficency and a cleaner running engine. Now my question to further this discussion would be......

Why does this modification allow the engine to idle at a lower rpm more "Happily"

Now my question to further this discussion would be......

Why does this modification allow the engine to idle at a lower rpm more "Happily"

Where did you read this?

Where did you read this?

It's suppose to smooth the idle and tame big cams.

Not really sure how that would effect how a large cam makes the motor idle.....those two should not be related?

Not really sure how that would effect how a large cam makes the motor idle.....those two should not be related?


Me either. Just what I read from some users.

Not really sure how that would effect how a large cam makes the motor idle.....those two should not be related?

That is the higher compression helping to tame large cams. Engine may idle smoother due to the guy detonating before the grooves. I know one article states that until he cut 2 additional grooves per cylinder he got severe detonation

So saying that it calms down the rough idle of a large cam is completely incorrect, it's just a band-aid for a badly designed motor combo.

So if this does improve effiency of combustion, why do head porters not do it, especially if it has no adverse effects on dyno results? I'm porting my heads and IF it could help squeeze an extra 1 or 2 mpg out of my F13 cammed car, it sounds like a good idea.

Pictures look good, and theory is sound, but I would not do it to a customers motor based on information found on the internet from an unknown source. It would require some r&d before actually using it. For the kind of motors I do, it never comes down to the extra 1-2hp or mpg so I don't plan on trying it.

So if this does improve effiency of combustion, why do head porters not do it, especially if it has no adverse effects on dyno results? I'm porting my heads and IF it could help squeeze an extra 1 or 2 mpg out of my F13 cammed car, it sounds like a good idea.

A big reason is ya haven't gone to the porters that do it and it has not been well advertised. It is also not a proven thing.

M1,
There are guys down here that are using it. One guy when he stopped the detonation he found so much low end the car had to be adjusted to get it out of the hole.

Sorry if i was a little vaque but on the last link the guys writes

"The engine will idle smoothly to below 500 rpm, but is limited to 650 rpm by the ECM. I can idle it while driving in 2nd gear below 500 rpm without it complaining too much."

Would this be caused by better low rpm flame propogation?

I have a stand up ski from the early 90's that i ride and tune alot. Manual states to set the idle to 1250 rpm. Mind you it is a 2 cycle but i would love to bring the idle down some and i just cant get the thing to idle right bellow 1100. i was wondering if this might help.

How can a more efficient burn not be accompanied by greater power?

For the kind of motors I do, it never comes down to the extra 1-2hp or mpg so I don't plan on trying it.

I wasnt aiming for MPG but since my buildup is for my DD, if there is an easy way to add a little more effeciency I'd like to. Since I'm upping my compression ratio a bit from decking the heads, I think I'll try it and let you all know in a month what the dyno results are.

Concurrent discussion that gets into this deeply on another site. Some of you may be following that one as well but for those that have not here goes.
http://www.speedtalk.com/forum/viewtopic.php?t=3652

The first rule of speedtalk is you do not talk about speedtalk. :thumb:

The first rule of speedtalk is you do not talk about speedtalk. :thumb:


That is Soooooo CORRECT.:thumb:

That is Soooooo CORRECT.:thumb:

LOL - I figure if guys can follow what is being said over there and understand it, then there's no harm.

LOL - I figure if guys can follow what is being said over there and understand it, then there's no harm.

Somebody might catch a snag and run with it.:D

Not really sure how that would effect how a large cam makes the motor idle.....those two should not be related?


Well larger cams are usually happier running rich at low rpm. When you lean them out you get that stupid off idle hesitation.

Maybe this modification burns more efficiently at idle and takes away some of the problems?

yea, i was thinking about that too, Gripenfelter

and also cold starting with a chokeless carb, gotta pump her to get her to fire, then if ya shut down without it warming up sometimes cheap plugs foul,

maybe this efficiency thing could help make larger more aggressive cams more streetable, maybe less warmup time, maybe one less pump on the accelerator to get her fired up, maybe even be able to let my foot off the pedal earlier while i warm it up?

on the other hand, i'd be worried that the thing wouldnt run at low idle with my cam anymore lol, it's interesting, gotta get some surface flow and hotspot data on that chamber surface.

but what i really wanted to post about is in the first link of the original post i believe, the guy grooved the walls of the intake port, it looks like almost THE WHOLE THING!! now i understand scuffing the port, but this looks like it would turn the entire flow of the port into the equivalent of 'whitewater rafting', i doubt it would flow at all at high rpm

This is a piece of one of the email's I sent the guy who's done the most R&D on it Randy.

Why it helps tame big cams...

....Ignition timing doesn’t vary much with RPM partly because the velocity of the flame front is roughly proportional to RPM. One of the main reasons of this is the increase in chamber turbulence. Which is caused by “high piston speed combined w/ squish reagons” right? Ignition timing is also influence by the density of the air/fuel mix. That’s why at low RPM combustion velocity is quite slow, b/c the low density & high manifold pressure.  And that explains why the grooves help the car idle better b/c it speeds up the flame, at low RPM...
-b

Hi All,
I recognized a few of the user names so I signed up. I have been cutting grooves in cylinder heads for some time now; I can answer some of these questions if you’re interested.

Idle quality? 13:1 compression 383 with 280+ degrees duration at 0.050”; idles at 600 RPM, lower if you desire, no bull.

Anyone going to the division 4 bracket finals in Dallas this weekend, ask the 2006 NoProblremRaceway foot brake champ in the 65 Vette, he'll be happy to tell you all about it. The team is bringing at least a half dozen or more grooved bracket cars.

Here's a picture of one of my current projects, 062 vortec heads...


http://members.cox.net/dnjunk/vortec%20r111.jpg

A-B

What's the difference between cutting the grooves in the head verses cutting them in the piston?

AND - What do you use to cut those grooves?

Denny

Denny,
I have grooved dozens of engines, I modified the cylinder heads similar to what was shown. Have you ever been involved with something like this?

I cut the initial grooves parallel with the deck surface with a 1/6” ball end mill. The groove is then widened and deepened at the chamber with a file. Here’s a picture that shows the end results at the chamber.

http://members.cox.net/dnjunk/vortec%20333.jpg

A-B

No!

But I read all the material that has been posted and went to the other sites. I also looked at the EMC engines and found one winner that had the pistons groved. I understand the principles there, now all I have to do is convince one of my customers to try it. But my truck has over 200K miles on it and probably could use a valve job - could I find a better way to test it out?

I saw some with 3 grooves on both sides in sort of a triangle shape - does it make any difference?

Could I use a ZIZ Wheel to cut the grooves?

Denny

…all I have to do is convince one of my customers to try it
Find someone that wants to extend engine design limitations like detonation. A good candidate is the guy that is convinced that he can run his compression a little higher than you recommend. With one groove in each chamber, take what you consider the highest you would safely go with the static compression ratio for the combination and fuel in use and build the engine 0.5 higher.


…my truck has over 200K miles on it and probably could use a valve job - could I find a better way to test it out?
Testing on an engine with over 200K miles on the rings is not ideal. If you decide to do it tell me more about the engine, what’s the squish to bore ratio?


…I saw some with 3 grooves on both sides in sort of a triangle shape - does it make any difference?
I don’t see any advantage for this type of groove layout, I haven’t tried it. I know someone that did this to a high HP LT1, he’s pleased.



…could I use a ZIZ Wheel to cut the grooves?


With skill this is the quickest way to cut the grooves. Be careful, one slip could ruin the gasket surface.

Cheers,
AB

One question, why don't you make the grooves a little shorter so they don't go into the deck and sealing surface? I like trying new things and I like to get away with compression&n20 on pumpgas so I may have to try this on my new heads. later

The groves DO NOT go into/through the gasket sealing circle.

If it works, why haven't I seen it on aftermarket heads?

...possibly because it works best with flat top pistons. The head manufacturor would not know what pistons are going to be used. That's my story and I'm sticking to it. :)

...possibly because it works best with flat top pistons. The head manufacturer would not know what pistons are going to be used. That's my story and I'm sticking to it. :)


Actually it works best with high compression domed pistons especially when the piston interferes with flame travel. Directing squish flow into the roof of the chamber has a very positive impact on combustion.

Flat top pistons works great also. With a dish piston the squish to bore ratio is very low, the grooves work but the effect is less pronounced.

As for why the cylinder head manufacturers don't use this idea, I suppose it's because the idea has not been widely accepted.

1racerdude is absolutely correct, if you cut a slot through the gasket surface the gasket wont seal at all, I stay 0.080" to 0.125" away from the sealing area.

i can remember a time whem multi layer head gaskets and plastic intakes were stupid. now they are the norm. it sounds like a lot of good theory and sounds like it may work. just need to provide good solid proof. as for the mpg and efficiency increase. i think nascar is one sport that would really care. i drive my car and if i can get better fuel mileage and more power that is a double bonus

Does anyone know of someone running an LT1 with grooved heads and what the results were? If the grooves helped in at least one of the three aspects they are supposed to help: reducing detonation, added hp/tq/, added mpg, that would be worth doing in my book as long as nothing else was compromised.

Does anyone know of someone running an LT1 with grooved heads and what the results were? ....

I have cut grooves into three sets of LT1 heads. None of the engines belong to me. The one I'm most familiar with is a 383 LT1 in a 65 Vette (ran 9.98 yesterday). It's a bracket car that belongs to a good friend; we race together every week end.

The primary reasons he runs the grooves are because with complete combustion the oil runs cleaner, fuel consumption is down about 20% and the car idles cold like never before with something like 270 degrees duration @ 0.050"

He does not know if the grooves helped HP/torque, he has made too many changes to determine performance benefits of the grooves alone.

He does not know if the grooves helped with detonation, he runs racing fuel.

Sounds like a good enough reason right there, if it idles better (no loading up) and fuel consumption is better (more efficient burn). How much would this typically cost to have a set of heads modified this way?

There does not appear to be a down side to it. The way I look at it is there is a gain or there is no benefit. Doesn't sound like it could hurt to try it. :)

I liken this to the aero wings I had cut on my crankshaft counterweights. I'm only expecting to turn no more than 6300rpm. Some people said it was a waste of time for my motor. Others said a small benefit would be gained. I did it anyways incase there was an easy 3-5hp to be had. :D If I had known of the grooves earlier I would have had it done. Could only help or not hurt anything.

... How much would this typically cost to have a set of heads modified this way?..

Get in touch with Mike, he can help.

http://www.powrehaus.com/

Mike Holler
email: mpgmike (AT) powrehaus (dot) com

(717) 438-3767

3424 Liberty Valley Rd.
Ickesburg, PA 17037

Sounds like a good enough reason right there, if it idles better (no loading up) and fuel consumption is better (more efficient burn). How much would this typically cost to have a set of heads modified this way?

Free just do it yourself!
-brandon

What about carbon build up in the groove? Would that affect the amout of air blowing into the combustion chamber?

I've read this thread regarding racing but what about daily drivers?