Singh grooves for VH45DE

[sijoko]

I posted in another thread about Somender Singh and his application of grooves in the combustion chamber to control detonation and increase efficiency. Basically, the grooves help in increasing turbulence and exposing the squish area to the flame front.

I posted this sketch of the VH45 head at http://www.somender-singh.com asking his opinion.



This was my post:

Hi everyone, I've been learning a lot about Mr. Singh's "Grooves" and would like to try it out on a Nissan VH45DE engine. The specs are: 10.2:1 CR, flat top pistons and pentroof chamber. The engine will be turbocharged with approx. 10 psi of boost. I'm hoping that the grooves will give me a slight reduction in Compression Ratio and also help in controlling detonation under boost.

This was the reply from Singh:

All you need to do is, 2 long narrow channels as indicated by you ! Simple straight forward ! Leave the other 4 for the rest ? i have done many 4 Valves heads with just 2 opposing narrow deep channels with mind blowing results ! Because the squish area is small in a pent roof setup ! Having more than one really has no great effects. Don't worrry about the sharp edges starting to glow ? Just sand them down a V bit !

You dont need to shave the head as the mild Turbo will do the job ! The Toyota head with 2 channels is a text book example ! The channels could have been narrower ?

i have no more tricks up my sleeve ! If any one can better them let us all know about it !

Anyone have any thoughts?

[elwesso]

does this help lower the compression as well?

[sijoko]

does this help lower the compression as well?

Yes, it will lower compression slightly. Figure each groove to be worth a 1cc increase. The main benefit is the improved detonation resistance which means that you can run more boost safely.

[mtcookson]

The majority of the people that do the grooves actually mill the heads a tiny bit to increase compression. There are some that go turbo so they don't do that but either way, I wouldn't consider it a way to reduce compression, I would think the difference would be minimal unless you cut quite a few grooves which has shown to be a bad thing to do on some applications.

The resistance to detonation after the mod is said to be much better. Fuel economy is usually improved and many have noticed their oil stays much cleaner as well.

I've been wanting to try these out for quite a while but the VG head didn't appear to be a good choice to try these on. The VH heads look great for trying it out so I'll be doing so for the Z32. I'll probably only do one groove per side to start though. I also am looking for a spare set of heads to actually cut open and check how deep the grooves can go.

[defrag010]

The detonation resistance isn't from the miniscule drop in compression, it's from the improved burn characteristics of a more turbulent chamber that the grooves create.

[DeXteR]

The detonation resistance isn't from the miniscule drop in compression, it's from the improved burn characteristics of a more turbulent chamber that the grooves create.

This must be the case. CR's will be mostly unaffected by the slightly larger combustion chamber volume resulting from this. Therefore it must have something to do with the physics/thermodynamics inside the chamber when the piston is coming to TDC for combustion.

Does anyone have a highly technical theory/explanation for why this works? I'm very interested to see WHY this works.

MODS: someone possibly, drag more infor/pictures from the other thread into this one? I think it will help make a great thread.

I'm going to try these grooves in my ka. I'm currently building it and I'd like to give this a whirl.

[mtcookson]

The grooves allow a more complete burn of the fuel. Some pictures I've seen of grooved engines after some use show a very even burn on the piston tops compared to without.

I believe the theory is that when the piston is coming up, it moves the air through the grooves to cause major turbulence and force the air to the spark plug (they say the spark plugs stay cleaner as well).

From there, when the spark plug ignites the fuel/air mixture the flame front travels outward and goes back through the grooves then down the cylinder wall. If I remember correctly, some say this effect pushes down on the rings which gives a better seal and also blows fuel out of the the ring area that accumulated there allowing that fuel to burn (I believe people think this is a very high possibility due to the oil being much cleaner in the grooved engines).

That's the gist of it that I've been able to understand so far. It definitely seems to be a worthy mod as there is tons of proof to show it does work... the only thing that is really questionable is the best way to do it as far as how many grooves, shape, size, etc. I think they've got down the shape and size pretty well but the number of grooves hasn't been covered too well from what I've seen so far.

[sijoko]

Here are the pics from the other thread.

[mtcookson]

I believe this one is the picture of a Chevy 350 head. They said that groove added 1cc to the combustion chamber.

[Raxephon]

I like this idea, with the exception of the edges left from the "grooving" process.

So, since I'm in the middle of rebuilding my Maxima, I've decided to add the Singh grooves to the VE30DE before I use it on my VH45DE.

I'll be using only a single groove on each side of the head, but I will be removing any and all sharp edges I find/make.

***Post edited for grammar and the addition of a preliminary pic.***
Modified by anlasak at 7:08 PM 1/13/2008

[mtcookson]

Just cut the groove then take a triangle file and slightly angle the edge of the groove, this will take away any potential "sharp edge" issue.

Also, while your VE is apart you should consider putting some VG30DE pistons in there. They're slightly domed, which should give you the 10.5:1 compression ratio the VG has, in your VE.

As far as the grooves... here's some info I've put together so far from what I've been reading. Hopefully this should all be correct:

- Mill to within .050" of headgasket- Width between .060" to .125". Any smaller or larger will cause carbon buildup.- If deck thickness is >.250" initial depth cut is .060" to .080" then bottom of groove is contoured into the combustion chamber cavity, getting deeper as it approaches the chamber- If deck thickness is <.250" initial depth cut is .040 then curved into chamber- Angle roughly 5° toward combustion chamber for higher velocities to headgasket after ignition (less deck thickness = less angle)

I'm still trying to compile more info as I find it but that's what I've been able to figure out so far.

[Mettler]

I'd be a bit skeptical about chopping into nice good condition alloy heads like that until you see some proper dyno with/without comparisons on the VH.

Who's gonna be the first guinea pig then?

Technically I could, as I'm almost at the point of putting my heads back on.... but I'd need some pretty hearty convincing that it's gonna be worth it!

[Raxephon]

I'd be a bit skeptical about chopping into nice good condition alloy heads like that....

Exactly why I'm testing this on my VE30DE & not one of my VH45DE's.

The Maxima has to be back on the road by this coming weekend.

[darinz]

Sounds great but as I'm already running 10psi on stock compression the only advantage would be being able to use lower quality fuel. That would save on hassle and cost so is good but???I also would like to see how it improves detonation. Does it allow more advance?I'd look at it if I pull the heads off but when I do that th pistons will get done anyway so it will be hard to judge the difference.

[Razi]

Yes I heard that the grooves improve detonation resistance so you can have your timing so it sparks closer to TDC.

[mtcookson]

I'd be a bit skeptical about chopping into nice good condition alloy heads like that until you see some proper dyno with/without comparisons on the VH.

Who's gonna be the first guinea pig then?

Technically I could, as I'm almost at the point of putting my heads back on.... but I'd need some pretty hearty convincing that it's gonna be worth it!

Without modifications it wouldn't make much of a difference minus that you should be able to run low octane fuel. You can bump the ignition timing up, which I would definitely do if you aren't modifying the compression ratio or adding boost, to squeeze out some more power. Should get a little better fuel economy as well.

I'm definitely thinking about trying it out on the Z31 I'm working on. The VG is a bit more difficult to do these grooves on due to the location of the squish area and spark plug hole but if I can make it work I'll know for sure if it works as I've already blown a head gasket due to detonation. If it works in that car then I have no doubts at all about the VH as the grooves can be pointed to the spark plug much better.

[DeXteR]

I'll try this on my KA24det. however, the design of the combustion chambers kind of limits the grooving. I'm willing to give this a try as I have yet to see or read or hear of anything getting worse by doing this.

MtCookson, where did you gather those specifications from? I've spent some time trying to find technical information and specifics, but have been unsuccessful. The infor you shared is quite helpful.

[mtcookson]

I read 23 pages of an old thread about the grooves with only one more to go, but their site is down at the moment or something. A lot of the pictures are gone now but a lot of good info is still there when it works. http://www.mpgresearch.com/viewtopic.php?t=160

[defrag010]

you can also find alottttttt of info about the grooves on speedtalk.com forum

[mtcookson]

Read through a tiny bit over there and it looks like one of the guys (automotive breath, does A LOT of grooving) recommends using a 1/16" ball end mill, going 1/16" deep and pointing the groove to the exhaust valve side of the spark plug. Since we have a pentroof head we can't really do that so probably just aiming them at the plug would work find, that's what Somender seems to always recommend.

[sijoko]

Read through a tiny bit over there and it looks like one of the guys (automotive breath, does A LOT of grooving) recommends using a 1/16" ball end mill, going 1/16" deep and pointing the groove to the exhaust valve side of the spark plug. Since we have a pentroof head we can't really do that so probably just aiming them at the plug would work find, that's what Somender seems to always recommend.

I asked Somender Singh about doing 3 grooves per side like on the sketch above. He basically said that it was not needed. Just point the grooves at the spark plug and make sure that the quench is less than 1.5mm at peak revs but not less than .5 mm.

[mtcookson]

Yeah, that's what I would recommend doing for the VH from what I've read so far.

[Mettler]

Does anyone have a link to anything resembling dyno proof of this? I've done a search around and I've found plenty of theoretical discussion and pretty pictures of nicely done grooves... but until there's actual dyno comparisons & wideband 02 sensor logs proving a power increase with a difference in combustion efficiency, then this technique's success is nothing more than anecdotal.

Not trying to be a d!ck but I'm someone who likes the cut & dried facts. Also, with my cylinder heads yet to be assembled and fitted to my new engine build, this would be a good opportunity to have this mod done to them if there was some hard evidence of this being a good idea.

[ultrapulse]

I totally agree. When I went to Singh's website it looked like more of a greenpeace sales speil. I have seen ideas come and go. Like the ford falcons alloy 6 cyl scalloped exhaust valve 'swirl' chamber design of the late 90's(or thereabouts)...the next models after that canned that idea, going back to a hemi-style chamber with no protrusions.If it had absolutely no negative effect I guess it wouldnt hurt then mettler, but talk is cheap.Proof please!I will print this info out and take it to someone I know, just to see what he says.

[ultrapulse]

Sorry to hijack thread (couldnt find pm). Did you buy a q45 mettler a while back? Or just a front cut? I am looking for a cima or q45 diff as I understand they are approx 3.5:1 and r200...would be good for high speed

[Mettler]

Sorry to hijack thread (couldnt find pm). Did you buy a q45 mettler a while back? Or just a front cut? I am looking for a cima or q45 diff as I understand they are approx 3.5:1 and r200...would be good for high speed

Yeah man, we have the Q45 LSD round home at the workshop! Drop me an e-mail (in my profile) for my number & we can suss it out!

Cheers!

[defrag010]

mettler, go to speedtalk.com forums and do a search for "singh" and "grooves" and you will find all of the before and after information you need along with pictures of chambers and piston tops before and after.

[mtcookson]

Here's all of the dyno stuff on Singh's site:

Stock Chevy 6 liter truck enginehttp://www.somender-singh.com/files/ken.pdf

Modified Dodge 360 - before and after with only the grooveshttp://www.revsearch.com/grooves/grooves.html

Chevy truck - 350 c.i. I thinkhttp://www.herningg.com/projects/groovyheads.html

Definitely check out the speedtalk.com site like said above, tons of good info there.