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Somender singhs groove theory tried.

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finding my groove..so to speak.

Dang.
I read this post from begining to end in one sitting.
And now im all inspired...and its 3 in the morning.

sleep fast..drink coffee...find a 531

AutomotiveB, you had mentioned earlier in the thread that you had started experimenting with curved "feeder" grooves. Feel free to share any of that, or still in the works??

Thanks
 
illumin8 said:
AutomotiveB, you had mentioned earlier in the thread that you had started experimenting with curved "feeder" grooves. Feel free to share any of that, or still in the works??
Thanks
Click to expand...

I did some work to set up my crude homemade mill to cut curved grooves. I was able to cut some but have never put any into a engine.

Somehow I got sidetracked cutting multiple parallel grooves similar to the three grooves Morten is planning on his far squish pad. I have several examples running like this with good results. One set on a 580 HP NA engine running on 93 octane fuel. Something similar in my 68' running 12:1 compression, I'm thinking it will run on the pump stuff also. It's important to note both run late IVC and relatively high RPM.

In addition I have numerous examples running two "converging" grooves. It's like a V that doesn't actually come together at the bottom. These are working very nicely.
 
Hmmm...
So there is no doubt in my mind that greater turbulence=greater, or rather more equal and complete burn. And a basic understanding of physics would say that somenders grooves would direct turbulence in the direction of the groove opening.
So looking at the various groove designs, they all should be fairly effective in increasing turbulence over all, and aiding in the formation of the flame kernel(thanks for the edumakation AB). But I wish i had access to more complete combustion chamber data using specific combos of pistion type, compression ratios, etc.
I wouldnt know how to begin to search for this data.
I guess i want to know if there are specific weak points in the combustion chamber of a b21ft
...where detonation usually occurs under higher boost levels, or higher compression.
Can anyone recommend some reading?
 
Opinions please

Some interesting news on the groove front. I have a head (530) that's at the shop now. Ported and polished by another board member and I'm continuing down the path with 38mm ex valves (ex side is unshrouded) and some grooving as well. I told him that I only wanted one groove.

Here's where things get interesting. He didn't know about grooves so I got a lot of pictures together for him and explained the deal for the most part. I tried my best to explain the process and even gave him some print on the topic.

This morning I dropped by the shop to check out how things looked and drop off some shims. I looked at the grooves and noticed something strange. As it turns out, there is no incline or grade if you will along the floor or bottom of the groove. It's my understanding that the groove is deep where it enters the cc and get's more shallow as it works it's way out towards the edge.

That's not what's going on here. :wtf:

He did everything else wonderfully well, but I don't think he was really paying attention to me when I talked about the grooves.

Anyway, here's what I think the options are

1) Junk the head, which I don't want to do!!!
2) Weld, re-shape and leave it be.
3) Weld, re-shape, and cut two grooves off center (imagine something like the 3 groove setups but with the center not there).

I really like the idea of number 3.

Furthermore, before everybody jumps on his case, this was just a lack of understanding. I should've done more to make sure he completely understood what I'm after. Besides, I know he's going to feel like sh1t when I tell him that it's wrong. I'd rather make an ally of him for life by not being pissed and working out a solution. :)
 
Damnit! I say weld and re-groove...

I was actually thinking of going the one or two groove route last night, as a way of keeping some of the compression ratio I'd like for an NA engine, even though 3 or even 4 grooves may be better.

Edit: Didn't see Billy's post until after I posted... But, doesn't Endyn weld high hp heads for his style of chamber left and right?
 
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I personally don't think the incline makes any difference as far as scrapping the head is concerned, the way i see it (i could be wrong) the grooves collect squish wave all down the groove so it should get deeper and wider as it progresses, the grooves should still work being the same depth, who knows they might even work better.

I'm currently running a 530 head with 4 grooves similar to mortens no1 pic except the groove in the small squish pad points at the plug, i'm not impressed and shall be returning to my other 4 groove layout when i get 60 thou skimmed from one of my other 531's.

I'm currently at 10:1 CR with 10psi on a T3, i reckon 60 thou off a 531 should get me to about 10.3:1, hopefully i'll still be ping free and as i'm using euro regular fuel and have a carb and standard dizzy i'll leave it at that, i'm sure others with electronic wizardry could take it further but as this is my only car used daily, and as it's now great to drive off boost and on i'm happy.

Morten your no 4 layout looks a damn sight better than the number 1 layout i tried, i look forward to reading your findings, i wish i'd seen your pics before i wasted a head.
 
Well, i don't know if it's essential, but it definitely makes sense. As you get closer to the combustion chamber there's going to be more mixture squeezing itself into the groove.

With the groove down/up to the top of the chamber and brought out all the way to the side of the cylinder, it seems like it's making a weak spot in the head. It's like telling it to crack there. Maybe. It'll still be open on the combustion chamber side of the groove though allowing the relief of pressure buildup... Blah
 
When i was researching a couple of years ago i noticed 1 of the guys doing grooves, MPG Mike i think it was did his on a milling machine which gave the same result, i don't remember him reporting any problems but AB will probably know more about it, it was AB's work that got me interested so if we are wondering about longevity he's the 1 who'd know lol.
 
Can you use a triangular file to add a slightly angled valley? It might help direct flow... but I'm assuming they cut straight down into the head with a thin blade - like a cutting disk on a Dremel?
 
I think I'm going to go 3 groove and just leave the center as is.

As for the existing grooves, I spent all day yesterday trying to envision flow in the combustion chamber and how these may work. I can still them being of benefit, but not as much as a typical approach with an inclined floor.

But, as others said, this may work better.

Anyway, 3 grooves it is! I'm off to see Phil (the guy doing the work).

Oh, and Les: 10:1 with 10 PSI with a carb and dizzy and mid-grade is amazing!!! :)
 
bdkr, if you find the pics i posted of my layout they turned out really nice. I mean i'm getting away with running 20 psi on pump gas with only pulling 3 degree's of timing. And have run 20 psi without any timing but but get get a throttle tip in ping, nothing after that tho, thus the reason for the 3 degree retarding. On race gas i can get away with 3 degree's of advanced timing and 20 psi and it makes a big difference. and i ran 15ish psi all summer in 100 degree weather with +3 degree's too so they grooves are doing something as before at 15 psi and standard timing i'd get a bit of ping in the heat. . .
 
Icecold, could you post that again in old person non turbo expert speak, it sounds really interesting but i hadn't got a clue lol, or pm me if you don't want to bore everyone else.

BDKR i'm running 12 degrees static timing and 25 degrees max centrifugal timing, i'm thinking that if i get some ping with the new 10.3:1 - 10.5:1 head i can knock the timing down to 20 degrees (preferred) or go to super gas (expensive).

I'm a real turbo newbie as i only did my +t 4 months ago and was running 5psi on a mitsu lpt turbo before fitting an ex volvo diesel T3, the wastegate actuator is a 10psi one so i don't need an mbc.
 
Les said:
When i was researching a couple of years ago i noticed 1 of the guys doing grooves, MPG Mike i think it was did his on a milling machine which gave the same result, i don't remember him reporting any problems but AB will probably know more about it, it was AB's work that got me interested so if we are wondering about longevity he's the 1 who'd know lol.
Click to expand...

I cut the grooves parallel with the deck surface mainly to avoid cutting through. (Most of the stuff I do has a large squish area, cutting on much of an angle would make them rather deep.) Then with a hand held hacksaw blade I deepen the groove as it approaches the chamber. I find widening is best done with a triangular file.
 
automotivebreath said:
I cut the grooves parallel with the deck surface mainly to avoid cutting through. (Most of the stuff I do has a large squish area, cutting on much of an angle would make them rather deep.) Then with a hand held hacksaw blade I deepen the groove as it approaches the chamber. I find widening is best done with a triangular file.
Click to expand...

Well we ultimately decided this morning to do pretty much what you've described. At the entry from the cc, we are adding some incline.

On the first head I did (which still hasn't yet made it onto a car) I used the same hacksaw blade / triangulated file combo.

Cheers
 
Les said:
Morten your no 4 layout looks a damn sight better than the number 1 layout i tried, i look forward to reading your findings, i wish i'd seen your pics before i wasted a head.
Click to expand...

Sorry about you wasting a head, but i can't think faster than i read and get some information.
The results would likely be in the new year, as im preparing the head, for some 38 mm valves, and it's getting cold around here.
 
I bought a 760 turbo for bits and as it was a 90 it had a 530 head on, i had no use for it and just thought i'd try something different, i'd actually took it back off and refitted the 4 groove 531 but i must have dropped a screw into the intake when i was doing some carb work, the screw went into no 4 and made a right mess of the combustion chamber and piston surface, the marks in the piston came out well but the head was shot so the 530 has had to go back on while i get another 531 ready and as you say it's getting cold out.
 
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