Combustion Flame Speed

beth · Post by **beth** » Sun Aug 06, 2006 12:42 am

Great information. Thank you so much Darin.

cboggs · Post by **cboggs** » Sun Aug 06, 2006 1:45 am

Darin,

Great photos, ..

I've got a few questions for you, ..

The vortex you eliminated on the quench area, .. did it help power that
you could measure?

A little off subject, .. it looks like your wet flow just uses a thick plate
for the bore and doesn't have the bore and collection system like
the Mondello system, .. how are you collecting the fluid??

Last, .. how are you getting these photos, .. I tried to get good photos
of my wet flow stuff and my digital camera just makes a blurrrrrr, ..

Curtis

automotive breath · Post by **automotive breath** » Sun Aug 06, 2006 4:56 am

beth wrote:Air flow is important and usually equated with power but the largest gains left to be discovered in the IC engine will come from combustion speed and efficiency.
beth

Thanks Darin,

This has been great, like Beth said earler; the largest gains left to be discovered in the IC engine will come from combustion speed and efficiency. Looks like you are paving the way.

Unkl Ian · Post by **Unkl Ian** » Sun Aug 06, 2006 12:54 pm

Darin: if you suddenly had an extra .150" to play with,
would you add a quench pad beside the exhaust valve ?
Or increase the size of the quench pad in the intake side ?

Rod Rocks · Post by **Rod Rocks** » Sun Aug 06, 2006 1:15 pm

The wet flow pictures are fantastic and that spark plug location is ideal.

I' m sure some trial and error went into the small intake side squish area. What changes have been tried that didn't work out?

beth · Post by **beth** » Sun Aug 06, 2006 1:49 pm

automotive breath,

This is a great indication that your groove(s) have an effect (good or bad) at times other than TDC and overlap.

beth

Darin Morgan · Post by **Darin Morgan** » Sun Aug 06, 2006 2:08 pm

I don't use a collection system. I get wet. Very wet! The florescent dye is not toxic so I don't worry about it. In order to get pictures you must have a camera with high zoom and some digitals do not like ultra violet light for some reason. I have tried about five different one and only one works. My old 2 Mega Pixel Olympus. Its a battery eating machine but it has a big lens, a good zoom factor (not digital zoom). that way I can set it in the corner of the room and zoom in on the chamber so it wont get wet. That camera is now broken and I am currently looking for another that will take that good a shot but have not found one yet. That's why I have no new shots.

Did the elimination of the vortex effect power? Yes but very little. it did however fix a trace detonation problem. Before the fix we would literally blow the parts of the seat rings off in the middle of the chamber when we leaned on the timing a little to heavy. Mike Edwards is famous for this and every time a lease engine came back from him it was bad. we actually had to replace seats. Once we did the chamber mods., that went away. before, if you had two degree to much you would hurt the heads. now, you can have five or six and not hurt anything but the power. That amazed us to say the least. The most power we can see from doing it is about two. like I said, not a lot.

When I saw the grooves people are machining into the chamber I thought about that vortex there on that side of the chamber because it is really big a on a 23° head!

Darin Morgan · Post by **Darin Morgan** » Sun Aug 06, 2006 2:10 pm

Unkl Ian wrote:Darin: if you suddenly had an extra .150" to play with,
would you add a quench pad beside the exhaust valve ?
Or increase the size of the quench pad in the intake side ?

It has a negative effect on the exhaust side. Dont know exactly why or the specific reason but it definetly does hurt power.

automotive breath · Post by **automotive breath** » Sun Aug 06, 2006 2:44 pm

beth wrote:automotive breath,

This is a great indication that your groove(s) have an effect (good or bad) at times other than TDC and overlap.

beth

Beth, I intentionally took a back seat on this one trying to learn as much as I can, this guy is a real pro. I totally agree with what you are saying and I continue to try to understand what’s happening inside of my modified chamber to produce the results that I'm seeing.

Darin brings up a very good point. Most of my work is on a very inefficient combustion chamber design being the 23 degree SBC. To some extent the improvements I see are likely related to how the grooves affect this inefficient chamber.

Enough said, Id rather not distract from this most informative thread.

cboggs · Post by **cboggs** » Sun Aug 06, 2006 3:13 pm

Darin,

I don't want to side track this thread, .. but you don't use a collection system, ..
so you have black light dye flying all over your shop???????

Where my bench is in my shop, .. Llyod who does all the shop's paperwork, ..
would shoot me, ..

Curtis

cboggs · Post by **cboggs** » Sun Aug 06, 2006 3:16 pm

Darin Morgan wrote:
Unkl Ian wrote:Darin: if you suddenly had an extra .150" to play with,
would you add a quench pad beside the exhaust valve ?
Or increase the size of the quench pad in the intake side ?
It has a negative effect on the exhaust side. Dont know exactly why or the specific reason but it definetly does hurt power.

I've flowed a head backwards and played with a string looking at flow
in the chamber entering the exhaust port, .. too much quench makes
a "lip" on one side of the flow path to the ex port that it doesn't like.
Seems like the simple answer but it's the only thing I could find.

Curtis

Darin Morgan · Post by **Darin Morgan** » Sun Aug 06, 2006 3:30 pm

cboggs wrote:
Darin Morgan wrote:
Unkl Ian wrote:Darin: if you suddenly had an extra .150" to play with,
would you add a quench pad beside the exhaust valve ?
Or increase the size of the quench pad in the intake side ?
It has a negative effect on the exhaust side. Dont know exactly why or the specific reason but it definetly does hurt power.
I've flowed a head backwards and played with a string looking at flow
in the chamber entering the exhaust port, .. too much quench makes
a "lip" on one side of the flow path to the ex port that it doesn't like.
Seems like the simple answer but it's the only thing I could find.

Curtis

screwing up the efficient flow of the exhaust port seems to be the most likely culprit doesn't it? Maybe I am reading to much into it. the simplest answer will usually suffice.

dbusch · Post by **dbusch** » Sun Aug 06, 2006 8:37 pm

does the .150"-.160" squish area apply to inline valve (no cant) heads too? Specifically, on small blocks that dont have bores quite as large as big blocks do.

there is one head i know of with a .200" squish area next to the valve and that is the SBF Glidden Victor head. The valve placements are moved a significant amount, necessitating a small exhaust valve to make it work. Is it a good thing to leave this squish area intact, or open it up to the bore for more flow? The regular Victor head has more standard valve placements with no squish area next to the valve, unless it is left there on purpose, which would shroud the valve a significant amount.

Maybe i have looked at the side clearance/squish area the wrong way. Maybe the whole reason for running a bigger bore is to add more squish to the side, and NOT grind it all the way to the bore. But, without cant in the valve angle, i cant see this being as benificial when you consider the losses in flow...

beth · Post by **beth** » Sun Aug 06, 2006 8:59 pm

One thing I haven't seen mentioned is that the squish area is not limited to the flat areas of the head and piston. The squish can continue up the side of the dome if required. Another point is an ill fitting dome can disrupt the expected squish action. The squish can be directed by dome shape and clearance.

Rod Rocks · Post by **Rod Rocks** » Sun Aug 06, 2006 11:34 pm

beth wrote:One thing I haven't seen mentioned is that the squish area is not limited to the flat areas of the head and piston. The squish can continue up the side of the dome if required. Another point is an ill fitting dome can disrupt the expected squish action. The squish can be directed by dome shape and clearance.

I often wondered if Larry Widmer was creating additional squish area with the piston dome.

Darin, Can you post a picture of a pro stock piston? Do you use the dome for squish area?