"Dimpled" combustion chambers?
#531864
11/20/09 06:12 PM
11/20/09 06:12 PM
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BradH
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Anybody who does this stuff for a living think there are benefits to be found from applying dimples to the combustion chamber as shown in this PHR article link ? The builder also did this to certain areas of the piston tops , too.
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Re: "Dimpled" combustion chambers?
[Re: neonic]
#531866
11/20/09 06:59 PM
11/20/09 06:59 PM
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Joined: Nov 2003
Posts: 10,384 Upstate NY
Bigcube
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Here's a little bit of info I heard from a local guy many years ago when he was experimenting with it. Think about a valve like a spray nozzle on a hose. The less you squeeze it, the wider the water spray is. At very low lifts the intake charge will be a wide spray. The fuel can have a tendency to come out of suspension and return to liquid form as it travels past the chamber around the intake. The dimples around the intake valve help to agitate the mixture and return the fuel back to a gaseous state by "stirring" the mixture back up. His findings on the dyno was it didn't make any more power but strangely the motor did not need as much timing to make the same power. This was tested on a BBC and was probably back in the late 80's. I think if there was any real benefit from it you would see it much more.
Jim
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Re: "Dimpled" combustion chambers?
[Re: BradH]
#531867
11/20/09 07:21 PM
11/20/09 07:21 PM
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Joined: Jan 2003
Posts: 6,591 Canton, Ohio
Sport440
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I dimpled my first engine, both the head and the piston back in 1972. So Im the true Pioneer of it My testing of its results wasnt very scientific though. I judged the results by the Sound and Shake of the engine. And boy did it sound mean and had plenty of shake. A success for sure! BUT, I was only 12 years old and the said engine was a 3.5 hp lawn mower engine. The theory then was if I make more room for gas and air to fill then any explosion of that fuel and air would have to be bigger. In reality All I did was lower its Compression. Ok , Sorry for the story, it is true though. On the Dimpling shown, I can only speculate on its possible advantages or disadvantages. One fact I can state is that a dimpled surface will allow air to flow more smoothly over it. On the head where its dimpled it may slightly improve the intake charge flow. The dimples on the Pistons , hey if it keeps the pistons cleaner for improved heat reflection, that could be a good thing. Would any of these two things be enough for any noticeble improvement, I dont know. mike
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Re: "Dimpled" combustion chambers?
[Re: Sport440]
#531868
11/20/09 07:35 PM
11/20/09 07:35 PM
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Bob_Coomer
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Wouldnt then make more since to dimple the intake runner on the intake, and the head intake runner? I mean by the time it reaches the face of the piston and chamber how much more does the mixture gotta go? Interesting read but IMo if it was worth its time and effort it would be conman practice by engine builders, and dimple tools would line the catalogs of Jegs and Summit Racing.
[color:"red"]65 Hemi Belvedere coming soon [/color] [color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]
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Re: "Dimpled" combustion chambers?
[Re: Bob_Coomer]
#531873
11/21/09 12:13 PM
11/21/09 12:13 PM
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rowin4
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Quote:
Wouldnt then make more since to dimple the intake runner on the intake, and the head intake runner? I mean by the time it reaches the face of the piston and chamber how much more does the mixture gotta go? Interesting read but IMo if it was worth its time and effort it would be conman practice by engine builders, and dimple tools would line the catalogs of Jegs and Summit Racing.
Many years ago, at a seminar put on by Jack Roush, he stated you should leave the intake runners rough to break up the gas. Old technology? Why no blast the combustion chamber with course sand.
it's ok to butt heads, just don't do it with a butthead
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Re: "Dimpled" combustion chambers?
[Re: dizuster]
#531875
11/21/09 07:32 PM
11/21/09 07:32 PM
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Joined: Jan 2003
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Sport440
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Quote:
Are you sure they aren't carbon deposite buildup holders to increase detonation?....
Dimples = Carbon Anchors
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Re: "Dimpled" combustion chambers?
[Re: rt66jim]
#531877
11/22/09 12:54 AM
11/22/09 12:54 AM
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cheapstreetdustr
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i had taken a jewlers dremel..and drilled holes in the valve seat just inside the throat .. i pressed in small pieces of stainless wire.. to do the same.... we never got it wet flowed...but i still think it would work..
that and even putting stainless mesh over the intake gasket port opening...to keep things emulsified..? i dont have the fixture to test it thoroughly.. cheapst
365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured [image][/image]
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Re: "Dimpled" combustion chambers?
[Re: BradH]
#531880
09/27/10 07:31 PM
09/27/10 07:31 PM
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vcummins
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Re: "Dimpled" combustion chambers?
[Re: Bob_Coomer]
#531881
09/27/10 07:37 PM
09/27/10 07:37 PM
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70HemiGTX
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Quote:
Wouldnt then make more since to dimple the intake runner on the intake, and the head intake runner? I mean by the time it reaches the face of the piston and chamber how much more does the mixture gotta go? Interesting read but IMo if it was worth its time and effort it would be conman practice by engine builders, and dimple tools would line the catalogs of Jegs and Summit Racing.
My one friend works for a shop that does alot of sprint engines. They used to dimple the intake runners and intake ports of the heads. Don't know if they still do it or not. I'll ask him the next time I see him. Their theory was the turbulance would keep the gasoline in a gaseous suspension instead of it running down the bottom of the ports.
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Re: "Dimpled" combustion chambers?
[Re: vcummins]
#531882
09/27/10 10:11 PM
09/27/10 10:11 PM
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Joined: Jan 2003
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BradH
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Taking time off to work on my car
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Taking time off to work on my car
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Quote:
don't wast your time
V - Is this because you've tried it w/ no success, or because of what you saw while doing wet-flow testing, or ???
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