SOHC? Twin-spark? Why?
MBWorld Fanatic!
Joined: Mar 2003
Posts: 3,445
Likes: 3
From: WOT somewhere in the Bay Area
1951 Caterpiller D6
Because of the SOHC vs. DOHC? Both styles have proven to be VERY reliable. One might argue that the DOHC versions are less reliable because they have more moving parts but that is ludicrous.
MBWorld Fanatic!
Joined: Jul 2005
Posts: 1,224
Likes: 6
From: S.E. FLA.
05 ML-500 , 03 CLK5.5 AMG has left the Garage
3 valves & twin Spark plugs
All are Great explanations , But RJC is on the right track . Twin spark plugs use by MB , is to get them through , the 50,000 mile US EPA emission standards. Some automobile engine manufactures use a Single plug with Twin Side ground straps ,set 180 degrees a part , For the same reason . Remember a 5.5 AMG has 11to1 C/R and the combustion chamber gets pretty violent , if it detonates. the knock sensor feels the knock , then reduces the spark advance. You can harm a spark plug tip in as little as 4 seconds
On a engine ,in good shape & is tuned up properly. We saw no real benificial increase in Hp or decrease in Emissions , but as spark plugs start to Erode from the hi intense voltage , the gap widens over a length time . The hp goes down & Emission rise.
As you may have notice there are many Spark plug manufactures that are using more specialized metals to help increase the life of the spark plug , but make no efforts in indication a increase in hp . Read their fine print . Look at what happen to SPLIT FIRE spark plugs, where did they go ?? They were asked too prove their claims . They couldn't and were not able to back them up with documentation ,So The government told them to cease & desist.
On 3 valve heads, I did a small small 3 paragraph answer to a cylinder head Technology question at another form. If you wish to view it . it's at AMGPOWER.com under forms. General discussion. #32 down the page. PTE author/ reply. A guy by the name of James Feuling did a large reseach program for Ford . Other companies like Recardo technologies in Michigan , have done reseach for Mercury Marine, Imore , Chrysler. and Evinrude. They seem to like 3 valve heads.
Hope this also helps. Champion spark plugs help me through a lots of growing pains. I found that extended / projected tips actully ran cooler , because they where inline of the cold incoming air fuel mixture ( if there was piston clearance). I could run a heat range hotter plug than the cross referance chart gave. And had lower emissions from better spark propagation , being deeper into the combustion chamber. I find them easy to work with and they speak my language
On a engine ,in good shape & is tuned up properly. We saw no real benificial increase in Hp or decrease in Emissions , but as spark plugs start to Erode from the hi intense voltage , the gap widens over a length time . The hp goes down & Emission rise.
As you may have notice there are many Spark plug manufactures that are using more specialized metals to help increase the life of the spark plug , but make no efforts in indication a increase in hp . Read their fine print . Look at what happen to SPLIT FIRE spark plugs, where did they go ?? They were asked too prove their claims . They couldn't and were not able to back them up with documentation ,So The government told them to cease & desist.
On 3 valve heads, I did a small small 3 paragraph answer to a cylinder head Technology question at another form. If you wish to view it . it's at AMGPOWER.com under forms. General discussion. #32 down the page. PTE author/ reply. A guy by the name of James Feuling did a large reseach program for Ford . Other companies like Recardo technologies in Michigan , have done reseach for Mercury Marine, Imore , Chrysler. and Evinrude. They seem to like 3 valve heads.
Hope this also helps. Champion spark plugs help me through a lots of growing pains. I found that extended / projected tips actully ran cooler , because they where inline of the cold incoming air fuel mixture ( if there was piston clearance). I could run a heat range hotter plug than the cross referance chart gave. And had lower emissions from better spark propagation , being deeper into the combustion chamber. I find them easy to work with and they speak my language
