nothing new...
When I worked in an old parts store in a small town,where parts didnt always sell that fast,I saw some strange looking carb gaskets in dusty packages on a shelf in the upstairs of the store where old parts from the 40's 50's and 60's were stashed away--they were thick gaskets,and had what looked like stainless steel screen sandwiched into the gaskets,--they claimed on the box it would "de carbonize" the intake and valves,pistons,and increase fuel economy--judging by how many were on the shelf,it appeared they didnt sell very well..
I showed them to a few of my customers that were "gearheads" like myself,one bought one and installed it under the holley carb on his 74 K5 with a 396 we rebuilt in the machine shop for him--he drove it to his summer camp in maine and he claimed it did feel a bit more ballsy climbing the steep hills on the highway,and he used about a 1/4 tank less of fuel than usual--I was tempted to try one on my own truck,but I never did..the "screened"intake gaskets must do pretty much the same thing--
I can see that making the air/fuel mixture a "fog" rather than raw fuel spitting into the intake would improve the combustion process(much like EFI does today)--but I doubt it would make enough difference to tell without a labratory--and I wonder if the motors they were used on had any detonation or pinging problems??--with todays gas,I bet the screens would carbon right up with soot,and choke off the engine!--
I was amazed at the deposits on the valve heads on a car my friend did a head gasket on the other day--looked like a charcoal briquet under each intake valve head--and the car ran great,except for the anti freeze leaking into the cylinders due to the gasket rotting out--he took the valves out and wire brushed and chiseled all the carbon off the valve stems,and re-assembled the head with new valve stem seals,and a new head gasket --the customer said it went so much better he thought he swapped another motor in it--
He claimed it had been sluggish since he bought it 5 years ago!!...I have heard from many mechanics carbon build up is a big problem again--it was a big problem in cars of our fathers and grandfathers,then it wasnt an issue for a long time--now its being a problem on many newer cars again,especially the northstar caddy motors and many others--must be the gas they are selling us now,or the engine design
...
