Re: Quietness of 4 vs 2 cycles.
actually you will see crud under the intake valve and even in the intake olenum, the more valve overlap the more crud.
and sound waves play a very large part in exhaust tuning.
me and a buddy years ago were playing with AR baffles welded in the header tubes long before they were commercially availible.
the adjustable rocker kit for the 455 olds sold by compitition cams was my idea, I told comp cams what I was doing and sent them a sample and 2 years later they had a slick kit on the market that requires no machine work and is woth 20+ HP.
my version used a 2 piece fulcrum similar to the chevy and big block chevy studs.
to use the big block chevey studs requied making the original 5/16thx18 threads into 7/16th x 14.
they used a one piece fulcrum and a custom stud.
overhead cams,4 valves per cylinder and variable cam timing were around before WWII, inverted V12's with nitrous oxide were used in certain german bombers in WWII.
modern electronics made all the difference.
kinda like the rochester fuel injection of the late 50's and early sixties, if you could keep it adjusted it worked well.
try to keep it adjusted.
the old hilborn injection made lots of power, its a pain to manually prime all the cylinders with gas before each start.
so not a lot is really new, just a new method of doing it.
back in the 70's honda told chevy how to redesign the heads on the small block and gain 30 HP and 15% or more fuel economy. they were laghed at so honda did it. in the late 80's early 90's the vortec was born. surprise the heads were almost a copy of what honda did.
was a kit some years back to convert the old 350 SBC to a dual overhead cam monster.
their was also a kit to add 4 valves per cylinder to the BBC motors.
back in the day when I was the lead programmer and setup lead man in a CNC machine shop and worked part time in an automotive machine shop in the CleburneTX area we tried all sorts of stupid things.
in 1987 I almost killed a close friend street racing.
that was it for me.
I have not built another racing engine since.
his car was destroyed but he mostly walked away.
had he left the road 10ft or less sooner he would have broadsided a telephne pole at about 100 MPH. I still beat him though
.
we hit the "finish" line and I shut down and he suffered a total brake master cylinder failure.
but I still think about trying it again. I am older now and more patient and wont street race ever again.
my ride was a 1970 W-30 442 that I bought in high school in 79.
