I had a couple of those VETEC Hondas good cars.
But this SOHC designation applies to Hondas original inline four motorcycles. Started production in 1969 model year, continued to the early eighties.
There is a Satanic Mechanic who is a member of the online club. Hence my question.
No, that is certainly not me.
Single OverHead Camshaft engine.
Ahh, the classic Honda CB-750. It was a seminal design in the history of motorcycles. At that time I was a huge fan of Gary Nixon and Dick Mann. Sadly Dick passed away last year, but he was the man who took the CB-750 and gave it itâs first big win, the 1970 Daytona 200.
Personally I was not enamored by the CB-750 (too good, too sterile), the BSA triple 750 with a collector megaphone still makes my spine tingle thinking of the sound that gave out.
For what itâs worth, hereâs my two cents worth on âClimate ChangeââŚ
Every time I hear somebody getting frantic about âclimate changeâ and how, âWe need to STOP IT,â I just shake my head and roll my eyes. And every time I hear or see the phrase, âSave our planet,â it literally makes me laugh out loud. Hereâs whyâŚ
Until somebody can develop a way to control the rotation of the Earth and its orbit around the sun⌠Until somebody can figure out a way to control the position of our moon and its orbit around our planet⌠Until somebody learns how to precisely manage the paths of the other planets in our Solar System, along with the movement of our Solar System during its timeless journey around our Milky Way Galaxy⌠Until these things are possible, Climate Change cannot and will not be stopped. It will happen no matter what we puny humans do in our feeble attempts to prevent it. The Earth was here billions of years prior to the arrival of humans, and it went through countless climate changes prior to, and even after, our arrival. And the Earth will still be around many millions or billions of years after the departure and/or extinction of humans. And it will be just fine and hunky-dorie without us until the time our sun becomes depleted, super novas, and turns our little blue marble to cosmic ashes. Basically, people who believe we need to âsave the planetâ simply crack me up. 
On the scale of the unimaginable timeline from the Earthâs formation until the âDawn of Manâ, our existence here up to present day is barely the length of a hummingbird heartbeat. And in just that short period, we have advanced in technology just far enough to be a severe danger/threat to ourselves. (In other words, itâs too bad the mental capacity/maturity to RESPONSIBLY USE such technology is so damn far behind the actual technology.) And despite all of what we consider to be our current âadvanced technologyâ, all it would take is one big global natural disaster⌠a massive seismic shift at a key location⌠just one stray âpebbleâ the size of Deleware busting through our atmosphere⌠and all that technology we rely on will vanish in almost an instant. Welcome back to the days of Hunters-Gatherers, ladies and gentlemen.
Now, do we know when/if any of those things might happen? Nope. No way to predict it. One thing is for certain, though⌠Climate Change is going to happen on a planetary scale regardless of what we puny humans do and regardless of what disasters may or may not strike our planet. Meanwhile, is this something that worries me or keeps me pre-occupied?.. 
⌠Nope. Not even remotely. I do my best to try not to waste time and energy worrying about things beyond (waaaaay beyond) my control. Again, just my thoughts on the matter.
When I was a kid in the 50âs and 60âs our family went up to a lake where we had a cottage. I distinctly recall all of the fishing we did, even looking into the water to observe the sunfish. I returned in the 80âs and that same lake was dead, from pollution. This lake was directly downwind of Chicago.
It was predicted, even expected. But the lesson learned is that mankind does influence the environment.
I have read a lot about the carbon imbalance and how it amplifies the greenhouse effect. I also recall with clarity warnings from the scientific community over 20 years ago that if the global warming trend continued, the weather would become more extreme.
When I was a kid, we had more frequent, colder days of winter in Florida. Now, we might get a week or two of winter-like weather dispersed after the holidays.
Didnât Alex whatâs his name just get fined for denying an event that is clearly happening and happened? 'Cos this reads just like his playbook on climate change. Man made climate change is the problem and can be addressed, all the high faluting word press regurgitation ainât going to change that rabbit.
WE are changing the climate and WE can change it, or at least mitigate the worst effects of fossil fuel burning.
Failure to act NOW will see our grandchildren grow up in a very hostile natural world of OUR making (or at least capable of prevention), The science is in, as rock solid as evolution.
Climate deniers ( those that hide under a rock claiming "itâs all natural/ we cant do anything) are as culpable as the âits godâs willersâ when confronted with evidence of peadophilia in the church. Guilty, ignorant and condemning their grandchildren to something they can change NOW.
the SCIENCE is available for your inspection, the conclusions seen inevitable. But by all means spout the unfounded but well financed shite propounded by the fossil fuel companies ( who are busily divesting themselves of their interests as we speak) and their well paid media minions and bought and paid for politicians.
âŚ(chuckle)⌠Whoops. Guess I should have expanded a bit more. My bad. It was late and near my bedtime when I wrote that. Please allow me to elaborate a bit more now that Iâve had my morning cup of coffeeâŚ
If it helps to relieve a few concerns, I do not deny in any way that our exponentially increasing human population (and all that goes with it) most certainly has a major impact on our environment and overall world climate. How could it possibly NOT have a negative effect? And I have no doubt in my mind if we continue at our current rate of population growth and resourse consumption and forest annihilation and overall environmental pollution, that âelastic bandâ of sustainability weâve been slowly stretching to its limits will soon snap with devastating results. I do not deny that at all. And if/when that happens, the Human Race is in for one helluva nasty ride. Maybe it could recover, maybe not. Who knows? At the very least, though, the overall setback of modern civilization would be unbelievably drastic. (To say the least.)
Obviously, I hope that never happens. I want my grandson to be able to grow up and live his life without that problem. Therefore, I also hope our scientists will be able to find ways to divert such devastating events. (And there IS some hope there.) Unfortunately, we still have our narcissistic power-hungry âworld leadersâ and the greedy-ass multi-billion dollar corporations and industries with which to contend. THEY are the ones who currently control what really happens in regards to implementing any helpful measures scientists might develop. Meaning, in my opinion, those of us billions of âantsâ at my level are just along for the ride.
Now, all that being said, my original post still stands. Sure, we (Mankind) might finally come to our senses and eventually find a way to prevent our immediate demise before itâs too late. (Again, I really hope so.) But that would only be a temporary reprieve. Because regardless of what we do to âfixâ our climate now, it WILL eventually change drastically beyond our control unless we advance enough to be able to manipulate the course of the planets and the angle of the tilt of the Earthâs axis and the shifting of the magnetic poles. So, like I said, I donât waste my time worrying about such things.
Perhaps itâs because I also am a product from the 60s - grew up in the 70 & 80 ⌠and so forth.
I lean optimistic towards our future and the challenges. I remember âDonât be a litterbug!â (Because folks just tossed trash out the window) and âOnly you can prevent forest fires!â (Because we use to have a habit of not putting out fires when leaving campsites). I remember being tossed in the back of trucks or station wagons (no seatbelts) with other kids while the driver had a beer or two while driving.
I remember pollution and acid rain and horrible deforestation WITHOUT replanting. And so forthâŚ
We do have the technology, materials, and knowledge to reduce pollution and our âfootprintâ - BUT the âwillâ? That comes from Corporations and government.
Products that actually last (not built in obsolescence); using hemp; better public and cross country transit ⌠itâs there for us.
Perhaps when the greed starts to kill off enough folks, the remaining ones 
Not only this but doing away with motor vehicles as an option for personal transportation altogether, IMHO.
I have yet to think of any possible way how, if one doesnât like automobiles for what they are, one is not then bound to dislike them for what they do.
BINGO! There you have it in a nutshell. Matter of fact, I speculate we have had that technology for many years, with even better advancements having been developed within recent years. Like you said, though, greedy and power-hungry little minds that run the Corporations and our governments are the ones who control that technology and how/when it is used.
As a kid back in the 70âs and 80âs, I had a friend whose dad was something of a tinkering âengineerâ. In his own garage, he built a gas carburetor one time that would allow a car to get 50-60 mpg. But we are made to believe that modern automotive producers are incapable of such improvements to engines? I have a small 2007, 5-speed, four cylinder pickup truck, and I MIGHT get 21 mpg on a good week. Pathetic. But Iâm sure the filthy rich greedy bastard oil companies have NOTHING to do with the suppression of fuel-saving improvements. 
And that is just ONE tiny little example of why I donât sweat the stuff like that I cannot control.
And I like that you mentioned how everything is disposable now. NOTHING is made to last anymore. Cheaper to throw it away and get a new one rather than repair it. Done by purpose design⌠for profits. Meanwhile, our landfills become more and more packed with plastics and other materials that will likely still not be decomposed even by the time our sun goes super nova⌠(chuckle)âŚ
Sure, I do try to have hope. We humans have definitely advanced our technology to a point where it can have a positive impact on our current global situation. No doubt. And more advances are being made almost daily. But Iâm also a pessimistic and cynical olâ bastard who sees the reality of the fuckers in charge of that technology. In that particular area, we are currently shit out of luck. Just sayinââŚ
Good gracious. Talk about the mother of all missed opportunities.
Especially in the pre-fuel injection/TB 70s, starting an aftermarket company making a standardized version of that piece alone (or even hiring a tech transaction firm for protection to sell the design to a manufacturer) would have likely made the dad into a multimillionaire.
So it goes.
Do you honestly think he was the only person ever to be able to do that? And that was long before the computer technology we now have. Yet we are STILL driving vehicles that average only maybe 25-30 mpg, with those on the upper end of that (29-32 mpg) actually BRAGGING about their âsuperior gas mileageâ. Itâs laughable to me. How many billions of dollars in profit would the money-hungry oil companies stand to lose if vehicle gas mileage effeciency were allowed to keep climbing? So letâs say he DID get a patent and submit his idea to a manufacturer. Iâm sure the multi-billion dollar oil company executives and their armies of corporate lawyers would be perfectly okay with allowing that carburetor to be put into full production⌠RiiiiiiiightâŚ
Wow, now this is what I was hoping for in this discussion.
Itâs amazing some of the crazy technology that was suppressed or just abandoned because it was too far ahead of itâs time or costly.
Honda, which I am very fond of as a car manufacturer, still miss my old 1992 Honda Prelude SI Vtec POS, had some very cool ideas for better mpg. Honda actually had a motor called the CVCC which had a multiple combustion chamber design.
So basically how an engine works is a spark ignites a chamber of fuel mixed with air. Due to spark plug limitations you could only ignite so much fuel and air before you end up with left over fuel and air igniting in your exhaust. So Honda made a mini combustion chamber on top of the main cylinder chamber and separated by a mesh screen. This mini chamber could be packed with a higher fuel ratio which was obviously condensed closer to a spark plug. Once ignited it would rush through the small chamber into the main combustion chamber through the mesh. Allowing for a lower fuel to air ratio in the main chamber because the mini chambers ignited fuel was basically a giant spark plug for the main chamber. Honda showed test results nearing 40 mpg back around 1978.
Obviously 1970s machining, tooling, and material quality couldnât make this design practical. Often times the mesh between chambers clogged or blew out and made this design inferior and almost ruined Honda in America.
Honda ended up ripping off BMW at the time who was toying with cam phasing around 1980. BMW used one cam profile but changed its timing at certain RPM ranges. Where as Honda had two cam profiles and used hydraulic lifter engagement to switch between the two. I actually built a bunch of Honda SOHC D series engines found in 1990s Civics, Crxs, and Del Sols.
I got fascinated with combustion chamber design for a while. Studied quench area, chamber design, and piston surface design. Started building a 14:1 naturally aspirated D15, with flat top pistons. Was aiming for 40 mpg build by leaning out fuel in the 35-45 mph and 60-75 mph range using crome. Using only stock parts from different D series model engines. I milled the cylinder head like .15â or something ridiculous I canât remember. Had to make a custom idler pulley because I took so much of the cylinder head.
Then lost my apartment, ended up switching jobs to night shift to make more money. Ended up selling everything and never putting it all together.
But I still have a sweet 24k gold plated valve cover for my old Honda Prelude.
Is there any conceivable way that oil and car manufacturing companies havenât done this time and again, yet the developers/ owners of the technology havenât still often managed to make out very well?
The case of the Ovonic companyâs large stake sale of NiMH battery technology to GM for likely not a small amount, then GMâs subsequent encumbrance to hinder the commercial development of these batteries for EVs, is a most recent example coming immediately to mind.
This sounds like the start of what Smokey Yunick did with a Fiero engine in the mid 80s to get itâs 4 cylinder up to 50mpg on the highway.
He leaned the hell out of the fuel, used excess engine heat to get the incoming air/fuel mix ultra hot, then a turbocharger to further blend the air and fuel so the very lean ratio wouldnât detonate.
The thing made somewhere around 200 hp, IIRC.
Ah the old Chevrolet iron duke 2.5L. I do remember looking at that build at one point.
I opted to not use a turbo because I was going for such a high compression ratio, I figured any boost would automatically cause detonation from the pressure.
Iâll be honest most of my build concept was actually based on a Honda 1.5L build by a member of the D series.org forum. He lived in Ukraine. He ended up having issues with Russian blended gas that wasnât the correct octane.
I think my calculations on desktop dyno were around 140hp, from an engine that originally made 98hp. Plus an mpg increase of about 20 mpg.
This is really when I started questioning technology and corporations. If I could come this close to a working 140hp engine netting ~40mpg average using existing parts and freeware. All while being in college and using junkyard parts, why werenât these manufacturers making better cars? Because it wasnât profitable enough was my only conclusion.
