Adding diesel to gas instead of marvel mo

[RogersJetboat454]

Re: Adding diesel to gas instead of marvel mo

please explain to me why many better marinas promote that there is "Valvetect" added to the gas that they sell.Charlie

I'll explain this with a question; Why are so many useless items, products, services, etc marketed? Answer; because there are suckers who are convinced by skilled salesmen and marketing people that said product, item, or service will some how benefit them, and most importantly they are willing to fork over their cash for it.

If Volvo Penta, Mercruiser, GM Marine, Evinrude, Mercury, Yamaha, Suzuki, Honda, Tohatsu/Nissan thought the fuel of today was really that terrible for engines, I'm quite sure they would be more than happy to come up with some additive sold at a premium price.

Feel free to add what ever you like to your tank. I will tell you quite honestly the 35 year old Volvo in my signature has never had a full rebuild, other than the head milled after an overheat, and a valve job (valve guides are still original) at the same time. That engine has never had anything added to the gas other than Stabil at the end of the year. It still runs great, just like countless other 20,30,40 year old engines that never had stuff added to the gas.

 

[HT32BSX115]

Re: Adding diesel to gas instead of marvel mo

I'll explain this with a question; Why are so many useless items, products, services, etc marketed? Answer; because there are suckers who are convinced by skilled salesmen and marketing people that said product, item, or service will some how benefit them, and most importantly they are willing to fork over their cash for it.

I couldn't have said it any better!


A great way to describe ECON 101. Buy products at wholesale and sell them at retail after telling your customers that they "must" have them!! PT Barnum said essentially the same thing I hear........"There's a sucker born every minute"

Someone else also said Caveat Emptor

 

[QC]

Re: Adding diesel to gas instead of marvel mo

If you need upper cyl and valve stem lube then why don't you need it in natural gas and propane fueled engines?

It is all right there, you tried it twice, and you never got an answer . . . :facepalm:

I work with 4000+ bhp Natural Gas engines. There is no addtional upper cylinder lube required. No additives, no nuttin'. GM and Ford V8s are very popular NatGas and propane conversions, even factory approved, no change to the lube system. No additives. Even crappy NatGas and Propane conversions work without any change to the lube sytem or any additives. Heck I know where there's a propane marine engine used in a water ski school. Even marine, no additives, nuttin' . . .

What I hate the most is OEM Dealers with fuel system flushing stuff. I ask them to show me where that is recommended or required in the manual. Ends that discussion . . .

 

[rallyart]

Re: Adding diesel to gas instead of marvel mo

HT32BSX115 is right, in everything he has said in this thread. I suspect most people can tell that and hope the others learn.

 

[PiratePast40]

Re: Adding diesel to gas instead of marvel mo

I've heard many many times that lead in the fuel also acted as a lubricant for the valves. If that is untrue, then why did we keep hearing it in the 70's? You also hear that modern engines have hardened valves and valve seats that the earlier engines did not have. I'm not trying to be a smart ***** here, just wondering if the hardened valve seats are unnecessary and that the myth of lead and valve seat lubrication is false. I have an engine that was built in the early 70's and had a heck of a time finding a replacement head due to the heads I was finding had excessive valve seat wear (among other problems).

 

[sdowney717]

Re: Adding diesel to gas instead of marvel mo

today the motors use bronze valve guides and stellite or stainless valves.
the bronze guides are self lubricating.
the seals put on the valve stems keep oil out.
the valve stems run without much if any oil.
perhaps the fuel helps lubricate and cool the intake a little, but the exhaust can get red hot faces.
that is why you need a good valve face to seat seal to help dissipate the heat into the head from the valves.
In the past, lead was needed to lube valves then they switched to bronze guides and positive stem seals and more durable valve and seat metals.

another problem is flat tappet camshaft lobes wearing out due to zddp levels being dropped. so you need to add that back to the oil or use oil that has decent levels of zddp on flat tappet engines.

 

[crazy charlie]

Re: Adding diesel to gas instead of marvel mo

I've heard many many times that lead in the fuel also acted as a lubricant for the valves..

Thats what I was referring to when I stated that gas used to have lubricating qualities.Charlie

 

[RogersJetboat454]

Re: Adding diesel to gas instead of marvel mo

Thats what I was referring to when I stated that gas used to have lubricating qualities.Charlie

Almost every engine built after '72-'73 has hardened exhaust seats. Unless you are running something older than that, your engine has hardened exhaust seats. If you are running something older than that, MMO, Diesel fuel, sea foam, etc isn't going to be a source of significant lubrication to the exhaust valves post combustion. Also, if you are running a Pre-unleaded era engine, chances are; A. by now the heads have probably been rebuilt with hardened exhaust seats installed, or B. If the heads haven't been rebuilt, they probably need to be.

 

[coolguy147]

Re: Adding diesel to gas instead of marvel mo

what about seafoam

that works

 

[HT32BSX115]

Re: Adding diesel to gas instead of marvel mo

Almost every engine built after '72-'73 has hardened exhaust seats.

yeah. My previous boat, a 66 Mark Twain with a 150 Mercruiser, ran unleaded gasoline for most of it's 39 year life until I sold it in 2005.

It got unleaded gas even before it was widely available. neither me or my dad (who bought it new) ever used any secret sauce fuel additives and we never had the head off.

I've heard many many times that lead in the fuel also acted as a lubricant for the valves..

Specifically, it was the scavenged lead IN THE EXHAUST that was thought by some to "lubricate" the valve face-SEAT contact (only).................I've heard that for many years also..........but I never believed it...........(for stock engines with stock valve springs)

If that were true, all those cars that ran on propane would have had serious valve problems from the get-go.....And all those engines in the oil fields, (Clark, Ingersol Rand etc) that run on natural gas that don't get even get shut down for an oil change didn't have valve seat problems either!!...........and some of them ran for 10 or more years without even being shutdown at all!


Back in the 50's, 60's and 70's in the oil fields, A LOT of "people" ran what was called "drip", "Casing-head" or "condensate" ........ (liquid gas) that was basically condensed natural gasoline from a "wet" natural gas line.......It was mostly pentane, iso-pentane, octane, and nonane and a little iso and normal butane that in those days was simply dumped on the ground (well.....most of it never made it to the ground ) .........some of it had such a high vapor pressure that during summer it would literally boil in an open container!! (can you say vapor-lock?)

It had an extremely LOW "octane" (number) too.......... ["Octane" is not the same as "Octane-number"]


To run this stuff, one had to retard the timing a fair amount....... and/or mix it with "store-bought" gas...or the engine would "ping" like a son-of-a-gun!!...................................





so.........I just don't always believe what I "hear" about "lead replacement" products.......

What we usually hear is almost ALWAYS anecdotal or testimonial "evidence".......The internet is FULL OF IT!

Most (or ALL) "Snake-Oils" are sold based on anecdotal evidence because nearly ALL of it DOES NOT stand up to standard scrutiny. This is why NONE of the engine or petroleum manufacturers will recommend using ANY of it. .........except maybe a fuel stabilizer like STABIL or Mercury, Yamaha, Evirude's or Seafoam, etc....BRANDED fuel stabilizer.....which is probably repackaged/rebranded STA-BIL anyway.....!!






ymmv.......



Bottom line? Just run good fresh gasoline (10% ethanol or less) . Change your oil with good oil and do it at the end of the season when you "Winterize"

You can even use the oil that I use in my signature! (but I'm not telling what I use!!)

It's classified!


Cheers,


Rick

 

[sdowney717]

Re: Adding diesel to gas instead of marvel mo

what used to be understood as common knowledge has now turned into myth, legend, and or been forgotten.

 

[RogersJetboat454]

Re: Adding diesel to gas instead of marvel mo

what used to be understood as common knowledge has now turned into myth, legend, and or been forgotten.

At one time it was common knowledge that the earth was flat, and the center of the universe.

I more or less agree with HT on this. Tetra-ethyl lead most likely didn't make an appreciable difference to the longevity of valves. Were talking about a time when it was a big deal for an engine to reach the 100K mile mark. Think about how common place it was for your corner garage to have a valve machine with worked lined up for it. That was in a time when cars ran the leaded gas that supposedly protected the valves.

Look at thing's today. Better metallurgy, and hardened seats have made all the difference in the world (no-thanks to anything added to the fuel). Hundred's of thousands, if not millions of engines are produced yearly that will easily turn that 100K mile mark, then keep going for 200-300K + miles before needing attention. 99.9% of the owners manuals for these engines makes absolutely no mention of adding anything to the fuel short of a fuel stabilizer for long term storage.

But... open your wallet, pull out 5 bucks, and buy the can of (fill in the blank) to add to the tank if it makes you happy. I'll be using my extra 5 bucks for something I need.

I'm done with this one......

 

[sdowney717]

Re: Adding diesel to gas instead of marvel mo

ever heard of valve recession?
this is where soft cast iron seats on old engines made for leaded gas recede into the heads, leaded gas helped prevent this problem.
But it still happened anyway, even using leaded gas, just not as much as unleaded gas.

http://forum.woodenboat.com/archive/index.php/t-2783.html?

today, the metals design is better, valves dont wear the same, but some people will always be disagreeing.

 

[HT32BSX115]

Re: Adding diesel to gas instead of marvel mo

ever heard of valve recession?
this is where soft cast iron seats on old engines made for leaded gas recede into the heads, leaded gas helped prevent this problem.
But it still happened anyway, even using leaded gas, just not as much as unleaded gas.

http://forum.woodenboat.com/archive/index.php/t-2783.html?

today, the metals design is better, valves dont wear the same, but some people will always be disagreeing.

It was also a problem in aircraft engines. The fix was to install stellite valves and seats.

It's been well known that soft seats would wear faster. It's also true that tetra-ethyl lead in the fuel reduced the wear a little.

You're absolutely right about today?s valves and seats.......they are harder and far less susceptible to that type of wear. Most of the machine shops suggest using hard valves and seats in engines that are going to use propane or CNG fuel.....

In a boat engine however, they almost always fail for other reasons.........like neglect, NO oil changes, freeze or water damage(submersion) etc.

Usually, by the time a marine engine needs a valve job, the cylinders are full of water or the boat is sitting in a junk yard getting ready for the "saw"!

 

[Cap’n Ray]

Re: Adding diesel to gas instead of marvel mo

Just to add my .02... Our boat (77 Carver) is on it's original engines, starts up easily and runs great. I've had the honor of speaking with two of her three owners and they never put anything but stabil in it. The older owner also said he didn't believe the original owner added anything either. The meters show ~700hrs each. I'm gonna stick with no additives- more $$$ for fuel!

 

[BonairII]

Re: Adding diesel to gas instead of marvel mo

Raw egg radiator repair was proven by mythbusters.

I can stop a headache by taking an aspirin...doesn't mean the cause of my headache has been fixed. People use gas additives, fuel injector cleaners, etc etc because advertising people feed on your fears....and people are always looking for the "cheap fix".
I've been guilty of it myself. I've used fuel injector cleaners and have tried Lucas transmission fix etc etc. None of those things actually FIX anything, they just postpone proper repairs, and sometimes make the problem worse.
Always makes me laugh when I hear people heeding advice of "old timers" or "friend" that recommended this or that. I was in sales for a decade...and I'd always hear things like, "My friend says blah blah blah(about a particular product etc)". I would then always ask them.."That's great, How long has your friend been in the (whatever product we were discussing) business? 99% of the time they just went silent. priceless!

 

[scipper77]

Re: Adding diesel to gas instead of marvel mo

Man I'm glad my boat uses a new fussion reactor for power.

Submarine or carrier? You actually get to shoot jet skis that don't yield the right of way don't you?

 

[RogersJetboat454]

Re: Adding diesel to gas instead of marvel mo

I can stop a headache by taking an aspirin...doesn't mean the cause of my headache has been fixed.

No kidding....
The point of the raw egg repair was to TEMPORARILY fix a leaking radiator.

 

[Brewman61]

Re: Adding diesel to gas instead of marvel mo

No kidding....
The point of the raw egg repair was to TEMPORARILY fix a leaking radiator.

Yeah, everyone knows that the egg trick is to get you to a shop. The real permanent fix is to drop a few cups of raw rice into the radiator.

 

[RogersJetboat454]

Re: Adding diesel to gas instead of marvel mo

Yeah, everyone knows that the egg trick is to get you to a shop. The real permanent fix is to drop a few cups of raw rice into the radiator.

Thats right! And when they are adding the rice, make sure you have them check the tension on the pantyhose fan belt too!