Has anyone seen or installed a DynoValve?

[Frank Lee]

When does it go on then?

[t vago]

Some of the air goes through the throttle, and some of the air goes through the PCV system. The Dyno-doodad apparently just allows more airflow than the traditional PCV valve.

Hm...

[user removed]

The source of the air flow won't change the mixture ratio. I can't see the mileage claims from changing the PCV flow. Crankcase blow by, the source of pressure increases as the engine slowly wears and ring leakage increases. mwebb's idea of a balloon over the dipstick tube shows there is no more blow by to bring into the manifold in a properly operating system unless ring leakage is excessive. Maybe they were comparing it to a malfunctioning PCV system where the excess blow by would push oil past the rings.

The difference in pumping losses can not account for the claims of increased mileage. Actually increased EGR flow provides additional combustion chamber pressure without additional fuel, since the oxygen content in the exhaust gases is low. Maybe they rationalise that the unburned fuel in the blowby would be consumed on the extra trip through the cylinder. If you were loosing 20% of your fuel that way, you would have some badly diluted oil and an engine on it's last gasp.

I know in the old MB sedans in the early 80s a vacuum leak in the central locking system would allow the engine to run on the air passing through a 1.5 MM ID vacuum line in one of the doors. In 82 they eliminated the throttle butterfly in all of their diesels and claimed a 7% increase in efficiency from eliminating all manifold vacuum completely.

Unicorn.

regards
Mech

[EdKiefer]

It would act like a idle control valve , bypassing the throttle-body . only thing at low speeds, idle it suppose to work like stock, same vacuum .
On some of the vehicles the vacuum goes down lower at 2500 rpm so the valve is less restrictive than OEM PCV .
Thing is that would mess with map sensor as any extra flow would really be vacuum leak except it still gets metered if there is a MAF sensor used .

There is 1 review on there forum and in the end, longer time testing he got same mpg .

I don't like the fact the valve is closed for 2 min either, not good IMO ,if in fact it is totally closed .

[ConnClark]

Originally Posted by Old Mechanic

I know in the old MB sedans in the early 80s a vacuum leak in the central locking system would allow the engine to run on the air passing through a 1.5 MM ID vacuum line in one of the doors. In 82 they eliminated the throttle butterfly in all of their diesels and claimed a 7% increase in efficiency from eliminating all manifold vacuum completely.

Unicorn.

regards
Mech

Ahem, the reason why the Mercedes diesel sedans in the late 70s and early 80s would continue to run with a vacuum leak is that they used the vacuum to shut off the engine. A severe leak would drop the vacuum enough it couldn't pull the injector pump to the off position. There was no butterfly valve on the diesels. The diesels had a dedicated vacuum pump. The gains made in 82 were due to an improved cam with more lift that allowed the engines to breath more.

[EdKiefer]

This won't work on turbo engine or SC either, as OEM spring loaded PCV closes off when IM enters boost condition . Then your using the vent connection from valve cover to intake to remove any combustion gases during boost .

They would need to sue another controller with MAP sensor to close off at boost or maybe add check valve but that defects the propose as that is all most PCV are ..

[ConnClark]

Before computers and O2 sensors on cars I know some fuel saving gadgets did bleed air in with the crank case gases to lean out the mixture. These devices had minor improvements to economy and reduce unburnt HC and CO but tended to increase NOx. Their improvements were nothing like the claims these guys are making.

IF what this does improves air flow through the PCV valve then a minor improvement will be made by the increased vacuum in the crank case. This is because the bottom of the pistons aren't moving as much air around in the crankcase. There will not be as big of benefit as these guys are claiming though.

[user removed]

Originally Posted by ConnClark

Ahem, the reason why the Mercedes diesel sedans in the late 70s and early 80s would continue to run with a vacuum leak is that they used the vacuum to shut off the engine. A severe leak would drop the vacuum enough it couldn't pull the injector pump to the off position. There was no butterfly valve on the diesels. The diesels had a dedicated vacuum pump. The gains made in 82 were due to an improved cam with more lift that allowed the engines to breath more.

Ahem, the information I provided was from very ancient memory, when I was working for Mercedes in Houston Texas in 1982. It was a factory bulletin, so while you may disagree with me the information was provided by MB. Now memory is a fickle thing when age starts to degrade the mental pathways, but I do remember Mercedes (not me) claimed a 7% increase due to the improvements made around 1982. Part of the improvement was due to the elimination of the throttle plate.

Engine braking or drag? - Page 2 - PeachParts Mercedes ShopForum

Sounds like this fellow knows what he is talking about. I remember they started using a vacuum pump driven by the timing chain around 1982. Again old memory. After that they just controlled engine speed and power through the injection pump exclusively. Not saying the camshaft was not a part of the improvement just saying what I remember from the factory bulletin covering the changes from the previous model year.

Maybe you have better information than a factory service bulletin?

I was working at Intercontinental Motors on Kuykendahl road which ran parallel to the Interstate running north from Houston. I 15 if memory serves.

regards
Mech

[ConnClark]

Originally Posted by Old Mechanic

Ahem, the information I provided was from very ancient memory, when I was working for Mercedes in Houston Texas in 1982. It was a factory bulletin, so while you may disagree with me the information was provided by MB. Now memory is a fickle thing when age starts to degrade the mental pathways, but I do remember Mercedes (not me) claimed a 7% increase due to the improvements made around 1982. Part of the improvement was due to the elimination of the throttle plate.

Engine braking or drag? - Page 2 - PeachParts Mercedes ShopForum

Sounds like this fellow knows what he is talking about. I remember they started using a vacuum pump driven by the timing chain around 1982. Again old memory. After that they just controlled engine speed and power through the injection pump exclusively. Not saying the camshaft was not a part of the improvement just saying what I remember from the factory bulletin covering the changes from the previous model year.

Maybe you have better information than a factory service bulletin?

I was working at Intercontinental Motors on Kuykendahl road which ran parallel to the Interstate running north from Houston. I 15 if memory serves.

regards
Mech

Looks like we both need schooling.

Why a throttle plate on a diesel engine? - PeachParts Mercedes ShopForum

In 1982 and after, the 240Ds had a throttle plate for increased EGR flow. Years prior to 1976 had a throttle plate for vacuum for the injection pump governor. The 300Ds, 300SDs, 300CDs, and 300TDs didn't.

[treebark]

The DynoValve does work. I get that people are leary that it's a gimmic. The mileage improvement will depend on which vehicle you install it in. It works the best for vehicles that get poor mileage, but the benifit to this planet is worth it for everyone. There is also a pretty great boost in power as well. I know a lot about this product and no I don't work for the company. I live in Wisconsin and they are in California. I will be receiving my new version of the DynoValve any day now for my Honda Accord and to see how the improvements perform.