If a V6 has a SOHC on each side, does that make it a DOHC?

[Dr. Evil]

I've always wondered this:dunno:

Anyway, I'm new here if you can't tell! Glad i found this board :)

[jaylo]

No it doesn't because the cam on each side runs the air AND gas valves

On DOHC one cam runs air valves and the other cam runs gas valves

[Audi Kid]

hmm intresting...didnt know that

[rage2]

Talk about misinformed =).

DOHC = Double Over Head Cam.
SOHC = Single Over Head Cam.

In a DOHC configuration, one cam runs the exhaust valves, one cam runs the intake valves (not gas and air). In a SOHC configuration, One cam runs both the exhaust and intake valves.

Now, on a V6, there are 2 banks of cylinders, so you would need at least 2 cams to drive the valves. The crazy folks at VW decided to start misnaming their engines by calling their 8V VR6 engine a DOHC engine, but in fact it's misleading because even though there are 2 cams, each cam drives both intake and exhaust valves. Some of the GM V6's are named "quad cam", which is just another misnomer for 2 banks of twin cam setup.

[GTS Jeff]

Originally posted by jaylo
No it doesn't because the cam on each side runs the air AND gas valves

On DOHC one cam runs air valves and the other cam runs gas valves lol, its intake and exhaust valves...fuel is normally sprayed into the combustion chamber with the injectors

[James]

Originally posted by rage2
The crazy folks at VW decided to start misnaming their engines by calling their 8V VR6 engine a DOHC engine, but in fact it's misleading because even though .

VR6's are 12 vavles, arnt they?:dunno: , could Rage be wrong?!??!:p

The new one is a 20 vavle, i think.

[OMOYYC]

The number of valves does not necessarily relate to the number of cams. Technically, you can have 1 or 2 valves per cylinder per cam.

Theoretically, you can have a car like this:

6 Cylinders x 2 Valves / Cylinder = 12 Valves (only 1 intake + 1 exhaust valve per cylinder)

Or

6 Cylinders x 4 Valves / Cylinder = 24 Valves (2 intake + 2 exhaust valve per cylinder)

Some cars has weird configurations with 3 Valves per Cylinder as well. So a 6 Cylinder can potentially have 18 Valves.

[rage2]

Originally posted by James
VR6's are 12 vavles, arnt they?:dunno: , could Rage be wrong?!??!:p

Busted =).

Yes I meant 12V (2 valves per cylinder).

[OMOYYC]

It'd be an interesting setup to have 8V on a 6 cylinder :D

[GT2NV]

Originally posted by rage2


Busted =).

Yes I meant 12V (2 valves per cylinder).
hehe was gonna say the same thing......:eek: :eek:
rage was wrong for once.......:nut: :nut: this cant be right lol:rofl:

[jaylo]

Originally posted by Jeff TYPE R
lol, its intake and exhaust valves...fuel is normally sprayed into the combustion chamber with the injectors

like whoa that's what I mean, man what was I talking about! sorry Dr. Evil

[Dr. Evil]

Originally posted by jaylo
like whoa that's what I mean, man what was I talking about! sorry Dr. Evil

It is okay, I will just have to feed you to my man-eating sharks with laser beams on their foreheads!:D j/k

Thanks for the clarifications everyone! Yes, my car has one cam on each bank, but when I say SOHC people think there is one cam total (don't see how that would be possible but these aren't the brightest people). I think I'll just start saying "dual-cams" & let them figure it out :)

[5.9 R/T]

Originally posted by Dr. Evil


Thanks for the clarifications everyone! Yes, my car has one cam on each bank, but when I say SOHC people think there is one cam total (don't see how that would be possible but these aren't the brightest people). I think I'll just start saying "dual-cams" & let them figure it out :)

I have a SOHC with only one cam. Actually all the cars in my family but one have only one cam.

[Dr. Evil]

Originally posted by 5.9 R/T
Actually all the cars in my family but one have only one cam.

Your R/T has one cam per bank, correct?

[Davan]

Originally posted by rage2


Some of the GM V6's are named "quad cam", which is just another misnomer for 2 banks of twin cam setup.

And on the other hand, GM's 4cyls named "Quad" or "Twin", are in fact, dohc. Like mine! :D :)

[5.9 R/T]

Originally posted by Dr. Evil


Your R/T has one cam per bank, correct?

Nope, it's a pushrod, only one cam. The only motor with 2 cams is the DSM.

[frenchdriver]

Originally posted by Cwave
Some cars has weird configurations with 3 Valves per Cylinder as well. So a 6 Cylinder can potentially have 18 Valves.

Then there's the VW 1.8T engines

inline 4 with 20Valves ---> 5 valves per cylinder! (does that mean its like 2 for intake and 3 for exhaust or something)

what about direct-port Nitrous systems? Does that been my engine for example would become a 30V instead of 24V ?! :D

[OMOYYC]

Hmm.. I believe they are 5 cylinder engines that has the 20 Valves. Does anyone else know?


Originally posted by frenchdriver


Then there's the VW 1.8T engines

inline 4 with 20Valves ---> 5 valves per cylinder! (does that mean its like 2 for intake and 3 for exhaust or something)

what about direct-port Nitrous systems? Does that been my engine for example would become a 30V instead of 24V ?! :D

[Fluidic]

To explain more about the 20V 1.8 Turbo-Charged engine from VW, follow this link and click on the video "Hygienist"

http://www.vw.com/commercials/index.html#

:) -- Fuck I love VW! -- :)

Peter

[OMOYYC]

I see.. so it IS 5 valves per cylinder. How strange. :dunno:

[Dr. Evil]

Originally posted by 5.9 R/T
Nope, it's a pushrod, only one cam. The only motor with 2 cams is the DSM.

I've got pushrod on my V8 truck, too.

As for Volkswagen, I love the commercials & like the cars, but their new Eliti$t pricing $tructure kinda puts me out of the game:(

[Alpine Autowerks]

The VR6 is an inline 6 with the cylinder bores packed together, it is a single head with 2 cams so it is a DOHC and it is a single bank of cylinders. VR is "V-Reihenmotor" or "V in-line. And they copied it from Lancia who had a "VR4" with 13º offset between the bores in a single block capped with a single head.

[5.9 R/T]

Originally posted by Alpine Autowerks
The VR6 is an inline 6 with the cylinder bores packed together, it is a single head with 2 cams so it is a DOHC and it is a single bank of cylinders. VR is "V-Reihenmotor" or "V in-line. And they copied it from Lancia who had a "VR4" with 13º offset between the bores in a single block capped with a single head.

We've discussed this before, it's not an inline engine, it's a V engine with, if i can remember correctly, 15 degree's between banks. The reason is that 15 is a number that goes evenly into 90 which is an optimal number in the engine building world. I can't explain it very well since I don't completely understand the physics behind it but here's a site that does.

http://www.thrasher-ep.com/tech_htm/adv_engine_design.shtm

[4wheeldrift]

Its sort of splitting hairs whether you call it an inline or a V. Either way, it shares more in common with an inline design than a V design.

[Fluidic]

Originally posted by 5.9 R/T


We've discussed this before, it's not an inline engine, it's a V engine with, if i can remember correctly, 15 degree's between banks. The reason is that 15 is a number that goes evenly into 90 which is an optimal number in the engine building world. I can't explain it very well since I don't completely understand the physics behind it but here's a site that does.

http://www.thrasher-ep.com/tech_htm/adv_engine_design.shtm

Alpine Autowerks
Master Engine Builder

He most likely knows tons more then you dude... no hard feelings of course! :D

Peter

[5.9 R/T]

This is the way i see it, and it's not technical at all...

Inline = straight = no angle between cylinder banks
V = angle = even at 1 degree it's no longer 'straight' so it should be considered a V design.

If this is not the case then at what point (read: angle) does an inline engine become a V engine? This is not meant to be sarcastic or to start a war or anything like that it's an honest question.

And peter, none taken, there are hundreds of thousands of people who know more about engine design then i do, this is just the way i see things. And lots of people have names above their avitars but it doesn't mean that is what they actually are...

[4wheeldrift]

I personally don't think in terms of angle, I think its whether there is only one head or two. if its one head servicing both banks its inline, if its one head per bank its a V. Narrow angle V's like the volkswagen VR series motors behave more like an inline motor in terms of the power delivery so thats how I tend to think of them.

[Fluidic]

Originally posted by 5.9 R/T
And lots of people have names above their avitars but it doesn't mean that is what they actually are...

I think it's time you meet Mr. Alpine Autowerks! :clap: :)

Peter

[T5_X]

from http://www.motorera.com/dictionary/index.htm

V-type engine: An engine in which the cylinders occur in two rows set at an angle to each other with the crankshaft running through the point of the V. The single crankshaft is turned by both banks of cylinders. The angle of displacement is generally between 60 and 90 degrees. Although the most common engines are V-8 and V-6, manufacturers have used V-4 and V-12.


I'd agree with 5.9 R/T.
While a V engine with hardly any space between the banks and only one head may behave much more like an inline, it is still a V-type, just like if a V engine had 175 degrees between banks it would behave like a flat, it would still be V-type. There's no grey areas. 0 degrees is inline, 180 is flat... anything in between has to be a V.

I don't like to be anal or anything, and I see where 4wheeldrift is coming from, but it took me a long time to find out that the VR6 was actually a V6 cause everyone always called it an inline without questioning. I'd like to learn more about why the banks are so close together without just going to inline... can anyone explain or link?

also... what is a "radial" engine?

[4wheeldrift]

Originally posted by Ranger_X31

I don't like to be anal or anything, and I see where 4wheeldrift is coming from, but it took me a long time to find out that the VR6 was actually a V6 cause everyone always called it an inline without questioning. I'd like to learn more about why the banks are so close together without just going to inline... can anyone explain or link?

also... what is a "radial" engine?

Volkswagen is using the narrow angle V motors to make them a smaller package. THe narrower the angle of a V engine, the narrower the motor gets, but the taller it gets. Volkswagen is using the narrow V motors so they are narrow enough to place them longitudinally inside the chassis for a more efficient FWD driveline and better weight distribution.

And a radial engine is one were all the pistons are in a circle about a center point. They were most common on early aircraft.

[Alpine Autowerks]

The VR6 has 1 head gasket for the 1 bank. The cylinders come out of the flat deck @ 7.5ºThe "W12" has 2 banks. The VR series of engines was made to fit a 6 cylinder between the frame rails of a golf while being narrow enough to allow for a crush zone in an impact. The cams are driven off of the back(flywheel end) so the engine can be built with different cylinder counts. VW has built VR3s through VR7 versions. The previous 4 cyl was built in 3 through 6 cyl. versions. The neatest prototype they considered before the VR layout was an oval piston. 90º is a natural bank angle for 8 cylinder and multiples of (4, 16). 60º and 120º are natural angles for 6 and 12 cylinder engines. 72º for 10 cylinders, although 10 cyl. F1 engines use 71º and narrower becuase of better high speed harmonics. BTW, rage2 picked my avatar name.

[5.9 R/T]

Originally posted by 4wheeldrift
Narrow angle V's like the volkswagen VR series motors behave more like an inline motor in terms of the power delivery so thats how I tend to think of them.

Did you read the link that I posted? Because if you did you wouldn't say that. They are no better then a 60 degree V6, but i'm not going to tell you why, you'll just have to read it for yourself. A 15 degree V6 is 15 degree's for a reason! Just because it has a narrower angle does not make it 'behave' like an inline engine. An inline behaves like an inline, a V (at certian specific angles) can be made to behave like an inline, but it's not the narrowness of the angle that determines this. Is the VR6 the best of both worlds in terms of packaging between an inline and V style engine? Yes, but it is still a V6, regardless of how many heads it has or does not have. It is the block that determines engine style, not the head.

And I apologize if I offended you Alpine, one must take things on the internet with a grain of salt.

RangerX i posted a link earlier in this thread that talks about angles for a V6 if you scroll down a bunch. That should answer most of your questions.

[Alpine Autowerks]

The link deals with balancing different cylinder and crankshaft arrangements and firing orders etc. It offers no specific info on the VR6 example. and yes it is the block that determines the style and when I am counting banks my register stops at 1. Where is the second bank, where is the valley and why does the VR6 have an inline 6 firing order?

[T5_X]

from september SCC, if you have it, check out the article on the R32 golf. I believe they say the VR6 is a "narrow angle V6"

Peter, why are you telling 5.9 to shut up? The argument hasn't come to a closure, and it's a friendly argument, so we can all benefit from what everyone says and gain insight, that's why it's called a FORUM. This isn't a popularity contest to praise whoever's right and ostracize whoever's wrong.

[5.9 R/T]

OK here's the deal straight off of the VW website, all can see for themselves if they want.

"In the VR6, though, we've brought the two banks of cylinders to a 15 degree angle (coming close to the way an inline engine is designed)."

Notice they say two banks of cylinders, and coming close to the way an inline engine is designed. Read: It's almost an inline, but it's not. It has two cylinder banks just like a 60 or 90 degree V6, but the VR6 brought the two banks closer together to form a 15 degree V6.

"Excellent handling and balance due to "V" engine design"

Doesn't that say it all?

"Type ......... 6 cylinder, 15 degree V, gasoline."

I don't know about you but to me this sure sounds like their admiting to the fact that it's a V engine. The reason there's no valley is because of the narrow angle of the banks the valley would be very small. As for firing order my link deals with that as well, here's a quote:
"Generally, successive power impulses are applied to alternate ends of the crank"
So there's the explination for a inline style firing order.

But unless someone can show me something from VW that calls it an inline engine, which would totally go against everything they have posted on their website, this motor must be considered a V6.

As for my website; I posted that because the VR6 uses a 15 degree V angle, which as explained on that site, is an optimal angle to have (multiplies into 120 evenly). This leads back to the smoothness and power delivery of the VR6 that is so similar to an inline motor. It doesn't use specific info on any motor because it discusses forces experienced by every motor, and what make a better design etc. etc.

[4wheeldrift]

Calling the VR6 a "V" motor is nothing more than a marketing decision on VWs part. You can argue semantics until you're blue in the face but it doesn't change whats going on. You shoot me down for saying a narrow angle V offers inline like power delivery, then in a later post you admit that it does offer that feature.


This leads back to the smoothness and power delivery of the VR6 that is so similar to an inline motor

Make up your mind. If it quacks like a duck...

[Dr. Evil]

The more I read on this post, the more I realize how mysterious car manufacturers keep the world of engines. Car salesmen don't really seem to know or explain the details when you buy your car.

It is almost some kind of conspiracy... like they don't want you to know the engineering under the hood, in case they really fu*k up, they can pass off poorly engineered products to us :eek:

[300rwhp]

you silly boys its a v6

[5.9 R/T]

Originally posted by 4wheeldrift
Calling the VR6 a "V" motor is nothing more than a marketing decision on VWs part. You can argue semantics until you're blue in the face but it doesn't change whats going on. You shoot me down for saying a narrow angle V offers inline like power delivery, then in a later post you admit that it does offer that feature.



Make up your mind. If it quacks like a duck...


OK well do you consider a 60 degree V6 to be an inline motor? Because a 15 degree would behave just like it. This is the point i'm trying to make. A 60 degree V6 would behave much like an inline motor just as a 15 degree V6 would, yet the 60 degree is a V6 and the 15 degree is an inline just because it has one head vs. two? Even Alpine said the block determines what design the engine is and not the head. As for VW marketing thats total speculation on your part, and has no basis in fact. If you look at the technical rundown on a car with the VR6 it lists it as a 15 degree V motor, not a 15 degree inline motor. This is a technical readout and NOT a marketing ploy. Thats like calling a solid rear axle an IRS because it markets it better. It just doesn't make sense. if a parrot can speak does it make it human? No, it's just a talking parrot.

BTW I did not mean to cut you down so hard earlier, and I apoligise for my wording if you took offense. :thumbsup:

[4wheeldrift]

You can call it either, and thats the point. Lancia used a similar engine design back in the 80s (a narrow angle V) and they called it an inline because the cylinder banks were slightly offset for a smaller package. You can look at it from either perspective. Volkswagen wants to call it a V, fine its a V. Lancia wants to call it an inline, its an inline. They are both correct from a certain perspective.

[4wheeldrift]

Originally posted by Alpine Autowerks
The link deals with balancing different cylinder and crankshaft arrangements and firing orders etc. It offers no specific info on the VR6 example. and yes it is the block that determines the style and when I am counting banks my register stops at 1. Where is the second bank, where is the valley and why does the VR6 have an inline 6 firing order?

This post pretty much explains my thoughts on the matter as to why its more of an inline than a V.

[5.9 R/T]

An inline motor has all the pistons lined up neatly in a row, 'inline' with each other if you will. a V6 motor essentially is two inline cylinders joined together (at this degree between banks). Now choose cylinder one and draw a line from the center of the pistion through to the center of cylinder 5. In the VR6 case does the line travel down the center of each cylinder (minus the 6th cylinder of course)? No. So how could it be an inline motor if the cylinder bores are not INLINE? But using the same method you would find two banks with cylinders 135 lining up in a straight line and cylinders 246 lining up in a straight line. There are your two banks, aka your V6 motor. I don't know how else you could consider this motor an inline design.

[4wheeldrift]

Originally posted by 5.9 R/T
An inline motor has all the pistons lined up neatly in a row, 'inline' with each other if you will. a V6 motor essentially is two inline cylinders joined together (at this degree between banks). Now choose cylinder one and draw a line from the center of the pistion through to the center of cylinder 5. In the VR6 case does the line travel down the center of each cylinder (minus the 6th cylinder of course)? No. So how could it be an inline motor if the cylinder bores are not INLINE? But using the same method you would find two banks with cylinders 135 lining up in a straight line and cylinders 246 lining up in a straight line. There are your two banks, aka your V6 motor. I don't know how else you could consider this motor an inline design.

if you want to really split hairs, they are TECHNICALLY in a line, just with the top of the bores offset from the bottoms :D

[Alpine Autowerks]

Originally posted by 5.9 R/T
An inline motor has all the pistons lined up neatly in a row, 'inline' with each other if you will. a V6 motor essentially is two inline cylinders joined together (at this degree between banks). There are your two banks, aka your V6 motor. I don't know how else you could consider this motor an inline design.


Thank you for making my point, NO part of the VR6 engine design consists of ANYTHING like "two inline cylinders joined together " It has 1 intake manifold, 1 exhaust manifold. The cylinders are staggered in such a way that 1 row has different piston velocities than the other row for the same crank angle because if is a deformed inline 6 not a .... How did you say? Two inline cylinders joined together" which would have identical geometry for each bank.

If you think the brochures tech info is the last word in accuracy ... how many engines out there have different displacements than the badge on the fender just cuz it "markets it better" or let's only allow published horsepower or acceleration times to settle all discussions and scratch the street encounters forum.

[5.9 R/T]

What I meant was two inline 3's joined together on the same crank. I left out the three, i apoligise for that ommision and can see how you would get confused. Could two inline 3's joined together at an angle to eachother at the crank (making it a V6) have differing piston velocities from bank to bank at the same crank angle? They sure could, so whats your point? And I still don't get why you keep talking about head's and manifolds, we already established that those do not have a factor in what layout the engine is.

As for your last comment, true automakers don't always list the true displacement, but they are always within 2 or 3 ci, so it's not like they are way off as would be the case if they called a V6 motor an Inline 6 motor. And who said anything about benchracing? I fail to see the relevence of that in this discussion.