Breaking News: New VAG 504.00 & 507.00 standards

[Dan_Ruddock]

The honda vtec system will be the one to use. With a diesel you can only advance or retard the cams a very small amounts because of the piston to valve clearence problem. Dan

[DPM]

"Remember my words when japan starts exporting diesels to the USA (if they ever do)I bet you they will be push rod"

So which of the Japanese manufacturers currently have an OHV high-speed diesel in a passenger car? None that I know of. They're unlikely to regress in engine design twenty years in order to flood an anti-diesel marketplace...

[MrMopar]

The honda vtec system will be the one to use. With a diesel you can only advance or retard the cams a very small amounts because of the piston to valve clearence problem. Dan

And with a variable cam, we can say goodbye to EGR clogging the intake.

[Dan_Ruddock]

DPM as I have stated before multivalve or vtec is a good idea for a diesel and would require OHC's (although I have seen multivalve done aftermarket with pushrods) but as for the VW TDI, the engine could be built with everything the same in a ohc or a ohv same head port layout valve layout just moving the cam down in the block using a simple two gear drive and push rods and rockers. Ask your self this question what problems would each design solve or create. Dan

[DPM]

Dan, the TDI (and indeed the PD versions) are all evolutions of the early gasser VWs. The blocks are common (give or take, although I seem to recall reading about 1.8T tuners using TDI blocks...) Why would VW want to re-invent the wheel, and move the cam away from it's current location?

BTW, I'm not supporting VW in any way, I don't have one, never have...

[Dan_Ruddock]

One very very very good reason no more belts to replace or have snap on you and the absulute mess it makes when it snaps. I saw one vw diesel were the cam was broken in four places from a belt failure. Think of it this way ever time you hand somebody $750 for a TB job or spend your saturday replacing your TB it did not have to be that way. Dan

[DPM]

So we're talking about timing belts now, not oil?

[Dan_Ruddock]

Well start a new thread about timing belts if you want, I have some interesting thoughts about a vtec diesel but I don't have the time to go there now. Dan

[Rustynuts]

DPM as I have stated before multivalve or vtec is a good idea for a diesel and would require OHC's (although I have seen multivalve done aftermarket with pushrods) but as for the VW TDI, the engine could be built with everything the same in a ohc or a ohv same head port layout valve layout just moving the cam down in the block using a simple two gear drive and push rods and rockers. Ask your self this question what problems would each design solve or create. Dan

" the engine could be built with everything the same in a ohc or a ohv same head port layout valve layout just moving the cam down in the block using a simple two gear drive and push rods and rockers."

All this just because you find it unreasonable to order oil by internet/mail order or (God forbid) visit a dealer and buy some from there? It rest's quite plainly on the retarded infrastructure of the US supply chain, that no motor store on the corner of your block chooses to stock a VW spec oil. Would you suggest perhaps that VW start visiting these stores and selling their specification oil directly to them, just because the US oil companies have no intention to do so? Or perhaps your suggestions of re-manufacturing the entire VW engine range (in fact, every overhead camshaft engine in production) are just a little bit misguided. They have already re-manufactured the 2.0ltr engine cylinder head to accomodate your (U.S.) emmissions requirements, poor fuel quality, and who knows what else.

I wish you could have the level of technical engineering we have access to in Europe without having to be sufocated with the problems I've just outlined, but until that happens, you could always find some other outdated technology based engine to power your specific requirements in a car. Or embrace the fact that VW try to give you the benefit of their work in the field of diesel combustion engines!

[Dan_Ruddock]

I have a lot of respect for what VW has done for diesels I own one but some things could use improvement. AS far as ohc engines they are a vast improvement over pushrods in gas engines or a diesel with vtec or multivalve. Just because something is old or not high tech does not mean it's bad. In some applacations it might be perfect for the job. You have to think out side of the box. Dan

[earthworm]

Ha tell that to everyone who has had a timing belt snap before the service interval. If VW really wanted to give us the best possible they would get rid of the timing belt. I don't care what other country's do I don't live there. Cars sold in the USA should have readily available the correct fuel and oil period. Look at those fine cloths the emperor is wearing. Dan
* * * * * the above copied * * * * * *

Key words : acceptance and cooperation.

America, sadly to say is a backwoods country - and maybe it always has been. It does not have to stay that way - our education system can and must be improved !
We need strong national leadership - not greedy political hacks...
The problems must be accepted - they can be solved ..

Cooperation - this must occur between customer, dealer, and government - we are receiving far too little of this.
A properly designed automobile will have a timing belt that can be renewed every - say 50K to 75K miles and no more than 1.0 hour labor - the motor vehicle must be designed to last over 250K miles, many are,of course..But they also must be engineered to be worked on - and this is a major failing point..
And, if it is true that the new oils are not available, then why not ???
American politicians are not the only ones with their thumb up their asses !!
In a way, I cannot understand this oil-spec fuss - tonight and tomorrow I will go to PepBoys and Autozone and ask pointed questions ...Mercedes and VW surely must use the same oil - I would think....

[nortones2]

Dan, IIRC OHC engines have fewer components than pushrod engines, which is why they have been adopted on common or garden passenger car engines. Its unlikely that an engine manufacturer would be fool enough to build a more expensive engine for diesel use, with less commonality. Re the multi-valve philosophy you approve of, I suspect its just aping the latest trends without understanding that the reasons for them are to do with the induction system limitations of naturally aspirated, high revving petrol engines. In the latest VW turbo diesels the 4-valve head is primarily to permit optimal injector positioning. With forced induction, and the oxygen rich combustion process of an unthrottled diesel, there is no need for variable valve timing to improve flow rates. Given an excess of oxygen, which is assured in the diesel engine, power requirements are modulated through the fuel injection system. If, for example, you were to fit a higher lift camshaft, there would be no power increase, because there is no benefit to be gained through better flow. There is more than enough oxygen available already as the engine runs "weak".

[Dan_Ruddock]

Push rod motors are not more costly. Eight push rods and lifters. No need for a belt or all the parts to encase it, tension it or idlers. Some ohc heads have cam brg caps some don't the ohv cam would slide into bores like a chevy low cost. Most ohc use rockers. Over all it would be a wash. Yes I understand the advantages of a four valve head volumetric efficiency. If getting more air into the motor is not necessary than why did VW put a turbo on it. Dan

[Dan_Ruddock]

I will give a real good reason the car company's might go ohc for their diesels !!! MARKETING !!! do you want two or three or four blades on your razor, how many times over sampling does your CD player have we are all suckers for this nonsense. Common folks give me a good engineering reason why an ohv diesel is bad. It is old, low tech, you have to put the cam somewhere, more expensive, all of these don't cut it. Take your choice what would rather have in a low reving diesel, gear drive for the cam like a $100,000 racing engine or a rubber belt. What real problem does ohv create? Dan

[03_01_TDI]

So which of the Japanese manufacturers currently have an OHV high-speed diesel in a passenger car? None that I know of. They're unlikely to regress in engine design twenty years in order to flood an anti-diesel marketplace...

http://www.honda.co.uk/change/