Vtec engines

[Tom]

I have a Honda Integra Type R and have noticed that the second cam doesn't seem to come in if the engine is cold. Is this normal? Is there an explanation for it? Or is there a problem with the engine?

 

By the way, I don't normally rev the engine when cold, but have done so twice now and noticed it both times. When hot, the second cam kicks in perfectly.

 

[julians]

I believe its normal, the honda ecu sets a lower rev limit until the engine is up to temperature.

 

At least it does on my s2000 and a friends civic type R.

 

The civic also puts a lower rev limit on if your in neutral.

[frankyknuckles]

yep, normal.

 

www.R300.net

[Tom]

😬 thanks guys

[PooPoo]

Over 1,000,000 VTEC engines have been built so far. Not ONE......ONE i say has yet gone wrong.....WOW.

 

I put a Civic Type R on hold for my 7.

 

Great car.

[martinwhitcher]

not one gone wrong?? are you sure 😳

 

Great marketing speak 😬

 

Martin

 

MW 51 CAT

Superlight No.171

now know as:Superlight DVA 207

[PooPoo]

Apparently!!! Obviously cars with VTECS have broken down but im talking about engine failures!! I hope someone can prove my statement wrong. I have nothing to gain from this!

 

Viper Blue 140 SV

[julians]

That statement is rubbish, just search teh forums on www.s2ki.com.

 

A few will be down to owner neglect (low oil etc), but quite a few just popped all on their own.

 

 

[frankyknuckles]

quite a few just popped all on their own

 

Probably, but I think Honda are saying that the 'vtec' has never 'gone bang'. Engine failures (and I have seen ony a rare few with Honda) do happen, but not because of 'vtec'.

 

If 'Turtle' posts on this thread, I'm sure he will add his 2 peneth.

 

www.R300.net

[andycox]

The v6 3.5ltr Vtec is awesome in the minivan and my Acura jas over 180K on it and it looks loke it will go for ever. I suspest the body will fall off the Acura before the engine goes bang.

 

 

 

Driving on the left side 😬

 

[Gambo]

I think that none has ever been split for warrantee work. How would Honda know if a 10 year old motor had or had not gone pop. 🤔 that in itself is an incredable achievement.

 

She's finally Home!!!!!!!!!

[Grubbster]

My Accord Type R did the same until the temp came up and my neighbours imported Integra Type R won't engage vtec if the car is in neutral (or not moving, or somehing like that ). Hoda claim there have been no VTEC related warranty claims . . .

 

Roadsport build photo's here

Le Mans 2004 photo's here

 

[Turtle]

Almost an urban myth this one. There have been failures of both vtec solenoids, and lost motion assemblies (the Honda term for the rockers and the vtec pistons). But normally done as a 'courtesy repair'.... hence not showing up as warranty work. Vtec is very, very, reliable though. But the stat is generally misquoted... implying that the whole engine is what you're on about rather than a small, very simple mechanism.

 

-Brian.

[tom7]

Vtec is a very simple mechanical device that brings in an extra cam at a certain rpm. The clever bit is electronic. There is really very little that could go wrong with this mechanism.

If you believe all the marketing speak ...more fool you

[bongomania]

I have heard of vtecs going bang previously.

 

Having said that though mine runs without too many complaints on low or no oil until I remember to fill er up!! 😬

 

Incredible engines. Love the scream as the vtec kicks in. Great fun keeping it above 5000 and going up through all the gears.

 

Seven-Ecstasy.co.uk Fully revised and updated for 2005 including more Le Mans and Goodwood pics

[john g]

I believe the vtec also works on oil viscosity. When the engine is cold the oil is obviously cold & "thick", when the engine reaches its normal operating temperature the viscosity of the oil is then "ready for vtec".

[Bare]

It's also possible/easy to significantly lower the onset of Vtec.. .. does 4000 rpm sound better ?..It's also possible to attach a Vtec head to a previously non vtec engine :-) But these are a rather large cyl. head, at least inna DOHC variants.. making adaptation to a 7 'problematic'.. not to mention the reverse rotation of the earlier engines

There are a few failsafes built... in like temperature .. just to keep cretins from bursting an otherwise reliable setup.

[dannylt]

Lowering the VTEC point without any reprogramming or remapping is a Max Powerish idea - the engine will be running very lean otherwise. But as you say, people do it because it "sounds" batter :)

[Bare]

IF one's clever enough to retime the onset of Vtec.. then they are also clever enough to get their Gettodyne to squirt the appropriate fuel quantty.. seemingly even Teenagers know how to do this here.

Remember Honda sold 850,000 cars in North America in '04 alone.

To say these are 'plentifull' would be an understatement :-)

[Lakey]

The Honda VTEC unit probably works in the same way as our Toyota VVTiL engine. The ECU controls the engagement of the VTEC magic, via a speed sensor to restrict its use in neutral and an engine temperature sensor reading to restrict it working until the engine is up to operating temperature. Obviously both of these things can be fooled into giving false readings but why would you want to.

 

Lowering the onset of the VETC in the Honda and VVTiL in the Toyota is not advisable, certainly in the unit I have in my SV. The Toyota engine works on a regular cam up to 6,200 rpm at which point the ECU send a signal to an oil pump to shift the engine up to the high lift cam. To lower the point at which this happens causes all sorts of crossover problems and has an overall effect on engine performance. To raise the point beyond 6,200 rpm would stress the regular cam.

 

I imagine that the Honda unit works in much the same way, and despite working for the competion the Honda is a suberb engine. We all have a lot of respect for it at Toyota. Our engines have gone pop, but the main cause, when the engine was first launched, was the driver shifting from fifth to second by mistake. The Toyota engines may be good but can't really deal with 13,500 rpm!

 

The remaining bits of my engine loom are being sorted at the moment in the SV, and then we will see what all this variable valve timing nonsense means in a Caterham, ear plugs I would think!

 

Caterham SV 190....Yes THE 2ZZ-GE!

[dannylt]

You can definitely gain midrange power by moving the VTEC point down - the original changeover was probably for good emissions/drive-by noise/economy. You just move the VTEC to where the torque curves cross over.

 

I've definitely heard of VTEC ECU hacks that JUST lower the VTEC point.

[DonkeyDave]

I've got just this arrangement in my 7, those clever people at emerald have got it to VTEC at 4000rpm, its a really flexible engine then, pulls really well from 6000-9200rpm

[Jenson Button]

The official line is that there have been no reported failures of VTEC in any market in the world within the warranty period. Any warranty repair would be reported back to head office as they need to pay the dealer for the work. Any repair done outside the warranty period would not necessarily be known. Either way, it's a great testament to the engineering. Fantastic engines too. Just a shame the CSR got the Duratec 😳 😬

[dannylt]

That's a bit of an urban legend I think... anyway, the Duratec has something the poncy little VTEC's *don't* have... monster torque 😬

[Jenson Button]

Danny - who needs torque in a car that weighs 500kg? 😬

 

Not an urban legend at all. Confirmed by Honda (no reported warranty failures of VTEC in any market in the world). That's not to say there haven't been problems with VTEC engines, just that the problems aren't attributable to the VTEC system itself.