Jap engines & valve lube

[carl0s]

Why does everybody automatically say that a Jap engine has softer valve seats and need valve lube? Yet most Germans don't.
Is there any science behind this? Might the materials vary from one engine model to another?

Secondly: valve seats - are they ever replaceable? I mean, would you consider not running valve lube, if it just meant you had to replace the valve seats every 15 - 20,000 miles ?

[volvobaggen]

I believe european engines have been overengineered with regard to material choice and alloy used in valve seats since the introduction of unleaded petrol. Japanese auto manufactures seem to have a different attitude to making cars than us; In my opinion they make finely engineered and balanced automobiles using as little raw material as possible. They probably use an alloy for their valve seats that is strong enough for petrol use, but nothing more, saving some pennies in the production process. Now there is even technology where engine manufacturers can spray on valve seats instead of machining and inserting the seat...

This link is good reading if you have interest in the subject of valve seats. http://www.aa1car.com/library/ar993.htm

Edit: How come you have over 200 posts and don´t know the answer to this.. I smell a troll.

[john_d]

Secondly: valve seats - are they ever replaceable?

i dont believe so, i also believe in santa and the easter bunny though!

[classicswede]

Yes they are replacable. You will normaly end up having to replace all the seat and usualy also the valves.

Not all egine rebuilders are able to fit the seats as it is not a common job but anywhere that does "unleaded conversions" will be able to fit new seats.

[Gilbertd]

Yes they can be replaced but it isn't cheap. I had to have two done because a head had cracked between the two valves and had to be welded. To do that the existing steel seats had to be removed from the alloy head. The alloy was then machined back to it's original shape before being bored and the new valve seats fitted. Once fitted they had to be cut to the correct angles for the valves before the (new) valves were lapped in. This must have been getting on for 10 years ago and I think the valve seat replacement was something like £40 a seat plus the cost of the new valves. So the answer is yes, you could be a cheapskate and not fit Flashlube, but it'll cost you a fortune in the long run.

The Japs have got it spot on. Use a grade of steel that is just hard enough to last the life of the car when running on unleaded. How many Jap motors do you hear of that have done 300,000 and higher compared with European ones? It's called planned obsolescence.

[volvobaggen]

I´m sure a japanese cars could run forever if it hadn´t been for high depreciation, roadsalt and hard to find spare parts when these cars are old. The undercarriage of my old Mazda looked like the Titanic on the sea floor, but the drivetrain was in excellent condition when I had to let it go. The engine never gave me any problems..

Look at all the high-milage japanese cars in this list :http://forums.consumerreports.org/n/pfx ... 2kmileclub

[john_d]

I´m sure a japanese cars could run forever if it hadn´t been for high depreciation, roadsalt and hard to find spare parts when these cars are old. The undercarriage of my old Mazda looked like the Titanic on the sea floor, but the drivetrain was in excellent condition when I had to let it go. The engine never gave me any problems..

your Mazda was probably a rebranded Ford.

[zipdip]

I would not convert a jap car,I was tempted by a 250 lexus a couple of years ago it was cheap and had all the bells and whistles but the 10,000 mile service and the soft valves made me decline,the thing is if I thought the flash lube would help I might give it a go but I cannot see how spraying lube at your valve stems is going to save the seats after all it gets very hot in the cylinder,so for me there are plenty of cars with engines that you can convert GM,Ford ,Jag,BMW to name just a few.

[volvobaggen]

your Mazda was probably a rebranded Ford.

Ahaha, LOL

[carl0s]

But how do you know BMW aren't going to softer seats, after all they are the masters of engineering obsolescence.

[volvobaggen]

They are probably getting softer seats carl0s. I mean, why would they give us quality valve seats for free if they can charge extra for a bifuel or flexifuel engine with proper valve quality?

The problem today as I see it, is that cars are getting cheaper and more affordable all over the line. Everyone has been imitating the japanese. It´s all about cutting costs to compete, the result is high depriciation. Just compare the new volvos to the old ones. Old volvos = honest engineering. New volvos - Full of plastic and advanced electronics that eventually will brake down and cost a fortune to fix. Valve seats are also softer.

[carl0s]

They are probably getting softer seats carl0s. I mean, why would they give us quality valve seats for free if they can charge extra for a bifuel or flexifuel engine with proper valve quality?

The problem today as I see it, is that cars are getting cheaper and more affordable all over the line. Everyone has been imitating the japanese. It´s all about cutting costs to compete, the result is high depriciation. Just compare the new volvos to the old ones. Old volvos = honest engineering. New volvos - Full of plastic and advanced electronics that eventually will brake down and cost a fortune to fix. Valve seats are also softer.

That makes me think of 90s Toyotas vs. today's Toyotas.

[volvobaggen]

And I forgot that you don´t even get a spare wheel in case you get a puncture. Just a small 12v china compressor and some @!## to put into the tyre. The tool-kit from volvo for unscrewing the wheel lug nuts is appaling. Volvo reduced vehicle weight and saved 50 bucks for choosing this option.

[rossko]

I cannot see how spraying lube at your valve stems is going to save the seats

How would you imagine it works for petrol, then?