if so, is the reason we have to do such frequent valve clearance checks because unleaded fuel speeds up valve seat recession?

If so, would adding a lead substitute additive reduce this from happening?

talkin bout the gs500e? if so, then i doubt it, regular  was discontinued before 1989

We had leaded fuel here until about the mid to late 90's


Unleaded was introduced in 86 and shortly after made mandatory for all new vehicles.

^^^^^^^^^^^
Same here (EU).

BTW, nice topic, interesting point.

A 4k valve inspection is totaly normal for an engine as old as the one in the GS5 (the basic design is well over 30y old now) and I doubt its anything to do with unleaded petrol, when it came off the drawing board it was probably the best they could do. The GS5 engine is designed to run on lead-free and has hardened valves/seats fitted that dont require lead to lubricate them and that prevent regression. So given the tiny amount of wear that takes place in normal everyday use I think it would be very difficult to notice any significant difference that an additive may give..... let alone see a benefit.

No they weren't. Any vehicle sold after '86 had to run on unleaded. the GS was introduced in '89 so they were all to run on unleaded.

Mine is a '93 model and it had a sticker on the tank that read "unleaded fuel only", that was till I removed it when I resprayed it. 

When I got mine serviced last, I got the valves checked and they were fine after 10,000k's.

Quote from: galahs on January 21, 2008, 05:22:57 AM
We had leaded fuel here until about the mid to late 90's


Unleaded was introduced in 86 and shortly after made mandatory for all new vehicles.

where the heck could you get leaded fuel until the 90-'s? 

In Poland, which is NOT the third's world country as some people think, you could still get the 98 octanes (RON) leaded fuel couple of years ago  , to be exact: in UE selling leaded fuel was prohibited in the beginning of year 2005.

Here in the US:  (citation from wikipedia)     "in the U.S., where lead was blended with gasoline (primarily to boost octane levels) since the early 1920s, standards to phase out leaded gasoline were first implemented in 1973. In 1995, leaded fuel accounted for only 0.6 % of total gasoline sales and less than 2,000 tons of lead per year. From January 1, 1996, the Clean Air Act banned the sale of leaded fuel for use in on-road vehicles."

cheers

KaMeL

i have never been to poland but have worked with its military in syria. if they are any indication i would put them in the 2 nd world def not 1st even though they are nato

Well , explain , why there are so many polish in the Uk? , there are polish shops all over southend , and theres a hospital just for the Polish in london . crazy world lol

An interesting article detailing the history of leaded gasoline:http://www.damninteresting.com/?p=932

Quote from: Jay_wolf on January 21, 2008, 04:05:16 PM
Well , explain , why there are so many polish in the Uk?

Why are there soo many Mexicans in the US?

The world may never know 

Quote from: frankieG on January 21, 2008, 01:00:18 PM

Quote from: galahs on January 21, 2008, 05:22:57 AM
We had leaded fuel here until about the mid to late 90's


Unleaded was introduced in 86 and shortly after made mandatory for all new vehicles.

where the heck could you get leaded fuel until the 90-'s? 

Australia had leaded fuel or SUPER (96 octane) available until the mid 90's then we switched to LRP (Lead Replacement Pretrol. Basically Premium with an valve seat lubricant added by the refineries)

Like sledge said the GS500 engine dates back to the 70s, arrived here in the US in a 77 or 78 GS400.  I wouldn't bother with any additives either.  They must have updated the exhaust valve and seat materials since then, there was at least one major update of this engine that I recall reading about besides the 400-450-500 displacement increases.

I check valves every 8k miles or so and didn't change any shims on the 97 until about 40k miles.  After that the exhaust valves began receeding faster and more and more frequent shim changes were required and one exhaust valve was down to the min 215 thickness shim at 80k miles.  The intake valve shims were never changed on that engine.

On the 02 GS I've followed the same extended intervals and it's followed the same pattern to it's current 56k miles.  I now set the exhaust valves at .004-.005" when I change shims to extend intervals.  Here's a complete record if anyone is interested:

http://img.photobucket.com/albums/v443/jcp8832/valveclearances.jpg

Quote from: Jay_wolf on January 21, 2008, 04:05:16 PM
Well , explain , why there are so many polish in the Uk? , there are polish shops all over southend , and theres a hospital just for the Polish in london . crazy world lol

is it a problem for you??
you sound like you didn't like that fact, sounds rasist to me!

but the explanation is easy - only two letters:   UE   
members of UE can do and work wherever they want to, whether you like it or not.

geez, now I know why Polish guys are going back to Poland -> too many unfriendly people in UK!


just my $ .02

Without wanting to start anything, that comment Jay made doesnt sound at all racist to me, nor do I think he intended it that way. However you have to understand that there will be resent from certain parties. The influx of Polish labour into the UK has caused the loss of 1000s of jobs and driven wage rates down. The government are not bothered because as a whole the economy is not suffering. Ask someone who has lost his job and livelihood to a Pole who works for lower pay and he will find it very difficult to be friendly......wouldnt you in his position?

Anyway...we are here to talk about GS5s, not rasicm or anglo-european relations, so lets drop the subject and move on.

kml.krk, Its EU , and it means that there are hardly any checks to get into the country , unlike the Us , which if uve got a Certain Conviction , u cant get in ,

There are Polish people who come to the Uk ,and go to london ,the fact they will happyly work on Building sites etc for 3 pounds a hour ,means they cant afford to rent a room on the wages ,and go live in toilets , There have been polish people stabbing people for taking there Toilet space ,

There will be up to 10 polish in a room , and all live on a mattress's and have no life ,

Its not a racist comment , its a fact that 1000's of people are losiing there jobs ,  Brickys *or Bricklayers , Builders etc* , used to work for 10 pounds a hour , it can be cut in half , and less , and because of the polish will work so cheap and they are very very good , and hardworking , but it has angered people ,

Look onto the other affects , Higher Population , Less space, More homeless . Not enought council houses , More taxes because of the benifits and Hospital Bills and not everyone who comes into this country are here to do work , some commint fraud and others thus ending up in prison ,and we have something stupid like 100 cells left in the WHOLE country , so people are being released early for Violent attacks , Street robbery , Muggings ,

I think its infact you , who instead of thinking outside the box , just assume its a racist statement , Im sure not every american thinks that Mexicans in the country is a good thing ..

and yea the gs came in 89 , leaded from 86 etc lol

Jay,kml?
C-mon guys, it really doesnt matter and this is not the place. There is only a few of us in here from Europe, lets rise above it and not let the side down eh? 

What sledge said.

This place is for discussing GS's, not Eurpean politics of immigration policies from around the world.

yuppers my bad