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OK... am I mixing my FJ's and Series trucks up? I was thinking that it was the Series 2.25 that doesn't need headwork to run unleaded...but now I'm thinking I was mixing it up with my old FJ's....


RJ
 

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Technically they canot run on unleaded, I use CD2 and have not had issues (then again I don't drive much)
Ron
 

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Leaded Fuel

I run unleaded gas in unmodified, daily driven series rigs and have for years. Hundreds of thousands of miles later no adverse effects.
-Ike
 

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Leafsprung said:
leaded gas
Is that what you meant to say?

Series 4cyl engines do not have hardened valve seats (just cast iron) so need them fitted to run unleaded or they will end up with valve seat recession (VSR). Scientific studies (that I saw whan I worked for an oil company) have shown that old engines which have been run on leaded for a long time can retain "lead memory" for up to 25000 miles after changing to unleaded, but VSR will occur after the lead memory is gone - the rate will vary though, depending on engine operating conditions.

I ran my IIA (when it was a 2.25P) on unleaded for 30000 miles or so and when I blew a head gasket a number of the valves were showing serious VSR. How much of that was wear and tear and how much the unleaded fuel are unknown though. I paid $100AUD to get hardened valve seats fitted when I had the head reconditioned - after that I always ran on unleaded and the head was perfect when I pulled it off 20000 miles later.
 

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leaded vs unleaded

Never been a problem for me. Have owned 35 series rovers and have driven a series every day since getting my licence. Have always run unleaded fuel. No probs yet other than the normal wear and tear. My rate of "VSR" has been negligable. However, when rebuilding I normally fit the hardened ones, but come to think of it, can you even buy non-hardened ones?
_ike
 

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Leafsprung said:
Never been a problem for me. Have owned 35 series rovers and have driven a series every day since getting my licence. Have always run unleaded fuel. No probs yet other than the normal wear and tear. My rate of "VSR" has been negligable. However, when rebuilding I normally fit the hardened ones, but come to think of it, can you even buy non-hardened ones?
_ike
You are probably getting some VSR just barely noticeable above the "normal" rate. The study I mentioned was a very extensive test and ALL engines showed increased VSR above the control engines (running on leaded) after they lost their "lead memory" (up to 25000miles). But the amount of increase can be very small - so that you may not notice above normal wear.

You cannot buy non-hardened valve seats AFAIK. All the iron head cars used the head material as the valve seat, and after a few regrinds if you need to fit valve seats you now have "hardened" valve seats.

Looks like I have 30 series rovers to go to catch up to you. But I still have my first one I bought 10 years ago.
 
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