xc90 V8

[262coupe]

Hi Clan, I have just had my 960 converted now instead of the V8 although I may intime do that too. Am I right in thinking that valve seat recession was also a prob on the 3L 960 engine even running on unleaded and that later versions of this engine had harder valves to prevent this?

[shimon340]

hi Clan,

Thank you for your reply. Im glad you clarified the situation! I recently asked a guy from volvo car powertrain about the bifuel engines. He hadnt worked on them but thought they were unmodified from the standard petrols.

thank you for clearing that up.

seems another case of the valve seats not being hard enough for unleaded but not for LPG. Im keen to learn more about the mechanism which causes valve seat recession in such vehicles running on lpg. I worked on a fuel additive for older cars running on leaded fuel that were swithing to unleaded. interesting how the seats function with unleaded and not with lpg.

as policy you mean volvo would pay 100% to get the head changes if the problem presented itself even when the car was out of warranty or were cars called back to dealers to get new heads. What was the range of cars affected? could you pm me?

thanks for another useful post!!

shimon

[ktrill]

I obtained a quote on a Prinns or more to the point I didn't due to valve seat problem. This was in 2006 and extracted the text here

Latest information from Prins NL, our preferred supplier, states that the 20-valve 2500 Turbo (2003 onwards) as used in the XC70, suffers from valve seat recession on LPG. This means unfortunately without expensive cylinder head modifications (hardened valve seats) you will have a very expensive bill looming after conversion. Should you wish me to provide a detailed quotation for the head mods, I will do so, but to give you a rough idea, expect to pay circa £1500.00 + VAT on top of the conversion which would be £1900.00 + VAT.

The info was provided by Alternative Fuel Systems Ltd and although obtained a quote from another dealer advising "wasn't aware" of a problem this did not feel me with confidence to splash out thousands of pounds on a conversion only for it to screw the engine up.