Pinto Unleaded Fuel

[Guest DAVE1954]

Hi I've got a 1992 Sierra 1.6 pinto engine, does this year run on unleaded petrol,haven't long completed a part built 2b Robin Hood and this hadn't crossed my mind. Cheers. Dave

[cb750]

Off the net: From January 1989 all OHC engines are suitable to run continuously on unleaded fuel and have the head stamped as below. Some earlier Sierra or Granada engines can continuously use unleaded and can be identified by letters stamped on the cylinder head by No. 4 spark plug.

 

1.6 litre engines would have M, MM or N, NN stamped on the head

 

Rob

[Longboarder]

Just here.

[Guest snowy2]

a local and very respected engineering firm who does lots of engines told me that the unleaded conversion i requested for my 2.0L pinto head was unnecessary he said the head should last as long as the rest of the engine being cast iron. he reckons that he has done a few and seen them side by side over a good few years and said there appears to be no difference in valve wear.

[Tazzzzman1]

Sorry mate but he's wrong... I know from painful experience. My pinto fitted to the 2b was supposed to have been modified with hardened valve seats. However noticed valve clearances on cam kept changing ( after I blew oil everywhere and lost compression) On investigation not only did I have a cracked piston but all exhaust valves had not been modified and were so badly receded that another 1 or 2 mil and valves would have busted through..... Ended up doing a full rebuild.

Edited July 9, 2016 by tazzzzman1

[richyb66]

Terry beat me to it. VSR is all about the hardness of the valve seats. Cast iron is soft so without hardened inserts, the valves will recede.

 

20 years ago when unleaded Pinto heads were cheap and plentiful I'd have just just kept running unleaded fuel and swapped the head when it became an issue but now that's probably not a good plan.

[IanS]

Been running a 1983 leaded head in a 2.0 pinto since leaded disapeared and not had any problems.

Done about 45,000 miles in that time.

There appears to be no consistancy in these heads

[Guest 2b cruising]

Ford engine castings up to and during the pinto era always came from different foundries.

That's possibly a part of the problem.

[Longboarder]

In the 80's ford were steadily switching all their heads to unleaded. Didn't just happen overnight in 1989. I don't know when they started the first hardened valve seats or when they started stamping unleaded letters on the exhaust face by number 4 plug. One nugget of info was that all injection heads, with the cam/pear shaped inlet ports, were unleaded. There's also the lead memory thing where a seat that has run leaded petrol retains the lead for some time despite running on unleaded although probably not for 20 years!

 

Nigel

Edited July 10, 2016 by Longboarder