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MG MGA - Leadlfree fuel - valves and guides info?

Would appreciate advice re selecting/installing valves and guides for use with lead free fuel.

Am VERY hazy as to what is actually needed.

I "think" I know that different guides and valves are needed- but not what to look/ask for etc

Thanks in adavance for any info as well as any other info re the engine modification required.

Mark

ps
just applied the fill/putty coat- Hopefully some actual COLOUR this weekend - and an end to paint engrained nails and hands!
M THOMPSON

Hi Mark,

I remember when unleaded was first introduced in the UK there was a huge rush to convert cylinder heads to "run on unleaded". Since then, I have seen quite a bit relating to the B-series engines that say changing the valve seats is unnecessary unless you are running either very high or very low compression (sorry, can't remember which way round it was).

I'm sure some of the Americans on the board will be able to advise better, as they've had unleaded forever.

Good luck,

Grant :-)
G Hudson

I have never converted my head ( a 1960 1600 ) and after running on unleaded since leaded stopped here in Oz( 5 years ? ) have never had any problems. whatsoever. I do use an additive in the tank. If any problems I intend to address at that time and dont believe there is any real downside to this approach.....and possibly a big upside.
Neil Ferguson

Ran an MG Magnette for years on unleaded without converting and have been running an un-converted Series 3 Land Rover (similar cast iron lump) on un-leaded since 1992 to this day, no problems. Wait until your head NEEDS seat replacement and do it then.
Lindsay Sampford

Lindsay...do you use an additive? I have often considered dispensing with mine but data on net is inconclusive so not had the courage. I buy in large bottles so the cost is small..but....
Also have you ever had the head off on either vehicle to see if any deterioration?
Neil Ferguson

Neil, no, I didn't use an additive in the Magnette and don't use it in the LR, but I do use an additive with an octane booster in my 1954 Royal Enfield Bullet motorcycle as it has a higher compression ratio and things get a bit hotter.
Lindsay Sampford

Neil, me again, missed the last part of your post! When I did eventually overhaul the head on the Magnette(after many thousands of miles), the pitting on the valves and seats was no more than you would expect for a high mileage engine. I hadn't taken the engine down because of low compression i.e. leaking valves, but the bearings were getting noisy and oil pressure low when hot (early ZA Magnettes had a by-pass lubrication system). The valves looked like they had been ground a couple of times before (pre-unleaded) and the seats were pocketed, so I opted for "hardened" seats and the reputable engineer (Ivor Searle) said that the standard exhaust valves were perfectly able to handle unleaded fuel.
Lindsay Sampford

Lindsay....thanks for that advice and based on that and my own experience todate I will continue my current practice and without any mod to head and await a compelling reason to remove the lid in the future..and then make a decision....
What did you do to your MGA?
Neil Ferguson

Neil, bought the MGA in 2006 as a runner. Basically a sound car, but the engine, although it wasn't making any nasty mechanical noises, ran like a real pig. I was just getting it to run somewhere near nicely, when it blew out the rear core plug whilst I was giving it a good thrash! As it was an engine-out job to replace the plug, I decided to pull the engine right down whilst I was at it to see what I had got (easier to dismantle the engine than to get the wretched thing out of the car!). The valve seats were badly pocketed, so all were replaced with hardened seats and all the valves bar one inlet were replaced.
New cam and followers, new bearing shells and clutch and I've got myself a sweet little engine now.
The body has now been rebuilt with new sills, A and B posts etc. and resprayed, but I didn't take it off the chassis; I know I should have gone the whole way and done a full restoration, but life's too short and I want to drive the thing! It looks very smart, it ain't going to fall to pieces, but it ain't going to win any concourse, and that suits me just fine!
Lindsay Sampford

This thread was discussed between 16/08/2010 and 17/08/2010

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