Leaded or Unleaded How Do I Tell

Post by **Tim_Hill** » Thu May 07, 2009 7:23 pm

Hi,
I have just bought my first Morris Minor, (and joined the oc yesterday!)
It is a 1967 Deluxe Saloon.
Although I bought it from a garage that took it as a part ex and as such they don't know if it has an unleaded head on. Is there any way I can visually check if it has had the head replacement?

Thanks, Tim

Post by **PSL184** » Thu May 07, 2009 7:56 pm

Not without removing the head and looking at the valve seats i'm afraid.... You could always contact the previous owners and ask?

Post by **Tim_Hill** » Thu May 07, 2009 7:58 pm

Damn was affraid that was going to be the answer. Don't really want to have to take the head off. I might try and get hold of the previous owner. Thanks!

Post by **PSL184** » Thu May 07, 2009 8:01 pm

(Anticipating the next question

) There has been a lot of discussion recently about using additives or not in leaded engines... I'll find the link for you to read and you can decide for yourself which way you want to go with it.

Post by **PSL184** » Thu May 07, 2009 8:02 pm

Here you go....

http://www.mmoc.org.uk/index.php?name=P ... ic&t=25161

Post by **bmcecosse** » Thu May 07, 2009 8:59 pm

The fact is - it doesn't matter - just use normal unleaded fuel and don't worry about it.

Post by **Cam** » Sat May 09, 2009 3:00 pm

If you are worried then use an additive. I can recommend Castrol Valvemaster Plus.

BUT if you do low mileages and keep the revs down then the valve seat recession will be minimal and you can get away with not using an additive.

The FACT is that valve seat recession (VSR) is very real which is why the FBHVC tested various additives and the 'control' engine - an A-series incidently did suffer recession.

For a list of additives that work then have a look at: http://www.fbhvc.co.uk/fuel/index.htm

If you just ignore it, then it will be fine... for a while.

Post by **bmcecosse** » Sat May 09, 2009 3:40 pm

That 'while' can be many many years! 8 years so far for me. Unless doing motorway work and lots of hard driving - the A series can manage fine without any additives. Just check the valve gaps every 5000 miles - and set the exhausts to 15 thou. And - the worst that happens is you may need to regrind the valves - but then that should be done anyway from time to time.

Post by **Cam** » Sat May 09, 2009 3:46 pm

So, again it's down to your own circumstances, the condition of your head to start with and your own inclination to worry or ignore!

Post by **bmcecosse** » Sat May 09, 2009 5:58 pm

As is life !

Post by **Tim_Hill** » Sat Jun 27, 2009 1:07 pm

Thanks for all the replies, I think I will go with adding additive as far as I can see this won't do any damage either way where as leacing it may cause damage over time.

Post by **bmcecosse** » Sat Jun 27, 2009 2:40 pm

Your choice - the damage of adding additive is to your pocket! Fuel is expensive enough at the moment. And unless using Tetraboost - it's debateable whether the other additives do any real good - although most do raise the octane number slightly - the Minor engine runs happily on 95 octane - nothing higher required.

Post by **rayofleamington** » Sun Jun 28, 2009 11:56 pm

The fact is -

Conjecture isn't fact. "debateable" advice is also not fact.

The scientific approach proves that VSR does happen on A-series engines and that some additives work, and some are a total waste of money.
Tests were run on A-series engines in controlled conditions (not just on and off my drive and round the estate a few times, bla bla) to simulate 50,000 miles of road use.

The additives that passed the testing were given FBHVC approval. The ones that failed were not - and worse than that, some companies refused to be part of the independant testing (obvious conclusions are easy to draw on their products!)

Obviously, the issue is only of long term damage to the valve seat area. Any old A-series could have eroded and pocketed seats , bent or chipped valves, overheating causing valve failure, poor rocker adjustmen etc... so over a few years at hobby mileage, VSR may be the least of the issues.

For those who want to avoid VSR in the long term, there is a choice based on factual evidence, of using an approved product. One of the other choices is not to use anything and save the money for a top end rebuild later on "if" one is eventually needed.
For those that don't DIY, a top end rebuild is worth trying to avoid!

Post by **MarkyB** » Mon Jun 29, 2009 8:55 am

Something that I haven't seen mentioned is that Minors were burning out exhaust valves long before unleaded petrol was around.
A decoke and associated valve grind was a standard bit of home maintenance for cars of this era.
Modern oils have reduced or eliminated the need decoking but standard valves will still need attention periodically.

Post by **rayofleamington** » Mon Jun 29, 2009 1:10 pm

Something that I haven't seen mentioned is that Minors were burning out exhaust valves

it does get a mention, in fairness... All of these being mentioned as they n lead to failed valves:

Any old A-series could have eroded and pocketed seats , bent or chipped valves, overheating causing valve failure, poor rocker adjustment etc...

Post by **mike.perry** » Mon Jun 29, 2009 10:14 pm

I am surprised that companies don't stamp their heads as uleaded. My unleaded s/v engine was stamped withe the builder's initials, the serial no. 001 as it was the first one he did and the date