Does anyone put lead replacement additives in their fuel? Or do we not do enough miles per year to worry about it?

No need to do it with our low compression, lightly loaded valves and bikes that where designed to run on anything!

I use Millers vsp e. There are a number of reasons for this. The most pressing was that I destroyed two sets of 16H grease lubricated guides and valve stems in short succession. I have yet to truly come to the bottom of this but I have a suspicion that the current highly volatile additive packages strip away lubrication rather than providing it. The vsp e includes a valve lubricant.

I haven't been able to assess why I'm one of the few with this problem (although I've heard of a number of cases with vintage OHV engines). It may be that engines which have run a while with 'kinder' fuels have built up a work-hardened surface. I should perhaps also add that I'm in Belgium so the fuel here may differ. It certainly stinks to high heaven and causes lots of domestic aggro if I bring the bikes into the integral garage without draining the carbs and wiping everything down.

A further consideration is that the Millers product includes an additive to delay the formation of water deposits in the ethanol which can only be a good thing in terms of tanks and fuel systems.

I can't offer any proof and I have no wish to preach to unbelievers but I'm a desperate man and I'll try anything !

I've run my M20/M21s/720s on ordinary lead free pump petrol without additives since its introduction and have experienced some problems but in quite specific circumstances...

An unexpected bonus of the introduction of lead free was it allowed me to fill my Royal Marines No7 petrol cooker directly from the bike as well.. ....

I had fitted a hardened exhaust valve seat to all my sidevalves for years anyway...This mod, irrespective of which fuel you run, extends the valve seat life and service intervals well beyond that of the standard cast iron valve seat....

Years back, running lead free petrol,I did find that I had some trouble with the exhaust valve on my M20 when used for regular long runs which included motorway work.
At the same time the M21 I was using for running about locally on short runs suffered no similar problems....

I wasn't able to pin down any fault with the particular engine and concluded that the problem was down to running at constant cruising speeds for quite long distances (said to be the 'worst case' situation for older engines...)

During this type of use (touring) I was getting through exhaust valves at the rate of about one a year, though damage to the seat was negligable with the hardened seat fitted...

I didn't try additives as a solution as I didn't want the inconvenience of carrying them and using them and found that for them to be fully effective the same additive should be used all the time. (RAC recommendation after testing additives under controlled conditions)..That also raised the question of availability when touring...

The solution I chose was to upgrade the valve specification... I modified a valve from an Iveco turbo diesel lorry to fit the M20 and had no further problems....

In conclusion I would say that in my experience if you aren't going to do any long distance touring you are unlikely to experience any particular problems...
In that situation I did, but I can't speak for others...

The hardened seat, even if used with standard valves will increase mileages between any remedial work...

It is worth noting that the much cooler running, more efficient OHV models suffer no such problems, irrespective of use and with standard valves and seats...(I have a B33 I have had for 34 years and have also run numerous others in that time)Ian

email (option): ian@wright52.plus.com

Thanks guys,
I think I'll motor on as before. I don't do many miles.

" have yet to truly come to the bottom of this but I have a suspicion that the current highly volatile additive packages strip away lubrication rather than providing it. The vsp e includes a valve lubricant."

that is exactly the advice I received form Burlen some years back; I had had trouble with sticky valvs on my G90 Matchless.

The stuff also dries out throttle slides.

Solution is to go back to using goold old fashioned Redex.

I have had no sticky valve problems since

email (option): deadsheds [ at ] yahoo.com

I have had no problems running plain unleaded and even e10 when times were tough.
An M20 will run on urine if you had a big enough night out.
The whole valve set bit was based on research done by the avaition industry and applies specifically to areoplane engines running at high revs at altitude under lean burn conditions.
Naturally our wonderful and totally technically illiterate third estate sensationalised this no end.
Apparently F1 did also have some technical troubles.
the rest of the auto industry did the minimum testing that they could to check there would be no warrantee problems with the switch to unleaded and a lot of makers took years to fully convert to hardened valve seats.

I am currently running a small engine repair business and no, nada , nil of the small engine makers are fitting hardened valve seats and those still making cast-iron side bangers still have the valves seating directly on the cast iron.

AFA the volatiles drying out the oxide layers on the carb body & slide, absolute total unadulterated crap.
The total volatile aromatics in the fuel we get down here is around 5 %.
The total amount of non volatile oil fins ( which is why you have to fit an after burner to your computer controlled fuel injected engins ) is around 30%.

Now some blends do have high amounts of oxygenators , which under some conditions might promote a thicker than desireable oxide layer growing on slides & carb bodies, the real problem is the zinc on zinc system was designed for daily use not one day a month. If you used leaded fuel in very occasionally used engines the oxide layer in the crabby will loose its trapped fuel lubricant and grow together thus fusing the slide in the carb the result of which is the syndrome known as gauling.
Victa recognised this 40 years ago which is why they developed the plastic carbys for their lawn mowers.

Now have a good think about this.
back in the day, real petrol was used for degreasing and general engine cleaning.
If you poured a jar of petro out and dropped the wheel bearings into it by the time you had removed them, repacked them with grease & refitted them there was nothing left in the jar, save the dry crumbling reminants of the old grease.
If you poured the real petrol into your cleaning dish , before you had removed the wheel bearings , by the time they were off the car, the cleaning dish was bone dry, SO where is the magical reminant lube ?

OTOH if you pour a jar of modern fuel and leave it there, it takes hours ( if not days ) for about 3/4 of it to finally evaporate and it then leaves behind a foul smelling goop that will eventually evaporate over a week or two in strong sunlight leaving behind a varnish like deposit, which oddly enough will not burn or redissolve in new fuel.

email (option): wariron@tpg,com,au

I wonder if fuel in Europe and Australia has the same properties ? Bikes with ticklers in the UK thirty-five years ago always had tarry brown-black carbs that took a lot of shifting and the fuel felt oily. The only paint threatened by it was rattle can cellulose.

Nowadays, fuel smells of gun wash, carbs are clean on the outside and even two-pack paint rinses off the cycle parts.

I've had no problem with valve seats but the incoming charge does seem to de-grease the inlet site of grease lubricated valve gear (not an M20 problem of course)

As I mentioned, I have no axe to grind but I've had problems that no-one has been able to satisfactorily explain so I'll carry on using the snake oil and hope that I don't need to fit my newly reconditioned spare cylinder too soon.

Although for some forum contributors I can think of it would be an irresistible temptation, I am loath to make a direct comparison between an M20 under long distance touring conditions and a lawn mower engine motoring round the rosebeds.. ...

I don't think these engines are really operating under the same conditions and it would be reasonable to imagine there may be a different outcome when both are run on lead free fuel...

The addition of lead to petrol was to enhance it's anti knock properties but also to provide improved lubrication for the valve seats etc...

Now whether the problems I experienced with lead free fuel under constant cruising conditions were down to the omission of lead specifically or some other factor in the changing make up of modern fuels I have no way of knowing...

But, I did have problems that were concurrent with the introduction of these fuels...and I did solve that problem by upgrading the valve specification...

Also, the use of the hardened valve seats does, quite definitely, extend the serviceable life of the seat...At least it does in an M20....Ian

email (option): ian@wright52.plus.com

Well the comparison is a lot closer than you might think.
Iron cylinders, air cooled run for brief periods then left sitting foe a long while between uses and oft left idleing for way too long.
Now Aussie yards used to be a little bigger than Pommie ones ( we are now selling 400 sq M housing blocks ) so we would be looking at 1 to 2 hours a month in the off season and 1 hour a week during peak growing seasons.

that sort of useage corelates quite closely to a lot of old bike owners.

As to personnal experience I have done a lot more highway riding on my M20 that I ever intended to do.
And being in Australia they are long stretches oft in the 400 - 600 km range or on an M20 a full 10-12 hours including bum massages, comfort , food and fuel stops.
My ex house mate moved to Albury and I have probably done the return trip 1300 km at least a dozen times
My bike had done massive mileage over the 20 years I have been riding it with not a hint of any valve problems , save the occasional flake of carbon getting caught under the exhaust.
the last time I had the head off we had to take .060" of the barrel to remove most of the erosion between the cylinder & exhaust port, which should give side bangers an idea of the running hours of this engine.
I have replaced 2 pistons, the linner & 1 exhaust valve the entire time I have been running this bike and the problem with the exhaust valave was it was cut too thin when I got the bike so it had started to burn on the edge.
The replacement valve has been in there 15 or so years and not been touched save a few grinds to bed it in properly and the last time I had to adjust the valve clearences would be before I moved to the farm so we are talking 5 years.

the only major difference between mine & yours would be the 626 hang in off the head and the fact that I used to run 20w50 in the engine which has now changed to 30w mower oil as I get it wholesale so it gets changed almost every time I take a load of oil to the recyclers.

email (option): wariron@tpg,com,au

Hi Ian,

I've just had my valve seats done, and put a NOS valves and valve guides,
On the 720cc barrel, so in this stage I will not replace it all,
(Did not assemble it yet.. waiting for some free time and cooler weather )

But maybe you can take it as one of your projects to make and sell this
Iveco turbo diesel lorry exhaust valve conversion (and seat?)?

Cheers,
Noam.

email (option): noam10@gmail.com

Hi Noam, That particular valve is no longer readily available as the truck is out of production...

It was actually perfect for the job being the right length and with a stem size slightly larger than the M20...So, the valve guide had to be resized for the valve, which meant effectively you got a 'new' guide....

The only real alteration was to remachine the collet grooves to suit the standard BSA collets and to reduce the head diameter to suit...

Modern trucks tend to have shorter valves so that could be a problem in looking for another 'donor'....

I have been meaning to get hold of G&S valves to see what they are using currently for their M20 valves....They do make a very good product...

Alternatively, when I have some spare time I'll trawl the catalogues again to try and find another 'donor' valve.

The seat only needs to be replaced on the exhaust side as the inlet is always passing a cold charge and seems to be unaffected by any problems...

Seats are available from many modern engine shops who stock them for repair work (and tuning work in some cases) on aluminium car and motorcycle heads etc...

If you want to get one fitted at some point I can supply you with a seat as a 'one off' but I don't have any intention to supply them generally at the present time.

You will then need to find a competent engine shop to fit the seat for you...

I still don't agree with the validity of Trevors direct comparison between the M20 and the lawnmower, but as you will see from Trevors posting, even his experiences with his M20 have been very different to mine in this regard.
So,it may be you don't experience any problems either.....

When I was rebuilding engines for a living and the subject of valve seats came up, which it often did, I would suggest that during a major overhaul fitting a seat was something to be considered, purely because the engine was apart...

However, I also pointed out that the other option was just to run it in a standard format and IF a problem occurred to do the work then...A valve or seat failure doesn't write off the engine after all...it just requires a repair job...

As stated in my previous post I have found fitting the hardened seat has extended the life of the seat and I always do what I believe will enhance the engines durability based on my own experiences...

It's something each person must consider for themselves I guess...Ian

email (option): ian@wright52.plus.com

Redex

email (option): deadsheds [ at ] yahoo.com

Hi Ian,

Thanks for your reply.
Very interesting !
I do add some potassium based fluid every fill or 2..

Funny how now vehicles only 15 or even 7 years old are obsolete
And you cannot find parts for them...

As you said: "That particular valve is no longer readily available as the truck is out of production..."

I am trying to get back to the road a 1960 BSA M21 with an WM20 motor and gear,
(The "Chopper" one, in the photo I posted some time ago, I got it cheap,
But this is a subject for another thread.... )

Anyway, as the current front fork is WAYYY too long, and actually is extended
And welded, I got a used fork from a Suzuki TS250,
(As the bike is not original anyway..) and I am missing the front brake caliper..
I was looking at eBay, went to scrappers, asked friends, tried the Suzuki parts service..
Everybody asked "Are you crazy? for such an old bike?.. you will never find it"
And we are talking on a bike from the mid 80's..

On the other hand, we seem to get whatever we need/want, sometimes even NOS
For the WM20, now 69 to 75 years old..

Best regards,
Noam.

email (option): noam10@gmail.com

Apparently, since being reformulated in 2004 Redex contains NO upper cylinder lubricant...Its only function is to clean internal engine components...

I got this information from the AJS/Matchless club site and it was supplied by Holts in response to an enquiry by a club member to the Holts Technical Dept., manufacturers of Redex...Ian

email (option): ian@wright52.plus.com

Hi Noam...I've sent an initial enquiry to GS Valves regarding their M20/21 valves...When I have all the information I'll post the details...Ian

email (option): ian@wright52.plus.com

that I didn't know Ian, as I said it was advice from Burlen within the last five years.
However I can't say I'm upset, as my stock of Redex dates from way before then as does my monograde oil stock.

That's about the only things I was glad to take away from the bike trade.

I even dispense it with one of those shot cans from the days when it was a 1d a shot.
dontcha hate smug buggers

I reckon a drop of 20 or 30 grade would do the trick these days



AJS/Matchless club, mmmm yeh well, not any more here

email (option): deadsheds [ at ] yahoo.com

Ian, there must be enough of those trucks still operating that spares must be still available. I don't know what model truck you use for the donor valves. But a very quick google came up with these.

http://www.ebay.co.uk/itm/EXHAUST-VALVE-FIAT-IVECO-8210-22-8210-22S-TURBO-DIESEL-13-8-1981-/151178628247

Ron

email (option): ronpier@talk21.com