Amanco 1-3/4hp chore boy

I only ever use the fine grinding paste on valves. The coarse is only ever for really badly pitted seats. (the double ended tins with half coarse & half fine are the best, I forget the make now, they blue, red & white striped I think).

I find most people tend to over grind valves. If they are already seating quite well they will need very little attention. I know some people say they start off with a cordless drill, but I wouldn't recommend this as valves should be lapped in with a backwards & forwards motion, lifting the valve every few strokes & moving it round by 90 degrees. Also, they shouldn't need lapping in for that long, I could have lapped one in by hand before I even got the drill set up.

If you use the sucker ended swizzle sticks (I never get on with those on smaller stuff) or a screw driver (if the valve has a slot, which I prefer) you just need to rotate it between your palms (like Ray Meeres trying to make fire in the bush). Put 4 tiny spots of the paste dotted around the seat of the valve, plus a tiny spray of WD40 (or similar) to lubricate it a bit (just a bit mind) & off you go. There should be a nice, dull grey area in the seat & on the valve, a neat little band where they meet.

I reckon, with well seated valves, only about 60 seconds or so on each one is enough. Also, if you are using a screw driver, you'll need to place the head over an open vice or some blocks of wood, so you can reach underneath & push the valve up every so often to rotate it by 90 degrees (I usually rub for about 3 full seconds, then lift, then another 3 full seconds, then lift, & so on. I grew up watching my dad do this & remember the popping sound every time the valve goes back down).

These things need approaching with a bit of caution, as any grinding or polishing is removing metal, & it's a lot easier to remove metal than it is to put it back.

Also, the bigger the area where valve & seat meet, the worse it will perform, as they need to seat quickly & can kind of rattle around as they seat, which in turn wears out the guides. But, as these engines are of an early design, they may have a large seat pattern anyway, my advice here is just general valve grinding technique for any engine.

Hope this helps & that I'm not teaching granny how to suck eggs. Just ignore me if I am.

nuts i am happy with any advice we are all learning, the valves have 2 holes so will make a tool up to fit and give them a slight bed in,

bIlly thats what i liked about this one was the tank under the unit - making a more compact engine, also it has the small imp mag which i read is a good unit, - does the thickness and length of the copper wire have an effect on the ignitors power?

i am looking forward to stripping it down for a re paint, i hope to have a few hours working on it later in the week.

You can not put a time on how long it will take to seat a valve every one burns different
When you think you have seated the valve lift out clean off , mark 3 marks on the valve with a pencil say 12 o'clock 4 o'clock and 7 o'clock put back in and do a quick grind backwards and forwards
Lift out if the valve and seat are both bedded in there will be no pencil marks left.
When fitting valves back in smear a bit of oil round the seat , once springs have been fitted a light tap on the valve job done
Jonesey

cheers Chris, - i have just cut the Gasket and put it on i will re tighten it in the morning, it will be the weekend now before i get chance to look at the valves.

Don't see the need for the angry face Jonesey, I thought this was the friendly forum? (& you an admin too).

It is a fact that most people over grind valve valves. You should be able to tell they are done by the nice even dull-grey band left on the valve & the seat. Experience will tell you that.

My advice was simply meant to avoid people doing damage when trying to do good, as so many do. I am very fortunate to have a very good & experienced engineer & mechanic at my disposal, as well as my own qualifications & background. If I can pass a little of that on I think it's a good thing.

I have a little tip that may make life easier when grinding valve seats. Put a small spring under the head of the valve so it pushes the valve head off the seat when released......saves having to push the valve from the other side when it is all set up....sometimes up on bricks and bits of wood to get clearance.

Steve.....is that you on about shiney stuff already??

I don t think the length of the wire we are talking about here....magneto to ignitor....will make much difference.

Talking about the wire, sometimes you see people put a tight few coils in the wire near where it terminates (at either end). This is because it is usually single core solid cable & with movement & vibration it can work harden & snap. It also looks nice. So, if you do use a single core (solid) wire, perhaps wind a small coil in either end. Just wrap it round a small socket extension bar or large screwdriver, or something like that, maybe 5-8 turns. It just takes up any movement or vibration. You might have seen it before, if I find a pic of what I mean I will post it. I think the wire needs to be reasonably thick on these LT systems though, as they are such low voltage (as volts go down, amps go up & it's amps that need the space in wire). I still need to research LT ignition systems though. I know about Buzz coils now (sort of), but not really up on LT mags, just going on what I've seen out & about.

i am looking forward to stripping it down for a re paint, i hope to have a few hours working on it later in the week.

painting is a long way off in the summer i should of put these as 2 seperate statements, -

good idea Billy with the valve set up - will make it alot easier,

the spark must be ok as it fires ealily, but the wire does seem thin but has a curl in the centre it it had ove near the ignitor it would foul the hopper, it doesnt seem brittle,

going to check the return valve today and look at the strength of the inlet spring, - just hope i can get the end caps of the valves as they look like they are tight on as they have split dowel pins in then painted,

i hate to fee fasteners painted - should just be a smear of oil.

turned it over this morning it fired up but didnt keep going when i took my hand off the choke - i have checked the return valve and all seems ok - i have the mouth full of petrol to prove it lol, - i have however got a leak of compression from the gaskets i put on hmmmm -

i dont like gasket seal but do you think a thin smear would hurt?

i also have a small amount of loss around the ignitor? i guess i will always have as this is a moving part with a little bit of play?

Nuts, I have to agree with Jonesey there's no way can you put a time limit on valve grinding the same to be said about hardy using the coarse paste, all I can say is you've been very lucky if you've managed after all these years just using fine paste and a 2 minute grinding in job. Also you say about over grinding, you'd have to be super human if you can grind a valve so much that it damages the face or the seat.
You also forgot to mention that when turning the valve or lifting it for any reason don't slam it back down as any particules under the face or on the seat will pit the valve/seat so you've just wasted your time grinding them in.
The way to check if you can is stand the head over some newspaper fill inlet and exhaust with water and see if they leak over night, this was a trick taught to apprentices by one of the leading engineers in the North East, and if they leaked you did them again till they didn't leak, job done.

Stu.

Steve you can always use some gasket sealer as long as it's just a smear and wait till it cures before starting the engine. Steve are the faces completely flat? try a straight edge over them and see what there like, you could get away with rubbing it over a bit of emery/wet n dry as long as it's done on a flat surface or it's on a block of wood that can't twist or move out of true.

Stu.

You're supposed to fill the ports with petrol, not water. If there's any leakage it should become quite apparent very quickly, but they are usually left over night. The trouble is, it can also leak past the valve guides on some heads, so not easy to test all heads. (my JAP model 3 was like this, so I couldn't test it using that method).

I don't think you could ever damage a seat by over grinding Stu, but even on my JAP model 3, with really badly pitted exhaust valve, I doubt I was on it longer than 5 minutes in total before it was done (I did use the coarse on that one, but generally find the coarse paste too coarse for most jobs & leaves ridges).

The problem with over grinding is you will "pocket" the valves in the seats/head (an engineering term), this is where the valve sinks too far into the seat. This will cause wear on the guides & bad running, as the valves won't be able to close quickly enough & tend to rattle as they seat down. Once this has happened you are looking at a very expensive repair bill.

Like I said, any process on old engines where metal (or material) is being taken off needs to be done as lightly as possible & with great care (even polishing needs thinking about). The way Steve describes these valves they almost sound as if they require no grinding at all, but without seeing them no one can really be sure. Certainly an engine which starts & runs well enough shouldn't need much work on the valve seats.

As a footnote, I don't think anyone should be making angry faces at other forum members, especially admin members, who should be setting a good example.

JONESEY wrote:You can not put a time on how long it will take to seat a valve every one burns different
When you think you have seated the valve lift out clean off , mark 3 marks on the valve with a pencil say 12 o'clock 4 o'clock and 7 o'clock put back in and do a quick grind backwards and forwards
Lift out if the valve and seat are both bedded in there will be no pencil marks left.
When fitting valves back in smear a bit of oil round the seat , once springs have been fitted a light tap on the valve job done
Jonesey

From what chris says this is what u got taught years ago when i was a teenager and i still go by it to this day , and no matter how much grinding you do with course paste you can not wear the valve or seat out , thats alot of grinding paste to do that ! then finish off with fine untill get all the lines out . I always use a dab of paraffin to lubricate the valve while grinding too . when you think your finished 3 pencil lines and a quick twist as chris says . if bedded right no marks left .

matt

You shouldn't use coarse paste unless the valve you are grinding is severely pitted (almost to the point of machining). I have seen people over grind valves & cause them to pocket Matt, you need to take into account how much the valve has worn, how much the seat has worn & how many people have ground it in before you have. You will not be the first, & probably won't be the last either.

No one likes to hear they may have been doing something wrong, but from the sounds of it they have.

BTW, I also forgot to mention, you should remove all traces of grinding paste afterwards. You really don't want that stuff floating around your engine.

(& still no one mentions the bad use of the angry smilie. I was only just saying, on another thread, how friendly this forum was as well).

matt but then its obvious to see the wear on a valve as if lipped get the refaced or if too far gone a new valve will be required .

But alot of older engines ushally have pits in the valve seats . And i allways wipe tge paste off clean off with petrol / paraffin and give a good blow out with airline .

Matt

You're missing my point here Matt (I think). For a start this engine sounds like the valves are fine anyway, so would you still go ahead with coarse paste, ruin the already good seats by putting grooves in them, then on with fine paste to buff out the ridges?

Also, it's not as hard to pocket valves as people think. These are old engines, usually they've had hard lives & many different hands working on them. The last thing they need is unnecessary material ground away needlessly.

All you are doing, when lapping in valves (normally), is polishing an already machined surface to ensure a reasonably gas tight seal. If the surface has corroded & is very badly pitted, then coarse paste is used (usually as a last resort) to try & get that out. If the face is only lightly pitted then a grind with fine paste is all that's needed (BTW, some pastes are better than others, apparently the Halfords one is useless. Chemico paste is what you should be using & is what most of us will be using). Ask any good engineer or mechanic, or look in their tin of paste, usually the coarse side is still full, whereas the fine stuff always runs out first (I was only discussing this with 5 motorcycle restorers a couple of weeks back on the way to a bike show in my dad's car, how much coarse paste get's thrown away when you buy a new double sided tin of the stuff).

It's a delicate process & doesn't require a lot of work in order to achieve a satisfactory result.

Also, I never said you didn't wash out the paste afterwards. I was just offering it as advice as both I & everyone else had forgotten to mention it before. I'm not the one attacking anyone here. Just being helpful & offering some of what I was taught as an engineer & have picked up along the way by experienced professionals.

Also, once a valve is pocketed it needs a new seat. & as most of these engines don't have separate seats it will need the head machining to fit a new seat in there. Pretty pricey work I reckon.

i agree nuts that you should be carefull with any old emgine material - once its gone its gone, i think alot depends as you say how the valves have been treated in the past. - i am sure the angry smilie wasnt directed at anyone and especially off Chris you cant find a nicer chap, - its a good idea about the pencil lines and i have picked up some good tips and thats what its all about. i will give the valves the grind they need when i strip the engine but for now - i think they are ok just to see it running before the spanners come out.

steve w wrote:i agree nuts that you should be carefull with any old emgine material - once its gone its gone, i think alot depends as you say how the valves have been treated in the past. - i am sure the angry smilie wasnt directed at anyone and especially off Chris you cant find a nicer chap, - its a good idea about the pencil lines and i have picked up some good tips and thats what its all about. i will give the valves the grind they need when i strip the engine but for now - i think they are ok just to see it running before the spanners come out.

You tend to get a feel for these things anyway. Sounds to me like you know what you're doing.

Tell you what, shall we move on now? After all, it's not really a thread about valve grinding. Anyway, I think we've exhausted that subject. In fact, I don't think I could intake any more.

good idea to move on or it might be more than a valve that blows

For the atmospheric valve to work correctly and effeciently the engine needs to have good compression.
That is why I advised to give the valves a grind in to ensure they are a good air tight fit . Head gasket would need renewing anyway after taking the head off and the igniter gasket needed replacing as it had blown .

These actions are what I would do to the engine if it was mine.

The valves would be ground in anyway.....perhaps only lightly but it would be done for my peace of mind to reach the goal I was after....good compression.

There may be other actions to take on the engine to achieve good compression but these would go a long way to get there primarily.

My advice is given to help not hinder and is given through my knowledge gained by experience. In short ...take it or leave it

billypurves wrote: For the atmospheric valve to work correctly and effeciently the engine needs to have good compression.
That is why I advised to give the valves a grind in to ensure they are a good air tight fit . Head gasket would need renewing anyway after taking the head off and the igniter gasket needed replacing as it had blown .

These actions are what I would do to the engine if it was mine.

The valves would be ground in anyway.....perhaps only lightly but it would be done for my peace of mind to reach the goal I was after....good compression.

There may be other actions to take on the engine to achieve good compression but these would go a long way to get there primarily.

My advice is given to help not hinder and is given through my knowledge gained by experience. In short ...take it or leave it

I would agree. I always grind valves when rebuilding an engine. Peace of mind, like you say. I don't think anyone would dispute that.

Thanks chaps - Billy i take everything anyone says onboard, i appreciate the advice more than you know as i have no one else to help me, - everyone on here is such a great help.

with reff to the gasket - i think i need a thicker gasket with a bit more give to make a good seal - has anyone got any links to what i need - from what was said earlier it has to be exhaust grade and withstand high temps and pressure.

There's a good seller on eBay called TYM gaskets & seals. They might have something suitable (they also do good deals on normal gasket paper & stuff called Tesnit, which makes good head gaskets but doesn't contain metal, so is easier to work with & won't blunt gasket cutting tools like hollow punches. Not sure that would do the igniter gasket though, as you might need something with metal in it, but it could be worth a try if you were to get some for the head).

There's plenty of different stuff available on eBay from other sellers as well, but I can't be more specific than that I'm afraid.

Steve don't forget the thicker the gasket is the more compression you'll loss and more air/fuel mix will be drawn into the engine. So it might be worth just sticking to roughly the same thickness gasket.

I was an engineer on HGV's so I know these things.

Stu.

stationary stu wrote:Steve don't forget the thicker the gasket is the more compression you'll loss and more air/fuel mix will be drawn into the engine. So it might be worth just sticking to roughly the same thickness gasket.

I was an engineer on HGV's so I know these things.

Stu.

interesting point stu, didnt think of that