LCGB Forums

dscscotty wrote:What gear set are they? I'd be airing towards the 5.2- maybe even around 5.0 if the motor proves to be torquey?

I've got a gp150 which is 5.6 with the sprockets, chains I have. Or 5.2 with li150 (Spanish).

The gp150 box gets slated for the big 3 to 4 jump but I fugure at 5.6 it won't matter.

If I use the LI box, I'll have to use the gp150 one in the suzuki 190 I'm doing next. That has LI side casing. Is it easy to use a gp box/clutch in LI casings?

The bike isn't foreseen as being a tourer, although I don't actually know what it is foreseen as

If it's really bad I can fit a 16 sprocket, 81 link chain and pull down tensioner later.

What do you think?

shane BBoys wrote:Sorry so that’s a 58 with a 110 rod?
Shane

Sorry, yes 58 stroke, 110 rod.

They're both pretty crap ratio wise-3rd to 4th!

If you add the 16T sprocket to the GP box you will make the jump from 3rd to 4th worse.
Its not just going up through the box but you will notice it when changing down from 4th to 3rd at high speed. At 55mph and on an incline or headwind that starts to labour the engine, changing into 3rd will cause the engine to rev its nuts off and the engine revs will increase from about 6000rpm to 8000- 8500 rpm as the speed drops.

CHRIS in MARGATE wrote:If you add the 16T sprocket to the GP box you will make the jump from 3rd to 4th worse.
Its not just going up through the box but you will notice it when changing down from 4th to 3rd at high speed. At 55mph and on an incline or headwind that starts to labour the engine, changing into 3rd will cause the engine to rev its nuts off and the engine revs will increase from about 6000rpm to 8000- 8500 rpm as the speed drops.

Thanks, I get that. I meant if it's too revvy and the jump doesn't feel too bad I'd maybe try a 16 tooth. We'll see.

dscscotty wrote:They're both pretty crap ratio wise-3rd to 4th!

Aye, but they're what I've got so......

I'm sick of spending money so my current philosophy is build what I can from what I've got.

Expect a nicely built POS on the roads of the North East soon.

dickie wrote:

shane BBoys wrote:Dickie not sure if I have missed something ( v possible ) what crank are you using? Only out of intrigue! Ip
Cheers Shane

I don't think you missed, I think I forgot to add it.

I tried to use the original crank, but it was beyond my salvation; warkton tornado no. 1 now has it just to see if he can save it!

So scotty DSC took a new SIL crank from AF and fitted it with a Yamaha 110 rod.

the motor is about finished now. I should fit the gearbox etc this weekend. Just as long as I can get my eibar winter ready for chiselspeed dyno on Tuesday.

I had hoped to get the 175 ready for the dyno too, but I'm just not dedicated enough..

Thanks again for the crank, & once I get my 10 tonne press functioning (ex Vale Onslow) I can have a go @ cleaning it up on my Myford lathe (thanks Warkton Tornado No.2) & re-rodding, along with the other Indian cranks that I have acquired. Gulp! (Anybody else on here any tips as to true-ing a crank between centres on a lathe, I would be grateful. TYIA)

Looking @ the state of tune you have, I would suggest that the GP150 gearing is worth trying, as despite the adverse opinions, I recall my own Innocenti GP150 being fine, but that had a gutted (straight through) silencer that allowed an amount of over-rev.

If you can fit, say, a 16 x 47 & ensure the silencer has a large enough bleed (tailpipe bore) then you may be pleasantly surprised by the results.....

Failed at building the box.

Couldn't get a thin enough shim. Tried down to 1.6mm and it just locked it.

Original layshaft, case and endplate. New hub bearing (mb type with extra seal).

Tried 3 different gearboxes, all the same.

Checked bearing dimensions against an old one from a 64 LI and no difference.

Bearing and layshaft pulled fully home; checked a dozen times.

I measured face to face from an old LI layshaft versus the GP one I'm using and the GP one is 0.8mm longer, which would explain it.

However, I can't get my head round the fact that it's been in that motor for 30+ years.

I could use the old LI one but the splines are a bit iffy.

Got cold and I needed to get the timing set right on my other one, so I threw the towel in.

I'll try the old layshaft to prove a point if nothing else.

It's a bit disappointing as I'd hoped to get it on the dyno while I was there. Oh well.

dickie wrote:Failed at building the box.

Couldn't get a thin enough shim. Tried down to 1.6mm and it just locked it.

Original layshaft, case and endplate. New hub bearing (mb type with extra seal).

Tried 3 different gearboxes, all the same.

Checked bearing dimensions against an old one from a 64 LI and no difference.

Bearing and layshaft pulled fully home; checked a dozen times.

I measured face to face from an old LI layshaft versus the GP one I'm using and the GP one is 0.8mm longer, which would explain it.

However, I can't get my head round the fact that it's been in that motor for 30+ years.

I could use the old LI one but the splines are a bit iffy.

Got cold and I needed to get the timing set right on my other one, so I threw the towel in.

I'll try the old layshaft to prove a point if nothing else.

It's a bit disappointing as I'd hoped to get it on the dyno while I was there. Oh well.

From a safety aspect, I hope you are aware of the failures acociated with MB hub bearings fitted with non metallic cages.

My own experiences with setting up gearboxes means that I have acquired loads of shims, many of intermediary sizes created by cleaning up old shims on a surface grinder. I check even brand new shims & engrave the actual size on each, & keep them in size order.

I also assemble just the loose gears for shimming purposes & only add the cluster when the target is achieved. Three thou" & no variation.....

However, I also have several end plates & their press fit bearing journals, (or housings).They can vary considerably, but all OEM Innocenti, Eibar & SIL seem to interchange.

I suspect the problem you experience is due to a bearing housing moving within the endplate. I've experienced this problem, so tend to press them out (a good vice will do it) clean the outer up along with the endplate bore using Scotchbrite pads, & press them back in with Loctite to prevent them moving again. (They will still press out if required)

In fact, with a good selection of shims, end plates & their bearing housings, I can claim to always achieve three thou" which is the optimum for conventional four speed boxes.

I hope my explanation is understandable & helps

Cheers warkton. I think you've cracked it. I'd forgotten that I'd replaced the bearing journal due to pitting.

I'll bet my left gonad that I haven't pressed it fully home.

Still, 0.8mm between the 2 layshafts!

But I don't know what you're talking about with regard to bearing failures.

Some early MB rear hub bearings have a plastic cage on the inside holding the balls apart. This cage is quite easy to dislodge, leading to the bearings becoming 'loose' in the race. I discovered this accidentally with a bearing I had when I picked it out and all the balls basically dropped to the bottom... I laid the beating down flat, spaced the balls out and refitted the plastic 'cage' and carried on to build the motor. I subsequently heard of instances where this cage had come out on its own in running motors - the motor is now out and awaiting me getting round to replacing that bearing.

When you say face to face I guess you mean from where the fourth gear runs to the top face of the layshaft?

Are your gear stacks taller than the layshaft when fitted?

Thanks for that Ross. I just bought the bearing a couple of weeks ago, so I assume it's not an early one...I'll check.

Face to face is from where the bearing touches to where the shim touches. If.it were shorter, the layshaft would sit lower allowing more room for the shim. I measured the GP one in situ, so it could be a bad measurement. If warkton's suggestion doesn't work, I'll recheck that. Actually I will anyway.

And yes, the gears are taller on all 3 of the gearboxes I've tried.

rossclark wrote:Some early MB rear hub bearings have a plastic cage on the inside holding the balls apart.

Can you remember what year they stopped using plastic cages for their rear hub bearings.

dickie wrote:Cheers warkton. I think you've cracked it. I'd forgotten that I'd replaced the bearing journal due to pitting.

I'll bet my left gonad that I haven't pressed it fully home.

Still, 0.8mm between the 2 layshafts!

But I don't know what you're talking about with regard to bearing failures.

rossclark is absolutely correct

(Non metallic cages are fine for the bearings utilised elsewhere in the engine as they allow the bearing design to incorporate more 'elements' (such as the rollers in NU2205 E) & increase the load bearing capacity. In addition, Kart engines have used phenolic resin cages for many years because the material can cope with the demand of the very high RPM of the 100cc fixed gearbox classes)

But plastic cages in bearings incorporated in any part of the wheel hubs is a disaster waiting to happen, IMHO

HxPaul wrote:

rossclark wrote:Some early MB rear hub bearings have a plastic cage on the inside holding the balls apart.

Can you remember what year they stopped using plastic cages for their rear hub bearings.

I'm not sure. I must have bought that one at least four years ago - I'll see if I can pin it down any closer from some of the old pictures.

I'll take that back it must have been 2011 or 2012 as that's when I was building that motor.

Here is a picture of the offending article -



I actually picked it out thinking it was a seal of some sort, but managed to get it refitted.

rossclark wrote:I'll take that back it must have been 2011 or 2012 as that's when I was building that motor.

Here is a picture of the offending article -

image.jpeg

I actually picked it out thinking it was a seal of some sort, but managed to get it refitted.

thanks very much for that Ross.

And the other side - just for the record...

Well the prize goes to warkton tornado no.1.

You were right, I hadn't pressed the journal home properly. However, despite it now being in spec (0.1mm clearance), I had to use a 1.6mm shim to get that.

Box turns nicely now. I can only assume that the previous layshaft bearing was smaller.

Whatever, onwards and upwards.

The threads for the chain tensioner stripped really easily so I helicoiled and used studs instead. I know they're not as secure with studs so I used loctite

20190218_164448 by richardhenderson1968, on Flickr

These studs aren't a fortune and are so easy to use so I bought 100. 40mm long incase anyone wants to get some. 35mm might look a little neater but might not be so good with nylocs.
20190218_164456 by richardhenderson1968, on Flickr

Bought a lightweight flywheel new for 25 quid. It was advertised as being a second so no complaints. This pic is at 18 degrees btdc

20190220_184859 by richardhenderson1968, on Flickr

So I moved the boss round one hole.

20190220_192432 by richardhenderson1968, on Flickr

External pick up is the solution. I half expected this so I've already bought one.