11 replies to this topic

[Big_Adam]

Ello folks.

Two questions for you and your mighty minds.

1) Do cam oil ways have restrictions of sorts in? Flicking through my Moss book there was a diagram with them in. Also on my engine that I'm building oil on one of the ends of the cam (for the life of me I can't think which) oil will flow thro quickly compared with the other cam oil feed where it's much slower to feed thro. Could it be I lost one?

2) Should I attempt a gearbox rebuild? You see my mother's birthday is coming up and I'd like to buy her a new bike to replace her current rather batted racer bike. My orginal plan was to go to good Mr Guessworks and buy a box for £130 odd and be on my way. With this bike plan the budget will take a hit. So should I buy some new bulk rings (that right?) and other bits and bob's to rebuild or just buy from Guessworks. I mean if I do *male chicken* it up I can still take the parts I have bought and give them to guessworks to do for me. But if I can do it myself then money save. The main problem is that I use the brute force ways of working normally. So there is that to consider.

I await replays and cheese.....well.....not too much cheese.

[stef]

mmm cheese.

im not clever so cant help you much, but i know its baulk rings. lol.

personally, i'd save more money and go to guessworks straight away.

depends what you want to do mate, if you want to have a go at it then you might as well, and it would be cheaper.

there is a guide on here somewhere isnt there?

[Sprocket]

Yes the cam oil feed from the main bearing housings have an oriface in them, they are like the brass gallery plugs but have a small hole in them. These prevent all the oil feeding the cam, starving the rest of the engine.

If you have never had a gearbox apart, dont do it to the only box you have and rely on, make your mistakes and practice on one that doesnt matter. Its a fairly simple affair though only if you follow the methodical procedure in the workshop manuals, vere from these and you will become unstuck, possibly loosing lots of small parts that are sprung loaded. You will either need a special tool, some main shaft 'C' spacers and a slide hammer or make a special tool up from a piece of steel tube and a spare main shaft nut and weld them together, you will still need the slide hammer. You can do it without the slide hammer, but its a royal pain in the arse and IMOH the slide hammer pays for its self by the ease of its use. Theres a lot to be said for a good eye in spotting flaws in the running surfaces, decisions have to be made as to what will be acceptable or not. I stripped three boxes and only managed to be happy with enough parts for building one, though i was being supper crittical as its not going on a 38bhp 998. Some boxes are plain dead when you pull them apart, others are like new after 80k, its a bit of a lottery.

I am no gearbox expurt, but wouldnt trust anyone to build a box for me.

Personaly, it depends what you get for £130, doesnt sound like something id want to put 140bhp through, No offence intended.

Edited by Mini Sprocket, 31 May 2007 - 11:43 PM.

[Guess-Works.com]

I concur...

The procedure for pulling a box apart and then rebuilding is not difficult, but it's the tools you need. Even something as simple as the large circlip which holds the single roller in is a pain to remove unless you have a large set of circlip pliers.. which are not an inexpensive piece of equipment.

when rebuilding apart from the obvious wear items, there's always the need for additional parts like shims etc... of which the ones in the box may no longer be within tolerance so having a second (or third) box to rob for parts is ideal.

I am no gearbox expurt, but wouldnt trust anyone to build a box for me.

could not agree more... which is exactly why I started building boxes..... Was completely done over by a recon box which lasted all of 3 weeks.

[Big_Adam]

Personaly, it depends what you get for £130, doesnt sound like something id want to put 140bhp through, No offence intended.

Hee hee, I'm a small bore man. No more than 60Bhp out of the wee 1050 (odd) cc engine I'm building. Looks like I'll have to go to good Mr Guessworks then. Have put my engine on hold for a while as I do want to get my mum a new bike for her birthday so she can scrap her old racer.

DAMN YOU LACK OF FUNDING, WHY DO YOU TAUNT ME SO!!

[Big_Adam]

Le Bump....of sorts.

Well I had a look round and the cam oil feed I'm talking about is the one on the pump side. With the timing gear on it. So I went to look at my scrappy block and it dosen't have one either.

..........so.....is there or is there not suppose to be one there?

[Sprocket]

You will find that that one doesnt as it also feeds the head with oil

[Big_Adam]

Ermm.....how? It gose from the bearing to the cam. The head is up.

[miniboo]

just get a rebuilt gearbox from GW for 50 quid. it will be fine i am sure otherwise he wouldnt sell them

[Big_Adam]

just get a rebuilt gearbox from GW for 50 quid. it will be fine i am sure otherwise he wouldnt sell them

£100. No gearbox to give to him, still using it.

[Sprocket]

Ermm.....how? It gose from the bearing to the cam. The head is up.

Have a close look at the cam bearing at no1 cylinder end, you will see a vertical drilling all the way to the top of the block. Then look at a cam and you will notice that this journal has a groove in it. so, the oil is fed to the cam bearing from the main bearing, it then flows round the groove of the cam journal and into the verical oil gallery to the head, while lubricating the cam bearing as well.

[Big_Adam]

Then look at a cam and you will notice that this journal has a groove in it.

Oooooooooow. I always wondered what the hell that groove was for. So I have my 1 single needed cam restrictor. Thats good then.