Catch can

[jcd]

1986 1100 slabby. 

36mm flatslides.  do they need a catch can? 

i had the top breather hose running to a filter but it soon cloged up then had it above the chain but was getting oil driping,  i have it runing into a plastic bottle now with a filter on top,  but thinking maby a catch can would be better?  but do you have the outlet running to the carbs?  and how? 

[Reinhoud]

Is there oil coming out of the breather? If yes, you need a catch can, If not, you don't

[jcd]

On 5/10/2024 at 11:16 PM, Reinhoud said:

Is there oil coming out of the breather? If yes, you need a catch can, If not, you don't

hi, yes oil does come out of the breather.  I would like to put a catch can on it , so breather hose goes into the catch can but I don’t  know where the the output hose from the catch can would go since there no air box to go into

[Wee Man]

Depending what you use for a catch tank. You can just leave the top of it open to let all the vapours evaporate. It'll fill with oily goo, that needs emptied from time to time. Yonks ago I used an old drinking bottle for catch can.

Edited May 11 by Wee Man

[TonyGee]

I have an aluminium shampoo bottle on mine !!!!  polished all the logo shit off first  the tube from the engine fits tight in the top but i drilled a few small holes round the top so it can breath. 

[Gixer1460]

2 hours ago, Wee Man said:

 Yonks ago I used an old drinking bottle for catch can.

A Budweiser (or similar beer varieties) can used to be std. fitment at the Bulldog Bash - no catch can, no racing! Not that they were hard to find ! Wedged into a gap or held with a single zip tie - them were the days!

[Dezza]

I used to use a Fullers Golden Pride can but they haven't done it it tins for donkeys' years .

[Reinhoud]

12 hours ago, jcd said:

hi, yes oil does come out of the breather.  I would like to put a catch can on it , so breather hose goes into the catch can but I don’t  know where the the output hose from the catch can would go since there no air box to go into

If your catch can works alright you can vent it into the air..

[RUPE]

This came in handy …ah it matches colour oh and keeps me coffee warm 

[jcd]

why do you have catch cans on the oil cap filler end?  I have put one on the top rocker cover breather but just wanting to know why they go on the oil cap ???

[Gixer1460]

Its usually the biggest opening, and for pressure relief and easier breathing - bigger is better!

[jcd]

On 5/21/2024 at 7:51 PM, Gixer1460 said:

Its usually the biggest opening, and for pressure relief and easier breathing - bigger is better!

I have new gaskets throughout the engine but it seems a few lower engine gaskets are seeping,  just wondering if it’s because of the increased pressure of high compression pistons causing it and if having a oil catch can from the oil  filler cap would stop that

[Gixer1460]

Its not the High CR pistons themselves, its the inevitable ring blow by that happens with them - increased cylinder pressures = blow-by and turbo's are even worse! Having crankcase ventilation is a must and more is generally better, for example my 1186cc GSXR turbo had a -10 hose from centre of clutch cover, a -10 hose from cam cover, -8 hose from oil filler fitting and another -8 hose from the cam cover breather tower. Big ones to bespoke vented catch tank and little ones to open topped bottle for easy / quick drainage. The catch tank is the thing behind the side cover - 2No. inlets at bottom, 2No. outlets via filters at top.

 

[jcd]

On 6/19/2024 at 9:57 PM, Gixer1460 said:

Its not the High CR pistons themselves, its the inevitable ring blow by that happens with them - increased cylinder pressures = blow-by and turbo's are even worse! Having crankcase ventilation is a must and more is generally better, for example my 1186cc GSXR turbo had a -10 hose from centre of clutch cover, a -10 hose from cam cover, -8 hose from oil filler fitting and another -8 hose from the cam cover breather tower. Big ones to bespoke vented catch tank and little ones to open topped bottle for easy / quick drainage. The catch tank is the thing behind the side cover - 2No. inlets at bottom, 2No. outlets via filters at top.

 

good to know, thanks, I thought the top cam cover breather was enough but then wondered why lower gaskets were seeping

[jcd]

So I’m half way through getting the fittings for a crankcase breather -  would it be ok to have the crankcase breather and cam cover breather going into the same catch can  ??   catch can is a plastic oil container 

[Gixer1460]

I did in the above example except mine was a vented alloy tank! As long as crankcase venting is available - anything tends to work - empty beer cans have often been seen at a RWYB drag event!

[jcd]

Thanks for the helpfull advice  gixer1460

[johnr]

i think lucky7 sells one that bolts on in place of the sprocket cover.

[BillyR]

Mine vents into the exhaust via welding a fixing into the pipe. 

[jcd]

now I have the catch can sorted I thought all the troubles with seeping oil were fixed because of crankcase pressure but I am still having problems with the main output shaft seal behind the front sprocket as it has leaked again , it’s the second seal and I don’t know why it’s leaking again

new seal, new spacer, new retaining plate

probally a really stupid question but should the spacer that fits in the seal turn with the sprocket? just seems would be better if just the shaft turns so would be a whole lot less wear on the seal 

Edited August 1 by jcd