Jump to content

Recommended Posts

Good day all. 

I am going to install a crankcase breather to my engine. After a rebuild, a raised CR and triple webbers, I feel I need to let the arse end breath. I do see a large nut blank bellow the manual fuel pump. Is this a straight hole to the case that I could utilise. Or, seeing the manual fuel pump is no longer in use, can this hole be used. 

Thanks for help. 

Link to post
Share on other sites

Its better to have the top and the bottom breath independent from each other. They can go to a catch tank or be recycled through the air box. Which I dont have. So, to my original question again regarding whats usable on the case please. 

Link to post
Share on other sites

There is a article in this months Practical Classic written by Nigel on here that deals with the issue, Basically he takes a feed from the fuel pump blanking plate (PI car) to a catch tank so if your no using the manual fuel pump that's your puppy.

Andy

Link to post
Share on other sites

Thanks. Good advice. I still had the manual pump on the block. Doing nothing. So I have stripped it completely down and bolted the bottom back on to the block. Ah ha. Now a breather. Albeit gassing into the engine bay. Oh the green party will love me. Ha ha

IMG_20201019_141619_623.jpg

Link to post
Share on other sites

It's called up cycling if they ask!

Link to post
Share on other sites

There is good advantage to running a small vacuum in the crankcase.  Reduced tendancy to leak, and better extraction of blowby gasses for less oil contamination.

Ed

Link to post
Share on other sites
2 hours ago, PodOne said:

It's called up cycling if they ask!

Luckily I live in Croatia and not north America. I will get a better more factory system manufactured. I will put a cam cover breather on same side and vent both the a breather tank with filter. That should work nicely. 

Link to post
Share on other sites

looks pretty under there presume your running EFI

Link to post
Share on other sites

Thats exactly what I'm thinking. What did you use for the fuel pump blank. Aftermarket part or home made? 

Link to post
Share on other sites
12 hours ago, ntc said:

The std pi blanking plate does it just drill and fit upright bend also as shown above you need to vent behind the gearbox those little filters are useless 

Yep and a tiny tank like that will back pressure.

Stuart.

Link to post
Share on other sites

This is my set-up.

Catch tank was designed and engineering to pick-up existing holes where pedal box is mounted. One very small hole drilled to inner o/s wing to mount it, through a tab welded to the side of catch tank.  A drain plug resides just next to the throttle cable, when it requires draining of fluid.  A Black silicon pipe comes off the cap, and runs along the outer o/s wing, using two P-clips, and runs into the o/s chassis leg, so is essentially self-lubricating the chassis. The other pipe comes off the regular standard rocker cover outlet, and into the side of the catch tank, as pictured here.

Catch tank.JPG

Link to post
Share on other sites

A crankcase breather should slope up to the catch tank, else all condensation runs down into it.    That's the disadvantage of a rocketcover vent, you can't get the tank high enough.

Link to post
Share on other sites

I've been happy with this for 24 years/ 135,000 miles. Earlier this year I replaced the diaphragm in the SMITHS* pcv valve; otherwise zero maintenance.

 

Tom

* original to the TR250

TR PCV AND SILENCER SHOTS 009.jpg

Edited by Tom Fremont
Link to post
Share on other sites
On 10/19/2020 at 10:33 PM, ntc said:

The std pi blanking plate does it just drill and fit upright bend also as shown above you need to vent behind the gearbox those little filters are useless 

 

19 hours ago, stuart said:

Yep and a tiny tank like that will back pressure.

Stuart.

Neil, or Stuart,

I understand the upright bend....but what do you mean by "vent behind the gearbox" ?

Would you attach a hose to the upright bend and just hang the hose at the rear between engine and gearbox?

 

Jochem

Link to post
Share on other sites
18 hours ago, TRTOM2498PI said:

Catch tank.JPG

+1 for John,

the hose on this photo is the deepest piont and the flame trap work as an oil separator,

Sorry Tom, it is very likely you collect oil in the hose and not in the container. 

Edited by Z320
aborber - separator
Link to post
Share on other sites
16 hours ago, Tom Fremont said:

TR PCV AND SILENCER SHOTS 009.jpg
 

Sorry me Tom,

the way you use the PCV valve it is not made for and it does not work.

It is a "suck valve", a vaccum pressure reducer and an oil separator (to guide the oil beck to the valve cover).

Link to post
Share on other sites
2 hours ago, Z320 said:

+1 for John,

the hose on this photo is the deepest piont and the flame trap work as an oil separator,

Sorry Tom, it is very likely you collect oil in the hose and not in the container. 

Hi There,

This set-up was installed in 2017, and covered 19,800 miles since installation.

I can indeed confirm that this catch-tank gets filled with condensation, etc,  and is emptied approx every 3 months.  The pipes are absolutely clear.

 

Cheers.

Edited by TRTOM2498PI
Link to post
Share on other sites
3 hours ago, JochemsTR said:

 

Neil, or Stuart,

I understand the upright bend....but what do you mean by "vent behind the gearbox" ?

Would you attach a hose to the upright bend and just hang the hose at the rear between engine and gearbox?

 

Jochem

We fit larger catch tanks like the Racetorations one with one pipe from the block which goes upwards to the tank and then another from the rocker cover and then allow them to breathe out of the catch tank through a long hose running down to the chassis by the gearbox with the end of the pipe cut at an angle with the bottom of the chassis so that when moving it creates a venturi effect to draw  into the catch tank properly

Stuart.

 

Link to post
Share on other sites
1 hour ago, TRTOM2498PI said:

Hi There,

This set-up was installed in 2017, and covered 19,800 miles since installation.

I can indeed confirm that this catch-tank gets filled with condensation, etc,  and is emptied approx every 3 months.  The pipes are absolutely clear.

 

Cheers.

Hi Tom,

good you checked this, this means the vapours, hoses and the flame trap are all hot enough to avoid the oil condensing there.

Ciao, Marco 

Link to post
Share on other sites

image.png.29ecd4d2e46b42a84dd5dbdf2cd36b28.png

Tom, please expalin your layout?

Looks to me as if you have a T-connector that links together the rocker cover vent, AND the rear air filter housing to the PCV, which is mounted on the centre Weber intake manifold, which will suck in rocker cover gas and air from the filter.    Since the filter will flow vastly more air than the crankcase, I would expect far more of that tahn gas, and since Weber manifolds are not linked by pressure balance tubes, your Nos.3 & 4 bores wil be getting a lot more air than the others.   Have you compensated for that in way you have set the middle Weber?

Further, a second hose appears from behind the rear of the block, and disappears under the PCV.  Is this the vacuum control for the Dizzy?   If so, I would fear fluctation in the vacuum not strictly to do with throttle opening, as the PCV open and closes so near to the take off to the dizzy hose.    Clearly, you are not concerned by this fear!

John

Edited by john.r.davies
Link to post
Share on other sites
1 hour ago, stuart said:

We fit larger catch tanks like the Racetorations one with one pipe from the block which goes upwards to the tank and then another from the rocker cover and then allow them to breathe out of the catch tank through a long hose running down to the chassis by the gearbox with the end of the pipe cut at an angle with the bottom of the chassis so that when moving it creates a venturi effect to draw  into the catch tank properly

Stuart.

 

Yep thats the way to do it, note for Tom I have never needed to empty mine in 15 years +

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.