Crankcase breathing

[Huey]

Hi all,

 

I have read the various posts on this subject and realise my TR4 does not have the original breather tube on the crankcase near the fuel pump and everytime I take the car out I end up with oil exuding from the cap all over the engine and bay. Now this is not all bad as it protects the chassis, but I would like it to exit lower down. I have read that the original breather seems to cause more problems then it fixes so I would like to fit a vent tube onto my original chromed rocker cover using the existing tapped hole where the brass plug is fitted. My problem is I can not find a neat solution to get the pipe to attach to this tapped hole as the thread is UNF 1/2" 20TPI. I want to fit an elbow here and then go down the left side of the engine either to chassis level or use something similiar the oil catcher sold by Quiller (http://www.triumphshop.co.uk/).

 

Has anyone any suggestions or ideas?

[TR 2100]

my TR4 does not have the original breather tube on the crankcase near the fuel

pump.

I have read that the original breather seems to cause more problems then it fixes

so I would like to fit a vent tube onto my original chromed rocker cover using the

existing tapped hole where the brass plug is fitted.

 

The original breather pipe is not the perfect solution - there is still a bit too much

crankcase pressure (which is why the factory introduced a breather in the rocker

cover). But the standard arrangement is not so bad really (assuming the engine

is in decent nick) - do you have any breather pipe at all? Or is the outlet blanked

off?

 

Try fitting the standard breather pipe - it will certainly reduce oil spillage, possibly

to the extent you won't be worried. It certainly would be a huge improvement on

either nothing or a blanking plug.

 

Then start to work on venting the rocker cover if you still have excessive leakage.

You should be able to get a pipe to fit the tapped hole. I don't know if the usual

suppliers can supply, if not then try eBay or the Forum.

 

I think an oil catch tank is OTT until you have at least tried the above.

 

AlanR

[Andrew Smith]

......Then start to work on venting the rocker cover if you still have excessive leakage.

 

It might be worth fitting the push-on (vented/open breathing) oil filler cap from the TR2 - 3A, and I think it should also be fitted to the 4 - is your engine fitted with the 'non-lipped' rocker cover?

 

Cheers

Andrew

[Badfrog]

Hi all,

 

I have read the various posts on this subject and realise my TR4 does not have the original breather tube on the crankcase near the fuel pump and everytime I take the car out I end up with oil exuding from the cap all over the engine and bay. Has anyone any suggestions or ideas?

 

Hi,

 

Funny enough, I just went through the same problem with my car.

In case I'd forget a point, please visit Kas Kastner's website (http://www.kaskastner.com/) and go to the forum (http://kaskastnersforum.yuku.com/forums/64/t/General-Discussion.html).

There, look for the thread : "Oil spraying should be restricted to beach parties" .

 

Basically, you should go down a "dual decision" tree: is my car blowing excessively (piston slap or bad rings) or normally?

If the engine is the cause, nothing will do. Have it rebuilt.

If blowing normally , how come you don't have a tube: TR4A engine or tweaked TR4?

 

You have the choice of reinstalling the tube with the consequence that you will be a mean polluter (see if I care) and that you will be the victim of the inherent defcct of said tube: it goes down to much and the air draft under the car sucks out the oil. This is known as "the Jabbeke disease", check Triumph historical sites to learn how to empty your oil sump in three minutes through that tube.

 

So, I'll assume you have a normal blow-by but that it can only evacuate through the filler cap which should be of the press-in, not twist-on, type. If it is a twist-on, it would indicate again a TR4A engine. First, get a rocker cover with an outlet (or have one welded) and install one of these mushroom filters.

NEVER install the stupid TR4A PCV: it fouls the carburation and amounts to nothing in terms of blow-by. Besides, any PCV system should draw from the crankcase and not the cover as it increases the tendency of oil to go in the upper engine. In any case, all your system should be atmospheric and not infringe on inlet manifold aspiration.

 

Last point: vent from the crankcase. Two choices again as your tube outlet has been plugged. Either you unplug it and use that for vent, or you leave it plugged, install an electric fuel pump and use the mech pump hole to devise a makeshift outlet (my personal solution). In both cases, what you want is a tube (1" diam that goes up along the block for 5-6", then resolves into a rubber tubing which goes into an oil catch can bolted at the front of the inner wheel arch. This way, blow-by will evacuate cleanly, no unwanted sucking from air speed and you'll collect the oil fumes in a responsible way.

 

If you want to do even more, consider oil baffles and crank scrapers. Don't forget that crankcase pressure will also attack the rocker cover and sump gasket and the crank seals and force oil through it. Check 'em carefully. Permatex ultra-black is a great solution for gaskets.

 

Have fun. Don't forget a good soap brand if you're DIY. If your car blows as much as mine used to before I did all these small arrangements, you'll be gunked for days .

 

Yours TRuly,

 

JF "Badfrog" Savouret.

[Huey]

Thanks for the replies, this does not stop me driving the car its just a bit annoying and I don't want to spend a fortune but I still want a neat solution.

First of all the engine was replaced by a previous owner (in the 90's) and looking at the engine number it was from a TR4a, hence no breather on the side. Second, I don't believe it is blowing excessively so will treat as normal excess pressure! As the rocker cover is original and has the push on type filler cap with gauze. Another member suggested it might be too much oil gettting up to the rocker gear via the added rocker feed hose. So currently I have it blanked off to see if this makes any difference- none yet, still copous amounts of oil leaking down the back of the engine.

 

Therefore my options are:

 

Fit the original crankcase breather (I beleive this can be quite auckward) has no one produced an improved shorter version.

 

Replace fuel pump for electric and vent crankcase from there (Any pictures Badfrog?)

 

Stick with my original idea (although I was going to use 1/2" pipe).

 

In addition, I have seen the little K & N type breather filters that fit onto the rocker cover, surely this would get gunked up with oil quite quickly and start dripping too?

 

Huey

[foster461]

Thanks for the replies, this does not stop me driving the car its just a bit annoying and I don't want to spend a fortune but I still want a neat solution.

First of all the engine was replaced by a previous owner (in the 90's) and looking at the engine number it was from a TR4a, hence no breather on the side. Second, I don't believe it is blowing excessively so will treat as normal excess pressure! As the rocker cover is original and has the push on type filler cap with gauze. Another member suggested it might be too much oil gettting up to the rocker gear via the added rocker feed hose. So currently I have it blanked off to see if this makes any difference- none yet, still copous amounts of oil leaking down the back of the engine.

 

Therefore my options are:

 

Fit the original crankcase breather (I beleive this can be quite auckward) has no one produced an improved shorter version.

 

Replace fuel pump for electric and vent crankcase from there (Any pictures Badfrog?)

 

Stick with my original idea (although I was going to use 1/2" pipe).

 

In addition, I have seen the little K & N type breather filters that fit onto the rocker cover, surely this would get gunked up with oil quite quickly and start dripping too?

 

Huey

 

I had assumed those little filters go on the input side of the breather system, I agree that if they are on the output side they would get saturated pdq.

 

Stan

[Badfrog]

Thanks for the replies, this does not stop me driving the car its just a bit annoying and I don't want to spend a fortune but I still want a neat solution. Therefore my options are:

Fit the original crankcase breather (I beleive this can be quite auckward) has no one produced an improved shorter version.

Replace fuel pump for electric and vent crankcase from there (Any pictures Badfrog?)

Stick with my original idea (although I was going to use 1/2" pipe).

In addition, I have seen the little K & N type breather filters that fit onto the rocker cover, surely this would get gunked up with oil quite quickly and start dripping too?

 

Hi,

Sorry for taking so long to answer. Photos are attached. I did not exactly followed KK's advice (no 6" upward tube) but sort of adapted to my car. The mushroom filter has been replaced by a second tubing going to the oil catch tank.

Braided tubing is plumbing hardware. The little red gizmo is the block outlet from a 122S Volvo PCV. I bolted it on a steel plate which blocks off the mech pump hole. These plates can be found from any supplier selling electrical pumps such as Moss (no advertising here).

Definitely avoid the downward tubing on grounds of Jabbeke syndrome (oil aspiration by air draft under car).

 

Best of luck,

 

Badfrog

Edited August 20, 2008 by Badfrog

[rob.tr4]

Hi all,

 

I have read the various posts on this subject and realise my TR4 does not have the original breather tube on the crankcase near the fuel pump and everytime I take the car out I end up with oil exuding from the cap all over the engine and bay. Now this is not all bad as it protects the chassis, but I would like it to exit lower down. I have read that the original breather seems to cause more problems then it fixes so I would like to fit a vent tube onto my original chromed rocker cover using the existing tapped hole where the brass plug is fitted. My problem is I can not find a neat solution to get the pipe to attach to this tapped hole as the thread is UNF 1/2" 20TPI. I want to fit an elbow here and then go down the left side of the engine either to chassis level or use something similiar the oil catcher sold by Quiller (http://www.triumphshop.co.uk/).

 

Has anyone any suggestions or ideas?

Hello

I have a 4 with original engine & breather still fitted & oil used to come out from filler cap.

I replaced original push over cap with a cheap halfords oil cap that fits inside filler hole ( took tape measure into shop with me).

Seems to have solved problem of leek. Drove over 300 miles malvern weekend.

Regards Rob

[Badfrog]

Hello,

 

A last minute info. I drove 700 miles this w-e and the starter engine got loose but that's not my main point : I had to modify the crankcase vent.

Initially, I had the lower vent connected to the oil catcher and the upper rocker cover vent fitted with a mushroom filter. I have an alloy cover (Moss type). The oil fill stopper has a built-in "waste-gate" that allows too much oil vapor through on account of the weak spring inside.

I have now connected the upper vent to the second outlet of oil catcher. I also removed the mechanism in the stopper and replaced with a heavy duty rubber gasket to seal the oil fill totally. All oil vapors are now forced into the oil catcher.

I also noticed that the blow-by varies in origin according to the rpm. When any vent, upper or lower, sends off vapor, the other one aspirates it (at least in part). Thus, connecting both to the oil catcher improves efficiency.

I now have a "cleaner" underbody and a decent engine bay. Thought a few of you might be interested in getting the same state of affairs.

 

Concerning the starter motor, it's one of those fancy hi-torque japanese gizmos. If you get one, be sure to check the screws that hold the motor to the adjustable plate as they are not seriously tightened at the factory. I suggest undoing the screws, coating threads with red Loctite and screwing back real tight.

 

Good clean fun....

Edited August 27, 2008 by Badfrog