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View Full Version : How To: OIF ATF in primary/real breather system



TigerChris
08-25-2010, 6:03 PM
Triumphs leak everywhere, we all know that. Most of the problem is really poor crankcase ventilation. The added pressure in the crank case from blow by/both pistons moving up and down at the same time can hammer oil right out of you rocker box gaskets. You will also notice that your clutch sucks balls and grabs/slips depending on the tide. Fortunately there is a solution!

Build yourself a real Breather system!

First, Pull your primary apart.....

I use Right Stuff gasket maker to seal everything.

http://i81.photobucket.com/albums/j204/ceason/Schoolin/DSCN3029edit.jpg?t=1282779605

The spring on the seal is important, if its the other way, the vacuum in your engine will pull ATF into your crankcase and your oil pump will pump it into your frame.

http://i81.photobucket.com/albums/j204/ceason/Schoolin/DSCN3144edit.jpg?t=1282779843

Now you need to find an adaptor to fit in your timing plug hole. (I cant remember where i found mine) a short piece of hose, a PCV valve (pep boys, Look through the boxes) and a long piece of hose. Here you can make a decision on weather you want to run a hose off the PCV valve all the way to the back so oil can drip out, or, drill, tap, seal a 90* fitting in your backbone so the oil drops go back in the oil tank. If you do the later, you need to make a larger vent further up the tube for the crank case gases to escape. No matter what, the pcv valve has to be upright with gases able to escape the crank case. (a PCV valve is a 1 way valve, the whole idea is to make a pump out of the engine. When the pistons come down all the air escapes, when the pistons go up a vacuum is created.)

http://i81.photobucket.com/albums/j204/ceason/Schoolin/littlekidpcv.jpg?t=1282780233

In my professional sketch you will note that the PCV hose is connected to the backbone almost in the middle of the stretch between the neck and the oil tank, thus allowing oil vapor to condense and join forces in the southern region of the frame while allowing gases to escape through a vent up near the neck.

This mod not only allows you to run ATF in your primary, but also keeps a vacuum in your crankcase, reducing oil leaks.

justice66
09-02-2010, 9:14 PM
I have a 71 tr6 that didnt seem to leek out of the rocker boxes but i just hardtailed it and have the engine out of the frame. Is it a good idea to make this breather for all oifs?

Torch
09-03-2010, 9:43 AM
question for you. if you are trying to keep the crankcase pressure out of the primary then aren't you putting the crankshaft seal in backwards? the rule of thumb is the spring always goes toward the pressure.
Look at the cam cover oil pressure seals. and the seals inside brake master cylinders.

Torch
09-03-2010, 7:18 PM
I have a 71 tr6 that didnt seem to leek out of the rocker boxes but i just hardtailed it and have the engine out of the frame. Is it a good idea to make this breather for all oifs?

The late model breather is the improved breather system and in my opinion the only time you need to mess with that breather system is if you convert it to a belt drive primary, and MAP cycle makes a complete breather kit for that application.
on 1970 and later Triumphs we have never had any problems with that breather system and don't usually have any leaking issues related to crankcase pressure.

sorry Chris, we would be out of business if all the Triumphs we build " leaked everywhere". There is a cause and a cure for every leak, but a properly put together Triumph engine does not " leak everywhere".

TigerChris
09-03-2010, 7:32 PM
question for you. if you are trying to keep the crankcase pressure out of the primary then aren't you putting the crankshaft seal in backwards? the rule of thumb is the spring always goes toward the pressure.
Look at the cam cover oil pressure seals. and the seals inside brake master cylinders.

Nah, You are trying to keep ATF out of your engine oil. so spring towards primary. once the bike is idling it instantly puts a vacuum in your crank case. There is really no way for pressure to build in your crank case anymore. You're right about the belt drive, when i put a belt drive on it I am def flipping the seal around the other way.

Torch
09-03-2010, 7:36 PM
Nah, You are trying to keep ATF out of your engine oil. so spring towards primary. once the bike is idling it instantly puts a vacuum in your crank case. There is really no way for pressure to build in your crank case anymore

ok then why is there crankcase pressure? and put you finger over the timing plug hole do you feel pressure or vacuum?

fozz
09-03-2010, 7:41 PM
Nah, You are trying to keep ATF out of your engine oil. so spring towards primary. once the bike is idling it instantly puts a vacuum in your crank case. There is really no way for pressure to build in your crank case anymore

Your saying it puts a vacume into your crank case , if you got a vacume the oils gonna be sucked in not blown out fuck ya tellin me all them trumps ive owned didnt blow oil out put yer finger over the breather pipe it blows a lot more than sucks , get back ta yer rangrovers ya know nothing about trumpys change ya name ta wanabe biker

Torch
09-03-2010, 8:56 PM
Nah, You are trying to keep ATF out of your engine oil. so spring towards primary. once the bike is idling it instantly puts a vacuum in your crank case. There is really no way for pressure to build in your crank case anymore. You're right about the belt drive, when i put a belt drive on it I am def flipping the seal around the other way.

ok there is a question if there is crankcase pressure or not, so let that go for now.
but there is absolutly no pressure in the primary cover so what would be causing the ATF to shoot into the engine, the primary is vented to the outside at the top so why would you need the spring facing outwards.
certanly there is some concern about crankcase presure blowing into the primary.

TigerChris
09-03-2010, 9:24 PM
I'm gonna try to break it down, its very complex and has references to vacuum/positive pressure, crankcase displacement all that shit, rdygo. Our 360* cranks cause a large variance in crankcase pressure due to both pistons moving up and down at the same time. The cheapo remedy triumph did is to put tiny holes in the crank case wall into the primary. This allows x amount of pressure out so that the blowby don't eventually build enough pressure to blow your gaskets out. Positive crankcase ventilation works on the displacement variance inside the crankcase. As the engine fires, some blowby fills the crank case, that coupled with the air in your crank case is pushed out through the PCV valve as the pistons come down through the stroke. When the pistons move up, the valve shuts, creating a vacuum in your crankcase due to the displacement increasing but having no place to find a replacement for the expelled air/blowby. There are many benefits to this system: 1. A lower pressure in your crankcase leads to better rocker oiling, due to excessive pressure trying to force the oil back into your tank instead of pulling it through the rocker shafts. 2. higher relative oil pressure on the mains. same explanation, (if you have 40 PSI oil pressure at the switch and 20 PSI crankcase pressure your oil pressure on your bearings is only 20 PSI) 3. The vacuum under the rings while the pistons are rising helps keep the rings tight to the bore and prevent ring vibration that can cause broken rings. 4. Evacuating as much combustion gas as possible from the crankcase slows oil contamination due to there being less carbon for the oil to absorb.

Torch
09-03-2010, 10:05 PM
ok here is this, those 3 little holes are oil level holes for the primary to relieve any oil over that level back into the crankcase for the sump pump to return. there is pressurized oil vapor coming out of the crank bearing and it condenses in the primary and returns back into the engine. secondly Map cycle has been making the PCV valve kit since before you were born. I have personally installed many of them every time we put a belt drive kit on. it will still has a positive crankcase pressure in the motor. as both pistons go up one is on a compression stroke and the other is pushing the exhuast gasses out, there is blow by and compression leaks that will cancel out any possible vacuum effect. you are not going to get enough vacuum from the pistons going up to erase all the crankcase pressure.
i think you are confusing modern sealed water cooled automotive engines with a vacuum controlled crankcase that get vacuum from the intake plenum. with out that vacuum they too would have pressure in the crankcase, and they are set up to a lot tighter tolerances that an air cooled engine

Chris, I admire your enthusiasm but the basic design of the Triumph twin has basically remained unchanged since 1939, do you really think you can out think 70 years of experience of legendary engine builders and certified college educated engineers and then you come along and set land speed records with 2 years experience as a parts changer at a Land Rover dealership on your first Triumph engine build.

Really?

fozz
09-03-2010, 10:17 PM
I'm gonna try to break it down, its very complex and has references to vacuum/positive pressure, crankcase displacement all that shit, rdygo. Our 360* cranks cause a large variance in crankcase pressure due to both pistons moving up and down at the same time. The cheapo remedy triumph did is to put tiny holes in the crank case wall into the primary. This allows x amount of pressure out so that the blowby don't eventually build enough pressure to blow your gaskets out. Positive crankcase ventilation works on the displacement variance inside the crankcase. As the engine fires, some blowby fills the crank case, that coupled with the air in your crank case is pushed out through the PCV valve as the pistons come down through the stroke. When the pistons move up, the valve shuts, creating a vacuum in your crankcase due to the displacement increasing but having no place to find a replacement for the expelled air/blowby. There are many benefits to this system: 1. A lower pressure in your crankcase leads to better rocker oiling, due to excessive pressure trying to force the oil back into your tank instead of pulling it through the rocker shafts. 2. higher relative oil pressure on the mains. same explanation, (if you have 40 PSI oil pressure at the switch and 20 PSI crankcase pressure your oil pressure on your bearings is only 20 PSI) 3. The vacuum under the rings while the pistons are rising helps keep the rings tight to the bore and prevent ring vibration that can cause broken rings. 4. Evacuating as much combustion gas as possible from the crankcase slows oil contamination due to there being less carbon for the oil to absorb.

chris ya keep quoteing what the book says but in reality it doesnt work like that, in reality it works like this , triumphs do build up crank case preasure thats why oil gets forced out of the cases , ask anybody thats owned a triumph ive had about 12 plus bsa s they all do it thats why a good breather is worth its waight in gold ,,
old cars used to divert the preasure through the intake manifold they probly still do.

TigerChris
09-03-2010, 10:33 PM
ok here is this, those 3 little holes are oil level holes for the primary to relieve any oil over that level back into the crankcase for the sump pump to return. there is pressurized oil vapor coming out of the crank bearing and it condenses in the primary and returns back into the engine. secondly Map cycle has been making the PCV valve kit since before you were born. I have personally installed many of them every time we put a belt drive kit on. it will still has a positive crankcase pressure in the motor. as both pistons go up one is on a compression stroke and the other is pushing the exhuast gasses out, there is blow by and compression leaks that will cancel out any possible vacuum effect. you are not going to get enough vacuum from the pistons going up to erase all the crankcase pressure.
i think you are confusing modern sealed water cooled automotive engines with a vacuum controlled crankcase that get vacuum from the intake plenum. with out that vacuum they too would have pressure in the crankcase, and they are set up to a lot tighter tolerances that an air cooled engine

Chris, I admire your enthusiasm but the basic design of the Triumph twin has basically remained unchanged since 1939, do you really think you can out think 70 years of experience of legendary engine builders and certified college educated engineers and then you come along and set land speed records with 2 years experience as a parts changer at a Land Rover dealership on your first Triumph engine build.

Really?

I don't get your point, If you EVEN cut 1 PSI out of your crank case pressure and can run ATF in your primary for $4 bucks worth of pepboys shit how are you not winning? Am I wrong? Am I spreading un-truths? What are you trying to say? A guy wanted to run ATF in his primary so I showed him how. Then i laid out all the science behind it. I believe I'ts worth the $4 bucks and I run it on my bike.



do you really think you can out think 70 years of experience of legendary engine builders and certified college educated engineers and then you come along and set land speed records with 2 years experience as a parts changer at a Land Rover dealership on your first Triumph engine build.
Yeah, Yeah I do.

The scary thing is my next build is gonna be better.
I'm already working on where the supercharger is going to fit.

Torch
09-03-2010, 10:49 PM
I don't get your point, If you EVEN cut 1 PSI out of your crank case pressure and can run ATF in your primary for $4 bucks worth of pepboys shit how are you not winning? Am I wrong? Am I spreading un-truths? What are you trying to say? A guy wanted to run ATF in his primary so I showed him how. Then i laid out all the science behind it. I believe I'ts worth the $4 bucks and I run it on my bike.


Yeah, Yeah I do.

The scary thing is my next build is gonna be better.
I'm already working on where the supercharger is going to fit.
you are not wrong about being able to run ATF in the primary with the pcv valve in the timing plug, that set up has been around since the mid 1970's. the shame is the advantages of the ATF do not exceed the value of a good breathing engine
and I hope you do build some great blower motors, my advice is just do some research and learn some lessons from the thousands of engine builders before you that have also built incredible race motors.
here is a clue. the crank journals and case castings can only handle so much boost.

fozz
09-03-2010, 11:00 PM
Ok chris , im with inovation an the more improvments that can be done to a triumph the better maybe were not understanding what your saying but the way you say it contradicts what we know from experience. i hope you revolutionise the world of bike building , i realy do , maybe we mistake enthusiasm for stupidity , as torch said theres been 100 s of bike builders breaking world speed records on triumphs ect all looking for that extra rpm or reliability theyve supercharged , tubo d . nitros ect lightened its all been done but we come back to the same old thing its a triumph its probly gonna leak , its fragile it vibrates its gonna break down ocasionaly if not a lot me i wouldnt have it any outher way