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bad oil blow-by

Will_Ringrose

Senior Member
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Hey everyone, I am new here. i have a 73 triumph GT6 that has just become my Daily driver. I have notice after a little driving that i get oil spraying out the filler cap on the valve cover. Any idea's on how to fix that?

On the 73 I have just a hose running to the 2 carbs from the valve cover, then it goes into the carbon can.

Any help would be nice, the smell of the oil hitting my exhaust pipe after dripping down the back of the engine is not fun.
 
First of all - welcome.

Does the filler gap tighten all the way down? No broken bits on the cap that would prevent it from sealing?
 
tdskip said:
First of all - welcome.

Does the filler gap tighten all the way down? No broken bits on the cap that would prevent it from sealing?

Tanks, and Yes it fits tight, and no, no broken bits... I just got back from a sort trip down the highway, and it also appearers to be spraying out round the gaskets on the 3 bolts on valve cover too
 
Have you checked that the hoses from the rocker cover are open? Sometimes they collapse or kink without the problem being obvious.

As a test, you might try disconnecting the hose from the rocker cover, and taking a test drive. If it still blows oil out the cap & bolts, you've got a major blowby problem, which will likely require at least new piston rings to correct.
 
Two thought one is the amount of blow by which may be to high. This can be checked by testing compression, or better yet a leak down test.

Second how much oil is on the top of the engine? there really should not be allot of oil on top. The rockers only need a steady flow of drops, not a stream of oil. If you have one of those hoses attached to the back of the head to increase oil flow to the rocker, this would be a good time to eliminate it.
 
Another thing to check is to see if the mesh is in the baffle at the top of the valve cover, but a leak down test is definitely in order.

Jim

If it does come to a rebuild, let me know. There are a few changes from stock that will improve that engine(flattop pistons instead of the domed and a return to the larger exhaust valves)
 
this is my only car at the moment. Ill get on a compression test as soon as I get the kit to do so (lent it to a friend and have to go get it back from him). A leak down test may be best, but I just can not be doing that right now. When I drive with the filler cap off, I get no wear near the oil leaking out as i do with it on. I mean yeah a little bit of oil comes out bit not though the bolt holes and whatnots.


I don't see any mesh in the baffle, I have taken the valve cover off, and looked in the tube with daylight hitting the inside of the valve cover, and i do not see anything but the sheet metal when looking in to the tube.

In the morning, before I go do my rounds, I will take the hose off and see how much oil I get spraying (if any) ill also wipe down everything and try to get a before and after shot.

This motor was rebuilt by a friend not too long ago. I want to say less than 5000 Miles ago. But right now rebuilding it again is out of the question. I am in-between jobs and may be having to deliver Pizzas in it for a while *shrug*
 
When I put a baffle in the alloy valve cover on my car I tried it both with & without mesh. It worked better without mesh.

Check out the carbon cannister - it may be plugged.
 
Solved the blow by issue, the was a bad hose and clogged Ts. So after i replaced everything I took it out for a quick drive... No Oil at all


as i started to leave again to get some groceries and whatnot I get to the end of my driveway and it just dies.

I pop off the distributer cap and see that the arm that pushes the gap open is worn out. I didn't have a spare so I thought no big deal ill just grab the Distro I have on the original motor and try to get that up and running...

The one that was on the motor is a Lucas, the one on the Original is a Delco.

Any issues you can foresee swapping them out?
 
Put a little greasy lube on the shaft and drip some 3 in 1 down the center of the shaft under the rotor and see, would be my advice.
 
The advance curves are probably not the same. Could create some drivability issues.
 
Soo after reading a lot about it, I just ordered the parts I need and will. *shugs* lesson learned If you are going to rely on a 40 year old car for a daily driver, make sure you have spare parts
 
Short-term, I'm sure you could get away with using the Lucas distributor in place of the Delco. I'd be curious, though, as to the source of the Lucas distributor, as GT6s pretty much all used Delco, while the TR6 (and Vitesse 6 / Sports 6) used Lucas.

Heck, somewhere in Germany there's likely still an MGA 1500 running with a Triumph Herald 1200 distributor! (Shhh! Don't tell anyone! Long story....)
 
Well i bought a Second Motor rebuilt by a friend, That is what i have in the GT6 now. I have my original motor in storage, waiting to rebuild it. The motor that I bought had the Lucas on it. He informed me it was what was there when we overhauled the block and head. It is also an "HE" motor. I was told it would be a little better then what was in there before.


so not to mess with anything too much I'll just replace the parts on the Lucas (parts are on there way)
 
When I looked up the numbers on the distributer (41558 A) the only things i could find was a 73 TR6. I'm not too sure about that because under the first set of numbers it has "04 74" witch I assume is the date.
 
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