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TR4/4A Road Draft Tube Modification

TR Tom

Senior Member
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I have a later version TR4 that originally came with the sealed oil cap, small vent tubes to the air cleaners and of course no road draft tube. I always thought this system did a pretty poor job of crankcase ventilation, so added a road draft tube and a later 4A style vented oil cap (and left the hoses to the air cleaners). It appears to do a better job of getting the fumes and moisture out, but I’m tired of the drip from the tube everywhere I park.

I’m thinking of doing the Kastner modification to the tube, but have a couple questions:

He seems to show just running the tube straight up and leaving it open at the top. I’m thinking topping it with a push on oil cap might be better.

How do you keep the modified tube in the block hole? The original has a bracket going to the oil pan, but that part is removed as part of the modification.

Has anyone done this modification, and how were the results? This is not a race car, so I don’t need a full on catch can system, I just want a little cleaner driveway.
 
Usually the side tube does not drip. It will if not sealed at the block. Make double sure
that the tube does not fall off or you lose a motor.Excess crankcase pressure is a symptom
that must be addressed(broken rings). With the vented valve cover and a proper road draft
you should be 59 fine.
Mad dog
 
This is only useful if you DON’T use the mechanical fuel pump.

And could be easily made where you are
You close off the original breather hole in the block with a core/freeze plug ( like used in the back of the head)
And fit this elbow pipe where the fuel pump went it’s bolts in so it’s secure and is higher up the block so less affected by oil splash.
You can then attach a rubber pipe straight up or to wherever you like to keep things clean
 
I installed a breather tube in my TR4 engine in my 59 TR3. To reduce eliminate dripping, I put some 1/4” wire mesh and glued it in the pipe and then some coarse scotchbrite sanding pad to catch droplets before they get to the elbow. Seems to work well for 2 years now
 
This is only useful if you DON’T use the mechanical fuel pump.

And could be easily made where you are
You close off the original breather hole in the block with a core/freeze plug ( like used in the back of the head)
And fit this elbow pipe where the fuel pump went it’s bolts in so it’s secure and is higher up the block so less affected by oil splash.
You can then attach a rubber pipe straight up or to wherever you like to keep things clean
I actually did a system like that years ago when it still had the electric pump the PO had installed. Rings were so bad at that time I had no idea if it was effective or not. Have long since gone back to OE fuel pump.
 
I installed a breather tube in my TR4 engine in my 59 TR3. To reduce eliminate dripping, I put some 1/4” wire mesh and glued it in the pipe and then some coarse scotchbrite sanding pad to catch droplets before they get to the elbow. Seems to work well for 2 years now
An interesting idea to consider-thanks
 
Usually the side tube does not drip. It will if not sealed at the block. Make double sure
that the tube does not fall off or you lose a motor.Excess crankcase pressure is a symptom
that must be addressed(broken rings). With the vented valve cover and a proper road draft
you should be 59 fine.
Mad dog
After recent rebuild I expected this to stop, but with less than 500 miles on the engine, maybe the rings aren’t bedded in yet? And yes, it’s sealed and bolted in. Of course it could be migrating from elsewhere…anything is possible. I’ll continue to keep an eye on things.
 
It is little used today, HOWEVER, a tsp of scouring powder in each cylinder
can force re sealing of rings. I have seen it done and it works. It is recommended
to not screw up in the first place of course. Rings that do NOT seal is mostly caused by oil
on the assembly when installed.It should be set in DRY without oil at all. This lets the rings seal in the first
minute of running.
A funny story from a former Jaguar mechanic, a factory rep was addressing excess oil consumption
and told the group that he recommended this but said he would not put it in print and would deny it if quoted.
Mad dog
 
It is little used today, HOWEVER, a tsp of scouring powder in each cylinder
can force re sealing of rings. I have seen it done and it works. It is recommended
to not screw up in the first place of course. Rings that do NOT seal is mostly caused by oil
on the assembly when installed.It should be set in DRY without oil at all. This lets the rings seal in the first
minute of running.
A funny story from a former Jaguar mechanic, a factory rep was addressing excess oil consumption
and told the group that he recommended this but said he would not put it in print and would deny it if quoted.
Mad dog
Sounds like an clever trick…hopefully I never need to use it.

My plugs are burning dry and a nice tan color, so I fortunately don’t think that’s my problem.
 
I knew some dirt track racers that used Bon Ami for that purpose on their freshly rebuilt engines.
 
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