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Engine Top Breather Pipe
Posted: Tue Jul 28, 2009 8:00 pm
by duncan234
The latter 4.2 engines were fitted with a 3/4'' bore breather pipe which is larger than that on the earlier engines.
Can any body comment on this and confirm if there are any advantages in fitting this to a 1965 engine to overcome the existing smaller bore arrangement occasionally becoming blocked by gunge?
I already have the later breather housing assembly and only require the elbow that goes on the back of the air cleaner box and some flexible piping.
The piping would be arranged to try and eliminate the inverted loop where the gunge collects.
Not concours but that does not bother me too much.
Posted: Wed Jul 29, 2009 7:02 pm
by stuarthardy
Hi
I am surprised that you are getting blockages. Do you have the gauze strainer fitted between the breather and the cylinder head? There should be a gasket between the gauze and the head and another identical one between the gauze and the breather housing.
Hope this helps in some small way.
Regards
Stuart
Re: Engine Top Breather Pipe
Posted: Sun Nov 01, 2009 10:29 pm
by DaveK
The latter 4.2 engines were fitted with a 3/4'' bore breather pipe which is larger than that on the earlier engines.
Can any body comment on this and confirm if there are any advantages in fitting this to a 1965 engine to overcome the existing smaller bore arrangement occasionally becoming blocked by gunge?
I already have the later breather housing assembly and only require the elbow that goes on the back of the air cleaner box and some flexible piping.
The piping would be arranged to try and eliminate the inverted loop where the gunge collects.
Not concours but that does not bother me too much.
Duncan,
On the original tubes there is a small hole on the bottom of the lowest point which allows condensation to drain out make sure you put that hole in.
The best thing you can do is to re-pipe the breather so it doesn't suck crap back into the engine like the early 3.8's. Mine had the smaller 5/8" tube which did hold a lot of gunk. I got a later XJ6 breather housing, removed the pipe and made up a reducer and fitted the aluminium flexi tube and no it goes straight out to atmosphere under the car.
Since my car is a 3.8 flat floor it looks like it should be there anyway.
Dave
Re: Engine Top Breather Pipe
Posted: Sun Nov 01, 2009 10:30 pm
by DaveK
The latter 4.2 engines were fitted with a 3/4'' bore breather pipe which is larger than that on the earlier engines.
Can any body comment on this and confirm if there are any advantages in fitting this to a 1965 engine to overcome the existing smaller bore arrangement occasionally becoming blocked by gunge?
I already have the later breather housing assembly and only require the elbow that goes on the back of the air cleaner box and some flexible piping.
The piping would be arranged to try and eliminate the inverted loop where the gunge collects.
Not concours but that does not bother me too much.
Duncan,
On the original tubes there is a small hole on the bottom of the lowest point which allows condensation to drain out make sure you put that hole in.
The best thing you can do is to re-pipe the breather so it doesn't suck crap back into the engine like the early 3.8's. Mine had the smaller 5/8" tube which did hold a lot of gunk. I got a later XJ6 breather housing, removed the pipe and made up a reducer and fitted the aluminium flexi tube and no it goes straight out to atmosphere under the car.
Since my car is a 3.8 flat floor it looks like it should be there anyway.
Dave