Hi,
Does anyone out there know how best to ventilate the crankcase on a Rover V8 engine? The SD1 donor had a large flame trap on one rocker cover which
connected to the carbs via a T-piece and a small vent pipe on the other rocker cover which originally connected to the air filter assembly.
My flame trap is a real mess and the wire wool inside is all falling to bits (not good for the engine if I was to refit it...) so I am looking for
options.
I can get a little K&N filter for the small 8mm hose on one of the rocker covers but I don't know what to replace the flame trap with. I want
to avoid the flame trap feeding the carbs because I understand this upsets the engine idle. I can get a new flame trap from Rimmer Bros but it is not
cheap and I'm not sure if there is a better way forward (eg. Catch tank).
Any advice/ideas most welcome.
Cheers,
Craig.
hi,
im ready to be told this is wrong. but I replaved the rocker covers with thoes from an earler RV8 that have equal sized vents on each side ran a pipe
from each vent to a catch tank the catch tank has an out let on the top witch I atached a K&N filter to.
works well for me
blake
I am venting the two rocker covers and the one that comes out the back of the block just above the bellhousing all to one catch tank.
I am also running the rocker covers that have a small vent pipe
Seems to work ok.
Regards
Agriv8
Was'nt the vents not only there to suck off vapours but also to make a partial vaccume inside the engine block so as to minimise oil leaks on oil seals etc..while running??
Yes I belive that was the idea. Dont belive it quite works in principle ? but burning the vapors makes em not run as nice - running EFI Hotwire
Still like the article I saw in PPC a while ago somthing like .....
The Tvr has a unique chassis anti corosion device fitted its called the Rover V8 engine which constantly cotes the chassis with oil .......
regards
Agriv8
[Edited on 31/8/06 by Agriv8]
Thanks guys - I've asked RPI Engineering the question as well so I'll let you know if I get a response. I'm using SD1 rocker covers so
I think I'll get a K&N for the little pipe and run the bigger one into a catch tank.
Do you know if the flame trap is required given that I won't be connecting the breather to the carbs? I'm not sure which way the flame was
expected to travel - from carbs to crankcase or the other way around. I would expect it is to stop a blow-back in the carbs from igniting the
crankcase in which case I shouldn't need the flametrap any more. Does that sound right?
Cheers,
Craig.
Craig,
I've been running mine for 2 years now with the breather pipes from each bank connected directly to the carbs to suck the fumes and occasional
bit of oil vapour out.
No flame traps, no problems so far and idle is as good as a v8 can be. Mind you I hammer the engine so it would burn off any deposits before they get
a chance to form.
Cheers
David
Hi David,
Do you just use the standard flame trap without any of the wire mesh installed or have you made something up?
I thought about cutting the flame trap down to half size (for bonnet clearance) but I don't have any of the wire mesh and I don't think you
can just use steel wool. The proper stuff seems to be more like lots of chain links rather than wire wool. Come to think of it I'm not sure where
my flame trap is any more... Maybe I'll just fit a second oil cap in place of the flame trap and drill a hole in my rocker cover for a new
breather pipe.
Cheers,
Craig.
I have been running my RV8 without any breater pipes but it does "chug" a little bit of oil vapour once the engine gets hot.
Latest atempt is to use a filter on the small (8mm) outlet and to place an in-line PCV (positive crankcase ventilation) valve from the top of the
flame trap to the base of the carb (inlet manifold). Doesn't appear to upset the idle at all.
Whether this works for you will depend on your setup but my view is that the engine was designed to run with some sort of breather system.
I agree that you shouldn't be using wire wool inside the flame trap - it will act as a barrier more than a filter.
I have been running my RV8 without any breater pipes but it does "chug" a little bit of oil vapour once the engine gets hot.
Latest atempt is to use a filter on the small (8mm) outlet and to place an in-line PCV (positive crankcase ventilation) valve from the top of the
flame trap to the base of the carb (inlet manifold). Doesn't appear to upset the idle at all.
Whether this works for you will depend on your setup but my view is that the engine was designed to run with some sort of breather system.
I agree that you shouldn't be using wire wool inside the flame trap - it will act as a barrier more than a filter.
I have been running my RV8 without any breather pipes but it did "chug" a little bit of oil vapour once the engine gets hot.
Latest atempt is to use a filter on the small (8mm) outlet and to place an in-line PCV (positive crankcase ventilation) valve from the top of the
flame trap to the base of the carb (inlet manifold). Doesn't appear to upset the idle at all.
Whether this works for you will depend on your setup but my view is that the engine was designed to run with some sort of breather system.
I agree that you shouldn't be using wire wool inside the flame trap - it will act as a barrier more than a filter.
[Edited on 31/8/06 by robinj66]
Hi,
Yes I've been readin up on PCV systems a bit and found the following article quite interesting. I think this is defintely the way to go:
https://www.burtonpower.com/technical/tt_eng2.html
Since I'm not using the vacuum take off from my manifold for a brake servo I might be able to use it for the PCV take off. I need to do a bit
more reading up on the subject first. The main thing I want to achieve is to blank off the unions on my SU carbs which normally connect to the flame
trap. I know from personal experience how much smoother the idle can be on an SU carb'd engine with these blanked off.
Cheers,
Craig.
Here's something else I just found on the TR7 V8 forum:
http://www.tr-register.co.uk/forums/index.php?showtopic=1341
The guy is talking about 4 barrel carb conversions by the way.
quote:
PCV system. The Rover V8 requires to be POSITIVELY Crankcase Ventilated. Most of the oil related problems in a RV8 in otherwise good condition can be traced to the PCV system or lack of it.This means that the engine internals should be subjected to a mild vacuum by the sucking the air OUT of the flame trap and IN through the small vent on the opposite rocker cover. The vacuum in the air filter is NOT sufficient for this, despite a number of installations I have seen with this feature. The pipe from the flame trap should be connected, via a PCV valve, to full manifold vacuum. The brake servo should be connected to a fitting on the manifold, and the PCV hose should be connected to the big inlet in the centre of the carb base. A PCV valve MUST be used or the vacuum will be too great and the whole engine will whistle. Suitable PCV valves can be obtained from Real Steel 01895 440505, part no BYFV184, cost about £2, it fits in the neck of the flame trap. Don't ask them for the Rover V8 PCV vave, they don't know about this trick.
Craig,
I did this
basically, removed the flame trap part, made new cap (old too high anyway) and connected to the vacuum. Other side has a filter
ATB
Simon
Hi Simon,
Thanks for that.
Are my eyes deceiving me or does your "flame trap" hose have the mandatory split in it? I have the hoses from the donor car and they are the
same - must be a design feature eh?
Cheers,
Craig.
quote:
Originally posted by Agriv8
I am venting the two rocker covers and the one that comes out the back of the block just above the bellhousing all to one catch tank.
I am also running the rocker covers that have a small vent pipe
Seems to work ok.
quote:
Originally posted by 02GF74
the crankcase is connected to the air box to draw in filtered air
hi,
does any one have a vlear picture of where the chank case breathers are located?
Hi,
Simon's photo above is pretty much as clear as you can get I think. Note that the "crankcase" breathers are on the rocker covers which
is maybe what is confusing you. There are no breathers (that I am aware of) on the crankcase itself.
Cheers,
Craig.
thanks for the info.