Are there any reasons you wouldn't install an oil catch can on a carburettor'd 3.5?

This thought may be academic now that the majority of P6 cars on the road will be weekend cruisers, but the better the crankcase ventilation the longer the oil and engine internals will stay clean and the longer you will be able to go between changes.
I only have 3000 miles on the insurance currently, so my oil gets changed annually anyway. But a 10,000 mile a year car would need two or three changes and good ventilation, converting to road draft and having no positive ventilation will not help cleanliness.
 
If you’re gonna use a spacer, might as well be one of these :p

View attachment 15848
ew ur, shiny my precious. I do like the look of some of the spacers put up but I would recommend a heat insulating spacer as an essential as the heat will possibly cause some fuel boiling problems, some thing I noticed on my 500 Weber which got cured by an appropriate heat insulating spacer.
 
When the nitrous kicks in it would keep things nice and cool :cool:

On a recent episode of Engine Masters they found the small block they tested responded best to an open spacer on a dual plane manifold, and a 4 hole on a single plane.
I’ve always planned on a tapered 4 hole in phenolic for my dual plane as a best of both, but would be interesting to see the difference on the RV8 if any.
 
I have to type this one handed while my other controls a cranky 8 month old (lol). Manifold is a adapted standard one. I appreciate the advice and I'm diggin' the N2O spacer (highly illegal here)! I seem to have plenty of space between the filter and the bonnet to put a small spacer in, the plate adapted to the manifold to mount the carb is about 1/2" alloy so I think a 1/2" phenolic open might be the go. Still keen on a small catch-can to keep the intake as oil-free as possible, but before I get to that I have to think what is the best way to open up the tube at the back - is the metal soft? It looks like it was just crimped with a vice grip or similar. I'm hoping I might be able to prise it open and ream it round again - I think just cutting it might drop shavings into the engine....
While I'm thinking of all this I'm wondering if it's worth adapting the air filter system to take cold air from the left side front bottom of the engine bay next to the radiator....?
 
I have to type this one handed while my other controls a cranky 8 month old (lol). Manifold is a adapted standard one. I appreciate the advice and I'm diggin' the N2O spacer (highly illegal here)! I seem to have plenty of space between the filter and the bonnet to put a small spacer in, the plate adapted to the manifold to mount the carb is about 1/2" alloy so I think a 1/2" phenolic open might be the go. Still keen on a small catch-can to keep the intake as oil-free as possible, but before I get to that I have to think what is the best way to open up the tube at the back - is the metal soft? It looks like it was just crimped with a vice grip or similar. I'm hoping I might be able to prise it open and ream it round again - I think just cutting it might drop shavings into the engine....
While I'm thinking of all this I'm wondering if it's worth adapting the air filter system to take cold air from the left side front bottom of the engine bay next to the radiator....?

you might just be able to cut the end off the pipe, they do twist out the block so its not hard to swap for another one if your careful.

theres so much heat built up or trapped in the intake not sure ducting the intake will do much, but it cant hurt
 
Hi, This is what it looks like. It's a light interference fit into the back of the block. John Craddocks the Land Rover part supplier stock them although that's not help for you there. The larger size goes in the block and smaller pipe sticks up.

31791-603143-inlet-pipe-crankcase-breather-not-efi.jpg

Colin
 
I transplanted mine from 3.5 into the 4.6 block, seemed rude not to. However I kept getting a pool of oil on the floor. Wusn't until I stuck a wire up the end of the large diameter I found it was open right into the valley and I had oil pouring down the bell housing - Doh !
 
When I first got Sparky, there was no rear tube, just hoses from both of the rocker covers into a t piece and into the rear of the air filter. I don't think it worked very well, it just made a awful mess in the air box.
 
I had a good look at the 'crimp' today... I might just be able to get an angle grinder in there but the size of the resulting fire is a concern. I don't think I can just 'open' it up and removing it is also out of the question. Would it be bad to just run breathers on both rockers for now??
 
I had a good look at the 'crimp' today... I might just be able to get an angle grinder in there but the size of the resulting fire is a concern. I don't think I can just 'open' it up and removing it is also out of the question. Would it be bad to just run breathers on both rockers for now??

the worst thats going to happen is it wont breath well enough through the rockers and will be more prone to leaking oil, but seeing as that breather is pretty small by the time its got its filter and pipework attached i dont think it will much much if any difference
 
Lets see a photo of the 'crimp'. Do you mean that the stubby vertical tube on the breather pipe depicted in Colnerov's photo above has been squished closed? I doubt you'll get an angle grinder in there but I reckon you can extricate the pipe from the cylinder head, trim it and refit it without too much trouble. Not much room back there to work in but surely doable. It is a tight fit and may need some persuading!
 
The rear point is an air inlet in the Rover scheme of things whilst the rockers are out lets. You do need an inlet for fresh air.
The standard Rover system works quite well but using a PCV valve in your carb setup is what you need to be doing.
 
@mrtask that's exactly right (sorry I don't know how to do quotes in replies). I think I could cut the flattened section off, but I'm concerned about filings dropping into the pipe as it's cut. I know they're interference fit...but how tight are they normally?
 
Maybe stuff a bit of something down there that you can retrieve afterwards (a pipe cleaner?), and have at it with a hand held hacksaw blade, with a vacuum cleaner cunningly positioned to suck away any debris?
 
A cutting disc on a rotary tool would slice through it in an instant. I had use of a nifty Proxxon 'Micromot' that was perfect for fiddly, difficult to access jobs like this. On my tool shopping list.
 
Would it be bad to just run breathers on both rockers for now??

The idea is to allow clean air into the engine and let induction system drag the dirty air out and burn it in combustion. So if you put a small filter on one rocker cover, and connect the other up to the air box, it will be better than nothing. If you put your foot down hard, you may get too much pressure build up in the crankcase, which can blow dirty, oily air out of the filter on the rocker cover.

To quote in replies, just click on 'reply' link on the bottom right hand corner of the post.
 
According to Robs other thread he does not have any oil in his engine.

Yes he does

No he doesn't

Yes he does

No he doesn't

Getting my coat..............................................
 
Last edited:
Back
Top