johndregg

Active Member

• Jan 11, 2015

• #1

I'm in the process of fitting BLOS variable mixers to my V8 on twin SUs. In order to do this I have to make my own air intake system as there is no place to fit the mixers on the original rover type. This means that I will be removing the alloy pipes that run from the flame trap to the carb mouth and replacing them with rubber pipe. This means there will be nowhere to plumb the breathers into.
What should I do about this? Will I encounter problems because of this?

 

Last edited: Jan 13, 2015

johndregg

Active Member

• Jan 13, 2015

• #2

Right as i've looked further into this i realise that the title of this topic might not be correct.
What i'm trying to understand is the crankcase breathing system on my engine. As i understand it air is drawn into the engine at one point and sucked into the inlet tract thus disposing of oily gasses.
Am i correct in assuming that on my 3.5 on SU carbs, the air is drawn in through the pipes from the air filter to the cylinder heads near the exhaust manifold and drawn out through the rocker covers into the inlet manifold?
Can someone help me with this?

 

johndregg

Active Member

• Jan 13, 2015

• #3

I'm guessing fresh air goes though this valve into the engine?

And that dirty air is drawn into the inlet from here?

But what does this one do? Draw air in or work as a release for excess pressure from the crankcase?

 

marccleave

Active Member

• Jan 13, 2015

• #4

The pipe from the elbows to the four little pipes that go into the cylinder head puts fresh air into the exhaust ports. It effectively dilutes the exhaust so emissions are lower. Surprised this hasn't been removed/ditched yet! You can removed the pipes and blank the holes off at the cylinder head.

The pipes from the rocker cover to the carburettors draws out fumes from inside the engine. Positive crankcase pressure and all that... I think... Will need someone else to confirm this.

 

johndregg

Active Member

• Jan 13, 2015

• #5

Cheers for that. As I'm getting rid of my standard air filter in order to fit the blos set up I guess I would be better blanking the exhaust thing off, I will fit a small filter to the other pipe where it currently enters the air filter system.

 

cooltide

sheep fancier

• Jan 15, 2015

• #6

marccleave said:

The pipes from the rocker cover to the carburettors draws out fumes from inside the engine. Positive crankcase pressure and all that... I think... Will need someone else to confirm this.

Click to expand...

Correct. Could also be piped to a catch tank for racing applications.

Glad you cleared the rest up.
I was going to say it looks like a load of unnecessary **** but thought if in doubt, say nowt

 

johndregg

Active Member

• Jan 15, 2015

• #7

I'm blanking off the detox exhaust holes and I've already sorted out the pipes to the carbs from the rockers. Once my blos mixers arrive the whole standard air filter system is coming out.
Got it clear how it all worked now!!

 

johndregg

Active Member

• Jan 16, 2015

• #8

While searching for a supplier of the blanking screws for the pulsair system I stumbled across a V8 builder near me. http://www.jrv8.co.uk
Just been up for a visit, it's a proper old school engine builder and tuners with a wealth of experience.

 

cooltide

sheep fancier

• Jan 16, 2015

• #9

Heard of him years ago. Didn't know he was in ulster tho.

 

cooltide

sheep fancier

• Jan 16, 2015

• #10

Just found his site.
So what's it going to cost to drop that Chevy small block in

 

johndregg

Active Member

• Jan 17, 2015

• #11

I shouldn't have gone, couldn't sleep thinking about the mopar dodge charger motor he has lying there!!