Hs6 Emissions Intakes

[richbike]

Hi,

Since I have a stinking cold and can't sleep I was wondering about the now redundant emissions intakes on the carbs. Currently they are blocked off but since originally they formed a sort of pre butterfly balance pipe albeit teed off the valve cover... pause for breath...is there any merit in sticking a link pipe back on?

 

Any thoughts other than buy more night nurse?

Cheers

Rich

[oldtuckunder]

As you have a balance tube in the manifold (where its really needed) and as you say these are pre butterfly then IMHO a link pipe would do nothing.

 

As an aside, as you have no doubt junked the ECV/PRV feed from the rocker cover (as I suspect most of us have) an amount of research and some upcoming testing is leading my thoughts to a feeling that we ditched this technology thinking it was just an emissions thing, whereas I'm starting to think it may have actually had some positive benefits. More on this anon :-)

 

Alan

[richbike]

Interested to hear what you're up to.

Tbh I ditched mine because it ran much better without it but the head if not the whole lump is a bit tired so it was pulling in alot of crap.

[Nick Jones]

Triumph knew how to design a proper PCV system - and then apparently forgot.  They were fitted into the early 70s on GT6s, Vitesses, Spit Mk3 etc.  This was the "flying saucer" valve mounted on or near the inlet manifold and worked well.  Then they stopped using them and went to the joke hoses to atmospheric side of the inlet system.  Presumably for cost reasons - or the PCV man retired.  The PI cars had had this laughably crap system the whole time - mostly good for filling the plenum with oil.

 

I like the flying saucer valves.  They work well when their diaphragms are intact and are correctly assembled.  Now fairly expensive for some reason.  When trying to create a PCV system for my PI I struggled to buy a decent sized valve with convenient layout in the UK and ending up importing one from US ebay.  It was very reasonable and seemed to work well.

 

IMO, blocked off is the best state for those tappings!

 

Nick

[oldtuckunder]

ECV/PRV Manifold adaptor.

 

Well I'm kind of pleased with myself, have just created a ECV/PRV and MAP sensor adaptor for the Vitesse Inlet manifold from an odd plumbing fitting.

 

I had blanked off the ECV/PRV inlet port with a bolt decades ago. A couple of months back I wanted to add a MAP sensor, so found an original ECV threaded inlet pipe and found that I could tap the ID to 1/8"NTP that would neatly take the adaptor for the MAP pipe.

 

I wanted to use the position in the balance tube to feed the MAP sensor as I think its probably the best place to get a consistent reading, and also avoided tapping in anywhere else.

 

So today I wanted to re-jig things so that I can play with secondary air feeds, trying out an ECV again, but also wanted to retain the MAP sensor as that tells me whats happening.

 

So the best place for the ECV/PRV is back into the balance tube, but also the best place for the MAP sensor, so I was scratching my head digging through a fittings box trying to work out how I could make a a T adaptor that would feed both.

 

Look What I found!

 

 

Its an ordinary plumbing brass drain tap, would you believe that the thread in the top takes the original ECV pipe, the drain spout has an ID that is perfect to run a 1/8" NTP tap into, and the boss that is normally soldered into a pipe was almost exactly the right size to cut a thread on to screw into the original manifold tapping!  I'm not actually sure what size that is (its about 9/16 UNF) and definitely didn't have a die the correct size, but I had bolt the correct size. So I found a steel nut the correct size and working on the theory that the steel is harder that the brass fitting just used it as a die in a socket and neatly threaded it.

 

I can remove it and revert to either the original pipe fitting, or plugging bolt, or if I just want to blank off the large inlet port the original train tap plug with the rubber seal cut off will screw back in blocking the port but leaving the MAP sensor port open.

 

Alan

[Nick Jones]

Love it!  Some things are just born to have an alternate purpose and "only" need discovering. 

 

Nick

[richbike]

Nice!

I might try using the intakes with my bike carb balancer.

Never know...

[richbike]

So..

With only atmospheric valve venting it's pushing a bit of oil out the valve cover.

And so...

I reverted the OEM setup for comparison AKA joke hoses. I suppose it's using the butterflies as the valve. But....yuck.

Doesnt weep oil but doesn't run as well and I'm fairly sure it's more smokey.

I had also buggered around with the Colourtune and mixture so not entirely scientific.

Looking into putting together a proper manifold connected pcv valve system.

Not sure I want to give Rimmer's 80 odd quid for the proper kit but might try botching something with a Jeep unit off the bay for a tenner.

[oldtuckunder]

As Nick said above, the ECV/PCV feed to the carbs is a crap design, however as Nick also alluded the original Triumph design feeding into the inlet manifold was actually well engineered. Finished some test runs today without ECV, using a manually operated bypass air feed, and reinstating the original ECV feed to the inlet manifold. I haven't got time to write this up as its a busy weekend, but lets just say I think I'll be competing at Loton on Sunday with the ECV fitted! its a much understood piece if kit!

 

Alan

[richbike]

Hmmmmmmm...might try sticking an electric fan on a catchcan.

Or might just stay in the deckchair...

I