Aluminium Rocker Covers: a baffling question

[rlabarre]

I have just bought an aluminium rocker cover as an early Christmas present for the Vitesse. Primarily in the hope that the stiffer cover would permit a better seal to the cylinder head, but also to improve the ‘under-bonnet appeal’.

 

What I only realised when I received it was that the manufacturers evidently do not consider that the breather tube should be fitted with a baffle to reduce the amount of oil being sucked back into the engine via the PCV.

 

The discussions on the internet on this subject are rather inconclusive. My feeling tells me that the conditions inside the rocker cover at medium to high rpm are such that a baffle would be required. Triumph were not renowned for running up manufacturing costs unnecessarily, but even they considered it necessary to fit a baffle to the steel rocker cover.

 

Before going too far, I would ask you what the experience in the club is in this matter? Is a baffle needed at all? I would be very reluctant to try to fit anything home-made inside the rocker cover. Does anyone know of a suitable device for mounting between the rocker cover and the PCV valve?

 

Thanks for any inputs.

[Pete Lewis]

the baffle is actually  more a fire wall, bit like a davey lamp  the gauze drops any flame from linking to  or from the carbs.

 

many cars  were fitted a flame traps in the breather  which always filled with  mayo and became a pain. 

 

without the dreaded external oil feed the  std flow wont give you any real oil carry over problems  

 

but a frontfire could ignite fumes etc. 

 

some thing to ponder over 

places like merlin motor sport do various filter also car builder solutions   for good ideas 

 

Pete

[GT6M]

Alot will depend on wot sort of rocker box ye got

one I had as v v narrow, and the rockers wer just aboot touching the sides.

 

on this type, the oil flung oft rocker arm /valve, an got sucked oot the pipe

used quite alott of oil on this,n

+side of this, as it used aboot pint of oil in 500miles, always topp,n up, I had fresher oil in me ingin.

 

Butt, the wols in thee,s things are farr too small.

the same size wol is fitted to 1100cc engines as are fitted to 2.5+ size engines.

 

then folk say, me engines leek,n oil,!!!!

 

there is a mod for ye t,doo, an easy mod if ye got some taps, an a bit of tin can.,

 

Drill a bigger wol, tap it, and also thread the new bigger pipe,

then insert into cover, and fit a bit of tin can owa it,

then tighten another ..slim nut,t hold it in spot, loctite it in

then folded doon over its self, so as it acts as a baffle

 

Or, ye can just extend yer OE pipe into cover a bit moer, and fit cover owa that.

Butt, still got problemo of a smaller dia pipe, which will build up pressure at higher revs

which meks yer engin leak oil

 

2 diff box,s same idea, but each slightly different

 jobs done,

 

M

[dougbgt6]

For added under bonnet appeal you could fit one of these?

 

http://www.rimmerbros.co.uk/Item--i-RB7432C

 

Don't know if it works, but it's certainly very shiny!

 

Late GT6s have no breather device, the rocker cover feeds directly into the carbs. The box does have the interleaved device before the breather outlet. I've seen a few late GT6s with alley rockercovers with breather outlets but apparently nothing internally so the oily air goes directly from rocker box to carbs..

[dave.vitesse]

If it was me I would be looking for some kind of inline fire/oil trap to fit in the PCV pipes.

 

But that just me.

 

Thanks,

Dave

[rlabarre]

Very many thanks for the replies.

 

I see that I evidently did not express myself correctly. My reference to the 'breather tube', was to the 1/2" tube on the side of the rocker cover, not to the oil filler. 

 

I the hope that pictures are worth more than 1'000 (misleading) words, I attach a couple of photos showing the two breather tube outlets on the two rocker covers.

 

Sorry for the confusion.

[dave.vitesse]

Very many thanks for the replies.

 

I see that I evidently did not express myself correctly. My reference to the 'breather tube', was to the 1/2" tube on the side of the rocker cover, not to the oil filler. 

 

I the hope that pictures are worth more than 1'000 (misleading) words, I attach a couple of photos showing the two breather tube outlets on the two rocker covers.

 

Sorry for the confusion.

 

Re picture on left - As Pete said the plate is a fire wall and to some extent stops the oil entering the breather pipe. 

[Pete Lewis]

here you go just the job

 

https://www.merlinmotorsport.co.uk/p/sparco-shield-rw-9-flame-resistant-long-johns-1765

[dave.vitesse]

here you go just the job

 

https://www.merlinmotorsport.co.uk/p/sparco-shield-rw-9-flame-resistant-long-johns-1765

 

Pete - Just the thing if you have had some beans!

[Pete Lewis]

How do you know whats for dinner ???

[dave.vitesse]

Very many thanks for the replies.

 

I see that I evidently did not express myself correctly. My reference to the 'breather tube', was to the 1/2" tube on the side of the rocker cover, not to the oil filler. 

 

I the hope that pictures are worth more than 1'000 (misleading) words, I attach a couple of photos showing the two breather tube outlets on the two rocker covers.

 

Sorry for the confusion.

 

The plate in the original rocker cover is a flame trap or fire wall. If the engine back fires there can be a flame produced in the inlet manifold. This in turn could, without the plate, get back into the rocker cover through the breather pipes and ignite the fumes which could cause damage. Without the plate its good practise to fit a flame trap in the breather pipes. Hence our comments about filters because these should act as a flame trap as well as stopping the oil being drawn into the carbs. Don't fit a plastic cased filter. In your case the engine has a PCV in the breather circuit and this should offer some protection.

 

Thanks,

Dave

[rlabarre]

Thanks to all of you for your contributions.

 

The conclusion that I draw from your inputs is that the baffle in the steel rocker cover fulfills at least two important functions - Triumph (or actually it was Standard who designed these engines) included the baffle for a reason.

 

I am not entirely happy about running around with the aluminium cover as it is. I have one or two ideas about how I can (partly) improve the situation.

 

Or maybe the solution would be to acquire Nomex underwear neverless!

 

Very many thanks for your help.

 

Regards,

 

Robin

[dougbgt6]

Robin,

 

The Rimmer device I sent you a link to earlier is described as a "Breather/Flame Trap" so you wouldn't need the baffles in the rocker cover. Even if this device is not right for you there must be something similar out there that would do the job?