Air intake design

[chadandsal]

More advice please.... maybe this is a silly question????
But it seems strange to me that someone designed the Triumph V8 air intake housing with the inlet manifold pipes partially obscured (see pic).
In a performance engine surely the objective is to get as much air through the filter and intake manifold as possible (within a correct mix).
Therefore can anyone tell me if the tabs indicated in the pictures provide any useful purpose? Has anyone trimmed them off and noticed any performance change?

Cheers,
John Chad

20140113_174318.jpg

[jleyton]

This has been asked and researched before.

IIRC the consensus is that they're designrd to induce swirl but they don't seem to have much effect.

Cheers

Julian

[V Mad]

My guess is that, due to the sharp bend in the elbows, without the restrictors the air velocity at the carb intake is too uneven. I noticed that the Hart racing car at some stage had the air cleaner box replaced with separate individual air filters. Perhaps by eliminating the elbows and restrictors this improved engine power?

[flying farmer]

I have a very early mk1 air filter base and these were missing, but a set of the restrictors had been bolted in over the hole. Maybe the factory realised there was a problem and added these later, or someone cut them out and found it was a bad idea.....

Neil

[Stagsongas]

More advice please.... maybe this is a silly question????
But it seems strange to me that someone designed the Triumph V8 air intake housing with the inlet manifold pipes partially obscured (see pic).
In a performance engine surely the objective is to get as much air through the filter and intake manifold as possible (within a correct mix).
Therefore can anyone tell me if the tabs indicated in the pictures provide any useful purpose? Has anyone trimmed them off and noticed any performance change?

Cheers,
John Chad

[ATTACH=CONFIG]26523[/ATTACH]

John,

To write an accurate and comprehensive response to this question will take several pages and some hours. This forum has an unusual attitude to proper explanation, it would either be ignored or argued with which wastes time either way.

Suffice to say the shape was designed to stem an aerodynamic effect which makes very little difference in practice, especially on such a low powered engine (relative to today's engines). Either leave them there or cut 'em out, it makes no appreciable difference.

Regards

Steve

[tractorjames]

John,

To write an accurate and comprehensive response to this question will take several pages and some hours. This forum has an unusual attitude to proper explanation, it would either be ignored or argued with which wastes time either way.

Suffice to say the shape was designed to stem an aerodynamic effect which makes very little difference in practice, especially on such a low powered engine (relative to today's engines). Either leave them there or cut 'em out, it makes no appreciable difference.

Regards

Steve

Quite an interesting subject, i can sort of see the point of them but can imagine they will do a lot of good.

Also would never shoot down someones response. Being so keen on engineering and restoration i like to read many replies and try and take as much advice and information from each to put into use on a job. When i go on work training courses a lot of people seem to see it as 2 days of easy work. Few people seem to do as i do and take as many notes and ask as many questions as possible I never turn down free knowledge, having said that it can be easy to belive rubbish as well

[dasadrew]

John,

..... This forum has an unusual attitude to proper explanation, it would either be ignored or argued with which wastes time either way...

Steve

Steve, don't believe it! There are a lot of quiet, studious and knowledge-seeking forum members that are hungry for more founded technical information, and I can think of quite a few names who would silently enjoy any information you have to share. Of course, anything concerning fluid dynamics will be debated as it is still a very empirical science!

Drew

[tractorjames]

Steve, don't believe it! There are a lot of quiet, studious and knowledge-seeking forum members that are hungry for more founded technical information, and I can think of quite a few names who would silently enjoy any information you have to share. Of course, anything concerning fluid dynamics will be debated as it is still a very empirical science!

Drew

+1

[jleyton]

Snap ?

This has been asked and researched before.

IIRC the consensus is that they're designrd to induce swirl but they don't seem to have much effect.

Cheers

Julian

John,

Suffice to say the shape was designed to stem an aerodynamic effect which makes very little difference in practice, especially on such a low powered engine (relative to today's engines). Either leave them there or cut 'em out, it makes no appreciable difference.

Regards

Steve

[V Mad]

This forum has an unusual attitude to proper explanation, it would either be ignored or argued with which wastes time either way.
Regards
Steve

The only problem I see with this is that a difference of opinion often leads to frustration and argument. When fact and logic goes out of the window, and so called 'common sense' kicks in, thats when it goes off the rails. I think it would be a shame if we could not rebalance the humour with some really good technical discussion.

Take a look at the Science Forum as an example. They seem to manage it.

[wilf]

Well hopefully, we mods can help a little to stop differences of opinion becoming arguments, it is one of the things we are tasked to do.

Not an easy task, but one we are happy to try as best we can.

[Jeff]

Well hopefully, we mods can help a little to stop differences of opinion becoming arguments, it is one of the things we are tasked to do.

Not an easy task, but one we are happy to try as best we can.

Especially with awkward and argumentative s*ds like me

[Staggard]

Firstly i think there's a big difference between a difference of opinion, debate and an argument. I believe the problem stems from, when someone asks a simple question then you get a technophobe `who tries to turn it into rocket science then when questioned start waving bit's of paper (diplomas certificates etc) shouting my Dad's bigger than your Dad. You don't have to have a degree or an ology to work on a Stag (or any other car of that era) just a bit of common sense. If you keep the answers simple with a bit of humor (helps the world go round) and not go into the in's and out's of a duck's a******e then the Forum does not get boring and everyone can join in.

[milothedog]

John,

To write an accurate and comprehensive response to this question will take several pages and some hours.

This forum has an unusual attitude to proper explanation, it would either be ignored or argued with which wastes time either way.

Suffice to say the shape was designed to stem an aerodynamic effect which makes very little difference in practice, especially on such a low powered engine (relative to today's engines). Either leave them there or cut 'em out, it makes no appreciable difference.

Regards

Steve

Can't say I have seen that Steve, some post do go on a bit and are OTT IMO, I have seen post where games of one up-manship seem to be the goal though.


I personally worry about the advice given by people who are self taught, hobby mechanics/weekend warriors and/or with no previous experience or professional standing in the subject being discussed. Fine, let them play with their own car but don't advise others. It can be dangerous!


Close to your interest, I was trained by Jet (the oil company) in 1999 to install and maintain LPG systems but have never done it apart from the course and therefore would not get involved in offering advise other than go to a specialist as I am fully aware of the dangers involved with unqualified people playing with such a volatile fuel. Common sense on my part?

So regards your comment I think maybe that's why some post take the path they do, as some will be wondering, and not having a dig at anyone, does this person know what he is talking about or just talking a load of rubbish. I do when I read something I know to be inaccurate.

Like I stated, just the way I see things and not aimed at anyone. Just the views of a fully qualified, time served technician with nearly 40 years experience in the motor industry, and with higher qualifications in the subject. And a fully paid up member and recognized by the IMI and IRTE.

Ian.

[V Mad]

when someone asks a simple question

But maybe there are questions on here which are very difficult to answer correctly. That's when people get frustrated because they just want simple answers, or they want other people to accept their simple but possibly flawed answer!