13 replies to this topic

[Keisar]

Hello, 

 

The engine of my mini have been removed for cleaning, seal replacement and silent block replacement and in the same time I want to replace the old exhaust manifold by a new one. 

 

Today the engine is 100% stock but in the futur i will put twin carburetor, improved camshaft etc... 

 

I don't want to buy a new one and replace in few month because of the preparation. 

 

 

For me the main question is LCB or Freeflow ? 38mm or 44mm ? I can't found a technical answer at this question. 

 

Do you know the difference between these two manifolds ? Where can i read some explication about that to choose one ?

 

The configuration is : 91 cooper with A+ engine 1275cc and HIF44. 

 

Thanks, 

[nicklouse]

For me a Maniflow medium sized LCB. Good for what you have now and upto about 100bhp.

[carthorse]

The cooper freeflow works best on the small bore engines or near standard 1275's. The LCB works best on 1275's from standard to modified if that makes sense?
Basically the LCB is the more logical choice for a 1275 as it will allow for any further mods later without becoming the limiting factor.

[Mrpeanut]

The cooper freeflow works best on the small bore engines or near standard 1275's. The LCB works best on 1275's from standard to modified if that makes sense?
Basically the LCB is the more logical choice for a 1275 as it will allow for any further mods later without becoming the limiting factor.

The freeflow is great on lightly modded 1275's. I had a free flow on my rover cooper with a very good head but otherwise standard. It pushed out 78 bhp with tons of torque. I could have added a wilder cam and the manifold would not have held it back.

I now have the maniflow stage 2 lcb on a 1293 with a slightly higher cam. It offers nothing more than the freeflow.

[nicklouse]

The cooper freeflow works best on the small bore engines or near standard 1275's. The LCB works best on 1275's from standard to modified if that makes sense?
Basically the LCB is the more logical choice for a 1275 as it will allow for any further mods later without becoming the limiting factor.

The freeflow is great on lightly modded 1275's. I had a free flow on my rover cooper with a very good head but otherwise standard. It pushed out 78 bhp with tons of torque. I could have added a wilder cam and the manifold would not have held it back.
I now have the maniflow stage 2 lcb on a 1293 with a slightly higher cam. It offers nothing more than the freeflow.

And what does that mean?
1293 Medium Maniflow LCB full race Howley head. Kent 296 (ish) cam high lift rockers 125 BHP. They thought it was a 1380.

Like I often say people go too big.

[Mrpeanut]

The cooper freeflow works best on the small bore engines or near standard 1275's. The LCB works best on 1275's from standard to modified if that makes sense?
Basically the LCB is the more logical choice for a 1275 as it will allow for any further mods later without becoming the limiting factor.

The freeflow is great on lightly modded 1275's. I had a free flow on my rover cooper with a very good head but otherwise standard. It pushed out 78 bhp with tons of torque. I could have added a wilder cam and the manifold would not have held it back.
I now have the maniflow stage 2 lcb on a 1293 with a slightly higher cam. It offers nothing more than the freeflow.

And what does that mean?
1293 Medium Maniflow LCB full race Howley head. Kent 296 (ish) cam high lift rockers 125 BHP. They thought it was a 1380.

Like I often say people go too big.

What is unclear? The freeflow is at least as good on lightly modded 1275's as a good lcb. Based on owning both.

[Dusky]

Have a read :www.minimania.com/EXHAUST___Manifolds__types_available_and_application__782

[Goacher65]

If in doubt. Read the yellow bible. Vizard shows, with power readouts to match, not just "having owned", which manifold and indeed exhaust system is most effective at difference capacities and different levels of tune.

If you've got an exhaust system (after manifold) that is restrictive, you may well not notice which manifold releases the most horses until the manifold is the most restricting factor in the whole system. Obviously there may be a difference from the more efficient manifold, but whether it could be detected from a spirited drive down the road, I'm not so sure... I know from putting aftermarket exhausts on cars you drive down the road thinking 'this feels faster', but you want to, having spend a few £hundred on a shiny new exhaust. In reality, I doubt you would feel up to 5hp increase in power.

This is my understanding.

[jaydee]

The maniflow freeflow isnt featured in the yellow book, i dont think it was even developed at that time.

Whether you want a freeflow or not its depending on where you want the power in the rpm curve.

Graham russel tested it, have a gander at his small bore blog there a full test comparing different exhaust manifolds.

[jaydee]

Have a read :www.minimania.com/EXHAUST___Manifolds__types_available_and_application__782

 

Thats just a seller's article plenty of wrong infos.

The freeflow is not a 3 in 1, its 3-2-1, actually a short type LCB.

[Dusky]

 

Have a read :www.minimania.com/EXHAUST___Manifolds__types_available_and_application__782

 

Thats just a seller's article plenty of wrong infos.

The freeflow is not a 3 in 1, its 3-2-1, actually a short type LCB.

 

Written By: Keith Calver
Article Date: Sep 28, 2000

[jaydee]

Yes i know who signed that article.

[Dusky]

Yes i know who signed that article.

Well, elaborate and enlighten us on exhaust manifolds. As that article is filled with PLENTY of wrong info, I'd like to know the 'right' info from you. Most thing sin here are the same as what vizard states.

[jaydee]

This is a typical 3in1, its a cooper S exhaust, look at the pattern, think about the firing order and work out the pulse

 

 

Thats an LCB -long centre manifold (now think about the firing order and work out the pulse)

 

 

Now this is a freeflow, what you recognise?

 

 

So, exhaust types..oh well..Its not just about terminology, its just they work different!

Didnt you know what 3-1 and LCB patterns are? Didnt you know they have a difference is pulsation, so cant classify them as the same?

Now i'm not good at writing techies, and wouldnt even know where to strat from, but KC might do, since he does this for a living. I've built my first mini engine just 7 years ago,  while hes been doing this for ages.

 

KC is a good engineer and very ackowledgeable but when writing as a seller gets too much 'poetic licence' and tend to fall off his bicycle.

Cant barely compare this stuff with vizard, sorry mate,The part when its says LCB are all about top end does not makes sense at all, its just hype.

From an engineer who writes tech articles i'd expect something more elaborated than 'you increase the size you loose speed' or buy this because its like this other. A bunch of banalities thrown together. Why not talking about backflow and how to minimize this? Best keep it secret, who reads that articles have no idea what backflow how can it be interested in a torque gain from that.

When i see stuff like this i just quit reading and prefer spend my time reading something that i may learn from, these articles are only for addressing a potential buyer (who knows nothing about engines) to certain products and show the range they offer.

And i wouldnt like such stuff as 'tech info' to someone.

 

I'm sorry for KC but i address people to graham russel's blog for techies.