4 replies to this topic

[chrisblackmagic]

I am an engineering student also restoring a mini (of course) and as a project we are to design and make a component, and exhaust manifolds are popular due to differing properties on different vehicles etc

I am planning to design and fabricate an exhaust manifold for my 998 mini, and before I confuse myself, can anybody of experince tell me what the difference is  (pros/cons etc) between LCB manifolds and freeflow manifolds?

Thanks in advance

 

[timmy850]

This is a good article with some dyno data of different manifolds on a tuned 1098 engine. The Supa pipes in this article come out on top...

http://www.minimania...ld_Combos_Weber

LCB manifolds are normally taller to match the taller 1275 blocks, and can hang down a bit low on 998 engines. They can also be a bit too big in diameter for 998 engines, and can be harder to install too.

[jaydee]

LCB stands for Long Centre Branch.

The maniflow 'cooper freeflow' IS an LCB............just a one piece version so more relaible and more suited for bottom end power due to the shorter joins.

 

I dont get what are you asking, but if you're looking at an engineering view of mini exhausts buy a copy of the vizard yellow book, but it doesnt feature the freeflow because it wasnt developed yet at the time he wrote the book. Makes an interesting read though.

 

Its a bit hard to find documentations about such a recent and niche item but performance difference were reported by Graham Russel here:

http://russellengine...ory/small-bore/

[chrisblackmagic]

thanks for the replies, sorry jaydee was a bit muddled, basically wanted to know why some people fitted LCB manifolds to 998s, or whether it was just what they could get?, will definitely give the vizard yellow book a look, thanks for the links, very helpful!

[timmy850]

The Cooper Freeflow by Maniflow was originally developed by company owner Dave Dorrington during his time at Downton Engineering for the 970 S, and initially for the 1275 racers too. The design gives better performance than the standard Cooper item and fits small-bore engines easily. The original Cooper design hit the mechanical fuel pump, so an electric one had to be fitted - more cost and hassle. It gives superb performance on practically all road-going small-bore engines, and better performance on mildly tuned big-bore engines than the commonly used LCB. One of its biggest design assets is its easier to get a good gas-tight seal where it joins the system by virtue of the fact theres only one simple joint to deal with.

If you look at Stage One Kits, the Minispares kits come with a Cooper Maniflow one, and the Minisport ones come with an LCB. That's probably the biggest reason for people picking one over the other?

There are some articles below written by Keith Calver, which are also helpful in picking a manifold...

http://www.minimania...zing_and_styles

http://www.minimania...and_application