Exhaust modifications

[Mr_Smartlew]

Hello, I was looking at buying the tubular exhaust manifold sold on ESM, do it need to change the intake manifold aswell, id like to keep the original carburetor if possible as I am on a budget and don't really have time to tune a new carburetor. If the intake manifold won't fit can it be modified to fit?

[philthehill]

Depends upon what combined inlet/exhaust manifold you have.
If you have the later single piece cast manifold you can cut off the exhaust manifold and just use the inlet manifold with the new tubular manifold from ESM. If you have the earlier two piece Alloy/cast iron manifold you will have to purchase a new inlet manifold to suit the carb being used.
You will have to tune the carb whatever combination of carb/manifold you end up with.
To be honest unless you do additional work i.e. carb & cam then fitting a tubular manifold is not worth the money. As part of a long term project it may be but not guaranteed.

[Mr_Smartlew]

To be honest I just need a bit more power, my moggie is my daily driver and a bit more top end power would go a long way, I think my exhaust is the 2 peice so ill either buy a single cast manifold and cut it or try and find a cheap hs4 carb, a mini cooper intake manifold will fit over the exhaust manifold apparently, but I can't find a cheap hs4 which is why I wanted to use the original carb

[philthehill]

In that case a Morris Marina cast iron manifold (not twin pipe) with HS4 attached will go a long way to improve the overall power. Vizard highly rates the Marina manifold and it will fit straight onto the Minor engine and exhaust pipe. Some classic minis used the same set up.

[Mr_Smartlew]

Oh right, I hadn't thought of that, ill have a look, in all fairness I still need a new exhaust system anyway because it is leaking and cracked to the point its not worth fixing, but ive been told that tubular manifold is well worth it for the power gain, I intend on towing a small trailer tent behind my moggie so ill need all the power i can get once ive upgraded the breaks.

[philthehill]

To be honest and as one who has experience of tuning the 'A' Series from basic tuning to building full race engines - the tubular manifold cost against power increase is not beneficial unless as I said in my post above you do more modifications to the engine to maximise the benefit of the tubular manifold. In fact just fitting the tubular manifold you can loose power. To sum up - do it all or leave well alone.
Phil

[Biggles1957]

I have a marina combined inlet/exhaust manifold and a HiF38 and the correct air cleaner, together with a Maniflow exhaust specially made to fit the manifold if you're interested? I was going to fit it all to my Traveller with a 12G925 head that I have ready to drop on to improve performance somewhat! I sold my Traveller so am selling the bits now.