Which inlet manifold when fitting a 3 branch exhaust?

[lacey444]

Hi everyone,

I have a 1098cc minor which I have just bought a 3 branch stainless exhaust manifold for and have just realised that I will need to change my inlet manifold. What would be the easiest option? I don't want to change the carb if possible

[panky]

You can cut the original manifold to separate the inlet and exhaust, but be careful where you cut and make sure you don't go through the casting into the inlet side. Best to start well away then finish the cut when you can actually see where the divide is.

[lacey444]

Thank you! Hadn't thought of that. Will take an angle grinder to it tonight

[philthehill]

Fitting a three branch exhaust manifold (LCB) unfortunately does not always work to the better.
You could find that the power/ response is reduced. Too large a dia of manifold pipe reduces the gas flow and scavenging effect (pulling the exhaust gas out of the combustion chamber).
A LCB works best with a performance camshaft and other related mods.
Phil

[bmcecosse]

As Phil says - this is a mistake with a standard 1098 engine - the LCB is for more highly modified engines with 'wilder' camshaft timing/bigger valves etc etc. Even when cut off - the standard inlet manifold is far from good-flowing. You would do better to look for a good alloy manifold and move up to a larger 1.5" SU carb, all of which will release ~ 5 bhp extra .

[lacey444]

Thanks for the advice!

After fitting the manifold I have just found out that the inlet manifold will now not fit as it doesn't clear the centre branch of the exhaust so it seems that I will need a manifold like this:

http://www.ebay.co.uk/itm/191879284171? ... EBIDX%3AIT

However I cant seem to find a suitable carb that will fit the inlet. I was looking for a HS4 but they seem to have 2 holes not 4. I am new to carbs so I hope this isn't a really silly question

[amgrave]

That manifold will do and you can use a hs4 carb on it, just use two of the diagonal holes and not all four. It says in the description a hs4 will fit

[philthehill]

When ordering the manifold make sure that you order the blanking plug for the manifold at the same time.
Phil

[bmcecosse]

It's a crazy price !! Why won't your inlet manifold fit? How much does it 'not fit' ? As has been pointed out - the LCB is far from ideal on this engine....

[firehor5e]

have a look on flebay..HIF38 with manifold maybe?.i am running hif44 (ON A 1275 ENGINE)Cost over £100 though!