Oil breather pipe

[Propshaft]

I am in the process of fitting a 1275 midget engine in my van it has a cylindrical breather on the timing cover with the outlet pointing upwards I ham also fitting a HIF4 carb my question is were do I pipe the timing cover breather to

[seriesmm_1]

Pipe it across the manifold to one of the pipes protruding from the carb,the nearest one to the manifold
Regards
BrianR

[Propshaft]

Thanks , do you mean across the top of the exhaust/ inlet manifold

[IslipMinor]

Do you mean an HIF4 or HIF44? The HIF4 is a bit small for a 1275 engine - it's 1.5", the same as an HS4.

Yes, the crankcase ventilation hose runs from the oil separator canister on the timing cover, over the top of the manifold and connects on to the port on the side of the carburettor. It can be either side, depending on which 'hand' yours is.

As Brian says it is the connection nearest to the manifold, as in the picture below:

SU HIF Connections.jpg (68.08 KiB) Viewed 1354 times

[Propshaft]

Thanks for the clarification on the breather , I was hoping the hit 4 would be big enough to do the job , I am not tuning the 1275 just leaving as standard . What do you think

[philthehill]

Unless you are wanting to maximise the air entering the engine the 1.5" SU carb of whatever variation is more than adequate for a standard 1275cc engine.
The original 1275cc Marina was fitted with a 1.5" SU carb (HS4) as standard.
If you over size the carb with a standard engine it can be a retrograde step and you end up loosing power.
If the 1.5" HS4 SU carb was good enough for BL fitment you will not go far wrong with the carb you already have.
In the main the later variants of 1.5" SU carbs were only fitted as a response to achieving better pollution control.
The reality is that the only mechanical difference between the 1275cc Marina and the 1275cc Sprite/Midget (as regards breathing) is the fitment of twin 1.25" HS2 carbs to both 1275cc Sprite and Midget.
Both the head and the camshaft fitted to the Marina/Sprite/Midget and which effect the ability to breath are the same items.
My recommendation is to stick with what you have.
Phil

[Propshaft]

Thanks for that just what I wanted to hear