How hard is it to cut a manifold to make it suitable for extractors? I'm thinking 1 3/4
How do you do it?

Get a hacksaw or angle grinder, cut the exhaust part off without damaging the inlet.
Then, grind the remains off the bottom of the inlet so it's sort-of smooth. If you go too far you can braze it.
When buying extractors beware. Some UK ones (like Maniflow LCB) won't fit. Most of the Oz ones- Perry etc do, the middle pipe goes down at an angle to clear the inlet.

1-3/4" eh... you would do better to buy a MiniSpares or Graham Russell manifold that flows, IMO. The stocker is just OK with a 1.5 carb.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Are those mini spares manifolds okay?
What is with the water flow? is it to warm or cool? What benifit is there? Do you just pipe it in series with your heater?

You're in Orstraylia, maaate.
It's to warm it...
Most people don't bother to hook it up, unless they live in Can-Bra, Goulburn, the Snowy or new England....

Yes the MiniSpares one is supposed to flow OK. But the GR one is better, and made here in Oz.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Nah ...in Canberra we don't bother either....we have Minis that run hot here just like everyone else

Then again, Penalurick runs a perspex grill blanking sheet ALL year round!!!

_________________
"Show me the Mini!"

I have the same problem. i have a set of extractors waiting to go on to my engine but i dont have a new manifold. so can u just cut off what gets in the way and braze in a peice of steel plate to seal the manifold???

cheers

by the way im am running a 1 1/2 SU on a 998

You don't have to braze plates in usually. At least if you're running an Oz made LCB or 3-1, they miss OK.
There's about 3mm of metal there, between inlet & exhaust....just don't cut through it..

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.