1.5" bore exhaust the old manifold clamp wont fit what

Post by **ssnjimb** » Sat Apr 11, 2009 5:01 pm

Hello Folks

Just fitting the kit that i bought from a fellow member.

It is the 12g940 head
seperated exhaust manifold
oselli torquemaster inlet
hs4 carb
k and n style air filter

The old exhaust to manifold clamp is now too small.

Is there a larger one readily available

Also I have fitted the 1098 headgasket was i right to do this.

James Stephenson

Post by **Peetee** » Sat Apr 11, 2009 9:09 pm

The exhaust is compatible with the Marina/Ital manifold so the standard clamp for these cars should fit. there are probably other BL cars that used the same one too. perhaps the Allegro and some Minis?
A good motor spares shop would have a reference book to help you source one.

Post by **ssnjimb** » Sat Apr 11, 2009 9:12 pm

the exhaust manifold exit is larger than the old manifold too.

Will i damage the exhaust if i try and tighten the existing clamp onto it.

What power difference will i achieve with these upgrades.

James

Post by **Peetee** » Sat Apr 11, 2009 9:33 pm

the exhaust manifold exit is larger than the old manifold too.

That's right. The Minor and Marina used different exhaust systems which included the manifolds - even though they look very similar.
What I said in the first post still stands. A 1.5 inch single pipe exhaust system is designed to fit the Marina/Ital cast manifold. You must not use the clamp from the Minor.

linearaudio · Post by **linearaudio** » Sat Apr 11, 2009 9:42 pm

According to all I've seen, you need to use a 1275 head gasket with the 940 head. Also, have you checked or made provision so the exhaust bvalves don;t hit the block face?

Post by **ssnjimb** » Sat Apr 11, 2009 9:55 pm

yes i bought it on the fact that it did not hit the block.

I have installed a 1098 gasket will i need to remove it again and put the 1275 gasket in. The reason for putting the 1098 gasket on is that one of the waterways at the very front just in front of the water pump was semi covered over.

James

Post by **bmcecosse** » Sat Apr 11, 2009 11:04 pm

You MUST use 1275 head gasket! Don't worry about semi-covered water ways - they will be fine. You must also use 1275 rocker gear - or re-arrange your original rockers so they act directly over the exhaust valve tips. You can't rely on the valves not hitting the block on YOUR engine - unless you carefully measure the actual valve lift, and then check the depth of the valves in the head. It's possible your engine lift may be higher than on the engine the head was on before - if the valves hit the block = disaster. You will likely also need to modify the top edge of the water pump (by filing - not difficult) - to make sure the cylinder head can sit right down on the block without fouling the pump. You must source a larger exhaust system clamp (Marina/Ital) - do NOT try to use the small Minor one.
I rather feel you are maybe out of your depth with these modifications ! If it's a 1098 engine (in good condition - I hope!) the power should increase from 48 bhp to ~ 60 if the carb and dizzy are suitably modified and set up. A crankshaft damper will be a v good idea!

linearaudio · Post by **linearaudio** » Sun Apr 12, 2009 6:57 pm

The first I remember seeing about crank dampers! Pray do elaborate, kind sir! Eg where to get/adapt one! Many thanks, Pete.
I agree, J, you may have slightly underestimated the possible "snags" with the job. Not that is a particularly difficult swap, only there are checks & little mods needed, certainly the valve clearance needs checking very carefully, taking into account the thickness of the correct head gasket. Nothing to fret over though, and its been documented on here recently. Good luck![/i]

Post by **bmcecosse** » Sun Apr 12, 2009 10:14 pm

Crank damper ex Mini engine. Will save the crank snapping if any enthusiastic driving is intended - which it surely is if going to the trouble of fitting this head!