Page 1 of 1
1.5" bore exhaust the old manifold clamp wont fit what
Posted: Sat Apr 11, 2009 5:01 pm
by ssnjimb
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
Posted: Sat Apr 11, 2009 9:09 pm
by Peetee
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.
Posted: Sat Apr 11, 2009 9:12 pm
by ssnjimb
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
Posted: Sat Apr 11, 2009 9:33 pm
by Peetee
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.
Posted: Sat Apr 11, 2009 9:42 pm
by linearaudio
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?
Posted: Sat Apr 11, 2009 9:55 pm
by ssnjimb
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
Posted: Sat Apr 11, 2009 11:04 pm
by bmcecosse
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!
Posted: Sun Apr 12, 2009 6:57 pm
by linearaudio
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]
Posted: Sun Apr 12, 2009 10:14 pm
by bmcecosse
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!