1098 Engine modifications

[John.n]

I have just entered into the world of Morris Minors with the purchase of a 1963 morris traveller. I have decided the car will need a full restoration and have decided to start with the engine.
currently the engine is a standard 1098cc engine with no modifications that I can see. the rev counter is showing 35500 miles.
I have no reason to doubt this to be genuine as the engine started very easily on the coldest of days.
I have stripped the engine down to replace many of the oil seals and gaskets in an attemp to cure many of the oil leaks as there is no sense in painting a leaky engine.
I am looking to improve the engine performance and efficentcy if possible with some modifications. I plan to keep the engine looking standard as possible externally.
my current plan was to change the head for something that will give a bit more get up and go combined with an improved cam shaft. I was thinking a 12g940 head combined with a MG metro cam?
would apreciated any advice and stories.
this is not my first engine rebuild but my first none standard rebuild.

Regards,
John

[chesney]

Need a good inlet manifold and carb too, HS4? And consider brakes too!

[linearaudio]

^^^^^ Agreed! Make sure the brakes are up to scratch,and that anything that may upset handling is sorted (dampers, bushes etc).
The 940 head, with the well-documented mods to stop foul-ups, is probably equivalent to a stage 4 head,and handily raises the compression to around 10:1 into the bargain.
Definitely worth separating the inlet from the exhaust manifold. Minispares will do an ally inlet manifold pretty cheap, or trawl eBay for an MG Metro one (good luck!) or an old-skool job like a Howley. HS4 or HIF38 will be a good carb to use.
Adding an MG Metro cam (again, good luck finding one!) will give a sharper edge to the power band, but still be very tractable,not even giving the reputed slightly lumpy tickover when put in the 1098.
However, the biggest single improvement will be the head

[John.n]

I will be going through the whole car as I go but will I need upgraded brakes or will well adjusted standard brakes be capable as I was intending to completly overhaul the brake system?
will the modifacations above result in a fire breathing monster or something I can quite happily drive down the road comparable to a modern car?
what is a stage 4 head? I have seen stages referd to often but what does it mean?
Regards,
John

[bmcecosse]

Don't bother changing the cam - just use that head (do you know what's involved??) and carb + manifold as suggested by others. It will drive very nicely. 8" front drums will be fine IF in good order. 9" drums from a Wolseley 1500 are even better.......

[John.n]

I had read that the MG metro camshaft was a good upgrade... is it just for the wider cams? i guess if im using the standard rockers there would be no additional stress on the camshaft as there is no increased valve lift. is the drive for the oil pump the same as standard?
is there anything special I need to do to the 12g940 head to make it work? I have read about larger valve and wasnt sure if this is part of the original head spec or is it an aftermarket modification? are double valve springs required or is that only required for race spec engines?
Kind regards,
John

[bmcecosse]

For a start - MG cam is hard (= expensive) to find (and uses a different oil pump) - and you say you want a nice drivable car. So use the standard 1098 cam which is fine to 6000 rpm which is the limit for a 1098 if you don't want to break the crank....even then....... You need 1275 rockers on that head and definitely NO double springs !! You need to have 320 thou clearance from exhaust valve face to head face. Measure it - if not 320 thou make it so by sinking the valves into the head slightly. 1275 gasket and file the top of the water pump to make clearance.

[linearaudio]

None of the above quoted mods will create a fire breathing monster. The porting and valve sizing on the standard 1098 is pitifully inadequate, so you are simply releasing the latent potential of the engine by letting it breath properly!
The car will be perfectly driveable, where normally the engine would start running out of puff at about 60mph,the 940 head continues to pull strongly. The approach of the 6000rpm danger point will let itself be known by the enormously busy sound of the engine!

[John.n]

so looks like the plan has changed a bit.
-I will be changing the head for a 12g940 head and fitting 1275 rockers.
- keeping the standard camshaft.
- looking out for a better carb and alli manifold.

I have found an MG metro cam for sale but dont fancy disturbing the oil pump if i dont need to.
Are there any other upgrades or modifications that would be worth doing whilst I have the engine to bits on the workbench and are all 12g540 heads the same specification?

many thanks for the help and advice so far,
John

[MarkyB]

Get yourself a copy of tuning the A series by David Vizard, it's great bed time reading and very informative.

[John.n]

Is that the yellow bible people refer to?

[chesney]

Certainly is

[bmcecosse]

You should be fitting new shell bearings and oil pump as a matter of course ...... By all means buy the MG cam if the price is right (and you are SURE it's an MG cam...)- but they seem to get more than £50 these days..... and it will give you a little more power at the 5000/6000 rev range - and lose you some of that driveability... It really is at it's best in a 1275 engine. If you want to buy something useful for the engine - get a crankshaft damper !!! You want a normal 940 (not 540) head - not the large inlet valve version - again, that comes into it's own on a 1275 engine.... Don't worry about an 'unleaded' one - in fact you WANT the exhaust valves to have a bit of recession to allow it to fit without any additional work!

[John.n]

I have had the big end shells out and inspected them looked in good condition as did the crank. I decided to to leave the piston rings allone aswell so that I did not need to run the engine in. bores looked in good condition as well. how long do oil pumps normally last. I have often heard of reproduction oil pumps (in general) haveing larger tolerances than originals and giving lower oil pressure than the original. are minor oil pumps of a higher standard?
I agree that any gain in the 5000+ revs is really not worth anything. I have no intention or reving the guts out of the engine.
What is the standard practice to recess valves if required? machine shop job?
what sort of proce should I expect to pay for a crankshaft damper? are these a normal requirement?

Regards,
John

[Suzukimorris]

Electric ignition, merr polish and one of them pine fresh trees to dangle from your mirror

[chesney]

one of them pine fresh trees to dangle from your mirror

Nah, has to be fluffy dice ;)

[John.n]

I would have to put the car back together first! not sure where the mirror ended up......

[bmcecosse]

Since you have the engine in bits...take the pump apart and post up pictures! New pumps are fine...... Get the 940 head first and measure it up..and then we can decide what you need to do. It took less than 10 mins to do mine with a 45 degree countersink in a pillar drill. This one is in the right price range..... http://www.ebay.co.uk/itm/Cassic-Mini-1 ... 19d7f6d4f7

[Suzukimorris]

Ha ha of course the furry dice, at one stage I had a pink glittery pair one of my mates got from college....nice

[John.n]

BMC that was the head I was thinking of. how do you ensure the countersink is centred, just let it self centre on the hole? Im assuming that the countersink will not touch the valve guides.
Are there any other good places to look for morris parts?

Regards,
John