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1275 Engine fitting
Posted: Thu Apr 01, 2010 2:28 pm
by yellowpinky
I have been having some problems with my 1098 engine, and I have always fancied fitting a 1275 unit. So, I'm thinking that soon would be good. I am after general advice as I'm not much of an expert with engines.
So far I have found a local company that would recondition and fit the engine.
I am also looking at fitting the following mods.
Duplex timing chain
http://www.moss-europe.co.uk/Shop/ViewP ... exID=17240
Crankshaft oil seal conversion kit
http://www.moss-europe.co.uk/Shop/ViewP ... exID=17659
Uprated oil pump
http://www.moss-europe.co.uk/Shop/ViewP ... exID=17244
I don't have a unconditioned 1275 engine yet, but I know of two that might be available. One is from a Sprite. One of my concerns is fitting the bigger engine. It seems fairly straight forward but have heard of different fittings for the clutch?? I am also wondering if I need to consider harder halfshafts?
I know I also need to consider an increase in insurance cost. After speaking to my insurance company they said I need to tell them the increase of bhp. But I don't know that yet. So if anyone has done this before I'd be keen to hear more.
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 6:14 pm
by hotrodder13
ive just fitted mine and rung insurance up before i did it, i went from 45bhp with the 1098 and told them 75bhp with the marina 1275 , (also told them disk brakes servo and alloys) only went up £300 so it wasnt to bad for an 18 year old
hope this helps tom
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 6:35 pm
by MarkyB
Unless you plan to thrash the living daylights out of it I wouldn't bother with any of those upgrades.
An ordinary duplex set up will last better than simplex.
Someone will be along shortly to recommend a chain tensioner and maybe say if cam timing adjustment is worthwhile or not.
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 6:48 pm
by sgray
hotrodder13 wrote:i went from 45bhp with the 1098 and told them 75bhp with the marina 1275
That sounds like a useful increase - how is likely to translate in day to day use ?
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 7:45 pm
by bmcecosse
Well - a 1098 is 48 bhp as it stands, and 1275's are ~ 55/60 bhp. So I hope you are not too disappointed! Only the 1275 Cooper S was rated at 75 bhp, and that had a FAR better head than any of the in-line 1275 engines, and was probably nearer 70 bhp anyway. An 'uprated'

oil pump for a 1098 engine won't fit a 1275 - don't waste money on rubbish like that! Duplex is only needed if fitting a fancy cam and/or daft high strength valve springs........ and if the engine is in good condition, it won't need an 'oil seal conversion' . No point trying to hide a poor condition engine with an expensive oil seal kit. Just make sure any engine you get is in tip top excellent condition - and make sure it has good crankcase venting via a suction tube to the carb. You will need to fit a modified 1098 flywheel, and of course - the Minor front plate if you get a Marina unit. A Spridget unit fits pretty well directly.
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 8:44 pm
by hotrodder13
bmcecosse wrote:Well - a 1098 is 48 bhp as it stands, and 1275's are ~ 55/60 bhp. So I hope you are not too disappointed! Only the 1275 Cooper S was rated at 75 bhp, and that had a FAR better head than any of the in-line 1275 engines, and was probably nearer 70 bhp anyway. .
how many bhp would mine have then, road race cam shaft, phrosferbronze valve guides bigger pistons, ally inlet manifold and 1 5/8 lcb and 12g940 head
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 8:51 pm
by bmcecosse
Depends what the camshaft really is 'road-race' means nothing! Need the spec of the cam. They ALL have the 940 head.....is it the big valve version ? And you say 'bigger pistons' - in what way 'bigger' - has the engine been bored out oversize ??
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 8:56 pm
by hotrodder13
bmcecosse wrote: And you say 'bigger pistons' - in what way 'bigger' - has the engine been bored out oversize ??
dont know the guy just told me it had a big rebore not much else i can say

,
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 9:02 pm
by bmcecosse
Well - the larger capacity makes little difference anyway, since power is always limited by the amount of air the head can flow. It will make the car more tractable - more power at lower revs where the head/flow limitation isn't reached. Cam details would be good!
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 9:09 pm
by hotrodder13
dont know what cam it is, if i see the guy i baught it off i will ask,

Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 9:14 pm
by bmcecosse
Hmmm - so you bought an engine, without knowing the capacity, or the details of the valve sizes, or the cam details..... I see....
Re: 1275 Engine fitting
Posted: Thu Apr 01, 2010 9:19 pm
by mike.perry
The easiest swap is the 1275 Midget, it is almost a straight swap. I fitted the cranksaft oil seal and it still drips.
Points to watch are the fan blade clearance between the canister on the timing chain cover and the rad, with spacers behind the blades there is just about clearance.
The thermostat housing angle is different, Birmingham Morris Minor Centre do a conversion housing
The heater tap is a different angle, this can be overcome by using the tap off an earlier engine or using an adaptor
You will need to cut a V out of the stabiliser bar bracket to fit the heater tap.
You will have to decide what to do with the carb & exhaust manifold.
The easiest solution to the clutch assembly is to use the 1098 linkage and weld an extra inch onto the lever on the clutch relay shaft that links to the clutch pedal and re drill the hole. This will restore the pedal travel and weight without the complication of a hydraulic clutch. For extra refinement you can fit a roller bearing thrust release.
I think that covers the engine instalation, then there are the brake upgrades and higher ratio diff to consider
I've been so long typing this, the phone rang, that the topic has drifted away from the original subject.
Re: 1275 Engine fitting
Posted: Mon Apr 05, 2010 8:09 pm
by yellowpinky
Some interesting replies, thanks! But I have another question.. Will having a 1275 engine affect the classic moggie warbling exhaust sound? Also, I think I need harder halfshafts..which classic car has the harder halfshafts for the Morris Minor?
Re: 1275 Engine fitting
Posted: Mon Apr 05, 2010 8:15 pm
by hotrodder13
my 1275 with one silencer sounds a beast

its about 2 times louder but still got that moggy overrun farting sound
tom

Re: 1275 Engine fitting
Posted: Mon Apr 05, 2010 9:34 pm
by bmcecosse
If you want better shafts - you need to buy them. Nothing had 'harder' shafts as standard.
Re: 1275 Engine fitting
Posted: Mon Apr 05, 2010 9:54 pm
by mike.perry
I have been running my 1275 on standard 1098 half shafts, no problems -YET!!!!
Re: 1275 Engine fitting
Posted: Mon Apr 05, 2010 9:57 pm
by aupickup
yes yet
i had a van with a 1275 and normal halfshafys and was ok
sometimes the half shaft being the weakest link will go first and not destroy the diff if that gives up