Marina 1275 - differences between A and A+

Post by **vincenth** » Thu Aug 17, 2006 3:57 pm

How can you physically tell the difference between a Marina A and Marina A plus engine.

Post by **bigginger** » Thu Aug 17, 2006 4:32 pm

The ribs on the side of the block and the different distributor fitting on the +

Post by **Peetee** » Thu Aug 17, 2006 5:30 pm

As big ginger says the obvious difference is the ribs ie:

Ital
http://img.villagephotos.com/p/2006-1/1 ... al1300.jpg

Marina
http://img.villagephotos.com/p/2006-1/1 ... na1300.jpg

Hope that helps

Post by **bigginger** » Thu Aug 17, 2006 5:35 pm

Sorry - I was trying to be more help, but couldn't find a pic of the Marina version...

Post by **vincenth** » Thu Aug 17, 2006 5:40 pm

I think this is a marina but is it an A or A+

http://img.villagephotos.com/p/2006-8/1 ... ngine1.jpg
http://img.villagephotos.com/p/2006-8/1 ... ngine2.jpg

http://img.villagephotos.com/p/2006-8/1 ... ngine1.jpg
http://img.villagephotos.com/p/2006-8/1 ... ngine2.jpg

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Post by **Peetee** » Thu Aug 17, 2006 6:16 pm

I'm fairly sure that's a Marina A.

Post by **bigginger** » Thu Aug 17, 2006 6:24 pm

Me too

Post by **aupickup** » Thu Aug 17, 2006 6:55 pm

and me, but a close up of the dizzy fixing plate may be a good idea.
also may tell from the engine number

Post by **bmcecosse** » Thu Aug 17, 2006 10:27 pm

But does it really matter ? Both have same power output.

Post by **Kevin** » Fri Aug 18, 2006 8:28 pm

But does it really matter ? Both have same power output.

Yes, it does make a bit of difference as the Marina engine gives out 54 bhp and the Ital A+ has 64 bhp in standard form and an extra 10 bhp must help when there is only 45 bhp to start with.

Post by **aupickup** » Fri Aug 18, 2006 8:34 pm

correct kevin

Post by **KirstMin** » Fri Aug 18, 2006 9:02 pm

Kevin wrote:Yes, it does make a bit of difference as the Marina engine gives out 54 bhp and the Ital A+ has 64 bhp in standard form and an extra 10 bhp must help when there is only 45 bhp to start with.

Erm, we've had this discussion before... I dont know where the above figures come from but they dont look right to me (or the BMC figures for that matter):

1275cc A series Morris Marina (1971-80) = 60bhp @ 5250rpm

1275cc A+ series Morris Ital (1980-84) = 61bhp @ 5300rpm

http://www.austin-rover.co.uk/index.htm ... eriesf.htm

Post by **bmcecosse** » Fri Aug 18, 2006 10:26 pm

Dunno where it would get the extra power from - they both have exactly the same head/valve sizes/cam spec - unless one has a bigger carb - which of course can be fitted to any engine.
Effectively - I say again - they both have the same power.

Post by **Kevin** » Sat Aug 19, 2006 12:27 am

Hi Kirsten my figures came from Owen Burtons book I have also seen the same spec as you quoted from the unofficial Austin-Rover site on another site as well so thats 2 to 1.
The Midget 1275 seems to be quoted with the same figures of 65bhp with a CR of 8.8 on all sites, so at least that is consistant & with twin carbs and better manifolds that can be regarded as reasonably correct.
The Marina also has a CR of 8.8 with single 1 1/2" HS4 carb.
The Ital A+ has a CR of 9.4 improved piston design 1 3/4" HIF carb with improved manifolds with twin down pipes.
So with those improvements over the original A series there must be a fair increase in output at least to Midget levels ?

Post by **bmcecosse** » Sat Aug 19, 2006 8:15 pm

Yes - the bigger carb will be the main increase - and it will be on a much better inlet manifold. Of course - many engines are bought withOUT the carb or manifolds.

Post by **KirstMin** » Sun Aug 20, 2006 5:33 pm

Kevin wrote:So with those improvements over the original A series there must be a fair increase in output at least to Midget levels ?

I guess so! I have a ital A+, modified head and cam and hif44 etc etc and on rolling road got 86bhp. But that's all down to the mods bolted onto and into the engine. I would have thought you could use a marina 1275, re-build it and plop all this stuff on and it would give the same output. I dont think there is much power difference in the block itself that is. Do you?

Post by **bmcecosse** » Sun Aug 20, 2006 7:14 pm

None at all - only perhaps the CR which can be adjusted by skimming the head. 86 sounds pretty good - considering Cooper S with the BIG valves head only gave 75 - but with restrictive twin 1.25" SUs (on the ghastly standard manifold!) and a very soft camshaft. What cam are you running Kirst ??
PS - Love those Minilites!!

Post by **KirstMin** » Mon Aug 21, 2006 12:34 pm

bmcecosse wrote:None at all - only perhaps the CR which can be adjusted by skimming the head. 86 sounds pretty good - considering Cooper S with the BIG valves head only gave 75 - but with restrictive twin 1.25" SUs (on the ghastly standard manifold!) and a very soft camshaft. What cam are you running Kirst ??
PS - Love those Minilites!!

Thanks mate! those are the 15" from JLH. My cam is the morspeed phase II which I believe is done by re-profiling a 288. Simon will have more info if he is still hanging around here. The head is also a morspeed: it's a stage 3 head with 35 x 29.0mm VALVES, 160lb double valve springs, polished and ported with a 10:1 CR. The rolling road were impressed with the figures.

Post by **bmcecosse** » Mon Aug 21, 2006 4:49 pm

Ideal set-up then - similiar to my Mini engine - although it is 1360 and has bigger exhaust valves. Morspeed certainly seem to know their stuff. The Minilites really set the car off nicely.

Post by **vincenth** » Mon Aug 21, 2006 5:30 pm

So in summary then, there is a power difference between the marina 1275 A model and the 1275 A+ model.

My original plan was to get a 1275, give it an overhaul, add HIF44 carb and water cooled manifold. I'm not after a vast increase in power, just enough to keep up with modern traffic and help with the hills in Derbyshire.

Just a question now of whether to keep looking for an A+ or to settle for a standard 1275 A unit