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MG Midget and Sprite Technical - MGOC Stage 2 1275

Does anyone have any experience of these rebuilds? Roughly what power output assuming the appropriate SUs fitted?
G Williams (Graeme)

hey graeme

do you have a link ?

the problem with stage designations are there not universial

ive seen some examples.of a stage 2 engine that where little more then a set of K&N air filters and a larger 3 in one exhauste header and a fresh new coat of red paint

btw FYI...red paint is the fastest and easist way to add 5 HP...I know, it worked for me.

prop
Prop and the Blackhole Midget

75ish I've heard

though I would also look at the usual engine builders who can tailor to your specific wishes

for example
http://www.skiptune.com/products/engines
Onno K

Hi Prop
Can't copy and paste spec, but I'll see if I can find another way. THere isn't a link just a spec sheet which you need to ask for.
The obvious thing, which I've now done, is to ask them too. Whether they will say or whether they might worry that it's taken as a warranty we will see.
G Williams (Graeme)

Onno: I've never really looked at power improvements. Current is what (find handbook) 68 bhp? What would be reasonable and still keep the car tractable... 80? 85?
Your estimate at 75 doesn't seem much extra grunt.. is that what I should expect?
G Williams (Graeme)

I think that MGOC use Ivor Searle

http://www.ivorsearle.co.uk/mg_engines.htm
Dave O'Neill2

That would make sense as they are both in the same neck of the woods. My current recon is an Ivor Searle. It does look as though they just turn out "standard" units though, not anything special.
G Williams (Graeme)

there are lies, damned lies and claimed power

IIRC 64bhp was BL's claimed figure when the (1275) cars were new, what method or standard of measurement they used to get this figure I don't know

I'd say if the rest of the car is in good condition and good operation 80/85 bhp would be tractable in a standard car, perhaps if the gearbox and halfshafts are a little shaky they might be weak spots

what ever you have at the engine then gets diluted by the transmission, tyres etc.

the engine's potential power also relies on good induction, exhaust, ignition, timing, carbs, etc.

then you have power to weight, a heavy lunch for some drivers will drop the car's p:w by a percentage or two
Nigel Atkins

you might consider one of those ebay universial electric turbo chargers...they "claim" around 50 hp pending which advert your reading....and there only around $50

so if you have duel carbs... youwould need 2, thats a whopping 100 extra hp on top of your factory 68 HP

so thats a grand total of 168 hp all for only $100

now that sounds inticing..lol


http://item.mobileweb.ebay.com/viewitem?itemId=230795064229&index=6&nav=SEARCH&nid=25585355603

prop
Prop and the Blackhole Midget

only 164 so not so good for $100
Nigel Atkins

oh your right... I forgot the tires rob HP....


yeah... not to good a deal, 16.4 HP per dollar just isnt a good return...

prop
Prop and the Blackhole Midget

OH... Electric turbos are back on.the menu....look at what I just found...

DUEL ELECTIC (compounded) TURBOS.... thats 4 turbos so thats what 50 hp x 4 turbos plus the (64) factory hp ....

thats 264 HP... for only $129.00

dont do it... please dont even consider it...you would need new everything to drive that wonken beast...brakes, suspension, tranny, rearend, tire and wheels...

it would be completely "undriveable" ....hahaha

check out the discription... thats almost criminal

http://item.mobileweb.ebay.com/viewitem?itemId=330741999533&cmd=VIDESC
Prop and the Blackhole Midget

hmmm its so turbo fast it updated the ebay page before I could.shout out....horse sh^t !!!

better buy fast... its now $149

lol...

prop


http://item.mobileweb.ebay.com/viewitem?itemId=330741999533&index=2&nav=SEARCH&nid=89663305566
Prop and the Blackhole Midget

my A had a self ported to Vizard guidelines big valve MG metro head with LCB and twin 1.5 inch carbs on a ported manifold. it made 75bhp and 88 lbft. It ate 2 A series gearboxes (stripped the teeth off 2nd and 3rd respectively) and is currently eating a third one (input shaft bearing) in dad's car. it has enough poke to make you think you need another gear on top of the 4 speed.

All the 'stages' are different - I think stage 2 is bigger valves and a bit of light porting generally.

Engines come in stages too which don't always match up to the head stages..
Rob Armstrong

Rob,
are you meaning output at rear road wheels whereas we were on about output from engine
Nigel Atkins

my A 1293 uses a Slark unleaded BV head 11:1 CR with LCB etc standard carbs, standard cam and on their RR produced 74 BHP at the flywheel. Bigger carbs would give another 5 BHP or so. Rebuilt the transmission at the time the engine was done (3 years ago) and this has been fine. Its fun to drive, returns decent MPG yet is tractable and practical in London traffic and on the open road. I agree an extra cog would be nice!
Bob Beaumont

THe MGOC engine produces "around 12%" which would raise 64 bhp to around 72.
Skiptune (mentioned by Onno) are talking about 80/85 bhp.
How much could you push through a standard gearbox without breaking anything. Then there's the vulnerable halfshafts.....
G Williams (Graeme)

I think providing the gearbox is in good repair and the oil levels properly maintained then all should be well. I think what happens is the engine is uprated and bolted to a gearbox that already has done a fair few thousand miles and it gives up in disgust.

i would not pretend the transmission is the most reliable but I beleive proper maintenance and ensuring the components are in good order goes a long way to ensuring longevity

I renewed all the bearings in mine and checked for wear on the gears/shafts etc and ensured all the tolerances were within manufactures specifications and its been fine so far. The other option is a 5 speed conversion of course.

I think the half shafts are OK providing they are the later spec and that the car is driven with a degree of compassion!
Bob Beaumont

>>How much could you push through a standard gearbox without breaking anything. Then there's the vulnerable halfshafts.....<< you don't read my posts do you :D
Nigel Atkins

But I do Nigel!
But I was also hoping that someone could reflect actual experience like "I have 75bhp and have broken three half shafts and 4 gearboxes."
G Williams (Graeme)

I have +80bhp and no broken half shafts and after 5 years of hard use and abuse (and before that who knows how many by the PO)a noisy 1st and 2nd

That is lot's of road miles (almost daily) and track and rally miles.

So I'd say it is a tough little box!
The basis (smooth case) was designed to cope with 50BHP max the upgrade (ribcase) handled 65BHP on crossply's

Onno K

Well I have almost 75 BHP and haven't broken anything so Nigel's original comment seems about right.
Bob Beaumont

My numbers were at the flywheel.

Graeme - I had 75 bhp at the fly and killed 2 gearboxes and no halfshafts :D

Though with kinder driving and less right boot you'd get them to last a bit longer. And I never had a new one.

I've not broken any halfshafts or diffs, even with the K (110 ish bhp at fly). Plenty of the K-brigade are running standard diffs&halfshafts. Some more successfully than others...
Rob Armstrong

Thanks lads, that's all very encouraging.

Onno: the people you suggested in your link (Skiptune) have been very helpful!
G Williams (Graeme)

I need to corect an error in my earlier post! The MGOC engine is expected to improve BHP by around 20%, not 12% as I stated. This would give about 76 or 77 bhp
G Williams (Graeme)

Speak to Peter Burgess. http://www.burgesstuning.free-online.co.uk/page3.html

He's the most sensible person I've met in this area. There's a distinct lack of fancy showrooms, expensive cars in the car park, or unhelpful sales 'experts'

You always get a straight answer from the horse's mouth with no BS.

Couples with the fact that any expectations can be proved on his dyno.
Dan Cusworth

Rob,
the numbers being at the flywheel suggests you possibly didn't need the twin 1.5" carbs, subject to condition of engine, with all you listed it might be that there is more to be had out of it
Nigel Atkins

May well be, but with the big hif carbs replacing small hs carbs I knew it wasn't limited by carbs. And I did port the head myself :-) so wouldn't be surprised if it wasn't up to commercial standards. But it was very very cheap
Rob Armstrong

Onno: You linked to Skiptune earlier in this thread - did they build your engine?
G Williams (Graeme)

Rob,
I'm sure you'd have done a better job than some professionals
Nigel Atkins

This thread was discussed between 27/02/2013 and 02/03/2013

MG Midget and Sprite Technical index

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