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MG Midget and Sprite Technical - Kent 256 camshaft in 1275cc Sprite?

Hi all. I'm still quite new to these car so forgive me if this is a daft question. I have a 1971 Austin Sprite with a newly-rebuilt (600 miles ago) 1275cc engine, standard other than an unleaded conversion. I have been offered a Kent 256 camshaft. I would like a little more power from the engine, but only for road use, I am not looking to compete or anything, so I want to keep the car looking stock and driving smoothly enough on the road. I also don't want to put in such a wild cam that the car is rough on the road and I have to go around uprating everything else to cope. So would this camshaft be a good idea, bearing all that in mind? Would I end up with a slightly quicker car that was still as usable on the road and could I then leave everything else standard? I'd like the car to stay as (broadly!) reliable as it has been to date. And how much of a job is it to fit? Small children and a new business mean that I'd be paying someone else to do it, but I can't spend a fortune..? And if this cam is entirely unsuitable for me, does anyone have any thoughts on what sort of camshaft I should look for to achieve a faster road car that still feels period and won't feel like a hot rod? And while I'm in demanding mood, I have just moved to the Peak District if anyone knows a specialist nearby who could do the job for me..! Apologies for all the questions and apologies if I'm missing some obvious fact. I'm still learning about the oily buts, it's my first Spridget and I thought I should ask on here before making a costly misjudgement! Many thanks for reading, Piers
PG Colver

Piers,
I'd recommend a 276 at minimum to get a really nice feeling of 'power' - the idle is slightly lumpy but as long as you keep the head pretty standard you will have a noticable change in power. It isn't a quick job though and the engine does need taking apart to fit it.
Rich Amos (1330cc Blaze Red '72)

Rich, hi, thank you for that, and do you (or anyone else) think that Kent or Piper are a better camshaft for the 1275 A series? Piers
PG Colver

I agree with the sentiment of Rich above... but really a 276 is not the cam for a smooth idle, not does it work below 2K.

The 256 is probably a bit too tame. if you're going to change the cam (and that means an engine-out job) I'd consider a 266 (24 56 61 29) the minimum spec to make it worhwhile. Similar to the MG metro cam (16 56 59 29), but a bit more lift.

A
Anthony

Piers,
I've just changed my cam for a Morspeed Phase 2. Others on here will recommend a Swiftune SW5. Good for low end torque. Check prices. It was more work than I had imagined. Everything came off the engine except the crankshaft. And while the engine is out, change the clutch and oil pump.
Steve Church

Piers.

As predicted, I would recommend the Swiftune SW5-07 which I have fitted to many engines and have had a 100% success rate with. The Kent 256 is far too tame for the 1275 and would give you no noticable improvement. As Steve says, it's not a 5 minute job.

Mark.
Mark Boldry

256 is indeed far to tame
the sw5 is a no brainer works perfect in annything from a stock 948 to a wild 1380.

wil deliver a smooth idle and a lot more umpf (as an example i've seen stock 1275's go to 76bhp with just a sporty in/outlet and a sw5)
o Könemann

Piers,
I note that the engine has just been rebuilt. Why not finish running it in (you are running it in aren't you) and see how it goes then. Seems a shame to have to have it all stripped down after it has just been rebuilt. They are enjoyable little cars even in stock form, especially if the carbs and timing are spot on.
Steve Church

Thank you for all of those comments, everybody. To answer last, first, yes Steve I can see where you are coming from. I bought the car with a very tired engine, not the original one from the car but another 1275 A series that was near its last legs, ran it for six months then it expired. It was in a mess so I got the rebuilt engine (from MGOC, not a rebuild on the engine I removed) figuring I'd know what I was getting and could start from a clean sheet. The car runs great (and yes, I'm running it in!) but there must have been some odd bits on the old engine as I'm missing the old zip she had. The new engine is much prettier - everything that could be bodged had been bodged on the old one and it wasn't a pretty sight - I have sourced an old Austin rocker cover in the correct green, put her back to SU carbs, replaced hoses, brake lines etc with original items - but now I have a pretty, authentic-looking car that I love but that feels a little down on power compared with what I got used to (I have had the car checked and what I'm getting is normal for a standard car with a fresh engine) so while I absolutely see your point, I think that changing the camshaft would lift the performance while keeping the period feel I'm going for. I'd like a period look with maybe period mild competition pace. Clearly I should have replaced the camshaft in the 'new' engine before I had it fitted last year...but then if we none of us made mistakes many of the strings on here would be much shorter and possibly less informative/interesting. And I'm only learning!

Thank you, everybody, for the comments on which camshaft you would go for if I were to go ahead. Clearly it is an expensive fix for a mistake of my own creation, so I'll ponder some more and wait for the premium bonds to come good(!). For the record, thank you, Steve, for nudging me towards Swiftune, somehow had never heard of them but what a great website. If I do bite the bullet they'll be getting my pennies.

Thanks again, guys.
PG Colver

Will the SW5 get you off the line quickly in Autotests?
Nick

I actually fitted a Morspeed Phase 2 cam. It is a bit like the SW5 but with a bit more lift. It is also cheaper than the Swiftune one although that may change as the availability of cams to reprofile reduces. The engine is waitng to go back in the car so time will tell if I made the right choice. Theres a lot of info on cams on the mini forums.
Steve Church

now that you have the old engine out you could start building that one to "look" stock on the outside while making it a really fast road engine on the inside such as playing with the head which ever direction you want to go with that, maybe raise the compression ratio, definitely port out the head. You could then swap in the sock looking from the outside motor you built on the bench at your own leisurely pace while still being able the drive the MG and enjoy it.

There is a million ways to keep them looking stock and still fun,
Stefan
Stefan

I have the Morspeed ph2 on a std 1275 9.5cr and I can say it's a good n'. Having driven both the SW5 and the phase 2 I can say I prefer the phase 2 as it feels more urgent and I think it's got the edge on the top end (think of it as a SW5 with 1.5 rockers)

I have a spare good 276 cam and matching new oil pump you can have in exchange for a couple of beer tokens (I'm quite local) if you want to give that a go.

I opted for the ph2 over the 276 as I used to commute daily on the M25 and the 276 would have been tiresome in traffic.

Let us know what you choose to do in the end.

Stoo
Stuart Robson

Stuart,
When I spoke to Simon at Morspeed he said the phase 2 was like the SW5 but with a bit more zing. It certainly has more lift than the SW5 which probably explains why you think of it as a SW5 with 1.5 rockers.

I hope to have mine on the road soon with 10:1 MG Metro head and HIF44/Titan.
Steve Church

To jump in here before Prop, are either of these cams available on the USA side of the Pond?
David "cam-lusting" Lieb
David Lieb

you can always order them directly from morespeed or swiftune and have them ship it
o Könemann

That tends to be the last resort. The international shipping of a single item like that is rather prohibitive, especially with a weak dollar.
David "cheapskate" Lieb
David Lieb

David,

I just took my turbo cam to the machine shop and am having it ran through a cam analyzer and then refreshed, and according to the shop if you get them the profile of a cam they can reproduce it, and reworking an old cam is far cheaper than buying a new one. I have two spare midget star drive cams if you can get me the specs from one you want.

Stefan
Stefan

Yes, but will the SW5 get you off the line quickly in Autotests?
Nick

This thread was discussed between 25/02/2008 and 27/02/2008

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