15 replies to this topic

[GermanMoreno]

Camshaft vs Stage 3 Cylinder head + Stage 1 exhaust system kit

I have been told that a change in camshaft would give a greater increase in performance for the cost than cylinder head+stage1kit.
any thoughts on this?

 

[timmy850]

Well it all depends what engine you have and what parts are in it already. For some engines the limiting factor will be the cam, others the head and others the manifold/carb/exhaust

The head and stage one kit is a “bolt on” modification you can do without taking the engine out. Most cars would respond really well to a decently modified head and a stage one kit.

To change the cam ideally you need to remove the engine, if it’s a 1275 with no tappet covers it’s more tricky than the engines with tappet covers as you can’t easily remove the cam followers. If you put in a big cam that moves the power band up higher, and you don’t have the required flow from the head, or you have weak valve springs that don’t allow you to rev the engine you can lose power and driveability.

[Minigman]

I’d do the head first personally as that’s key to unlocking the engine potential. A good cam is way cheaper than the head but it’s potential won’t be fully utilised until the head is improved. Ideally do both. As said above the cam swap on a big bore is a engine out job. But is doable on small bore in situ but is a hassle.

[nicklouse]

The head is the restriction on a Mini. 
 

depending on which engine it is a cam change is an engine out job so you might as well change everything else that can wear out.

 

a head swap is simple.

[dotmatrix]

I would start with a better flowing head

[Norfolk Boy]

My 94 1275 carb mini is currently having a Calver ST fast road head and Swiftune 1.4.1 forged rockers fitted on standard bore and cam, then being set up on the rolling road. It already has a stage one kit, I’ll have it back on the 24th so will post up the results ?

[GermanMoreno]

My engine is a A+ 1275cc. It is a Mainstream Cooper 91. I assume everything is standard in the car. Anyone knows what type of cam is fitted in these?
 

Well it all depends what engine you have and what parts are in it already. For some engines the limiting factor will be the cam, others the head and others the manifold/carb/exhaust

The head and stage one kit is a “bolt on” modification you can do without taking the engine out. Most cars would respond really well to a decently modified head and a stage one kit.

To change the cam ideally you need to remove the engine, if it’s a 1275 with no tappet covers it’s more tricky than the engines with tappet covers as you can’t easily remove the cam followers. If you put in a big cam that moves the power band up higher, and you don’t have the required flow from the head, or you have weak valve springs that don’t allow you to rev the engine you can lose power and driveability.

[GermanMoreno]

Exactly what I want to do, what is the "fast road cylinder head" from his website? Sport-spec or SuperSport head. Very interested in the results, please keep us updated!

 

My 94 1275 carb mini is currently having a Calver ST fast road head and Swiftune 1.4.1 forged rockers fitted on standard bore and cam, then being set up on the rolling road. It already has a stage one kit, I’ll have it back on the 24th so will post up the results

[Norfolk Boy]

I’ve gone for the sport spec, I’m lucky enough to only live about 15 miles from his workshop, he’s a great bloke too talk to and gives great advice he’s very busy though. Mines a Sprite model so I think I’m right in saying it started with less power/torque than your cooper.

[Norfolk Boy]

I’ve gone for the sport spec, I’m lucky enough to only live about 15 miles from his workshop, he’s a great bloke too talk to and gives great advice he’s very busy though. Mines a Sprite model so I think I’m right in saying it started with less power/torque than your cooper.

Just checked my big mini book and mine left the factory with a massive 50bhp and 66lb:ft of torque, yours should be 61bhp and 61lb:ft .

[Norfolk Boy]

Brief update:- a cv gaiter split whilst on the rolling road so needs replacing before the final power run so won’t now pick it up until the 31st. ?

[Dusky]

"Stage 3" means nothing really. Also, without knowing what you want and have at the moment it's impossible to give a good answer to this. Dont expect any big horsepower gains by just changing either the cam or the head. They both need improvement. Especially the cam is a weak point on the latest minis with the economy cams.

[Norfolk Boy]

Keith Calver said exactly the same regarding ‘stage 3’hence fast road spec, I originally went to him thinking I needed a full rebuild because of black smoke on start up and rattling top end. On being told to have a compression test that’s what I did and all was good, the rattle was rocker gear, black smoke, valve stem oil seals. So I decided to treat myself to a fast road head and 1.4.1 forged rockers. In the future no doubt the engine will need a rebuild so will have the cam changed then. I’m not after mega power just some more low down torque, it’s back on the rolling road next week can’t wait to get it back.

[Norfolk Boy]

My 94 1275 carb mini is currently having a Calver ST fast road head and Swiftune 1.4.1 forged rockers fitted on standard bore and cam, then being set up on the rolling road. It already has a stage one kit, I’ll have it back on the 24th so will post up the results ?

Well I finally have the car back from the rolling road and the figures are 73.6bhp @4900rpm and 88ft/lb of torque @3900rpm whilst I’m pleased with the numbers, the extra grunt I’ve now got is very noticeable pulling strong and smooth from as low as 2000rpm in top making it great fun on the lanes, but also more pleasant cruising at motorway speeds. Overall very satisfied ?

[Minigman]

The 88ft/lb is a good a result and must make the mini pull nicely. 

 

I only got 90ft/lb from my well built 1330 with a 276 cam, but did get 95.8bhp, but the torque is what counts on a road car.