20 replies to this topic

[Mini Manannán]

The world is your oyster, depends on your budget. 

[racingbob]

mg metro cam and mg metro head cost about £200

[Cooperman]

As above really
Gas-flowed head with 35.6 mm inlet valves as in MG Metro.
Cam also as above, but MG Metro cam is good as well.

HIF44 is a good carb on an alloy manifold and lightening the flywheel improves acceleration.

Then have the ignition advance curve set to match.

[InnoCooperExport]

Not wanting to hijack, but I was under the impression that fitting 1.5 rockers was similar to fitting a slightly hotter cam. So there should be some benefit to fitting them even if you're not swapping cams? 

 

The reason I ask is because when I bought my car it came with a bunch of tuning bits and an Innocenti 1275 engine to rebuild (basically a Mk3 S engine). So far it's been bored out to 1310 as the bores were spent, and it came with, amongst other bits, a lighter flywheel & pressure plate, orange diaphragm and a set 1.5 full roller rockers. I intend on fitting the rollers but not upgrading the cam. The current cam is an Italian equivalent AEG510 (the BMC Cooper S cam), and I will be running the original 12G1805 big valve head (not sure how that's different from the later MG heads with similar valve size). But would it still make sense to fit the 1.5 rockers or should I stick to the 1.3? The main argument I hear against fitting 1.5 rockers is that they're expensive without a great increase in performance, but as I have them anyway... 

[Northernpower]

Not wanting to hijack, but I was under the impression that fitting 1.5 rockers was similar to fitting a slightly hotter cam. So there should be some benefit to fitting them even if you're not swapping cams? 

 

The reason I ask is because when I bought my car it came with a bunch of tuning bits and an Innocenti 1275 engine to rebuild (basically a Mk3 S engine). So far it's been bored out to 1310 as the bores were spent, and it came with, amongst other bits, a lighter flywheel & pressure plate, orange diaphragm and a set 1.5 full roller rockers. I intend on fitting the rollers but not upgrading the cam. The current cam is an Italian equivalent AEG510 (the BMC Cooper S cam), and I will be running the original 12G1805 big valve head (not sure how that's different from the later MG heads with similar valve size). But would it still make sense to fit the 1.5 rockers or should I stick to the 1.3? The main argument I hear against fitting 1.5 rockers is that they're expensive without a great increase in performance, but as I have them anyway... 

It depends what you want to use the engine for. The 1.5 rockers work a lot better and give greater benefit at higher revs. If you're going to be doing mainly road work with a road diff ratio then the 1.5 rockers can be a disadvantage.

Edited by Northernpower, 08 October 2016 - 06:53 PM.

[InnoCooperExport]

It will be a road car, but a bit of extra oomph is never amiss. Might get the odd circuit outing but I won't be building it with that in mind. I will be running a 3.44 diff, Maniflow LCB and exhaust, twin HS2 with K&N pancakes. I guess the effect of running 1.5 rockers could be compared to for instance running HS4's; you gain more in the high revs but lose low end torque?

 

At least rockers are easily changed so I can always play around a bit.