So much info and so few brain cells

[alant]

I have decided for a couple of reasons to stick with a 998cc engine.

This is an A+ with HS4 carb, stage 1 kit and lumenition electronic distributor kit.

I am about to strip it down and will look at regrinding the crank, head skimming etc.

But?

Do I replace the cam, fit roller rockers, a differant head etc etc.

I want reasonable performance and cruising ability.

Which is better a new cam or roller rockers and which ones

Any help would be appreciated as there is so much info out there I am getting confused.

Regards

Alan

[Wildfire]

Do it!! Join the madness of small bore power!!! Everybody thought I was mad when I did my 1 litre. A cam change would be more beneficial than rockers, what sort of budget are you looking for?

I would reccomend the following:

Total clean up of block, crank
Lighten and balance
Unleaded hear ported and flowed with larger inlet valves. ie unleaded 12G295 if you can get one. Not silly expensive.
Piper 255, Kent 266 or Swiftune SW 5 Cam.
1.3 roller tipped rockers.

Crusing will be dictated by the Diff. 3:44 is a good diff for general use if a little high strung for the motorways. 3:2 or 3:1 are perfectly useable, although a little sluggish.

There is little point in upgrading the camshaft if you are not going to upgrade the head as the engine won't be able to breath well enough to make use of the cam.

[robpeacey]

i agree with wildfire, im part of the tuned 998 clan, i have this im workin on in uni at the mo.......

[alant]

Thanks for the replies.

With regard to budget, no particular amount set, more looking at value for money,

I have someone who can modify the existing head for me and have been advised to try this with a Piper 255 Cam and standard rockers, if this does not work out ok I can then change the head at a later date without having to take the engine out.

I will let you know how I get on.

Thanks

Alan

[miniman]

Have fitted a 12G295 and 266 cam to my 998 with a HIF38 carb. In February 2005, in fact. Still haven't started it to this day This summer definitely getting it back on the road!

[Wildfire]

If you are going to uprate the cam it is well worth uprating the head first. You don't have to go the whole hog like rob or I, but if you can get a 12G295, pay around £100-150 to make it unleaded, then you will get very good value for money.

I have heard good things about the SW5 cam, which IIRC an evolution of a Kent Cam.

[fwdracer]

Built a budget 998cc lump for my Brother's GTM years back (Due to insurance!). Used a Piper 255 cam and a cleaned up standard 998cc head, HS4 carb with small diameter inlet manifold and decent exhaust manifold (Don't mess about with an LCB on such small top end bhp output, just robs the engine of torque, a cooper freeflow manifold is more than sufficienct) electronic ignition system and it gave a good solid 54 bhp. Great little lump. I'd recommend doing the cam first, cleaning up the standard head, skimming it to get the cr to around 9.5/10.1-1 and then searching for 12G295 head at a later date when you've got some more pennies together.

3.44 to 1 final drive is recommended as best balance between acceleration and motorway on 12" wheels. Have got a good CWP set up if people are interested.

[Cooperman]

fwdracer said:

Built a budget 998cc lump for my Brother's GTM years back (Due to insurance!). Used a Piper 255 cam and a cleaned up standard 998cc head, HS4 carb with small diameter inlet manifold and decent exhaust manifold (Don't mess about with an LCB on such small top end bhp output, just robs the engine of torque, a cooper freeflow manifold is more than sufficienct) electronic ignition system and it gave a good solid 54 bhp. Great little lump. I'd recommend doing the cam first, cleaning up the standard head, skimming it to get the cr to around 9.5/10.1-1 and then searching for 12G295 head at a later date when you've got some more pennies together. 3.44 to 1 final drive is recommended as best balance between acceleration and motorway on 12" wheels. Have got a good CWP set up if people are interested.

54 bhp is what the original 1000 cc Coopers gave. Your spec is very similar to that, except for the head and the big single carb instead of two small ones. With a ported 295 you could, one might expect, gain another 5 to 8 bhp on top of that.The 255 cam seems similar to the original Cooper cam. I think I would go for a 266 with a 295 head if using a 3.44 final drive. I guess the original type 3-branch exhaust manifold is still available.
The 998 engines are always so smooth compared with the 1275's.

[myname]

wishing i had read this thread before bowing to peer pressure and getting myself a bigger engine... oh well, i have enough spares to make another mini pretty much so perhaps i'll just have to rebuild my 998 as well and then build myself another car and see what the difference is...

[robpeacey]

as an update, got it rollered the other week, 52bhp at the wheels. not quite as much as i was hoping for but still 1300 power, bonzer!