24 replies to this topic

[TimS]

Do you mean due to the more revs it produices for the same amount of power?

[MAGA7INE]

Not doubting that, but how often is the 998 rebuilt, vs the same 1380 ?

Not quite sure what you mean there, do you mean that 998's are weaker or need rebuilding more? (Sorry, not that clear to me )Turbo engines are under less stress than a high rpm na engine. 998's are if anything stronger than 1275's.

My old ST3 998 took some real abuse for 3 years and never broke anything, even with a small dose of nitrous on a stock bottom end. Not even rebuilt, (but low milage when converted).

The turbo engine with mapped ignition and an intercooler will last as long as a stock engine.

If you mean a high rpm 100bhp engine then they will wear more quickly, but that's not a route I want to go down.

If you mean the turbo 998 will for some reason need rebuilding more than a 1380, that's not the case. The proof is in the doing though so I will let you know!

[hb63]

I had a genuine 80bhp at the flywheel (on a dyno that read 40bhp stock), from an SW5 cam, 12G295 cooper 998 head, (they come up on ebay regularly), minispares ST1 kit with the drilled stock air filter housing. This is bolt together stuff. Morspeed do a recon, unleaded conversion and mild port on these heads for £250, though I just used an additive. Was great fun and easy to build.

Performance? Sub 10 sec 0-60 and GPS reported 110mph top end on 2.95 city E diff.

Which type of dizzy did you use with the SW5 cam. Was it just a standard one or was it a tailored advance curve? and was the cooper head ported with bigger than standard valves?

Harald

[MAGA7INE]

I had a genuine 80bhp at the flywheel (on a dyno that read 40bhp stock), from an SW5 cam, 12G295 cooper 998 head, (they come up on ebay regularly), minispares ST1 kit with the drilled stock air filter housing. This is bolt together stuff. Morspeed do a recon, unleaded conversion and mild port on these heads for £250, though I just used an additive. Was great fun and easy to build.

Performance? Sub 10 sec 0-60 and GPS reported 110mph top end on 2.95 city E diff.

Which type of dizzy did you use with the SW5 cam. Was it just a standard one or was it a tailored advance curve? and was the cooper head ported with bigger than standard valves?

Harald

I home ported the head following Vizards spec but with stock valves. 10.5:1 cr and optimax fuel.

I used a std dizzy to start with, just played with the springs to get a better advance curve, this still had a flat spot around 2000 to 2500 rpm but gave this peak reading.

I later swapped to megajolt ECU with the EDIS distributorless ignition and picked up torque and lost the flat spot and increased MPG due to the massive part throttle advance you can run with this system. I am doing a back to back test megajolt versus dizzy on a st1 998 so look out for that in the mag later this year.

Hope this helps.

[01smartc]

Which Mini mag was this in??? I have the January and February copies of Mini Mag and cant find it.

[Guess-Works.com]

Not doubting that, but how often is the 998 rebuilt, vs the same 1380 ?

Not quite sure what you mean there, do you mean that 998's are weaker or need rebuilding more? (Sorry, not that clear to me )Turbo engines are under less stress than a high rpm na engine. 998's are if anything stronger than 1275's.

My old ST3 998 took some real abuse for 3 years and never broke anything, even with a small dose of nitrous on a stock bottom end. Not even rebuilt, (but low milage when converted).

The turbo engine with mapped ignition and an intercooler will last as long as a stock engine.

If you mean a high rpm 100bhp engine then they will wear more quickly, but that's not a route I want to go down.

If you mean the turbo 998 will for some reason need rebuilding more than a 1380, that's not the case. The proof is in the doing though so I will let you know!

Sorry, only just got back to the post...

And should have made myself more clear... what I look at is basically, the cost of performance and IMO the amount of money involved in building a reliable high performance small bore is considerably larger than a reliable average performance big bore, where the performance figures are equitable.

Therefore if you try to buid a high performance small bore for the same budget as a big bore, then something has to give, and that's usually reliability.

[miniallsort]

what mods do you think can give a 988 more power with a stage 1 kit where do you go from there ?

[josh_tacon]

would a 40 DCOE weber be any good on a tuned 998?

the spec im thinkig of is....

stage one kit (maniflow exahst system, single box, and K&N air filter in drilled box)
stage 3 head
3.44.1 FD
minispares lightend flywheel
SW5 cam
megajolt ignition
single weber 40 DCOE???

what do you think?
at the moment i have a 998 with the first three mods and it flys!

i have been reading the mini mags and i think its a good idea to mod what you have. and it keeps the insurance down, and i think that 998s are nice lil engines!

cheers
josh

[miniallsort]

yep keep it 988 people there wicked engines

[Jammy]

I'd say the 40 would be overkill on a 998, of that spec anyway, keep it to twin HS2s or HIF44.