7 replies to this topic

[nzjb]

Hi all,

 

Still just in the planning stage of an engine build. My 998 has a blown head gasket so thought it'd be a good time to start thinking about a nice upgrade. 

 

Currently im thinking:

 

1293

RE13Ot, 1.4 rocker

CalverSt CST2001 35.7/29.5 head

twin HS4s

minispares evolution pistons

rebuild gearbox with central oil pickup, 3.44 X-pin on 10inch wheels

 

Aiming for 90ish hp, mainly for (very) spirited road driving, the very occasional track day, but still usable-ish around town and on motorway at 65.

 

does this spec sound suitable? is it maybe too aggressive and should stick to a SW5? Will a rebuilt gearbox and X-pin hold up or will i need a stronger box?

 

Cheers

[nicklouse]

your box will be fine.

 

I would ditch the twins and fit a single HIF44

 

otherwise seems good.

[postve]

I agree with nick as just finished mine and hitting 85-90 hp and very similar to what u are planning;

- 1293
- HIF44
- BP255
- CST2001
- 3.44
- 1.4.1 rockers
- sport coil
- Aldon Dizzy
- k&n cone filter
- KAD quick shifter
- 8.5 pistons
-9.5compression
- 25ccchamber

Runs like hell as had it out last night and only thing I might have done is go for a BP270 but worked for months with Keith Calver and he advised to stick with what I ordered from him to meet my expectations - lots of low end torque, range 1500 - 6000 as I rarely go past 6k and I would gamble majority of users don't either.

At the end of the day I am extremely happy with the doubling of hp and massive increase in torque! Work with Keith and be very clear on what you are expecting and he can design accordingly !

Edited by postve, 25 February 2020 - 12:20 PM.

[postve]

Hi all,

 

Still just in the planning stage of an engine build. My 998 has a blown head gasket so thought it'd be a good time to start thinking about a nice upgrade. 

 

Currently im thinking:

 

1293

RE13Ot, 1.4 rocker

CalverSt CST2001 35.7/29.5 head

twin HS4s

minispares evolution pistons

rebuild gearbox with central oil pickup, 3.44 X-pin on 10inch wheels

 

Aiming for 90ish hp, mainly for (very) spirited road driving, the very occasional track day, but still usable-ish around town and on motorway at 65.

 

does this spec sound suitable? is it maybe too aggressive and should stick to a SW5? Will a rebuilt gearbox and X-pin hold up or will i need a stronger box?

 

Cheers

 

At the end of the day I am focusing on the "torque" which is all that really matters for me..

[Minigman]

My 1330 with a stage 3 head, 276 cam, twin HS4s made 92bhp. There are cams out there like AC Dodd’s RS which claims real world builds will be very torquey from low down and still make 90bhp. My standard pre A+ Rod change box just threw a idler bearing and wrecked the box and transfer case. So I’d make sure you build the box out of a A+ version with the larger idler bearing.

[postve]

My 1330 with a stage 3 head, 276 cam, twin HS4s made 92bhp. There are cams out there like AC Dodd’s RS which claims real world builds will be very torquey from low down and still make 90bhp. My standard pre A+ Rod change box just threw a idler bearing and wrecked the box and transfer case. So I’d make sure you build the box out of a A+ version with the larger idler bearing.

humm, I never considered or even knew this might be a problem. I absolutely have a "pre-A+" rod change box but a much milder CAM - I think I should be okay and I see why Keith cautioned me about going with a more race spec CAM - I have a BP255 as above details

[imack]

I think a lot of the idler gear issues are more to do with the poor quality bearings available (assuming gearbox and transfer case condition is good and the gears correctly shimmed) these days rather than engine output.
A+ boxes with larger bearings seem to suffer other issues with greater misalignment and smaller idler shim surface area.

[postve]

I think a lot of the idler gear issues are more to do with the poor quality bearings available (assuming gearbox and transfer case condition is good and the gears correctly shimmed) these days rather than engine output.
A+ boxes with larger bearings seem to suffer other issues with greater misalignment and smaller idler shim surface area.

Thx Imack, I think I will leave well enough alone and good to hear another opinion.