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Increasing power in a 998 Auto?
https://www.ausmini.com/forums/viewtopic.php?f=2&t=95370		 Page 1 of 3
Author:  dawi03 [ Wed May 10, 2017 7:17 pm ]
Post subject:  Increasing power in a 998 Auto?
Hi guys,

So I have a 1988 998 Rover Auto, and in the next couple of months Im wanting to start looking at getting some more grunt to the car.

I want to keep it an Auto ( and yes I know some people will have opinions on this lol)

My question is, am I better off buying a 1275 auto spi from Japan to fit, or should I put a 1275 head on with some mods, or just bore out the 998?

Im completely foreign to any of this and I wouldnt be doing the work myself, I was just wondering what people think will be the cheapest option/easiest option?

Any ideas from anyone that has done the same would be fantastic

Thanks everyone
Author:  simon k [ Wed May 10, 2017 7:57 pm ]
Post subject:  Re: Increasing power in a 998 Auto?
stick with what you already have, get it tuned properly and running 100%, then make cheap & simple mods like head work, carb, exhaust etc.
Author:  ALPINE MOKE [ Wed May 10, 2017 8:07 pm ]
Post subject:  Re: Increasing power in a 998 Auto?
The 998 cc rover A plus auto engines go just as hard
as the later model Spi 1275 engines.

Keep the 998 with the 1 1/2 "SU , fine tune it.
as simon said.
Author:  dawi03 [ Wed May 10, 2017 8:13 pm ]
Post subject:  Re: Increasing power in a 998 Auto?
ALPINE MOKE wrote:
The 998 cc rover A plus auto engines go just as hard
as the later model Spi 1275 engines.

Keep the 998 with the 1 1/2 "SU , fine tune it.
as simon said.



Awesome I'm actually really happy to hear this.

What mods can I do to it though? Or what are the cheaper mods to do?
Author:  drmini in aust [ Wed May 10, 2017 10:16 pm ]
Post subject:  Re: Increasing power in a 998 Auto?
Put a 1098 crank and pistons in it. Or bore it to 68mm (1108cc). Either mod gives it a heap more torque, which is what they need to get mobile faster.
Author:  dawi03 [ Wed May 10, 2017 10:55 pm ]
Post subject:  Re: Increasing power in a 998 Auto?
drmini in aust wrote:
Put a 1098 crank and pistons in it. Or bore it to 68mm (1108cc). Either mod gives it a heap more torque, which is what they need to get mobile faster.



Thanks DR Mini. Which of those would be the cheaper option and the best option? I'll have to speak to Len Read when the car goes in to him too but I'm glad I'll get to keep original motor in the car.
Author:  drmini in aust [ Thu May 11, 2017 6:47 am ]
Post subject:  Re: Increasing power in a 998 Auto?
1098 crank and pistons is easiest, if you bore it as well you can get up to 1188cc without offset boring.
Even +.060" bore will give 1152cc.
Fit flat top pistons not dished.
Author:  dawi03 [ Thu May 11, 2017 7:14 am ]
Post subject:  Re: Increasing power in a 998 Auto?
drmini in aust wrote:
1098 crank and pistons is easiest, if you bore it as well you can get up to 1188cc without offset boring.
Even +.060" bore will give 1152cc.
Fit flat top pistons not dished.


Thanks mate. How much would crank and pistons set me back on average?

Thanks
Author:  drmini in aust [ Thu May 11, 2017 7:27 am ]
Post subject:  Re: Increasing power in a 998 Auto?
A S/h 1098 crank anything from $100 up. A crank grind is about $150, pistons $375 for Graham Russell ones then you have rebore & hone, bearings, timing chain, head service, etc etc.
Don't buy a 1098 crank without getting it crack tested.;)

Edit you want to regrind the 998 cam for more lift but don't get big duration. It needs to pull from low rpm. I suggest Graham's new S grind or his RE83.
Author:  TheMiniMan [ Thu May 11, 2017 7:49 am ]
Post subject:  Re: Increasing power in a 998 Auto?
std 1275 motors have more power than std smallbore motors
regardless of what gearbox its running

simple as that

however a "worked" 1275 will also have more power than a "worked" smallbore motor
again--> regardless of what gearbox theyre running

simple physics

i`m pretty sure you can work it out from there yeah??? :-)
Author:  drmini in aust [ Thu May 11, 2017 8:46 am ]
Post subject:  Re: Increasing power in a 998 Auto?
No substitute for cubic inches, except cubic money. :)
Author:  dawi03 [ Thu May 11, 2017 8:57 am ]
Post subject:  Re: Increasing power in a 998 Auto?
TheMiniMan wrote:
std 1275 motors have more power than std smallbore motors
regardless of what gearbox its running

simple as that

however a "worked" 1275 will also have more power than a "worked" smallbore motor
again--> regardless of what gearbox theyre running

simple physics

i`m pretty sure you can work it out from there yeah??? :-)



Haha yeah I know this I'm more concerned about the $$$ vs power factor what would be my best bang for buck. If I can get a 1275 auto for cheaper than modding the 998 i would do this in a heartbeat
Author:  drmini in aust [ Thu May 11, 2017 12:17 pm ]
Post subject:  Re: Increasing power in a 998 Auto?
Gearbox is basically the same but you would need a 1275 auto primary gear.
And it needs to be a 1275 auto block, as the much wider auto oil pump won't fit in a manual one.
Auto's oilways are different too.
Author:  Pd46 [ Thu May 11, 2017 12:47 pm ]
Post subject:  Re: Increasing power in a 998 Auto?
There's a couple of SPI 1275 auto motors on gumtree at the moment if you are looking.

Sent from my ASUS_Z017DA using Tapatalk
Author:  dawi03 [ Thu May 11, 2017 5:01 pm ]
Post subject:  Re: Increasing power in a 998 Auto?
Pd46 wrote:
There's a couple of SPI 1275 auto motors on gumtree at the moment if you are looking.

Sent from my ASUS_Z017DA using Tapatalk



Thanks
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