996 ST4S Engine - will it fit my S4?

[Shauns4]

So have been pondering about giving my S4 and torque and power boost this winter, high comp pistons, 45/50 mm exhaust, more aggresive cams etc but the best way is usually more cubes and so considering fitting a 996 engine out of an ST4S as this will probably be the cheapest bhp/£?

I think it should drop straight in, only difference may be in the injectors but I guess it would run with the S4 ones re-mapped via the PCM, that said the stage 1 ECU I have is actually for a 996 so maybe not so different. I'm not sure if the ST4S has the dual injectors?

Any comments on doing the swop would be welcome before I commit.

Shaun

[Albie]

You may try asking the DSC site for techy question s if no joy on here. Personally I cant see why not.

[Zimbo]

As far as I'm aware the frame and engine mounts are the same, so I don't see why not! Others know more about it than I do though . . .

[Scotty]

just looking at t'old moto one page again

http://www.moto-one.com.au/performance/monsters4diff.html

std s4 makes more torque than an st4 ~:?

and the gear ratios on the st4 engine are lower/higher err a bit different cf the s4

im sure the american 'there aint no substitute for cubes boy!' holds true though

but id still recomend the sps cams, its how it should have been all allong think theres that german shop on ebay still selling em on 'cheapish'

im sure i could let you have a go on mine if you wanted a back to back comparisom of cams

[Pedro]

One thing to consider is that the S4R 996 motor has a different head - the exhaust valves are shorter so the wheel doesn't hit the head when the suspension is compressed - dunno whether this would apply

[Shauns4]

but id still recomend the sps cams, its how it should have been all allong think theres that german shop on ebay still selling em on 'cheapish'



So the guy who has the engine for sale on ebay basically told me not to waste my money as the expense and difficulty isn't worth the extra cubes, well he is honest anyway!


So I have some Strada cams (not tried) but the SPS grind is very aggresive so have you lost the mid range torque? do you have to replace all 4 cams? Do you run it with 45/50 mm exhaust?

Shaun

[sjr999r]

One thing to consider is that the S4R 996 motor has a different head - the exhaust valves are shorter so the wheel doesn't hit the head when the suspension is compressed - dunno whether this would apply

That goes for the s4 aswell.......agree with the above

[Scotty]

So the guy who has the engine for sale on ebay basically told me not to waste my money as the expense and difficulty isn't worth the extra cubes, well he is honest anyway!


So I have some Strada cams (not tried) but the SPS grind is very aggresive so have you lost the mid range torque? do you have to replace all 4 cams? Do you run it with 45/50 mm exhaust?

Shaun

ahh right middrange torque now you mention it yes apparently there is less midrange torque, and i think i can just notice a small 'hole' if you have full throttel at about 5k rpm, id recomend a go just to set mind at rest or decide its not worth it

yup i got 4 cams in my kit which came with the 45/55mm exhaust (its a very tight fit )

[Shauns4]

ahh right middrange torque now you mention it yes apparently there is less midrange torque, and i think i can just notice a small 'hole' if you have full throttel at about 5k rpm, id recomend a go just to set mind at rest or decide its not worth it

yup i got 4 cams in my kit which came with the 45/55mm exhaust (its a very tight fit )

problem is I want more mid-range torque and more top end power and you don't get owt for nowt? there is a 45/50 mm kit on fleabay, £650, no cams though! didn't know you can get 45/55 mm kit....whats the going price for SPS cams then?

[Scotty]

a lot

think nattyboy got me a price once was silly money £1200 each ?, or was that a pair ?

http://stores.ebay.de/SD-Internethandel-Bike-Parts
that was the feller who had the kit i got, doesnt seem to have any in/to get rid of at the moment

maybe worth a email ~:?

[Scotty]

further to the performance discussion a bit of analysis of my rideing i do actuall spend most of my time at about 5 k rpm just cruseing around

it makes me think i should trade down in engine power

i did have a go on the way home useing the power and its just absolutly insane on the B roads i use

i think perhaps i prefer it like this with less midrange makeing an 'easyer' town ride and yet haveing the extra oomph for errm out of town/race track (i wish)

[Shauns4]

The main problem for me with more aggresive cams and larger bore cans is even though the motor will make more BHP by allowing the engine to rev higher and cleaner the mid range torque will suffer?

If you are like me only ride the bike on the road mainly around 5000 -7000 rpm then I guess you have to question why do it, also the cams are not cheap I guessed at £1200/set.

The mid range torque is good on the S4 due to fairly 'soft' inlet cam and the small bore exhaust, that said it stifles the top end rpm? @ 8000 rpm its all over.

What I am now consdiering is fitting the stada inlet cams (which I have), this would be slightly more aggresive and then some high comp pistons, the only thing thats puts me off the pistons is it may need a higher octane fuel or Octane booster - not sure to be honest (my CB125 bored out to 180 needs it!)...anybody tried these?

Or maybe I should have done with and get an M1000, bore it 1100, now that is a torquey motor.

Shaun

[Shauns4]

So did not go for the ST4S motor.

This is the advice from Ducati Kamna to improve the standard set up:

Fit high compression pistons + colder plugs, run on 95 octance petrol min

http://www.ducati-kaemna.de/cms_en/katalog.htm?&view=artikel&artikel=1324

Use open 45 mm termis (I have)
K&N (I have)
PCM (I have)
Type A cylinder head mods.....

http://www.ducati-kaemna.de/cms_en/katalog.htm?&view=artikel&artikel=1794

Put the bike on a dyno to set up the PCM

about £1100 for the above + my labour!

Shaun

[Zimbo]

Sounds like a fairly sensible way forward. I've generally found Kaemna to know what they're on about . . .

[Shauns4]

I've generally found Kaemna to know what they're on about . . .

bought lots of goddies from them in the past, always top notch!

[grunter]

has the same mounting points but the rear head could clash with tank? dont think the front pot is an issue under breaking?
www.ukmonster.20m.com bike mods page i think or photos shock lenght may also be an issue? and pivot point may be an issue?