748 to 853 conversion, have you?

Noobie

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I've heard of a few and of those who have done them they seem to think it is a worthy, if not expensive, upgrade. Have you had such a conversion done yourself or owned a 748 converted to 853 ?

One of the reasons asked is that whilst most of the mileage's seem low, on occasion engine work has been done and I wonder if the 853 conversion has been considered and also, occasionally one or two pop up for sale and it would be interesting to have information from those who have had such conversions done or owned a converted bike . Any technical, observational and experiences of such a thing would be greatly appreciated

It was pointed out one was for sale so if some haven't heard of the 853 conversion, this gives an idea

 

Nelly

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I’ve done several before over the years. It doesn’t make as much financial sense now, as it used to but it does create a characterful little motor. 916 hp, 748 revs etc. Just feels good.
ive got one at the moment that I built for a customer many years ago. Just recommissioned it over lockdown and am looking forward to having a ride on one again.
 

DesmoHyper

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I agree with @Andyb on this as my 848 spent a portion of its life as a 1040. Billed as having the torque of the 1098 and fast revving of the 848.
reality was even with a marreli ecu and dynoed it was just a big dollop of unusable power that saw you changing up and down the box frenetically.
Should have just had 1098 motor in it
 

Noobie

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I can see the reasoning for it before and now in some ways if you have a 748 you absolutely will not let go but wish it had a lil more pep, even more so if the bike is already paid off
 

DesmoHyper

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I can see the reasoning for it before and now in some ways if you have a 748 you absolutely will not let go but wish it had a lil more pep, even more so if the bike is already paid off
From an engineering perspective though there’s no such thing as a free lunch and something will have to suffer.
be it reliability or rideabilty
 

Andyb

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so back to ducati crank cases, cranks, rods barrels pistons .....

you could use deep sump crank cases and make a bore stroke combination you like as the availability of compatible bits evolved the choice isn't limited to the 853

so my original bitsa engine was 999RS crankcases, 1098 crank, 749R rods, and F06 pistons... all the numbers stack up with correct squish and CR.. equalling 1099cc...

and the engine is still going several years on..when its built correctly...
 

DesmoHyper

Elite Member
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so back to ducati crank cases, cranks, rods barrels pistons .....

you could use deep sump crank cases and make a bore stroke combination you like as the availability of compatible bits evolved the choice isn't limited to the 853

so my original bitsa engine was 999RS crankcases, 1098 crank, 749R rods, and F06 pistons... all the numbers stack up with correct squish and CR.. equalling 1099cc...

and the engine is still going several years on..when its built correctly...
But did it have foggy stickers as they are worth at least another 80bhp at the wheel 😂
 

Nelly

Active member
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From an engineering perspective though there’s no such thing as a free lunch and something will have to suffer.
be it reliability or rideabilty
It was though.... there weren’t any real downsides. You had essentially 916 cases/bottom end. The bigger bore unshrouded the valves as per 916 but with higher compression, making the top end more effective. It was a little down on torque vs the 916 but matched the bhp and had a few more revs. My own bike did 20k miles trouble free post conversion in quite a high state of tune, and I still look after a couple I built that are still going strong.
yes, I agree the modern motors make more and for relatively less money now, but it was a very viable conversion back in the day. Neil Spalding was noted as quoting it as “the best motor Ducati never built” and I’d agree. I’m not that nostalgic about the older bikes as such. I appreciate the modern stuff for evolution that it is, but the 853 motor will always be a favourite of mine.
 

sev

Well-known member
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I have to agree with Neil Spalding on this one.
It's about the way the 748 engine feels, and by 853'ing it you lose none of that particular character that a desmoquattro gives over the more refined 'stretta engines.

I also think that if you're looking at this conversion then the fact that it's dated , not cost effective vs a newer model engine, slower than xyz is of little importance.
It's because you want to keep it fundamentally a 748 in the way it plays and behaves, everything else takes a back seat.
 

Barry Hell

Elite Member
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Ive heard it said the 748 is the better road bike compared to the 916 as the 916 was too much for the road (back in the day) however, a CBR 600 could make 916 power give or take, was it down to the extra grunt that made the 916 seem too much? In which case the 853 makes sense in that era
 
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