Hybrid motor?

[Dezza]

I think I may have some sort of hybrid engine. The block is stamped 1052 but the cases have 750 numbers (beginning with R705). If so the motor has obviously been skillfully built as there are no external signs of bodgery. I was always under the impression that there were few interchangable parts between the 750s and 1100s (my experience is only aircooled until last week) so what bits do I need to examine to determine the motor's true identity?

[cregnybaa]

Slingshot 750s and 1100s are line bored the same so its fairly straight forward to build an 1100 into 750 cases. does it have a 6 speed gearbox?

[Dezza]

Good question - I can't answer immediately as the bike is nearly stripped downready for engine removal. I bought it as a rebuld project, but it's 1052 so it cannot be a slingshot top end and isn't the number incorrect for a slingshot 750?

[niknak750]

4 hours ago, cregnybaa said:

Slingshot 750s and 1100s are line bored the same so its fairly straight forward to build an 1100 into 750 cases. does it have a 6 speed gearbox?

So does this mean an 1100 crank, block and pistons could be fitted to a 750 short stroke (J model) motor ?

if so has anyone done this?

[Oilyspanner]

R705 is the early 750 engine, so an 1100 crank couldn't be used without line boring the mains out to fit the 1100 sizes (32mm v 36mm). More likely an 1100 block has been used for oversized liners ? and height reduced for 750 stroke.  You'll probably need to have a look inside to make sure.

https://sites.google.com/site/suzukitechnical/suzuki/sacs-enginecodes

The short stroke 750s , J/K, have the same size mains as the 1100s ,so in theory an 1100 crank should drop straight in, I don't know about primary drive/clutch arrangement. The GSX750F engine to 1997 shared the short stroke engine too

 

[Dezza]

1 hour ago, Oilyspanner said:

R705 is the early 750 engine, so an 1100 crank couldn't be used without line boring the mains out to fit the 1100 sizes (32mm v 36mm). More likely an 1100 block has been used for oversized liners ? and height reduced for 750 stroke.  You'll probably need to have a look inside to make sure.

https://sites.google.com/site/suzukitechnical/suzuki/sacs-enginecodes

The short stroke 750s , J/K, have the same size mains as the 1100s ,so in theory an 1100 crank should drop straight in, I don't know about primary drive/clutch arrangement. The GSX750F engine to 1997 shared the short stroke engine too

 

Many thanks for that OS. This all makes sense given my limited knowledge of GSXR motors and the differences between the 750 and the 1100. The bike has a sprocket cover from an 1100, 5 gears shown but I won't know for sure how many it has without riding it as I will not be splitting the cases unless I really have to. I could faff about with the motor and gear ler on the bench though I suppose. There is no evidence for block machining but the bike's still pretty grubby and I'd probably need a bike with a standard engine for comparison.

[Del]

On 14/06/2016 at 8:59 AM, Oilyspanner said:

 More likely an 1100 block has been used for oversized liners ?

Even more likely is that they have stuck a 750 engine number on a complete 1052

 

Edited June 15, 2016 by Del

[Dezza]

5 hours ago, Del said:

Even more likely is that they have stuck a 750 engine number on a complete 1052

 

Possible - if so whoever did it was an expert with a stamp as all the characters are in line and perfectly spaced

[grebo]

Don't know if I'm missing something here but as I understand it this is simply a 7/11 motor .ie 1100 barrels on a 750 bottom end giving an1100 with a 6 speed box .people seem to call 1100 motors in 750 frames 7/11 's but originally this would be where I know the term 7/11 from

[Gixer1460]

Yeah I think you are missing something - the hybrid motor isn't a common conversion and so isn't called 7/11 frequently. The 1100 engine swop into the 750 frame is the common definition used widely. Now put it into a 750 frame and does it become a 7/7/11 LOL!

[boilerdude]

I would stick with an 1100 bottom end and 5 speed rather than try to make this hybrid.  If you want to go faster. add a tooth up front. It will pull just fine. Err. imean. yea thats already been done here. What I meant to say was. dont abuse the tranny.

Edited June 18, 2016 by boilerdude

[Del]

11 hours ago, grebo said:

.people seem to call 1100 motors in 750 frames 7/11 '

Those people would be correct   A 7/11 or 7/12 or 6/7 or 6/11 or 6/12,etc,etc,etc is  the bigger borhters engine dropped into the little brothers frame(and it has been that way for years and years,Tritons,Hardons,Vintons,etc,etc)
This is the worlds first(Quite a few years before Bradley O'connors 7/11) sllingshot 7/11(1052 motor in a 750J)

 And some more 7/11's

5 hours ago, boilerdude said:

I would stick with an 1100 bottom end and 5 speed rather than try to make this hybrid.  If you want to go faster. add a tooth up front. It will pull just fine. Err. imean. yea thats already been done here. What I meant to say was. dont abuse the tranny.

I fitted a 6 speed into a 1186cc(powercreen 1127)lump,shit happened(bloody exes),so i never did get it finished(Jolly roger brought the bore kit and Adz had the rest) 

Edited June 18, 2016 by Del

[Reinhoud]

You're talking about a motor, and about Suzuki engine parts, it must be a hybrid!

Motors run on electricity / oil / air, when it runs on fuel it's an engine.

 

 

Edited June 20, 2016 by Reinhoud

[cregnybaa]

8 hours ago, Reinhoud said:

Your talking about a motor, and about Suzuki engine parts, it must be a hybrid!

Motors run on electricity / oil / air, when it runs on fuel it's an engine.

 

 

Wonder why they call them motorcycles??.

Edited June 19, 2016 by cregnybaa
mistake

[Gixer1460]

Or steam engines? LOL!

[Dezza]

A 7/11 to me has always been a GSXR750 with a GSXR1100 engine in it. Before 2 weeks ago I never knew any GSXR1100 engine parts fitted any of the GSXR750 bottom ends of any generation so I have learned this is not the case.

 

By the way, I think many years ago when GSXR 750s were still beinbg raced, someone was disqualified from the Daytona Superbike race after it was discovered that their GSXR 750 had an 1100 engine, although this may be an urban myth.

[russ69]

It's funny it really is a small world.

I read that Cycle World mag when it came out and found it again a few months ago when I was moving some stuff in my extension. A few years later my friend Julian had a 750m that wasn't fast enough so I put a 1100L engine in it for him (the black and purple one).I was running a JMC framed GSXR 1100 at the time and my now ex wife was riding a GSXR 1100K/L. When she found out how good the 7/11 was I had to make another one (the blue and white one).I did make a basic error when i put them in as I left them both on the 750 gearing so they had 43 teeth rear sprockets instead of 48 (doh) that's why they a bit slow in the article theywould have been faster in 4th gear ! but was a good day at Bruntingthorpe

I came on  the OSS because i'm thinking of injecting and turboing the JMC and the 7/11 when i do them up over the winter and found this thread.

 

[Duckndive]

On 18 June 2016 at 11:36 AM, grebo said:

Don't know if I'm missing something here but as I understand it this is simply a 7/11 motor .ie 1100 barrels on a 750 bottom end giving an1100 with a 6 speed box .people seem to call 1100 motors in 750 frames 7/11 's but originally this would be where I know the term 7/11 from

Putting 1100 barrels on a 750 bottom end does not make a 1100 

[CAPTAIN CRUNCH]

Not that motor savvy but Found the below on interchange list while back, was going to try when 750 slingy dies, was gonna ask if any one ever tried or know if below is correct, below or 813 build are me options. Thought below might be similar to dezza's engine maybe? Or should I be asking this in new thread sorry  in advance dez

750 Superbikes sometimes cheated by running 1100 barrels milled down to the 750 stroke (you also have to cut 12mm of the skirts and you lose the front lower cylinder bolt making it obvious) with custom drilled pistons. The biggest simple swap is 1127 barrel bored to 81mm for 1003cc (or 921cc on the short-stroke cases) but you need to cut out the case mouths and run an 81mm piston blank drilled for the 20mm pin.

 

[Gixer1460]

Can't comment on the 'cheating aspect' - see this years Classic TT for that little nugget! But if the 750 barrel casting is thick enough i'd take the 750 liners out, bore the block and install the 1100 liners to retain all the screw lugs and markings. Obviously the bottom edges get shortened and crankcase needs opening out but it would look externally completely 750 stock! I remember Sean @ Big CC did a parts bin hybrid 750 that ended up at 995 - very over square configuration so revved to 13k easily and made good power.

[canamant]

The 73mm bore liners from the short stroke 750 will fit the 750 longstroke block without breaking through the fins.  Not sure a liner with an 81mm bore - 11mm bigger than the long stroke 750 - would go without breaking through. 

[clivegto]

Have a set of short stroke barrels and some 1127 ones only about 4mm between the outside size of the sleeves so think it would work.