Slabbyruss712 Posted June 12, 2019 Posted June 12, 2019 I'm toying with the idea of a longstroke shortstroke hybrid, anyone ever built one, pros and cons, don't want to go 1100 many thanks in advance Russ Quote
Lachie04 Posted June 13, 2019 Posted June 13, 2019 (edited) Yep I've built one I used a GXF bottom end and a dot head barrel. Primarily just cause I could as had the parts around I have set it up pretty standard (meaning no real high performance options) for roadability and a general daily rider done around 4000 k atm and loving it really trackable But has performed well on the track only losing the liter bikes down the straight. Bearing in mind the result is only 60 odd cc's there's no real power advantage in standard trim like mine and pulls @ 100hp at the rearwheel and max torque comes in at @ 8000 the advantage is how it is setup to bring on the torque but if your going after power there's other options higher lift cams and stuff to suit. The only hard thing is to bore out the rod little ends an extra 1mm in diameter for me this resulted in only a 0.3mm reduction in meat on the end A spacer plate can be made or bought from here (see bottom of page) http://gsxrzone.com/cranks.html but they make them to order. and changing over the cam sprokets to suit the Hyvo Chain and using the long stroke chain slippers mine ended up with taking a link out of the cam chain also but I hadn't heard of that before in other builds This is an earlier run and going a little better after some more jetting changes Edited June 13, 2019 by Lachie04 2 Quote
richyrich Posted June 13, 2019 Posted June 13, 2019 (edited) http://oldskoolsuzuki.info/archives/404 That link is frankensteins guide to oil cooled from original site , well worth a read , discusses all manner of hybrid possibilities. It's also possible to go big bore with eg zx10 2004 pistons Edited June 13, 2019 by richyrich Quote
Ted M Posted June 14, 2019 Posted June 14, 2019 Wow @Lachie04 the power and torque curves on that graph are bloody good flat as a witches tit Quote
SiBag Posted June 14, 2019 Posted June 14, 2019 This is exactly what I was thinking Of. I have all the bits bar the gaskets... Just need to be brave and strip a perfectly working engine. (even have a spare set of rods to bore out).. Quote
zedhead Posted June 14, 2019 Posted June 14, 2019 I'm not sure if you can even get the 884 kits now... Quote
dupersunc Posted June 14, 2019 Posted June 14, 2019 https://www.Eblag.com/itm/Wiseco-Franx-Machine-Piston-Kit-for-88-97-Katana-750-and-88-89-GSXR750/223476958918?hash=item340843c6c6:g:JSsAAOSwKQ9aILkc looks like good value to get you short stroke 750 flying. 1 Quote
Lachie04 Posted June 15, 2019 Posted June 15, 2019 21 hours ago, Ted M said: Wow @Lachie04 the power and torque curves on that graph are bloody good flat as a witches tit After 6hr over 2 days on a dyno 10 hours ago, dupersunc said: https://www.Eblag.com/itm/Wiseco-Franx-Machine-Piston-Kit-for-88-97-Katana-750-and-88-89-GSXR750/223476958918?hash=item340843c6c6:g:JSsAAOSwKQ9aILkc looks like good value to get you short stroke 750 flying. Yep The only reason I ended up going down this route was I needed to rebuild the motor anyway as at 110k the gearbox was seeing the end of it's life and somewhere along the bike rebuild I ended up with a good 99 Teapot motor so thought why not for a little extra work and it saved a complete gearbox renewal. I was going for a daily rider that hopefully doesn't need another full rebuild for another 50 - 100 k IF your going for bang for buck then add all the big power stuff I have a 4-2-1 exhaust (with 1-4 & 2-3 paired) potentially a good quality 4-1 would increase the top end a bit but drop the midrange. Quote
Slabbyruss712 Posted June 15, 2019 Author Posted June 15, 2019 Do you have to use the short stroke block, can't you just bore the long stroke block to suit Quote
Lachie04 Posted June 15, 2019 Posted June 15, 2019 (edited) 11 hours ago, Slabbyruss712 said: Do you have to use the short stroke block, can't you just bore the long stroke block to suit yeah you can go find all the bits to overbore the longstroke but then it wouldn't be a "Hybrid" I think the general ethos of hybrid is bolting something together which is generally within the stress tolerances of the OME motor Edited June 15, 2019 by Lachie04 Quote
GSXR4814 Posted June 16, 2019 Posted June 16, 2019 I'm putting one of these back together at the moment. It was given to me by a nice bloke in Barnsley last month. It was a Bandit 600 cases, crank and rods with late gsx750 70mm pistons and barrels making it a 750. I have early 73mm barrels and pistons on the way to make it 814cc. Having read through the interchangability thread re oil burner motors it seems the little ends are different diametres or am i reading it wrong??? If they are different diametres are there compatible rods available or is getting the original Bandit rods machined the only option? Quote
GSXR4814 Posted June 16, 2019 Posted June 16, 2019 On 6/13/2019 at 9:34 AM, Lachie04 said: Yep I've built one I used a GXF bottom end and a dot head barrel. Primarily just cause I could as had the parts around I have set it up pretty standard (meaning no real high performance options) for roadability and a general daily rider done around 4000 k atm and loving it really trackable But has performed well on the track only losing the liter bikes down the straight. Bearing in mind the result is only 60 odd cc's there's no real power advantage in standard trim like mine and pulls @ 100hp at the rearwheel and max torque comes in at @ 8000 the advantage is how it is setup to bring on the torque but if your going after power there's other options higher lift cams and stuff to suit. The only hard thing is to bore out the rod little ends an extra 1mm in diameter for me this resulted in only a 0.3mm reduction in meat on the end A spacer plate can be made or bought from here (see bottom of page) http://gsxrzone.com/cranks.html but they make them to order. and changing over the cam sprokets to suit the Hyvo Chain and using the long stroke chain slippers mine ended up with taking a link out of the cam chain also but I hadn't heard of that before in other builds This is an earlier run and going a little better after some more jetting changes What carbs do you run? Quote
Lachie04 Posted June 16, 2019 Posted June 16, 2019 1 hour ago, GSXR4814 said: What carbs do you run? RS38's. I'll probably switch back to the BST36's and put the Flatslides on the 1052 I'm rebuilding so will be interesting to see how the 36 CV's differ, but that's a while off yet. Potentially the RS38's could be a little big for this motor. Quote
GSXR4814 Posted June 16, 2019 Posted June 16, 2019 I've got GSXR 750 slabbie 34mm sort of semi flatslide things(i ought to find out exactly what they are really) to try on mine.....when i eventually finish getting it back together! Quote
Lachie04 Posted June 16, 2019 Posted June 16, 2019 1 hour ago, GSXR4814 said: I'm putting one of these back together at the moment. It was given to me by a nice bloke in Barnsley last month. It was a Bandit 600 cases, crank and rods with late gsx750 70mm pistons and barrels making it a 750. I have early 73mm barrels and pistons on the way to make it 814cc. Having read through the interchangability thread re oil burner motors it seems the little ends are different diametres or am i reading it wrong??? If they are different diametres are there compatible rods available or is getting the original Bandit rods machined the only option? The B6 and the longstroke have the same little end diameters the short stroke is 1mm bigger I think frankestiens guide says 20mm but actually 19mm I dont know of any compatible rods I've seen a thread were the guy did it with the B6 cases/bottom end Quote
clivegto Posted June 16, 2019 Posted June 16, 2019 I have a lightened 1052 crank which I plan on putting in a 748 short stroke bottom end probably with 1127 decked barrels & pistons with the 748 short stroke dot head. Quote
Lachie04 Posted June 16, 2019 Posted June 16, 2019 4 hours ago, clivegto said: I have a lightened 1052 crank which I plan on putting in a 748 short stroke bottom end probably with 1127 decked barrels & pistons with the 748 short stroke dot head. Sounds interesting I presume you'll be expecting it to spin up faster I've been contemplating running mine with no starter clutch to reduce the parasitic drag (going to be a race motor anyway) I guess you'll be running into this also with the short stroke case I had heard about having to skim the rib This pic shows the 1052 rod end moving away from the short stroke case oil gallery. With the cyl. block just sitting here is very close, with it torqued down potentially will hit. I haven't measured the actual clearance and don't know it would be of any benefit anyway. Like others, for the sake of it, I will probably grind about 2mm out. In looking at it there seems to be about 5mm of "meat" above the actual oil gallery passage I'd be interested to see what the old 1052 case looks like in this area did they change the oil passage routing??? Quote
Lachie04 Posted June 17, 2019 Posted June 17, 2019 18 hours ago, GSXR4814 said: Cool, it should all fly together then! BTW no need to say make sure you dial cams in Mine came out with lobe centers at 108 inlet and 105 exhaust The inlet got slotted back to 104 and exhaust stayed at 105 Quote
clivegto Posted June 17, 2019 Posted June 17, 2019 @Lachie04have seen some of the lads on hear that have fitted corilo rods take the corner of the rod nut. Quote
Lachie04 Posted June 17, 2019 Posted June 17, 2019 (edited) They would be nice but for the price is a little out of my budget Edited June 17, 2019 by Lachie04 Quote
clivegto Posted June 17, 2019 Posted June 17, 2019 17 minutes ago, Lachie04 said: They would be nice but for the price is a little out of my budget My point is you can trim the nut as well as the crank case. 1 Quote
Lachie04 Posted June 17, 2019 Posted June 17, 2019 @clivegtoOf course sensational I wasn't reading that right Quote
GSXR4814 Posted June 17, 2019 Posted June 17, 2019 Hmmm.....my 73mm barrels and pistons turmed up today. They were listed as 1992 GSX750F. My current 70mm barrels are approx 75mm high...new 73mm ones are 69.5., these dimensions are approx as the battery is flat in my vernier so using a tape measure. Little ends are bigger and centre of little end to top of piston is greater by about 3mm??? Does this sound right? I didn't think 1992 GSX750F was short stroke which these parts seem to be? 1 Quote
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