R1guy Posted August 3, 2019 Posted August 3, 2019 Following on from a thread in air cooled, what Frankenstein big bore combos have people come up with/successfully created? What piston /liner combination? Im not talking about 1216 or 1246 but creations of 1300 or more. No gorilla blocks. What additional cooling steps would need to be taken? Discuss: Quote
Gixer1460 Posted August 3, 2019 Posted August 3, 2019 Not sure that it can be done - GSF liners are the biggest OD liners that will fit oil cooled barrels without leaving the barrel casting paper thin, hence why the 'overbore' barrels were created, to accept a liner capable of taking a 86mm piston for 1371cc. To go bigger needs a stroke job - oooh nurse! Usually drag racers are the most 'creative' when creating frankenstein capacity hikes but no one i've heard or read about has gone over 1371 - 87mm pistons would just be over 1402cc but no one as achieved it AFAIK! Its maybe why the oil cooled engines have never really been exploited in drag racing when the GSX aircooled motors can go out to 1800+ cc! Quote
Duckndive Posted August 3, 2019 Posted August 3, 2019 (edited) not done it but you can do 1307cc "84mm" or 1338cc "85mm" using the appropriate liners in a stock block allegedly ..... or go clever big "expensive" stroker crank and big bore .. Edited August 3, 2019 by Duckndive Quote
Oilyspanner Posted August 3, 2019 Posted August 3, 2019 It must be raining where you are r1guy ! G1460 has it right, for mega cc motors the air cooled, vey over engineered gsx is the one to go for. The lighter oil cooled motors have a link between the 750 and 1100 engines, so ultimate size will be limited as the 1100 is a stretched 750 to start off with. I missed the oc engines when I was spending money in the 90s, but like many knew others who worked with the motors - the big liners in a stock block weren't as reliable as big pistons in a big block. The head has more effect to power than capacity. A big engine making big power was hard to keep cool, oil cooling is 5 times less effective than water at cooling - it was this that prevented the oc engines remaing in the gsxr range for longer. The Hayabusa engine has become the modern 1100 engine, only not so easy /fun to work on. That's my take .. you can spend a lot of money on an 1186/1216/1246 engine, but done right it's a pokey, reliable, sweet engine, but still might need an extra cooler if you have a full fairing. Quote
johnr Posted August 3, 2019 Posted August 3, 2019 is there any similarity between the oilcooled gsxr range and the gsx1400 motor? Quote
Blubber Posted August 3, 2019 Posted August 3, 2019 31 minutes ago, johnr said: is there any similarity between the oilcooled gsxr range and the gsx1400 motor? None will fit. Gear parts of a 14 can be swapped with aftermarket hayabusa stuff. Like the output shaft, gears and shifter rod. Cams and pistons will not fit. Head won't bolt up on 1157 stuff. Quote
Gixer1460 Posted August 3, 2019 Posted August 3, 2019 4 hours ago, Duckndive said: not done it but you can do 1307cc "84mm" or 1338cc "85mm" using the appropriate liners in a stock block allegedly ..... or go clever big "expensive" stroker crank and big bore .. Just had a quick look through my printed APE catalogue and they say 1277cc / 83mm can be done in a Big Bore liner in stock block casting (not recommended though) but 85 and 86mm bore sizes need the Big Bore cylinder as well. Trying to find one of those these days is really hard but they are very stealthy ! Quote
Duckndive Posted August 3, 2019 Posted August 3, 2019 3 minutes ago, Gixer1460 said: Just had a quick look through my printed APE catalogue and they say 1277cc / 83mm can be done in a Big Bore liner in stock block casting (not recommended though) but 85 and 86mm bore sizes need the Big Bore cylinder as well. Trying to find one of those these days is really hard but they are very stealthy ! What size was moonies Dan Wagner outlaw motor ? I thought that had a stoker crank but seam to recall it had the origninal block ... As the only other stroker motors I,ve seen in the UK are yours and the one in Woodys "Ex BigCC" Spondon Kat ... Quote
no class Posted August 3, 2019 Posted August 3, 2019 my slingy drawthrough ran 1307 mtc resleeved stock b12 block Quote
Gixer1460 Posted August 4, 2019 Posted August 4, 2019 20 hours ago, Duckndive said: What size was moonies Dan Wagner outlaw motor ? I thought that had a stoker crank but seam to recall it had the origninal block ... As the only other stroker motors I,ve seen in the UK are yours and the one in Woodys "Ex BigCC" Spondon Kat ... I thought Dan Wagner's motor was GSX based with FBG dry billet block and a Ward cylinder head? I guess there is the cost against stroker engines but I think mine could go another 1mm on stroke and 1 or 2mm on bore so well into the 1500's LOL! Woody certainly flogged Seans 1460 and broke everything else but the crank so they can be strong. As regards weight - yes they do weigh a bit more but as they are 'one off's' weight can be pared off some areas and added to strengthen other areas. As regards mine, it got Carrillo rods and Cosworth pistons for turbo use, so it all balanced out and uses lower piston speed / rpm's, and the extra wasn't an issue. Quote
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