spiderpig Posted October 26, 2016 Posted October 26, 2016 (edited) Is it possible to do with a safe amount left in the liners? Tried searching but couldn't find an answer. Planning on going as big as i can in a slabby with bandit barrells. Going to be used on the road. APE are saying a big block is highly recommended.... Cheers Edited October 26, 2016 by spiderpig Quote
Oilyspanner Posted October 26, 2016 Posted October 26, 2016 1246 is the largest you can go with B12 liners (82mm bore) - and 1216 is the most with 1127 liners. A n 1186 or 1216 with a nicely flowed head will produce more power than a larger motor with a standard or reasonable head - the bottom end would be better on the big engine though. The standard valve sizes work well on engines around 1200cc, the further you move away from this the more you'll require to up the valve sizes and alter the cams to get the most from the big engine (gets costly and hotter). Depends what sort of build you're doing ?? Of course a good big engine will produce a lot hp and torque, but more money has to be spent to suit the big capacity. I settled on 1186 for my bike, would've been a 1216 kit, but the 1186 kit came up at the right money and there's little between them anyway. I did research going big, but the extra costs didn't seem attractive ! Be nice to see a serious engine build though . . . Quote
spiderpig Posted October 26, 2016 Author Posted October 26, 2016 Cheers. The plan is for a reliable motor, that I can get the most power from without spending crazy money. Have a skimmed, ported and polished dot head with reground cams that came of Rob Beans thunder bike I think, slotted sprockets, 1052 bottom end, RS40s, micron system with a new link pipe, APE tensioner, dyna coils. Looking at the 1246 kits there, same money as the others, and the barrells have to be bored anyway, may as well go for them and the 40s would be better suited. Quote
Oilyspanner Posted October 26, 2016 Posted October 26, 2016 I think the cases have to be bored out a tad to accommodate the larger liners of 1157on the 1052. Capacity will be 1225cc with 58mm stroke. Quote
cregnybaa Posted October 26, 2016 Posted October 26, 2016 Dot heads will not go in a slabby with rs carbs fitted. Quote
spiderpig Posted October 26, 2016 Author Posted October 26, 2016 Yeah, plan on having the cases bored out, want to go bigger than 1109. Whats the maths behind 1225? I know the slabbies have less stroke (.5mm?) no idea of the maths tho. Its going in a 750j/k frame so should fit i think, if not ill get the tap moved, its a 750wp tank. Quote
Jaydee Posted October 26, 2016 Posted October 26, 2016 (edited) 1 hour ago, spiderpig said: Yeah, plan on having the cases bored out, want to go bigger than 1109. Whats the maths behind 1225? I know the slabbies have less stroke (.5mm?) no idea of the maths tho. Its going in a 750j/k frame so should fit i think, if not ill get the tap moved, its a 750wp tank. For slabby 81mm bore is 1201cc (1216 kit) and 82mm is 1225 (1246 kit). Handy to do the maths. Take slingshots capacity and divide by its stoke (59) then muliply by slabby stroke (58) Edited October 26, 2016 by Jaydee Quote
spiderpig Posted October 26, 2016 Author Posted October 26, 2016 5 hours ago, Jaydee said: For slabby 81mm bore is 1201cc (1216 kit) and 82mm is 1225 (1246 kit). Handy to do the maths. Take slingshots capacity and divide by its stoke (59) then muliply by slabby stroke (58) Cheers Ah that makes sense Quote
spiderpig Posted October 26, 2016 Author Posted October 26, 2016 5 hours ago, Jaydee said: For slabby 81mm bore is 1201cc (1216 kit) and 82mm is 1225 (1246 kit). Handy to do the maths. Take slingshots capacity and divide by its stoke (59) then muliply by slabby stroke (58) You dont know if shane wogans place in slane bores out crankcases/cylinders do you? Quote
Jaydee Posted October 26, 2016 Posted October 26, 2016 44 minutes ago, spiderpig said: You dont know if shane wogans place in slane bores out crankcases/cylinders do you? No I don't know. Thought Shane is mates with Jack Frost up in Holeshot so possibly goes through him(?) Isn't there some crowd near you in Santry that does rebores and tuning. They might be worth a shot. I can find for you. As for boring cases, maybe try Dave Walsh in Bessington. Quote
spiderpig Posted October 26, 2016 Author Posted October 26, 2016 Yeah, was trying to decide whether to send it up north or find someone down here. My usual engineer cant do boring, but he races cages and recommended http://howardengineering.ie/ supposed to be the best when it comes to motor work. Will ask around Quote
minty Posted October 29, 2016 Posted October 29, 2016 How much difference in torque/bhp is there between 1216 and 1246? Quote
Gixer1460 Posted October 29, 2016 Posted October 29, 2016 Not enough for anyone to tell the difference sat on the bike! 1 Quote
MeanBean49 Posted October 29, 2016 Posted October 29, 2016 My old head? Off my 837 motor? Cant even remember what happened to that engine lol. Was a really good lump. High comp dot head might be a bit much for an 11 based motor. Standard Dot head puts compression up a fair bit on its own Quote
spiderpig Posted November 26, 2016 Author Posted November 26, 2016 On 10/29/2016 at 7:26 PM, MeanBean49 said: My old head? Off my 837 motor? Cant even remember what happened to that engine lol. Was a really good lump. High comp dot head might be a bit much for an 11 based motor. Standard Dot head puts compression up a fair bit on its own Yep, thats the one, reground cams as well. Yeah was thinking that, have a set of busa pistons lying around might put to use Quote
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