Dangerous Posted January 26 Posted January 26 Hi Folks currently have a few questions about the 1216 build I’m using Gen1 busa pistons on bandit rods Am I right in thinking that after the rebore the block needs decked to lower compression and if so how do I measure how much to take off the block ? I’ve the option of a standard B12 head or I’ve a 750 Dot head in my parts bin I can use which would be best ? the engine isn’t gonna be boosted just B12 carbs which leads me to what size jets would I need in the carbs ? hopefully there’s a 1216 Guru that can help. TIA Dangerous Quote
colinworth79 Posted January 26 Posted January 26 I would get the block bored then put one piston in the block and you can measure top of block to top of piston at tdc . Is it turbo you wanting ? I build one years ago and took 0.5 mm off the block . Quote
Dangerous Posted January 26 Author Posted January 26 22 minutes ago, colinworth79 said: I would get the block bored then put one piston in the block and you can measure top of block to top of piston at tdc . Is it turbo you wanting ? I build one years ago and took 0.5 mm off the block . No it’s just gonna be a carb’d motor so no turbo mate Quote
spiderpig Posted January 26 Posted January 26 The block needs to be decked because the pistons sit above the deck, but that's with busa rods iirc. Busa slugs will give low compression, dot head would bring it back up a bit but still on the low side. @Duckndiveis the man to talk to. 1 Quote
Duckndive Posted January 29 Posted January 29 On 1/26/2025 at 1:17 PM, Dangerous said: Hi Folks currently have a few questions about the 1216 build I’m using Gen1 busa pistons on bandit rods Am I right in thinking that after the rebore the block needs decked to lower compression and if so how do I measure how much to take off the block ? I’ve the option of a standard B12 head or I’ve a 750 Dot head in my parts bin I can use which would be best ? the engine isn’t gonna be boosted just B12 carbs which leads me to what size jets would I need in the carbs ? hopefully there’s a 1216 Guru that can help. TIA Dangerous Gen 1 Busa Pistons on Bandit Rods in a Bandit Block Get the block bored then do a dry build measure and then do the sums .. Sums For the above engine "do your own based on your parts and measurements" The Above with a set of chucked on RS38.s 2 Quote
McLean Racing Posted January 30 Posted January 30 is there any reason you are going this way rather than using gsxr1100 block and pistons which will give more power as an NA setup? Quote
Joseph Posted January 30 Posted January 30 18 minutes ago, McLean Racing said: is there any reason you are going this way rather than using gsxr1100 block and pistons which will give more power as an NA setup? Budget big bore using busa pistons, maybe ? @Dangerous Quote
Gixer1460 Posted January 30 Posted January 30 (edited) Decking the block won't lower compression - it'll raise it! Edit - Based on Clive's calculation above, those 60cc's aren't doing much! CR is less than stock 1157 Blandit and thats with deck flush pistons! Certainly won't be getting more torque that way! Maybe skim the pistons a bit to lose bowl volume, then deck the block and you may get to 9.5:1 CR - better but not outstanding! Really need pistons with a crown, not a bowl ! HP is a function of Torque and depending at what rpm you make max HP will increase Torque number eg 100hp @ 10,000rpm gives 50ftlbs but 100hp @ 8,000 rpm gives 75 ftlbs (not calculated just random figures for demo) Edited Thursday at 02:44 PM by Gixer1460 additional stuff 3 Quote
Dangerous Posted Thursday at 12:46 PM Author Posted Thursday at 12:46 PM On 1/30/2025 at 8:12 AM, McLean Racing said: is there any reason you are going this way rather than using gsxr1100 block and pistons which will give more power as an NA setup? Just looking for a bit more torque bud, it’s going in a B12 so not building it for speed Quote
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