wraith Posted August 20, 2015 Posted August 20, 2015 Has anybody tried using the GSXR1300 pistons in a GSXR1100 (1127) motor and using the GSXR750 dot head? As far as I see it, using the gsxr1300 pistons on 1127 con rods gives a 1216cc big bore, but with lower compression that standard gsxr1100 piston or 1127 normal big bore kit. However, as the dot head also lifts the compression, by using that too would you get a standard compression engine but with the bigger cc grunt? Wondering if it's a viable budget trick if you've got the spare bits knocking around... ;-) Quote
clivegto Posted August 20, 2015 Posted August 20, 2015 There was a good right up on old site about this by musthava (I think). Busa pistons are about 2mm down the block giving a comp of arount 8 to 1. From memory the dot head raises comp by 1.2 to 2 he said the block needs to be decked so yes it can be done. Was going to do it myself but never got round to it. Quote
Gixer1460 Posted August 21, 2015 Posted August 21, 2015 If you've the bits lying around why not but you'll still only get you back to standard CR without extra machining and the Busa piston crowns don't match a GSXR chamber once you've decked the block so more potential machining which lowers the CR again. And decking the block that much alters cam timing so adjustments there - lot of pissing around for not a lot of gain IMO. Sell the pistons and head and put the coin into proper high comp JE pistons that work out of the box! 1 Quote
Captain Chaos Posted August 21, 2015 Posted August 21, 2015 or sell the head and put the coin into a proper turbo to put the Busa pistons to good use 2 Quote
Gixer1460 Posted August 21, 2015 Posted August 21, 2015 or sell the head and put the coin into a proper turbo to put the Busa pistons to good useYeah - earn some money and spend about 5 times as much and miles of smiles! Quote
Duckndive Posted August 21, 2015 Posted August 21, 2015 There was a good right up on old site about this by musthava (I think). Busa pistons are about 2mm down the block giving a comp of arount 8 to 1.Err I don't think so Gen 1 Busa Slugs on 1127 rods end gives a Zero Deck Height....In fact the inlet crown is a few thou above deck... Quote
Phill106 Posted August 21, 2015 Posted August 21, 2015 Err I don't think so Gen 1 Busa Slugs on 1127 rods end gives a Zero Deck Height....In fact the inlet crown is a few thou above deck... is that with stock rods? Quote
Duckndive Posted August 21, 2015 Posted August 21, 2015 is that with stock rods?Yes ................ Quote
Gixer1460 Posted August 21, 2015 Posted August 21, 2015 You sure Clive? - I always thought they were down the bores and if you use the Busa rods they are above deck? 1 Quote
wraith Posted August 21, 2015 Author Posted August 21, 2015 Cheers all just a idea so yes will look at an out the box way Quote
Buddy Posted August 21, 2015 Posted August 21, 2015 You sure Clive? - I always thought they were down the bores and if you use the Busa rods they are above deck?x2 Quote
Jaydee Posted August 21, 2015 Posted August 21, 2015 (edited) I think Musphadump on the old site said he had to skim 1.2mm off the deck height to get the correct squish and compression. (1127 with busa slugs running n/a) I.R.C.C. That was with an 1127 head. Edited August 21, 2015 by Jaydee Quote
Duckndive Posted August 21, 2015 Posted August 21, 2015 You sure Clive? - I always thought they were down the bores and if you use the Busa rods they are above deck?This convince you ............ 1 Quote
Duckndive Posted August 21, 2015 Posted August 21, 2015 (edited) I think Musphadump on the old site said he had to skim 1.2mm off the deck height to get the correct squish and compression. (1127 with busa slugs running n/a) I.R.C.C. That was with an 1127 head.Mister dump said and promised a lot ...................And I recall a few had to chase him for some time to get there promised stuff back..................Then he suddenly dropped of the coupon I also seam to recall Edited August 21, 2015 by Duckndive 1 Quote
Jaydee Posted August 21, 2015 Posted August 21, 2015 Don't know the fella @Duckndive. Just relaying tech I remember from a similar subject thread from the old site. Quote
kokolis Posted August 21, 2015 Posted August 21, 2015 Busa pistons with 1127 rods in 1127 liners 2mm below deck Quote
Phill106 Posted August 21, 2015 Posted August 21, 2015 Busa pistons with 1127 rods in 1127 liners 2mm below deck with a 1127 crank or 1052? Quote
Duckndive Posted August 21, 2015 Posted August 21, 2015 Busa pistons with 1127 rods in 1127 liners 2mm below deck my 1127 rods must have stretched then.................. 4 Quote
clivegto Posted August 21, 2015 Posted August 21, 2015 (edited) Not done the conversion myself but think it can be done.In my opinion best power upgrade is to get the head flowed and carbs set up right.The dot head will raise comp and if followed will save the cost of fresh pistons.If no dot head then skim standard head and get it flowed. Cheapest power upgrade in my opinion. PS edit not work as I wished Edited August 21, 2015 by clivegto Quote
Gixer1460 Posted August 22, 2015 Posted August 22, 2015 This convince you ............As they say 'A picture speaks a thousand words' but still confused as a few have been done with turbo builds and they appear to be low comp - certainly not as that picture would suggest....................so remain confused! Quote
vizman Posted August 22, 2015 Posted August 22, 2015 my motor 1127 block and rods, busa pistons and a 1mm base gasket for turbo use. 1 Quote
Gixer1460 Posted August 22, 2015 Posted August 22, 2015 Picture and personal experience stated - seems conclusive! Quote
vizman Posted August 22, 2015 Posted August 22, 2015 if I have any doubts I'd ask people like clive and loopie 1 Quote
Duckndive Posted August 22, 2015 Posted August 22, 2015 As they say 'A picture speaks a thousand words' but still confused as a few have been done with turbo builds and they appear to be low comp - certainly not as that picture would suggest....................so remain confused!They will sit 1mm down from deck if you use 1052 rods on 1127 Crank.... Vizman I know 2/5th off #uckall...........But I,ve never been afraid to join bits together to find out if it will work............. 4 Quote
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