nlovien Posted February 25, 2017 Share Posted February 25, 2017 See if you fit a dot head to something like a GSXR1100L - given the raised port roof advantage - do you need to be selective with the carbs ? i.e. does the dot head need carbs that have the float bowls at an angle to match the port or can you use the std 36 / 38mm CV's from the L ( or bandit motor) cheers Quote Link to comment
jameskat Posted February 26, 2017 Share Posted February 26, 2017 The ports are just higher up, same angle, so standard carbs fit. Not sure which inlet rubbers to use for 38mm carbs as I have only got 36mm carbs. Quote Link to comment
nlovien Posted February 27, 2017 Author Share Posted February 27, 2017 great thanks this helps Quote Link to comment
boilerdude Posted February 27, 2017 Share Posted February 27, 2017 I'm wondering If dot head with bst38 will even clear the tank. Anybody happen to run both dot head and 750m carbs? on any bike? Quote Link to comment
Fula28 Posted February 27, 2017 Share Posted February 27, 2017 (edited) Yep, billet tops will fix this issue or we have done another with notched frame inside, these carbs and dot head made 147bhp, so worth it for sure! I had them on my 750.g also same issues ,if you want to run 38,s then you will have to get carb top solution. As for tap pingel dual outlet only way to go, with slingshot you may have to dress tap mount area dished in buy 10mm or so. Edited February 27, 2017 by Fula28 2 Quote Link to comment
Gsxr750m Posted February 27, 2017 Share Posted February 27, 2017 Was looking at mine at weekend , b12 engine 38mm carbs in 750 m frame tight as it is, I've got a dot head waiting to go on just got to work it all out very tight fit 1 Quote Link to comment
dupersunc Posted February 27, 2017 Share Posted February 27, 2017 3 hours ago, Fula28 said: Yep, billet tops will fix this issue or we have done another with notched frame inside, these carbs and dot head made 147bhp, so worth it for sure! I had them on my 750.g also same issues ,if you want to run 38,s then you will have to get carb top solution. As for tap pingel dual outlet only way to go, with slingshot you may have to dress tap mount area dished in buy 10mm or so. Where did the carb tops come from? I've got the same combo for my 750f Quote Link to comment
Roger P. Posted February 27, 2017 Share Posted February 27, 2017 This tap worked for me on that Suzuki which shall not be mentioned. It still needed the handle trimmed to clear the tops of my RS38 carbs. Much cheaper than a Pingel. Use of wood screws not recommended. https://fortnine.ca/en/acerbis-replica-Gurls blouse-tank-petcock 1 Quote Link to comment
nlovien Posted February 27, 2017 Author Share Posted February 27, 2017 great picture - taking what looks like the 38mm tops are almost flush with the cam cover as a guide, quick check and i'm fine for 36mm carbs but going to have frame clash with the 38's - this could turn out to be the reason to port the std L head versus fit a dot one - or stick with the 36mm carbs, funny how decisions can be sorted by not so initially obvious things - thanks aha! even better idea, so if you're looking for that reason to go bag a set of 38mm mikuni FS smoothbores - this is it they will fit no bother - and they come with sloped carb tops as an added adv. 1 Quote Link to comment
boilerdude Posted February 28, 2017 Share Posted February 28, 2017 (edited) I may have forgotten this but is there an advantage to the raised port or is the advantage mostly from the added compression and the cams. If one was doing a big bore for example and high compression pistons. Would you necessarily need the dot head for anything rather than just use the cams out of it? Edited February 28, 2017 by boilerdude Quote Link to comment
colinworth79 Posted February 28, 2017 Share Posted February 28, 2017 I would say the dot head has better inlet ports as well as raising the compression. If doing a big bore conversion you can normally spec the compression you want . Pic of 750L slingshot frame bandit 12 motor and carbs with dot head . 1 Quote Link to comment
nlovien Posted February 28, 2017 Author Share Posted February 28, 2017 in my limited knowledge, raising the roof on the inlets for most of the older generation engines is a good thing - especially on 4 valve heads - huge subject that requires expert knowledge versus opinion but my stab at an explanation is 1) helps to unmask more of the valve circumference and reduces the negative impact of the turn into the valve pocket on the port low side = better flow 2) helps to promote tumble down into the bore - this tumble down works on 4 valve heads whereas swirl around the valve and across the head works on 2 valve motors this is internet warrior info versus hard earned experience, so it could be fake news 1 Quote Link to comment
boilerdude Posted February 28, 2017 Share Posted February 28, 2017 seems logical. Quote Link to comment
boilerdude Posted February 28, 2017 Share Posted February 28, 2017 so who made those custom slabby caps and where can I get a pair... Quote Link to comment
Fula28 Posted February 28, 2017 Share Posted February 28, 2017 Stuart at warpspeed made them for me! 2 Quote Link to comment
boilerdude Posted March 1, 2017 Share Posted March 1, 2017 which warpspeed? got a link or contact? Quote Link to comment
Fula28 Posted March 1, 2017 Share Posted March 1, 2017 The Best one, http://www.warpspeedracing.co.uk/ 2 Quote Link to comment
boilerdude Posted June 8, 2017 Share Posted June 8, 2017 Hey I had a thought about this... What if instead of having special diaphragm caps machined. What if I was to just grind mine down and if I grind a hole in them just epoxy that shit closed when I'm done. Is that good enough or do they need to be "just so" on the inside? Quote Link to comment
Gixer1460 Posted June 9, 2017 Share Posted June 9, 2017 Not unusual but tricky to avoid looking like a dogs dinner! They all MUST be air tight obviously - pin prick holes can play havoc! Quote Link to comment
Oilyspanner Posted June 9, 2017 Share Posted June 9, 2017 Fula - what did you do to the dot head to get 147hp ? A std dot head normally nets a handful of horses on 1100R, a lot more on B12s with cams as well. The only way I've ever managed to get BIG gains is with flowing work, often pretty subtle looking work. I'm guessing you had some head work ......147 is a good figure with standard capacity....nice ! The high entry on dot heads eases the short turn radius and helps open up the front of the valve/port - the floor at this point is eased to help this when you get a head flowed. There's a slight help with gravity too, but not like true downdraft heads. 1 Quote Link to comment
boilerdude Posted June 9, 2017 Share Posted June 9, 2017 (edited) I wish I knew who to go to for master level dot head porting in eastern US. Or maybe I could take it off and send it to... somewhere. Edited June 9, 2017 by boilerdude Quote Link to comment
Gixer1460 Posted June 9, 2017 Share Posted June 9, 2017 2 hours ago, boilerdude said: I wish I knew who to go to for master level dot head porting in eastern US. Or maybe I could take it off and send it to... somewhere. Aren't Orient Express based in New York state - they should be able to handle a job like that! ....... http://www.orientexpress.com/c-305-cylinder-head-porting.aspx Quote Link to comment
boilerdude Posted June 9, 2017 Share Posted June 9, 2017 It was my understanding that these old suzuki's require a special touch. And only a select few know the true way to maximize oil cooled output. Quote Link to comment
Gixer1460 Posted June 10, 2017 Share Posted June 10, 2017 They don't need a 'special touch'! They are an engine pure and simple - what they need is someone skilled in the work, Orient Express I'd trust - they haven't won multiple racing championships by NOT knowing what works! 1 Quote Link to comment
boilerdude Posted June 10, 2017 Share Posted June 10, 2017 On 6/9/2017 at 3:55 AM, Gixer1460 said: Not unusual but tricky to avoid looking like a dogs dinner! They all MUST be air tight obviously - pin prick holes can play havoc! I'll put red gorilla tape over the bastards and be proud. Quote Link to comment
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