K30/K35 vs Modern Open Reeds

mtk1977

Member
I’m starting to read about the Komet series engines. Never knew too much about them, but I know the big CC ones were very well built. The K30 rotary valve, TKM 150, PCR 135 and K35 reeds were popular open engines back in the day for dirt racing, and they are strong motors. Pound for pound (CC wise) it seems they would still be viable options if you can get parts for them and had a hot shoe light driver. Are they truly obsolete compared to more modern air cooled stuff like 116’s and 125 Sudams? If so, is it a porting deal? This is just out of curiosity and nothing more.
 
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Derek woodbury few yrs back ran a tkm 150 he use to kick ass on it at duqouin indoor.but 3 port exh stuff is way to go.i had bought a k35 yrs back and it had alot of work to cylinder but the crankshaft was split where someone pressed it back together,so i wrote that off project list pretty quick when came time to buy a crank.these hoarders are hoarding cranks,motors old and new,buried away in garages going to waste.sad thing they will never do anything with it but talk about it.😂if they do sell it they want 2500 for it,when they probgave 500 for it,guess the 2000 is the fee for digging all the stuff off top of it😂
 
Derek woodbury few yrs back ran a tkm 150 he use to kick ass on it at duqouin indoor.but 3 port exh stuff is way to go.i had bought a k35 yrs back and it had alot of work to cylinder but the crankshaft was split where someone pressed it back together,so i wrote that off project list pretty quick when came time to buy a crank.these hoarders are hoarding cranks,motors old and new,buried away in garages going to waste.sad thing they will never do anything with it but talk about it.😂if they do sell it they want 2500 for it,when they probgave 500 for it,guess the 2000 is the fee for digging all the stuff off top of it😂
Kermit sells crank halves.
 
You can do this to your K30/35. folks make them 150CC- 160CC too.
K30 k35 3 ex port.jpg
 
A correctly modified K30 or K35 will smoke any 116 out there. Wouldn't even be close. The Komet 30 or 35 in the right hands will run with a Sudan all day long. Heck my Dap T 60 will smoke any 116 out there it should at more than 25cc. Just saying I'm done Chuck.
 
Who did this?
That's Kermit's liner and work but I'ts easy to do the same. BTW the Ex. port is similar to a Sudam's but that is about it. The only tricky part is sealing the ex. stud holes. The 54mm version with stock stroke at 129cc is at least as strong as a 116 and you can twist it to 17,000+ with a modern IAME rod, not Kermit's. The bigger bore ones seem to have piston issues if you twist them. A K35 ported like the pic. sold on E-bay last month for under $2k.
 
That's Kermit's liner and work but I'ts easy to do the same. BTW the Ex. port is similar to a Sudam's but that is about it. The only tricky part is sealing the ex. stud holes. The 54mm version with stock stroke at 129cc is at least as strong as a 116 and you can twist it to 17,000+ with a modern IAME rod, not Kermit's. The bigger bore ones seem to have piston issues if you twist them. A K35 ported like the pic. sold on E-bay last month for under $2k.
What about kermits rods are they no count or ?.ya got me curious i just had one put in my engine.
 
A correctly modified K30 or K35 will smoke any 116 out there. Wouldn't even be close. The Komet 30 or 35 in the right hands will run with a Sudan all day long. Heck my Dap T 60 will smoke any 116 out there it should at more than 25cc. Just saying I'm done Chuck.
I do agree with Chuck, they will be faster than a stock Sudam. Don't think they will be faster than a good stroker Sudam though, but there are many things to consider other than just the engine. In the last UAS GN Dave out qualified Bams, 450s, Jawas, etc on his (Qualified 32 out od 48 was just one second from pole and half a second from top 10 but within 2 tenths of top 20. Strahl Gallup might be the guy to ask since I think he built both and Billy Tapman i think he drove some of them if I am not wrong. Now I think when modified the K30s were more unreliable though I haven't been lucky with my 131 Sudam so who knows. A properly built 116 can be very fast. My friend Troy had an open TT75 thatI itthink hold the record in the open 2 cycle class at Langley for years (I recently found it on a box in his shop when I thought he had sold it years ago). New project. Some of the last generation air cooled 100cc ICAs like the last reedjets and the PCR TSL 98s were faster than the older 135s believe it or not, at least on asphalt tracks on small 24 mm carbs, and the rotaries FA and SA even faster (in fact they kept track records on most European short tracks for many years). The last ICAS (both rotary and reeds) water cooled were around 35 hp stock on gas with small carbs nd faster than the 125 TAGs. Now those engines were not run on alky or big carbs with the exception of the SA rotary class, but the last air cooled 100 rotaries were faster than the older 135s basically because cooling and porting improved through the years and that allowed the direct drive classes rev higher in the last generations. Anything modified by the right builder can beat something more recent if not modified, of course, and do not forget tires and setup, plus driver weight. There has been guys very difficult to beat even on 125 Sudams like it used to happen in Florida with Mike Nicosia for many years. Concerning rods my experience with Kermit's rods have been better even than with the original ones from IAME. Every part I have ever broken in my Sudam like cranks or rod has been original parts and not Kermits. Once replaced by Buller's I never had issues with those parts again. The originals were never built to be run on modified engines.
 
What about kermits rods are they no count or ?.ya got me curious i just had one put in my engine.
Kermit's rods are very nice but heavy. If you spin them any where 17k you are going to have problems with big end bearings and pistons. If you only twist them 15k or so you should never have a problem. Kermit made them Beefier because I think he said it was the Browns from Tx. that broke a couple of his earlier ones. One thing that is better about his newer rods as they are shot peened. IAME ones aren't. I spin pre '09 Leopard rods over 17k but remember I'm using a smaller, lighter, single ring, better material pistons. That said after ~ 2 hours the rod gets tossed as the big end is now much bigger. Good K30 / K35s with out goofy porting are real hard to find. When I was running 55.xx bores I broke TKM and other pistons In less that 2 hours. So Speedparts AKA Big Mikes Carillo rods are also very nice but heavier too.
 
Kermit's rods are very nice but heavy. If you spin them any where 17k you are going to have problems with big end bearings and pistons. If you only twist them 15k or so you should never have a problem. Kermit made them Beefier because I think he said it was the Browns from Tx. that broke a couple of his earlier ones. One thing that is better about his newer rods as they are shot peened. IAME ones aren't. I spin pre '09 Leopard rods over 17k but remember I'm using a smaller, lighter, single ring, better material pistons. That said after ~ 2 hours the rod gets tossed as the big end is now much bigger. Good K30 / K35s with out goofy porting are real hard to find. When I was running 55.xx bores I broke TKM and other pistons In less that 2 hours. So Speedparts AKA Big Mikes Carillo rods are also very nice but heavier too.
Yes, but Kermits are designed mostly for those of us running dirt or opens so we don't turn over 15,000 rpms. If you sping any engine over 17,000 my guess is you are running direct drive because most pipes/clutches won't let you turn over those rpms. Stock TAGs don't turn over 17,000 with their clutches, not even close. If you run any engine over 17,000 you are gonna be replacing other parts very frequently, specially top end parts like pistons and so. Engine turning over 17,000 are usually have less powerful torque so better on low end, I rarely had to go through my low end on DD days, but they are bad on pistons. I have seen the smaller rotary 100s turn over 21,000 but they would change piston every day they run or even after every run during those days of SA. I learned the hard way this difference when I messed the lower rod bearing on my 131 Sudam, something I never suffered on the 100s DD, and it wasn't a Buller's rod, but an IAME. I don't know why you spin a Leopard over 17,000, my guess i that either you have modified it or you are not running the spec pipe/carb/clutch on them, right?
 
Rainmain I'm spinning both my DD K35 and my twin piped that hard. What can I say. The lap times pushed me in that direction with the twin. The twin is probably slower at the end of the biggest straight but it is faster coming off all of the slow turns which makes a bigger difference. It's odd as everyone says that what I did won't work, it'll fall on it face, don't do it, etc. I fell into it accidentally as when I switched from twin 100s to twin 135s. I guessed wrong on the gearing for Adams two years ago. I kept taking off teeth and kept going slower. As far as Leopards go I had a conversation with Steve O'hara and he said the only real problem he had with pre '09 leopards was the big end bearing and rod when he spun it routinely to 17k. And that was after almost 20 hours on the bottom end. When he backed it down a bit he quit having those problems. It was 100% stock and legal. I run the DD 135 4 or 5 times as much as the twin and I was shocked when I pulled the crank apart this winter to find out that the rod big end had grown by .0008" and the rollers and pin were good for another .0002/3" of wear. That was only after almost 10 hours of total time and 6 pistons. I've stuck it a couple of times...
 
Rainmain I'm spinning both my DD K35 and my twin piped that hard. What can I say. The lap times pushed me in that direction with the twin. The twin is probably slower at the end of the biggest straight but it is faster coming off all of the slow turns which makes a bigger difference. It's odd as everyone says that what I did won't work, it'll fall on it face, don't do it, etc. I fell into it accidentally as when I switched from twin 100s to twin 135s. I guessed wrong on the gearing for Adams two years ago. I kept taking off teeth and kept going slower. As far as Leopards go I had a conversation with Steve O'hara and he said the only real problem he had with pre '09 leopards was the big end bearing and rod when he spun it routinely to 17k. And that was after almost 20 hours on the bottom end. When he backed it down a bit he quit having those problems. It was 100% stock and legal. I run the DD 135 4 or 5 times as much as the twin and I was shocked when I pulled the crank apart this winter to find out that the rod big end had grown by .0008" and the rollers and pin were good for another .0002/3" of wear. That was only after almost 10 hours of total time and 6 pistons. I've stuck it a couple of times...

OK, so you are talking about DD, right? Of course you can run 17,000 with mostly 2 stroke reed engines and even way higher depending on year and specs. When I ran ICA most were turning 19,000 on the air cooled at the end of the straights.
 
OK, so you are talking about DD, right? Of course you can run 17,000 with mostly 2 stroke reed engines and even way higher depending on year and specs. When I ran ICA most were turning 19,000 on the air cooled at the end of the straights.
I'd love it if the twin was DD. Pro81/2 seem to have pretty good overrev. capability. Talking to folks that ran K35s and K30s DD back in the day the twisted those over 19k for the big races. I can't afford to put that many parts in them and I have no spare engines unlike my 100cc stuff.
 
Modern TAGs won't rev like that. The excuse of FIA/CIK when killing ICA and SA was maintenance, but instead they came out with sealed Rotax nonsense that other than slower in the long run they were not cheaper since the only people allowed to seal and work on them were the approved dealers and they would charge like crazy in Europe. By early 2000s Kart engines had reached their highest ever level in performance and technology but they just killed it taking on their way most of the best old engine builders too. Listening to those engines at 21,000 was interesting. 1st time I tried a Rotax I was bored after 2 laps.
 
That's Kermit's liner and work but I'ts easy to do the same. BTW the Ex. port is similar to a Sudam's but that is about it. The only tricky part is sealing the ex. stud holes. The 54mm version with stock stroke at 129cc is at least as strong as a 116 and you can twist it to 17,000+ with a modern IAME rod, not Kermit's. The bigger bore ones seem to have piston issues if you twist them. A K35 ported like the pic. sold on E-bay last month for under $2k.
I've heard others say they have piston issues with anything over 56.5mm. I didn't have any problems in years past running the 58mm wiseco's from the 125's that I re-pinned in my K35 and Dap T62, 14,500 and up all day long, maybe I was just lucky.
 
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