2 Stroke Expansion Pipe Builder Reveals PIPE SECRETS - A day at Mick Abbey's.
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- เผยแพร่เมื่อ 19 ก.พ. 2024
- Today I show you a visit I made up to see Mr Mick Abbey who had made me some two stroke pipes for me to try. Join me to see some of Mick's top-tips and to see how well his pipe works
Mick is available through: / mickabbeytuning - ยานยนต์และพาหนะ
Made me laugh when Mick complained about his phone never stopping, Once you get him on the phone your there for an hour or more.😁
cool that mr. abbey is willing to share his knowledge
Yep, he's a top guy. I had a great day there with him and Andy.
What a legend, effortless talent by Mr Abbey
Yep - a very top bloke is Mr Abbey
An absolute pleasure to watch 👍
I'm pleased you enjoyed; I enjoyed the day a lot too.
Excellent vid Dave very enjoyable, tops 😁👍
Thanks Andy - pleased you enjoyed
Brilliant video mate really enjoyed that👌👍😎
Pleased you enjoyed Nigel 😀
Thanks so much for this informative and hands-on video. Really cool when you can get into a shop with somebody I’ve done it a couple of times. Love your stuff man Godspeed.
Cheers buddy :)
Great insight to the two stroke masters work. Mick seems like a very patient and nice guy.
I'm pleased you enjoyed. And yes Mick is a great guy with lots of top tips :)
great video lad mick is your man noes is stuff keep at it ul get it
Cheers, Mark. And yes, Mick is the man!
Top result there Dave ,great to see you ,mick and scooby on the video all the old 50cc moped racing clan,we all still have that passion for them and our 2 strokes ,nice result Mick Abbey on the pipe build v nice rpm extension gained.
Cheers Darrell :)
Hopefully, we can do something similar soon.
Mick makes a fantastic pipe, has done 2 for me over the years, top engineer.
Great to hear :)
Absolute gent too.
The legend of mick abbey , Two stroke wizard !!
He certainly is 😀
Its all area under the curve. Having that peak hold for 700rpm longer allows you to shift up with a 700rpm advantage when entering the next gear so a 2+ hp / 1 ft/lb increased midrange drive which will be very noticeable. Great video!
Hi, thanks Mitchell :)
FIngers crossed it helps. The original magazine challenge bike had the T40 pipe and struggled to get 6th gear (it couldn't) so maybe with Mick's pipe I will be able to.
Gearing is another aspect I find interesting, it's really another piece of tuning for speed
@nickywalsh8492 agreed, I need to get some sprockets ordered 😊
comparing a 300rpm-plateau with a 1000rpm-plateau, I d say, the 300rpm-plateau is not drivable, more so, if you can have the option... Logically, one can say, the one with the 300rpm-plateau needs 3,3times the gears-number of the alternative... It´s not that bad in the praxis, but such a disadvantage surely carries over in the praxis (is very noticeable).
Damn how much I would love to work for Mick. You can see how much he likes his job for how he takes time to explain what he's doing and the reasons behind it. So much to learn.
Also it's beautiful that there are grown people dedicating time to such small CC's bikes, and not completely driven away by big bikes.
To me I find 50cc the most interesting size to tune too.
Especially the older air cooled ones.
Yep, Mick really is very passionate about his job, it was really great for me to experience this first hand being lucky enough to spend the day with him. There's many years of experience there.
@@peterjohn3180 Indeed! I am more used to the LC ones mostly because I live where Summer starts in May and finishes at the firsts of November. 35° C and more. Mid July 2023 we touched 47°C. Need a massive radiator and two fans to run my 80cc at 55° C.
@@att49356 why do you run at 55 degrees C?
I remember when lc Moto X bikes first came out people would "cold seize" as they needed longer to warm up for correct piston to bore clearance so piston over heated locally.
But if I'm honest I'm not sure what the optimum temperature for such bikes is!
Obviously the cooler it is , the denser the air/ charge is, but the tighter clearances you will need to cool piston by conducting heat to the bore then to water or air dependent on how it's cooled.
I do wonder how this AC ar50 manages with cooling fins designed for cooling something with 4-6(?) Bhp as standard!
@@peterjohn3180 it Is a modified kit, slightly ported, tight tolerance kit! Not really suitable for the Road. I also have a second bike with similar setup but less fragile as It has 6cc more and more torque means i can not over do porting etc. I posted a video on my account but audio sucks! I Need to find a Better solution.
For these engines i'd never go over 65°. On air cooled engines instead i have no experience at all! Would like to modify an air cooled cylinder to adapt It for my bike. Do you perhaps know any cylinder kit that has 40mm stroke, 90mm rod lenght and needs casings intake? 52x52mm stud spacing would be awesome!
Mick Abbey. What a legend. He tuned 2 of my friends bikes around 20yrs ago. I knew the name, now I know the guy. He knows his 2 strokes. Seeing the piston box on the back of Micks bench took me back to TZR 125 and doing piston swaps ever 6000 miles. Blue and yellow box. Don't remember the brand, do remember the colours. Thanks for taking the time to make this video.
Hi, I'm pleased you enjoyed it and got to know Mick a bit better 😀
I'm pretty sure the brand of pistons in those boxes is Mataka
Great video Dave👍👍👍
Cheers Marcus :)
Great video..... I'm so glad I didn't see these when I was 16 and riding a bored out a 50 as I never had to pennys to rub together at the best of times :D
I honestly can't wait until track day :D
Cheers Trevor 😀
Great stuff
Cheers James
Mick is a top guy. Helped me out on the phone when fault finding on my self tuned/ported TS185.
Yes, Matt, he's a proper top bloke. I had a great day there with him and Andy
@@AutoBeta2T if he wasn't so far away, I'd ask him to make me a pipe..Do you know anyone competent in the midlands? Where are you based Dave? 👀
@mattcooper8882 I'm Lincoln but just do my own pipes. Abcon Pipes are based in Notts I think. Not sure if he does Pipes still?
Thank you!
Great to see you back with a BANG wow 20 hp amazing congratulations what's next ?, keep safe love the video.
Cheers David.
Next is a vid I recorded before Christmas about the transfer flow testing. I need to get that edited and up then for some further head testing.
thank you!
Man great content, glad to see you back! Would be great to see speed attempts after improvements.
Thanks - good to be back. I'm not sure where I'm going to be able to do the speed attempt... Something I need to look at as I do want to go for it this summer.
Watching this video almost angers me of how much I could have improved the performance of a 350LC that I fabricated expansion chambers for, back in the 80's. I didn't have much to go on and dynos were pretty expensive back then, I only had a book on 2-stroke tuning by John Robinson. I used one of the formulas to fabricate the pipes and had them fitted to the bike. The diameter on the neutral chamber section was small compared to what you see today but it turned out to our advantage as we had reversed barrels and they had to pass under the rider's thighs and they got pretty hot lol. They did work and the LC was turning out pretty decent times at the quarter mile strip but it could have been so much better if I had the information and a dyno. I am 64 now, but 2-stroke engines still give me a thrill whenever I hear (and smell) one.
Hi, that sounds like some project reversing the cylinders! How much power do you think you had in the end?
@@AutoBeta2T No idea about power, we reversed the barrels to get the frame as close to the ground as we could so we could pass the pipes straight to the back and on the sides. I think it ran in the 11 second bracket. I remember we had a 250 head with the squish machined to fit the 350 barrels, carbs were 2 from a KH750, we still had the standard reed blocks with the centre rib removed and one piece Harpowa reeds. The engine was fitted on an older air-cooled RD350 frame that I totally hacked horizontally and re-welded it. Rear arm was lengthened and welded to the frame. We increased the rake by heating the top tube supporting the steering head and bent to whatever degrees that looked good lol. Front forks and wheel were off a Yamaha YB100. Rear tyre was spinning in the rim so we fixed the problem by tap screwing into the rim and into the tyre. Crank was welded because it spun out of true (LC cranks are not splined). At least two clutch baskets were destroyed. We ran it on Avgas fuel and the only way we could acquire it at the time was to get someone that had a pilot's license for small aircrafts, then go to where the plane was and drain the tank. Safety, what safety? We didn't even have a front brake and when I pointed it to the owner/rider to be careful he replied: "I just wanna go fast why would I need it." Quite a character, sadly he passed away 2 years ago. I believe there is a TH-cam video albeit low quality that shows us racing the bike I will put a link to it if I find it. We're from Malta and when my friend went to the UK to buy parts he went to Bob Farnham and when he showed him a pic of the bike he was impressed, he even came to Malta on holiday and to meet us and have a look at what we were doing. Great times indeed.
I have only just had time to watch this video through. I wish I had seen a video like this when I was teaching myself (because no one else would) to build 2t pipes , it was a long lonely road with plenty of dead ends and screw ups. Still, I have picked plenty of good tips from this video. What a privilege to spend a day with an experienced guy like Mick Abbey, most tuners won't let you see how they do things. For anyone looking to learn how to make pipes, this is gold.
Me too John, it was mostly the same for me with learning how to make pipes. I did get some help from a mate in Oz but learing to weld and how to make pipes at the same time took plenty of goes. My first few pipes had so many holes in them as I struggled to get the cone faces flat and then played the game of trying to fill them before burning an even bigger hole into it.
Yes, it was great spending the day watching Mick. He has so many tips and tricks to make pipes easier and it was great of him to share them with all of us. A top bloke 😄
@@AutoBeta2T I have just picked up a full oxy acetylene welding kit from the merchants today. Have not used one since I was in school metal work lol. Let see if I can make a pipe lol.
@john63397 should be interesting to see how you get on. From what I could see gas welding seemed to be more forgiving and quicker than tig. Saying that Mick has many years of practice.
@@AutoBeta2T OK, I'm back for another look at the gas welding lol. I am having reasonable results. Main issues are popping/blowing holes and deformation. I am using 1.2mm mig wire as filler , this may be causing problems. Also Mick is using a much more aggressive flame and moving quicker. But yeah, gas welding could be the way to go for faster pipe building and testing. Its got potential.
@john63397 cool, sounds like fun.
Mick did mention that you had to use the proper gas welding rods... something about carbon, I think?
Top man mick a gentleman
He certainly is!
Great 👍 Built for a smoking lil 2 stroke 💪 20hp under 200cc... super solid... sometimes the ol boys know more than they tell 😉😁
Cheers buddy 😀
awesome!
Cheers 😀
Ahhh, There you are!
Was wondering where you went =)
*sitting back*
Hi Patrick. Yep, still here... its been a busy time for me since Christmas, but I'm getting there now.
Quite funny, i planned to do a clip about design a pipe in mota.
Cool. It'll be good to see how you go about it.
@@AutoBeta2T I have some rule of thumb that i do not let Mota optimize, and i might keep them a little bit secret also :)
I seem to recall that MZ were the original past masters of the 2 stroke exhaust geometry. Quite remarkable how such small variations make such difference.
Hi, yes I believe it was. I have a book somewhere called: Stealing Speed. I need to dig it out and have a read.
Yes, it's amazing how a.small.change can affect the power output. It's one of the reasons of why I first got into making expansion pipes.
That's terrific. Best vid I've seen on making pipes. What a great idea cutting the sections out of a flat cone - definitely trying that next time. Will try 22ga steel too, I've only used 20 before which is about 0.9 as I was a bit paranoid about cracks. Thanks both!
Pleased you enjoyed Joe. Yes, Mick has some great tips that save time and increase accuracy.
Do you gas weld pipes?
I have tried 0.7mm sheet before on my X7 pipes. I could weld it with Tig but it was a little trickier. Gas seems to be a bit more forgiving - I'd love to have a try.
Weeell. I've only made 3, 1 test and a pair for an RD250, but yes. Gas is easy enough once you get the hang of it. I use a little filler, like Mick does to tack, which takes some heat away and avoids holes, then autogenous. On the small seams you have to whip the torch away so you don't blow away the ends. My set up is an old Smith Airline AW1 handle, and AW201 tip, I really like it. Works fine at low pressure for 22ga, anything thinner is hard. I've never tried Tig so I can't make a comparison, I'm afraid. You use very little gas on thin stuff, so it's cheap to play with too. @@AutoBeta2T
@joemarchant1424 cheers Joe. Tig is similar, I think, to gas but until I have a go I can't say. I can tack with no rod but I do need use it every so often when there's a bit of a gap.
Argon seems to go quick too. I'll have to ask Mick to let me have a go next time I go up.
There's something relaxing about the flame whispering away and it's nice not to have to wear a mask. Can't believe how fast Mick rolls those cones, that set up on the slip roll working along loose to tight I definitely need to try. The baffle cones take me ages. I have serious mandrel envy too. Thanks again for the vid - great content!@@AutoBeta2T
Excellent pipe - wonderful video thank you. I need to become proficcient at making pipes, skill I don't have. The engine is really really rich on pilot/early needle. Probably good for road use and air cooled.
Cheers Derek, Mick did a great job on the pipe.
And yes, Mick was saying I need to fit a smaller pilot. I do have some smaller ones to fit.
I love his casual style...so relaxed...fag in mouth welding...
Don't see people like that in industry.
He even has the same jacket as myself..
Gas welding great...loved doing it
I am of the same age roughly and my workshop in the same state... special tools everywhere..
Wonderful 👍
Great video
Yep, Mick is a top lad. He loves what he is doing.
Nearly ready for a top speed run...😎
A bit more power required I think but getting there.
@@AutoBeta2Thow much does the bike weigh?
About 80kg as standard.
Haven't watched the vid but glad your back
Cheers Brian
@@AutoBeta2T man bet mick has a Kung fu grip. Gas welding pipe making guru. Incredible. Grate job thanks for sharing.
No problems - pleased you enjoyed.
In 1974 I used to tune 2 cycles. I had a 70 Yamaha 175 that put out 43 hp @ 14,500. It had 9 ports, analog 32 mm fuel injection, 8 reeds, and an expansion chamber that had a 8,000 top hp but I check it out and I got 14,000 the the gases did exit! I ran it in open class and got several first places. But in 1976 open class motorcycles were more torgue, hp, and better suspension!
Cool, that sounds like a screamer!
I worked in a Suzuki/Yamaha dealers in 80's.
Hated those little Kawasaki 50's, they were always completely trashed after about 3 months. (nearest Kawasaki dealer was about 20 miles away in Cardiff)
Everything was worn out, shock bushings, swing arm bearings, seals, even the wiring and switches.
Honda MT50 was impossible to tune (British market ones couldn't be ported to 'continental' spec of 6.5bhp)
Yamaha was the easiest to tune and slightly better build quality than Suzuki. (was tuning 'Fizzers' in 70's, although knew a lot less so 63mph was best I could get)
Stan Stephens was the 'go to' two stroke tuner back then and 'everyone' wanted Micron's on RD and GT 250's😁
Many years ago, I fitted a Suzuki RG125 'learner special' tank onto Honda RS125 road racer for Ian Lougher to do TT
Lot of work cutting out complete bottom and making it fit Honda like it was supposed to be there. He removed all the fuel filters though and seized it 2~3 miles in when a bit of rust or dirt got into carb.
LOL, it's probably 40 years since I heard 'southern shandy drinker'
Yah, I think a lot of 16 year olds didn't know how to look after their bikes!
My first bike was a Honda MT 50, and yes it was pretty slow... slower than my mates AR 50 anyway... which is why I got one
thanks and fried for help him fascinating
Hi Dave, that peak power curve is a great result.
Your take about this sort of curve helping you achieve your goal is spot on based on my experience running smaller Land Speed 2 strokes.
As far as other things that can help, such as Aero etc.
I found that minimising your Frontal Area on small bikes is the first thing to explore.
Then base everything else on this smaller profile.
Cheers Mate
Pete
Hi Pete, that is really great to hear from someone with actual real world land speed experience.
The original magazine challenge used the T40 pipe and they really struggled to pull 6th gear (it couldn't) so I have always been conscious of not getting too peaky with the curve and spreading the power.
Noted on the frontal area, I have a nose cone for my AR but again on the original challenge they found it faster without.
I need to get on a diet then to reduce my cross sectional area :)
Thanks again for you insight and tips Pete, much appreciated.
Cheers
Dave
Hi, I just discovered this channel a day ago and autimatically love it. I've got a purpose for a possible video, what about cylinders exhaust duct diameter? It's something that people tends to enlarge it, and I would never know if that adds or rests. And more important what exactly does. I just saw the previous video and couldn't resist to coment this theme. Thank you very much for the work you're puttting, most of us are concerned of the amount of hours involved in doing this type of content.
Hi, I'm pleased you are enjoying 😀
I definitely want to explore the whole exhaust duct diameter thing. I have a plan on how to do it but I need to get a few other tests done first. But definitely something I want to cover.
Cheers again for the kind words.
Very informative video! Not everyone would be as happy to help as Mick Abbey, he comes across very well! It’s the little gems and snippets of information that I particularly like. What’s the brand of tin snips that Mick uses?
Hi, many thanks, and they are Stanley
I just subscribed, thought i already did.
These are one of the most interesting videos on TH-cam.
Id love to make expansion pipes.
Have you considered having a new liner made with just a single intake port bridge rather than 3(or is it more?!)
I wonder how well it would work with a smooth bore throttle body and injection?! I hate electronic thoughbut you could have i nice constant taper and trumpet and thin throttle slide?
Hi Peter, thanks for the sub and I'm pleased you are finding the video(s) interesting - it's good to know they are being appreciated :)
Reference the liner - maybe one day... That day will come when it seizes I guess. Currently though the inlet port is just a single bridged port. I did cut a floor port in a previous video which gave some more power.
I'm going to stay away from injection at the minute and see how far I can get on a carb. The ignitec ignition I run can control power jets an carburetors so possibly some electronic control.
cheers, Dave
From where I live, those wheel worth a fortune! Ranging from 2000-4000USD depending on what conditions they’re in,
I saw a guy that bought a new old stock from an old dealership and he sold it for nearly 10k.
Yeah, I heard they can reach some good money! Ironically, I want to use the spoked wheels.l on mine
The compromise on a bike is available space and the noise you are willing to tolerate. A megaphone style exhaust sized and tapered for the engine displacement is just as effective but a lot louder. Some tricky extending stinger or water injection will give you a good balance of low end and still compensate for top end for those wanting to get crazy with it. Any 2 stroke stuff is good stuff..
Yeah, water may be in order if the power band gets too short. Hopefully we can do it without but it's an option
Had a chuckel to myself when I saw the old 2-stroke "Tuners Handbook" oncarb adjustments between pipes the bench. Did you do any carb adjustments between pipes. I remember way back when just changing the angle of a pipe would upset the mixtures (on a very highly strung T-500).
Hi, sorry for the late reply. No, we didn't, with the jetting, but we kept track of the lambda and it was similar for.all pipes.
We did change the ignition curve from a flat 20 deg curve to one I had found worked best on my pipe. It made Micks pipes work even better so no more adjustments were made.
But noted your point, both jetting and ignition should have been optimised for all pipes, but as always, we ran out of time. ☺️
👍👍
Fantástico!!!!:):)
obrigado
Very informative video,
Can I ask what software you use for the printing of the pipe sections.
Thanks.
Cheers and I believe it's this: www.conelayout.com/
Hello,
This is so cool 👀 with good result AT the end.
Question: what's your dyno configuration dynomec ?
Roller dimension,weight, final ratio ? For comparaison with my dynomec setup.
Many thanks 😊
Cheers :)
As for the spec of the dyno I'm not sure. Mick may be along to answer that.
Absolutely brilliant watch with the legend Mick Abbey. Did he say where he got the snips from Dave ?
I reckon you'll be buying a cheapo laser cutter next to speed things up even more .
Hi mate, I think they are Stanley snips. Mick sent me home with them, so I'll
double check.
I would like a laser cutter... maybe one day?!
@@AutoBeta2T Thanks mate, keep me posted, I've cut all my cones for mine now, but I had mega problems with them binding up on the cuts , these would do away with that problem. Also I can't believe Mick hasn't got a guillotine for the amount of pipes he's done over the years, invaluable for the straight edges .
Hi, I believe these are the snips that Mick was using. They look a bit different but I think it's because they are newer.
www.amazon.co.uk/Stanley-Aviation-Snip-Offset-2-14-567/dp/B0001IWB2G?th=1
@@AutoBeta2T Thanks mate 👍
That over rev is very nice. I wonder how the T40 would work with a longer belly (large section between the cones).
Hi David, we did actually try that on the day but it didn't get into the final cut. However, we tried longer and shorter on the belly of the T40 and it only became worse both ways.
🏍👍👍
How do I get my ar50 to rev past 7.5k is it an electronic limmiter and how do I get rid of it?
Hi, yes, the ignition curve on the 50 is very restrictive. BDK do a mod to a standard cdi also Firepower engineering sell a programable ignition for the AR.
mint !
Cheers buddy :)
Another very insightful video, he makes it look so easy! 👍.. how do you seal where the pipe slips onto the barrel? I've got a bdk pipe on mine and it leaks a bit where it slips on 🤔
Cheers - and yes Mick does make it look easy. Years of experience.
I'd use a bit of high temp sealant. Is it a slip fit? On my BDK pipe it uses the standard AR style split collar and gasket.
@@AutoBeta2T yes it's a slip on.. i picked it up off a guy that used to race AR50's.. he even had a watercooled one! Is yours a genuine Autisa barrel or one of the remachined steel ones that come out of a factory in China?
It's a genuine Autisa. Problem is that it's on 54.5 mm now.
I could really do with another but they appear to be like hens teeth
@@AutoBeta2T wow you were lucky to find that.. I've never seen one in years of watching eBay.. so whatever you do, don't blow it up!! 😲
@user-ye8xx7gl3j yeah, I bought it from a mate. Really lucky.
An AR!!, haven't seen one of those in ages...
Yes, a bit af a rarity nowadays
Nice. Have you done a run yet? Get yourself to a straightliners event. You will need good aero and gearing to get 100mph with 20bhp. We needed 30+ on scooters.
Hi Ian, I will. I think 23-24 may do it so more to go.
Did you work on the bike mags at emap / Bauer?
Nope. I did however, make the pipe for the Practical Sports Bike magazine article's detailing the 100mph moped challenge
Have you ever looked at the FOS-pipe-Concept by Frits Overmars (there’s some images online on the Kiwi Biker Forum)…..he says it’s for thermally sound engines (ie: water cooled), but for one speed run it may be OK, no sure how safe without increasing stinger diameters and lengthening slightly for a lower EGT’s / reliability on an air cooled engine.
Hi,
I have tried a FOS concept pipe design in the sim and it gave a nice power curve, but as Frits himself says: it's just a starting point to then progress from with testing. That said I may try one of the calculators and maybe build one at some point.
So what is ormwhere is the difference in the pipes? 1 inch shoter tunelength or the stinger pipe diameter?
Mick's pipes were about 50mm longer than mine (T40). All of then stingers were the same diameter
What was the tip size on the torch?
I asked Mick, and he said a No. 1
Are you hoping to ride it (Maccy Ds??) Is a fairing envisaged in the future attempt? as you appear to be getting close.
Hi no fairing if at all possible.
I have a stunt rider lined up... but maybe me if I can get off the maccys
I would be curious to see the difference with a stamped header...?
Me to!
I will at some point try a cone header verses a hydroformed one. Not stamped I know but close.
Mate just seen video am I right in thinking you are trying to do ,100 mph on a at 50 what size piston are you using lol I'm 50 takes me back to being 16 and mate the best we ever squeezed out of them with Autisa 93 bore kit was around 70 mph at it felt like 170 mph good luck to you I'm very interested 👍👍
Hi, it's a 93cc Autisa kit I have. But it's now at 54.5mm bore so nearer 97 cc
Yes, I had an Autisa on mine when I was 16... 70mph max but lots of fun
What cc is it? I had a 80cc with a 93cc big bore kit on it in 1988.
Hi, it's on an Autsia 93cc kit but it's on a 54.5mm bore so nearer 97cc
20hp from an AC - cracking result!!!
Cheers mate - note however, it is a big bore kit and 97 cc
mtx130 guys make over 40 hp on a air cooled engine
What bore and stroke are the mtx130's?
@@AutoBeta2T 57mm bore and 52.5mm stroke
@@AutoBeta2T th-cam.com/video/EOc5ZI1VRkc/w-d-xo.html
Traditional manufacturing methods still doing the business. 👍Will 20bhp be enough for the ton?
Hi Bobby, yeah it was great to see gas welding. I really want a go now.
20hp isn't enough. I recon 23 on Mick's should do it... so another 15% power I recon.
if I wanted to go fast on a 50, first thing would be to lose weight. good video.
What RPM ranges for different engine sizes are used mostly when going for max power? I've noticed 125's around 12-14 000rpm and 250's at 8-10 000rpm mostly.
If I wanted to hunt for more power should I set my port timings to work at a certain RPM and then build a pipe around it. If too peaky then playing around with other things?
Its no rocket science but at the same time it is if you want to go into small details :) I heard somewhere that oversquare engines dont have the same pipe design as square 2-strokes (old yamahas vs modern every 125)
Why wouldnt a modern pipe off a 30hp 2-stroke work on a 20hp DT125 for example?
Hi, I'll give it a go at answering but I'm certainly no expert. RPM I believe is really down to piston speed limits. Smaller engines, shorter stroke so less distance (slower speed) for the piston to move at higher rpms. Also bigger cc singles have bigger pistons - more mass etc...
From what I can see, regardless of timing the pipe tuned length plays a major part in the rpm of the engine. In a previous video I went from about 192 duration in the exhaust to 203 and the peak power rpm only changed a few hundred rpm. Port wise you need the STA for the power you want - particularly exhaust blowdown.
Pass on the oversquare design. I couldn't answer for sure. A thing to note is that oversquare two stroke engines have less port area than a square engine of the same cc and port duration.
A modern pipe may work but it comes down to the rpm range the engine has been designed to work in I guess. Putting a higher power pipe of say a road racer on a DT125 may make it rev but if the ports don't have the area to work at that rpm it won't make the power. Also ignition would need tweeking too.
Okay thanks for the long answer :) We just tried an exc125 pipe on a dt125 with my friend over 10years ago and it was super peaky at super high RPM, I even got 143km/h on the GPS with it so it definitely made more power than stock. The DT cylinder also has a longer exhaust duration than a 1988 yz125 if I remember correctly which is weird to me :) Both are 56mm bore or the yz could be 56,4 with 50.0 stroke where the 1989 onwards DT is 50.7 stroke and 56.0 piston. Cheers :)@@AutoBeta2T
Could you broaden the area under the curve with a valved stinger in theory? Start with a stinger larger than you would run, test some restrictions in it,build a map like you do for ignition timing, install a valve controlled by rpm. I was thinking the heat in the pipe is controlled by stinger size, and sonic wave speed varies with heat,etc. Maybe having to get rid of the exhaust gasses or it just not working in this manner makes this idea impractical. Or just dumb😂.
Yes, you could. I did some tests on my race bike some years ago with the stinger and smaller did give more power. However, I got greedy and melted the motor. The ignitech would be able to control what you suggest.
I was thinking water injection but a variable stinger restriction should work similar.
That's why I like 4 strokes. A piece of bent water pipe is not hard to design. Lol.
my lc350 runs mick abbey tune and pipes.... has never run better
I bet it's great fun to ride!
That was meant to read "on the bench".
I wonder what little dofferences make it so the powerband is wider. Dark magic knowledge lol
It should allow the bike to get into top gear without falling out of the powerband. In the original magazine challenge they had this issue. The original challenge used the T40 pipe design. I recon with Mick's giving the extra rpm range they may have got into sixth gear!?
That looks nice Dave , but i think the big-bore should make at least 28 HP
Cheers Henk. Yes it should be making a bit more power and it needs too. I'll get there... It'll just take a bit more time. Note - my standard RGV 250 made 56 hp on a dynojet years ago when I had it tested. Dividing power by cc and multiplying by 250 gives 51.5 hp.
Gotta look at leaning the bike and front wheel travel .
I'm only going straight 😊
But yes it is a consideration. I think you would just be okay as it is but it is close.
There will be no issues with all these pipes going around corners and the clearance from the front wheel will be fine 👍
so mota x works to calculate pots
It does pipes and ports.
In that cc you can go at least 30+ horse power if you want
Maybe... I recon 25 - 26... I have a really short Stroke of 41.6mm which hinders time.area
Hurray, another 'fastest 'ped' ever vid! 😀
Yep - I'm getting there 😀
Sounded like he was just holding the throttle open a little longer with his two pipes versus yours
The reason why I was holding the revs on longer was due to the pipes still pulling longer before tailing off
What Mick said 😄
th-cam.com/video/uXMy4GoFtPA/w-d-xo.htmlsi=-UjZ8Vau7PfwvCG_
Maybe this will work for you. After doing it I would probably have tried to push the flow in a different direction somewhat to get the exhaust out faster.I don’t have a dyno so actual testing wasn’t possible but I would say 5-8 mph increase.
Cheers Roger - so a noticeable improvement then!
@@AutoBeta2T yes whether it was because of the case being stuffed in a sense I can’t honestly say my opinion would be, though that beyond the increase pressure volume the flow can be directed. It would just take some fine tuning. I worked with a couple of people on this idea in the first place and came up with it because they told me that I couldn’t change the flow with a heavier journal or a lighter journal and there was no other option that I could realize at the time. I know it’s a crude video but hopefully you can makes sense of it.
I bought an AR125 in 1983. at the first service the fork stanchions were replaced due to pitting from the rust. other faults were kick start stop wearing, went through 3 different kick starts, gear linkage wore through, rotary disc disintegrated, the resulting carbon fibres punctured the water pump seal and it needed a complete engine strip. probably the worst bike I have ever owned
Bugger, sounds like a bit of a lemon!
Bits for them are like hens teeth nowadays.
Someone pjt a mcdonalds in a cupboard for 24 years and it never went mouldy someone else did it for over a year and both never rotted
Must be all of the wholesome goodness inside every McDonald's 😂
:-)
Good work!! Only thing I feel is not really OK, smoking on the video. We want to discourage young ones from that filthy habit.
Ya know it would be easier to hit 100mph with a smaller rider...
On a totally unrelated note, I'm only ~135lbs and good on experimental bikes that were never intended to go that fast
Yeah, noted. I have a mate who doesn't eat much and runs a lot so maybe he could be the stunt rider. Believe it or not I was about 140lbs in my prime but quite a bit more now! Maybe I should do a get to 140lb challenge!?
Dave, i have lots of oxy acetylene torches for you, please don’t buy any and i will donate some this friday when i see you 💪🏼
Cheers mate 👍👌😀
Catch you Friday
That workshop is a tip. When I see a workshop in that state it creates a bad impression. 😯
Hi Alan, never judge a book by it's cover 😀
Stan Stephens tuning is the best in the business as far as im concerned..🎉
Is he still tuning?
talk English man
We are buddy.