On a younger man that could alter the family tree.
Bike builders that have machine tools/shops
- Thread starter Tom from Rubicon
- Start date
Burn it it's a DEMON!
I bought one of them and they are looking for youngsters, and if you are are a 14 year old they are ok! Nope,I'd NEVER buy one of them at my age!
I'm having some real fun setting up, equipping and modifying my mini-lathe to suit my purpose. Stuff is arriving daily and has been the case since I first ordered the machine. I've re-assembled the lathe after de-burring & cleaning up the sharp edges left from the manufacture of the tool. The ways were well machined and finished. The carriage actually was fitted quite well to the ways, which is not typical in these import machines. I've fitted a slide lock to it and the compound slide as well The tail stock lock was fine. Once I fitted a bushing to the quick release tool post it also is rigid. The compound gibs rework rounded out my compound slide rigidity issues. I turned a few aluminum replacement handles on the adjustment controls. Both the carriage and compound handles would back out when reversing direction. I also increased the size of these controls as I don't have miniature fingers! I also hollowed out the lever I made for the tail stock lockout so it can be used as a tail chuck key holder. I've one more lever to machine and that being the quick release post bolt, which now requires a large hex wrench to function. I really don't like searching for wrenches when setting up for lathe operations. Thus the levers and thumb screws. I can keep up with the chuck key, most of the time.
At the moment waiting on face plate & dogs. 3 MT center for the head and a 4 jaw chuck (independent jaws) with which I can multiply the lathes functional capabilities with small parts. Here's where I make a statement of reality. Heavy cuts in even mild steel at high feed rates will quickly ruin the accuracy of these small machines. I bought this lathe to work in aluminum primarily, brass/bronze an hard synthetic materials too. My eyes were wide open before buying and the mods I'm making were anticipated. I'm pleased to this point and for the base price it's hard to beat for the work I intend for it. Since I have access to large lathes I have the option of these so I'll not be tempted to tackle jobs the mini-lathe is ill suited for. Careful turning of small steel parts on occasion is fine, but I'm hoping to avoid steel most of the time.
I've also parts on order to fab a tool post cross drill/grinder and a lathe dividing plate for the chuck plate. The lathe, regardless of size, is a needful thing!
Rick C.
At the moment waiting on face plate & dogs. 3 MT center for the head and a 4 jaw chuck (independent jaws) with which I can multiply the lathes functional capabilities with small parts. Here's where I make a statement of reality. Heavy cuts in even mild steel at high feed rates will quickly ruin the accuracy of these small machines. I bought this lathe to work in aluminum primarily, brass/bronze an hard synthetic materials too. My eyes were wide open before buying and the mods I'm making were anticipated. I'm pleased to this point and for the base price it's hard to beat for the work I intend for it. Since I have access to large lathes I have the option of these so I'll not be tempted to tackle jobs the mini-lathe is ill suited for. Careful turning of small steel parts on occasion is fine, but I'm hoping to avoid steel most of the time.
I've also parts on order to fab a tool post cross drill/grinder and a lathe dividing plate for the chuck plate. The lathe, regardless of size, is a needful thing!
Rick C.
Damp day in SE Wisconsin.
When I was building my Sportsman Flyer 80, I tried to incorporate left over components from the Huffy Davidson build.
One was a hand brake lever spare that activates a side pull rim brake. Functioned fine with the Huffy side pull brake.
SF 80 has a Husky front wheel Sturmey Archer XL drum brake.
The side pull brake lever never had enough cable travel to begin with, but over time and cable stretch 2020 front braking the XL was more wishing than stopping.
Couple years ago our Township recycle had unloved mountain bike standing by the dumpster. I salvaged the handle bar with goose neck complete with rotary shifters and brake levers, plus two sets of V brakes. (Big plans for the Huffy). Ha!
Forward today. Managed to weasel off the Donkey handle bar grip with a little help from ClearGlide Wire Pulling Lubricant, 1 Quart Squeeze Bottle. Think KY for conduit.
Once the grip was off, time to tackle the mountain bike lever. Once mounted the new brake lever gave the XL brake adjuster 80% of it's range back and much reserve lever travel once the brake pads are fully engaged.
So that was the fun had today in the machine shop. From left, new improved and replaced side pull lever.
When I was building my Sportsman Flyer 80, I tried to incorporate left over components from the Huffy Davidson build.
One was a hand brake lever spare that activates a side pull rim brake. Functioned fine with the Huffy side pull brake.
SF 80 has a Husky front wheel Sturmey Archer XL drum brake.
The side pull brake lever never had enough cable travel to begin with, but over time and cable stretch 2020 front braking the XL was more wishing than stopping.
Couple years ago our Township recycle had unloved mountain bike standing by the dumpster. I salvaged the handle bar with goose neck complete with rotary shifters and brake levers, plus two sets of V brakes. (Big plans for the Huffy). Ha!
Forward today. Managed to weasel off the Donkey handle bar grip with a little help from ClearGlide Wire Pulling Lubricant, 1 Quart Squeeze Bottle. Think KY for conduit.
Once the grip was off, time to tackle the mountain bike lever. Once mounted the new brake lever gave the XL brake adjuster 80% of it's range back and much reserve lever travel once the brake pads are fully engaged.
So that was the fun had today in the machine shop. From left, new improved and replaced side pull lever.
Attachments
Small shop victories are quite satisfying Tom. I spent a couple of hours on improving a mod made to my mini-lathe, carriage lock, and consider it an investment. The ability to lock all the slides on a lathe or mill is fundamental & I'd say quite expected as a key design factor from the manufacturer,, even on small hobby machines. Sadly the Chinese seem to disagree with me on this as few mini's under the $1,500. price point have more than two lockable slides: carriage & tail stock.
Overall I find the Sieg 7" x14" lathe a value that can be fine tuned to provide rather nice turning. I've mentioned previously that machine cost is quickly exceeded with the addition of tools and accessories , easily doubling the original machine costs including shipping and tax totals. This I've proven to myself once again. I've already invested one and a half times the machine cost in basic tooling and accessories. This not including a four jaw chuck which may arrive in June? It's back ordered. There is also the time I've spent in fine tuning and optioning out the lathe(still ongoing). To me it's fun, but to others I can see how this could be frustrating. To me the mini is worthwhile for my hobby use, but I'd not think it would suit those who are using larger, proper machines in their shops. If you have the space and can find a Logan or Atlas, both of which I've owned in the past, I'd suggest going that route. There is no way past spending for the extra stuff unless it comes with the machine and finding accessories for the Logan's and Atlas lathes are hard to find and not cheap. A used lathe may also reveal a lot of wear or actual damage which can be difficult to detect on stored machines. Let the buyer beware no matter the selection they make.
Rick C.
Overall I find the Sieg 7" x14" lathe a value that can be fine tuned to provide rather nice turning. I've mentioned previously that machine cost is quickly exceeded with the addition of tools and accessories , easily doubling the original machine costs including shipping and tax totals. This I've proven to myself once again. I've already invested one and a half times the machine cost in basic tooling and accessories. This not including a four jaw chuck which may arrive in June? It's back ordered. There is also the time I've spent in fine tuning and optioning out the lathe(still ongoing). To me it's fun, but to others I can see how this could be frustrating. To me the mini is worthwhile for my hobby use, but I'd not think it would suit those who are using larger, proper machines in their shops. If you have the space and can find a Logan or Atlas, both of which I've owned in the past, I'd suggest going that route. There is no way past spending for the extra stuff unless it comes with the machine and finding accessories for the Logan's and Atlas lathes are hard to find and not cheap. A used lathe may also reveal a lot of wear or actual damage which can be difficult to detect on stored machines. Let the buyer beware no matter the selection they make.
Rick C.
Sportscar Pat, replying to my question of what can be done to get more out of the 79cc Predator engine, gave this advise.
It is recorded on another thread on this forum and in an email to me personally.
Two changes improve a stock 79cc Predators. Decking the head .050" and 18# valve springs. Forget the cam.
Pat's empirical data suggests that a high lift cam on a 79cc engine gets you nothing.
That said. I am stripping down an engine to not only increase compression, but do the port and polish work in my shop.
Purchase parts from AGK, will be just the finned billet flywheel, valve springs, and complete gasket set.
A list of fastener torques would be deeply appreciated.
Tom
It is recorded on another thread on this forum and in an email to me personally.
Two changes improve a stock 79cc Predators. Decking the head .050" and 18# valve springs. Forget the cam.
Pat's empirical data suggests that a high lift cam on a 79cc engine gets you nothing.
That said. I am stripping down an engine to not only increase compression, but do the port and polish work in my shop.
Purchase parts from AGK, will be just the finned billet flywheel, valve springs, and complete gasket set.
A list of fastener torques would be deeply appreciated.
Tom
Small Engine Performance Mods | How To DOUBLE Your Engine Power! - YouTube
Gotta luv the genius porting the exhaust on a built engine.
Valve lash spec. not defined.
Tom
Gotta luv the genius porting the exhaust on a built engine.
Valve lash spec. not defined.
Tom
Tom I love U-tube "bragadoshit" how to and they lift my spirits, though not my hopes. I view a lot of work shop stuff and U-tube is great source of info, but I take a weighted average on a given topic by watching several channels for a given topic. Reviews are often heavily weighted on equipment/product reviews however. A finely tuned BS meter is recommended for those looking for advice.
Rick C.
Rick C.
Hi Rick, I'll give ya that the technician in the vid. had me grimace a couple of times.
like when when he was breaking corners around the valve seats. But AGK endorsed and paid for the production.
And I still don't know what the valve lash is for intake and exhaust of a 79cc Predy.
My plan with the engine on my bench is to perform the port and polish myself and deck the head 0.050".
Two ways to skin that cat. Either flycut in a Bridgeport or mount to the face plate of my Logan. Wudaya think?
Purchase parts will be a finned billet flywheel, keyway cut at advanced spark, Gasket set, and 18# valve springs.
Saturday had me beginning governor removal.
Tom
like when when he was breaking corners around the valve seats. But AGK endorsed and paid for the production.
And I still don't know what the valve lash is for intake and exhaust of a 79cc Predy.
My plan with the engine on my bench is to perform the port and polish myself and deck the head 0.050".
Two ways to skin that cat. Either flycut in a Bridgeport or mount to the face plate of my Logan. Wudaya think?
Purchase parts will be a finned billet flywheel, keyway cut at advanced spark, Gasket set, and 18# valve springs.
Saturday had me beginning governor removal.
Tom
The official AGK 79cc engine mod youtube.
Ignore numb*uts in my previous post. Mind you, the flywheel break was edifying.
Here's How AGK Can Help YOU With Your 79cc Predator Build1 - YouTube
Tom
Ignore numb*uts in my previous post. Mind you, the flywheel break was edifying.
Here's How AGK Can Help YOU With Your 79cc Predator Build1 - YouTube
Tom
Amen, Rick,
I watch the YouTube furniture restorers with their fancy shops and great instructions on how to do things in great detail then find myself wanting to stop by with a large, long handled shovel and clean up after them.
The most frightening part is they get views in the million plus in a matter of about two weeks.
Steve.
I watch the YouTube furniture restorers with their fancy shops and great instructions on how to do things in great detail then find myself wanting to stop by with a large, long handled shovel and clean up after them.
The most frightening part is they get views in the million plus in a matter of about two weeks.
Steve.
Tom I know you've been rolling 79cc mod around your mind for quite some time and are getting a grip on how to proceed. I'm a fan of small motors & I define small as 125cc down. The industrial 100 cc and smaller size and weights are really nicely balanced for use on a bicycle frame. Going with larger multi-speed unitized transmission & clutch are tough to deal with as design elements. Same goes for the 212cc predator. I've built two of the former & seen tons of the later. I suppose the physical size of the motors is what bothers me most in my own bikes. Large power and great dependability from these larger motors though.
Over the years 5 to 8 hp motors & small dimensions have been my sweet spot for riding enjoyment, so 7 hp from 79cc sounds super to me. Agk mods seem reasonable to make hp in the 7 range and the mods you've mentioned are good too. As to choice for milling I'd say the face plate well fixtured would work as well as the mill. If I had a knee mill in house I'd probably opt for that as setup is so simple for that head on the mill table. Face plate is a bit harder to set up time wise.
Carb work by AKG seems a bit Voodo I'd op for a real Mikuni 22mm and tune it. Millions of cycle using them and they make power, all things factored in. Cost isn't horrible either. I'm certain the 79cc will have plenty of mix to work with using the Mikuni.
I believe in polishing the head chamber too. I did this on my karts and scooters and it really cuts down on coking build up. The 79cc shown in the videos cumbustion chamber is pretty rough and to smooth it will effect chamber volumne, so compression will be lowered. I offset that with taking .003" or.004" more off the head during surfacing. Not knowing the chamber dimensions I'd make certain the valve to piston clearance is ok.
Pat's heads up on the re-grind cam is something I'd trust. 18# spring setup has been the go to mod for those removing the governer and using higher rpm, floats no punk on the industrial motors & springs are great insurance on our single speed 4 stroke bikes.
Good project that I'll look forward to following.
Rick C.
Over the years 5 to 8 hp motors & small dimensions have been my sweet spot for riding enjoyment, so 7 hp from 79cc sounds super to me. Agk mods seem reasonable to make hp in the 7 range and the mods you've mentioned are good too. As to choice for milling I'd say the face plate well fixtured would work as well as the mill. If I had a knee mill in house I'd probably opt for that as setup is so simple for that head on the mill table. Face plate is a bit harder to set up time wise.
Carb work by AKG seems a bit Voodo I'd op for a real Mikuni 22mm and tune it. Millions of cycle using them and they make power, all things factored in. Cost isn't horrible either. I'm certain the 79cc will have plenty of mix to work with using the Mikuni.
I believe in polishing the head chamber too. I did this on my karts and scooters and it really cuts down on coking build up. The 79cc shown in the videos cumbustion chamber is pretty rough and to smooth it will effect chamber volumne, so compression will be lowered. I offset that with taking .003" or.004" more off the head during surfacing. Not knowing the chamber dimensions I'd make certain the valve to piston clearance is ok.
Pat's heads up on the re-grind cam is something I'd trust. 18# spring setup has been the go to mod for those removing the governer and using higher rpm, floats no punk on the industrial motors & springs are great insurance on our single speed 4 stroke bikes.
Good project that I'll look forward to following.
Rick C.
Honestly Rick, HP wise 5 is what claimed from the mods. I'm a little dubious of 7.
Shane in the stage 2 build also includes a new $$$ cam and Pat nixed that. I guess I will find out soon enough.
I am running a 19mm Mikuni clone now with Pat's intake manifold on the in frame engine .
I will certainly clean up the head chamber. I am no stranger to metal finishing. A third of my career was as a Mold Maker.
Where possible I will draw polish to enhance flow.
One thing Shane at AGK did that got my attention was his use of a counter bore to make flush the valve guides.
That and his wearing shorts while machining.
Thanks for the input Rick, anything else comes to mind, I'm all ears.
Tom
Shane in the stage 2 build also includes a new $$$ cam and Pat nixed that. I guess I will find out soon enough.
I am running a 19mm Mikuni clone now with Pat's intake manifold on the in frame engine .
I will certainly clean up the head chamber. I am no stranger to metal finishing. A third of my career was as a Mold Maker.
Where possible I will draw polish to enhance flow.
One thing Shane at AGK did that got my attention was his use of a counter bore to make flush the valve guides.
That and his wearing shorts while machining.
Thanks for the input Rick, anything else comes to mind, I'm all ears.
Tom
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Shorts while machining metal. Somehow I can imagine that would add something to the excitement.
Steve.
Steve.
No shite Steve!
When Shane is using the carbide burrs? Needles flying everywhere.
I will use a Dremel when needed, but files and scrapers for control. especially the turbulence inducing valve seat countersinks.
I totally agree about the "Long Shovel" You Tubers but we are missing the $$$ boat? Pondering whilst I ponder.
Tom
I wondered about no eye protection when using a metal grinder on a crankshaft. Two people with one to hold the length not being ground I viewed being done. In any case being retired I just try to keep from messing my spine with too much weight. The extra time using levers, pulleys, and ramp has been my way.
The vids are at least entertaining to guys that have spent lives working around and with rotating machine tools. Once I knew he was alright after the fly wheel started shedding weight; I had a good laugh. I find the billet flywheel a good looking safety necessity. and when advanced a nice performance addition too. AKG will sell flywheels as a result of this little failure of a stock flywheel. Thankfully it wasn't a complete flywheel explosion. However I was a little taken aback with the AKG videos, but I know they have a good reputation and the info was spot on if not completely forthcoming with details. I'd think valve lash setting not to be a trade secret when already revealing valve grind angles. In defense of Youtube there are many awesome how to presentations & some of the best have libraries of information available and worhwhile to study.
Tom I've had mixed success with the Mikuni clones some worked well others have been really bad. I run a clone on my Simplex 125cc Honda pushrod clone a 22mm carb & it's great & makes over 12hp. I'd think your 19mm would be fine to stay with after tuning for the new mods. Once you find a Mikuni clone that works I see no reason to spend more for the real thing. My track record with the clones is buy 3 to find one. Real Mikuni buy one and it just runs! I've encountered the same problem with Dellorto clones, but even when they run ok (clones) the real Dellorto outperforms the clones noticeably. I've not been able to determine why however.
You tool & die guys are the bomb on grinders so I just skipped over the caution of protecting valve grind work when polishing the cumbustion chamber. Ideally the chamber is cc'd prior to milling and polishing, then after polishing is completed check the chamber volumne again to determine the mill cut to correct for the increase in chamber volume and taking care to provide a safe margin for valve to head clearance. Then complete the valve grind. If they are re-grindinding cams with both increased lift and duration AND also milling .0050" from the head you have room to take a few thou more off with the mill running the stock cam Tom. At any rate I'm not a fan of high compression on a street bike past a certain point & it sounds the guys that are building these street tune motors have dialed in on the amount of head cut for all around use with reg gas.
A real high flow air cleaner (not just advertised as high flow) can give an actually increase that the rider can feel. I've been able to run richer jetting to take advantage of this often overlooked tuning tool. Read the plug and adjust accordingly: plug heat range is often off as well. This all takes time but is well worth it. Chop the plug till it runs well and the plug will read well too.Like I said in a previous post guys try to make carb tuning a sort of Voodoo ritual and it's not. It does take patience and some knowledge of practical performance theory to tune till it runs well. .Always build from a good foundation. Starting with a good carb design is just basic common sense .
Rick C.
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Tom I've had mixed success with the Mikuni clones some worked well others have been really bad. I run a clone on my Simplex 125cc Honda pushrod clone a 22mm carb & it's great & makes over 12hp. I'd think your 19mm would be fine to stay with after tuning for the new mods. Once you find a Mikuni clone that works I see no reason to spend more for the real thing. My track record with the clones is buy 3 to find one. Real Mikuni buy one and it just runs! I've encountered the same problem with Dellorto clones, but even when they run ok (clones) the real Dellorto outperforms the clones noticeably. I've not been able to determine why however.
You tool & die guys are the bomb on grinders so I just skipped over the caution of protecting valve grind work when polishing the cumbustion chamber. Ideally the chamber is cc'd prior to milling and polishing, then after polishing is completed check the chamber volumne again to determine the mill cut to correct for the increase in chamber volume and taking care to provide a safe margin for valve to head clearance. Then complete the valve grind. If they are re-grindinding cams with both increased lift and duration AND also milling .0050" from the head you have room to take a few thou more off with the mill running the stock cam Tom. At any rate I'm not a fan of high compression on a street bike past a certain point & it sounds the guys that are building these street tune motors have dialed in on the amount of head cut for all around use with reg gas.
A real high flow air cleaner (not just advertised as high flow) can give an actually increase that the rider can feel. I've been able to run richer jetting to take advantage of this often overlooked tuning tool. Read the plug and adjust accordingly: plug heat range is often off as well. This all takes time but is well worth it. Chop the plug till it runs well and the plug will read well too.Like I said in a previous post guys try to make carb tuning a sort of Voodoo ritual and it's not. It does take patience and some knowledge of practical performance theory to tune till it runs well. .Always build from a good foundation. Starting with a good carb design is just basic common sense .
Rick C.
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I appreciate the feedback Rick, small engine mechanics is not one of my specialties.
Air, fuel, and spark I get. The rest is pure voodoo to me. I should stick to diesels.
Tom
Air, fuel, and spark I get. The rest is pure voodoo to me. I should stick to diesels.
Tom
Out to the machine shop to (shred apart) disassemble top end of the 79cc Predator. Still got the two long studs to remove.
My bench vise did not have enough travel to also use two wood blocks to protect the engine case. Just as well,
I opened up the Bridgeport precision ground vise and firmly gripped the crankcase. (I already had the side cover off).
Holding the engine case firmly is needed as the flange headed head bolts do not loosen their grip easily.
Loosening the bolt is done incrementally to avoid distortion or cracking of the head.
Not so important with cast aluminum, but good practice should you ever encounter a cast iron engine head.
Once head bolts were free, time to free the rocker arm adjusting nuts. Once off, out come the rocker arms, and push rods.
Back to the bench and removed the valve assy. All parts removed to a pristine poly bin.
Thinking of doing all port and polish work before decking the head to ensure a sharp shutoff.
The combustion chamber is rustic as in sand cast texture. I will not mess with valve seats if I can help it.
Tom
My bench vise did not have enough travel to also use two wood blocks to protect the engine case. Just as well,
I opened up the Bridgeport precision ground vise and firmly gripped the crankcase. (I already had the side cover off).
Holding the engine case firmly is needed as the flange headed head bolts do not loosen their grip easily.
Loosening the bolt is done incrementally to avoid distortion or cracking of the head.
Not so important with cast aluminum, but good practice should you ever encounter a cast iron engine head.
Once head bolts were free, time to free the rocker arm adjusting nuts. Once off, out come the rocker arms, and push rods.
Back to the bench and removed the valve assy. All parts removed to a pristine poly bin.
Thinking of doing all port and polish work before decking the head to ensure a sharp shutoff.
The combustion chamber is rustic as in sand cast texture. I will not mess with valve seats if I can help it.
Tom
