Re: Mutant Manual Sachs Trike Build

so kinda like an extra snake bend in the header without having to add an extra buncha snakey bends in the header?

I know alotta moder n4 strokes use a similar pipe boner for exhaust scavenge or something, i think it works like a shitty EGR for emissions?

Re: Mutant Manual Sachs Trike Build

yeah a lot of four stroke mx bikes have gone to the 'power bomb' and 'boner' style pipes... i don't really understand the theory in depth but i think you are adding volume to the exhaust without making it longer.

I have that 70 CC dt50 parmakit with the bogus too tall exhaust port, plan is to experiment with these on that project but its hella back burner

Re: Mutant Manual Sachs Trike Build

Dig into the polini snake radiator today since I don’t want to do major work without my students.

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Found something interesting besides a dirty radiator.

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I seems between the backplate and the main body of the radiator there is a hard plastic plate. This plate seemed to have some residue from something leftover in the pattern of the snake.

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I’m wondering if that was some kind of heat transfer tape?

It looks like the design is to have deep water channels that have the heat rise up the top, and get cooled by air blowing through the spaces between the cracks in in the little cross sections.

I would definitely say a pump would not help this design cool any better because the radiator even with air blowing by still wouldn’t be cooling the water fast enough to warrant a higher waterflow(my opinion, would love to hear yours on this).

I’m wondering what the deal with this plastic is....doesn’t seem to have any special properties to transfer heat. Makes me wonder if it’s just a sealing gasket and causes the radiator to perform worse?

I’m wondering what would happen if I used thermal tape like this: Thermal Interface Products Heat Sink Thermal Tape - 3M 8810 - 80mm x 80mm (1 piece)

http://www.amazon.com/dp/B00QSHPH8E/

On both sides of the “plastic” piece.

Or perhaps replacing the plastic with just that thermal tape?

Hoping to get a small discussion on this, toss around some thoughts.

I do have a more conventional aluminum radiator I could use but if I’m cooling both the head and clutch, I’m going to do separate loops so I’ll still need two radiators.

Re: Mutant Manual Sachs Trike Build

"I’m wondering what the deal with this plastic is....doesn’t seem to have any special properties to transfer heat. Makes me wonder if it’s just a sealing gasket and causes the radiator to perform worse?"

I think you pretty well nailed it .

That thermal tape instead of the plastic might be much more efficient .

Re: Mutant Manual Sachs Trike Build

haha, i was gonna quote that same line. sealing, no heat transfer. it may be carbon bonded which would help, could have some heat transfer but i doubt it.

probably copper would be a great option except I doubt that face porvide seven enough pressure to seal anthing besides a pretty pliable plastic. On top of that maybe some sealer would work, some silicones especially the copper silicone have pretty good heat transfer.

honestly if that's the back face it probably doesnt represent that big of a % of the total heat transfer anyway, at least not while moving

Re: Mutant Manual Sachs Trike Build

> Born to be WillD Wrote:

> -------------------------------------------------------

> honestly if that's the back face it probably doesnt represent that big

> of a % of the total heat transfer anyway, at least not while moving

Or , could it be that piece of plastic is exactly what makes that particular radiator less than optimum , in most peoples view ?

Re: Mutant Manual Sachs Trike Build

I'd put the front and back together with no gasket and see ust how well the line up with each other . If the mating surfaces seem viable , I'd simply shoot them with a spray gasket , bolt the together and then run a leak test with hot water . Maybe even a bit of pressure added for good measure .

While doing that^ , hit both front and rear with a temp gun to see any difference .

Re: Mutant Manual Sachs Trike Build

DrGeorgeTompson (Alan) /

You could maybe cut a gasket out of a copper sheet. I'm willing to bet that copper spray would work if you make sure both sides are flat. There's a lot of screws on that thing

I was also thinking that plastic bit may attribute to the hate this thing got.

But yeah the upwind side is more important idk. Still kinda weird.(edited)

Re: Mutant Manual Sachs Trike Build

Unfortunately you can’t mix copper and aluminum in a water loop, get a reaction that costs the inside of the radiator and waterblock(head in this case).

My other concern is the “plastic” piece had groove protruding in the shape of the radiators loop. I’m wondering if that separates the channel from just running together through the open space. I’m not sure how well it will seal that area without the plastic.

Possibly some thing aluminum sheet could be made into a gasket?

Definitely correct thinking that the backplate offers limited cooling benefit. Nonetheless a benefit if I can make it more efficient.

The other major thing I noticed is this radiator is really only cooled by blowing through those open slots in the middle. If this radiator is mounted parallel to the frame, or right up against the underside of the tank, it won’t cool efficiently.

It’s seems between the forks or something similar is key, doing that with an efficient thermosiphon will be a PITA.

Re: Mutant Manual Sachs Trike Build

Just space it out from the frame . Maybe add a couple of collection 'fins' on the sides .

As for gasket , you might consider High Tack or possibly 1104 .

K.I.S.S. ;)

Re: Mutant Manual Sachs Trike Build

Dirty30 Dillon /

The 3M 8810 doesn't specify wet condition use, nor compression use. I think it is mostly meant to be a surface-mount adhesive for heat sink material.

Honestly, I would not mess with this much, they're cool radiators but not the most modern. After all, they were add-on units for mopeds. The biggest benefit is durability and rebuild-ability.

Re: Mutant Manual Sachs Trike Build

> Dirty30 Dillon Wrote:

> -------------------------------------------------------

> The 3M 8810 doesn't specify wet condition use, nor compression use. I

> think it is mostly meant to be a surface-mount adhesive for heat sink

> material.

>

> Honestly, I would not mess with this much, they're cool radiators but

> not the most modern. After all, they were add-on units for mopeds. The

> biggest benefit is durability and rebuild-ability.

A lot of this build is just experimentation. I won't kill myself over anything but this will be a somewhat leisurely build as I've finished most/all my other projects and main bikes.

Hoping to try some new things and share some interesting information with the community. I'll play with a few alternatives to the plastic but I'm not gonna go too crazy.

That being said I love the experimentation, even for minimal gains.

Re: Mutant Manual Sachs Trike Build

Anyone done any work with thermoelectric cooling? (Peltier). I'm wondering if it would be beneficial to slap a Peltier on the clutch side of the case before the water block and cooling that way, as opposed to the water block directly on the clutch case?

The Peltier uses 12v so that should be fine for the moped electrical; one of my concerns is if the clutch case will get too hot for the Peltier and damage or melt it. Peltier is only meant to operate up to 83C.

Thoughts? I could just slap a water block on the clutch cover and call it good but if I'm doing this I want to be efficient.

Re: Mutant Manual Sachs Trike Build

when I worked at ORNL I was involved with a DOT project investigating using vanadium dioxide ceramic thermoelectrics on engines. Basically you could run no coolant and have the waste heat converted to electricity by exploiting a vanadium phase transition, it got published - John Fairbanks was the principal investigator

Looked at a few ways to do it, in the exhaust was most efficient cuz it's alot of the heat, and in diesels it can go in the EGR.

Coolant and exhaust waste heat is responsible for like twothirds of the energy of gas. that sucks!

In the end it was decided to be too expensive for most vehicles, pay back was like 600k miles, but for trucks that's pretty achievable, just too long to be worth it. It did get some attention for cabin cooling though since AC takes a shitload of energy and if you can do it without refrigerant that is a big deal for emissions. depending on polarity you can heat or cool. cool!

I think its still active though looking at how to use the same thermoelectrics to cool down batteries and recover waste heat there. much more direct use

Anyway, it's expensive, but can work, if you have a draw for it. For the temps on a cylinder vs ambient the efficiency isn't great and you'd probably have to have it go to a resistor and just be a heat dump radiator anyway cuz it's probably more power than all the stuff on the bike can use

Re: Mutant Manual Sachs Trike Build

Finally some photos!

Students came for their first day of the after school program. We went over the inspiration and plan for the build; essentially I supply the parts and they build it with me.

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My students did an excellent job splitting the cases. I made sure to go over stripping bolts and how to tell if the bolt needs more oomph, or if you’re just gonna destroy the head.

They really enjoyed watching how the gears inside work. That pedal start setup is truly a marvel of engineering in a 505.

Additionally the aluminum water blocks for the clutch came in. I have two small 40mm ones and a larger 80mm I’d like to put across the cover. I’ll have to grind off the Sachs logo for that though.

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I’ve also decided to add an hpi to this build for easy starts. As well as the rope start adapter. I have a feeling it will be a pain to start by pedaling even on flat ground. Plus I’ve always wanted a reason for an hpi.

Bottom end should be in next week so I’m hoping we can get the engine rebuilt during the next day of “Pit Crew”. My classroom is called The PIT, thus the name.

Re: Mutant Manual Sachs Trike Build

very interested. I hope you don't get screwed up by cancellations

Re: Mutant Manual Sachs Trike Build

So far New Hampshire is of low risk, especially the North Country where we are. Hopeful we can stay open!

Started taking apart the second motor which has an old 70cc Athena kit and the original clutch which I planned on adding the extra spring to(thank you dos!).

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And wouldn’t you know it! Previous owner had already done the mod. Couldn’t believe it really. After all that work sourcing the spring, and there was already an extra. Oh well.

I did see some extra heat showing it’s face on one of the clutch discs. However, I plan on upgrading to a 7 piece not a 5.

As I continued I pulled the jug and found some more interesting.

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It would SEEM the PO ran this with no clips for the wrist pin AND no piston ring. This would maybe make sense considering the MASSIVE carbon buildup in the jug.

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Gonna split the case and figure out which lower end I want to use.

Anyone ever remove the gear connecting the pedal shaft to the rest of the engine?

Kinda wanna do that but keep the pedal for braking.

Re: Mutant Manual Sachs Trike Build

Andddd our school is closed until April 3rd (so far).

I did pick up the kx80 big wheel front end today but who knows what the plan is.

I can continue some stuff myself in the meantime if my school lets me go in.

Re: Mutant Manual Sachs Trike Build

Noticed something interesting with my two motors.

Both were 505/2b.....different main gear design though.

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Is it better to use the lighter gear?

Do we think it’s okay to mix and match internals from both of these motors?

Re: Mutant Manual Sachs Trike Build

DrGeorgeTompson (Alan) /

Mine has a holy gear and it vibrates a bunch. I don't know if that is related. Mopeds

Re: Mutant Manual Sachs Trike Build

> DrGeorgeTompson (Alan) Wrote:

> -------------------------------------------------------

> Mine has a holy gear and it vibrates a bunch. I don't know if that is

> related. Mopeds

coworker mentioned it might lubricate better with the hole-y gear? I think that's reasonable to say....that being said your statement does make me more hesitant to use that one, if it was easier to swap them I'd test each one.

I'll definitely pull and weigh the gears though, see if there's a big difference.

I'd also be curious if the solid one is stronger.

Re: Mutant Manual Sachs Trike Build

So....unfortunately this build has taken a bit of a turn; beyond just not having students at school.

The shop that I paid back in November for the Sachs frame and Trike rear had never shipped; things got a bit crazy and the whole ridiculous thing ended in me getting a refund. I suppose it could have been worse.

Anyhow that kind of killed the flavor of the build. I was at a loss for what to do, finding that rear end was already hard enough; plus finding another person who would be willing to ship it to me, no chance.

Thinking about what I have and what I was building I decided I'll just replace the trike rear with a "dirtped" type setup from the kx80 parts I bought.

It's always frustrating that the fall and spring around here can be finicky with weather(-20 degrees - 50 degrees). The roads are often too wet or sandy to safely ride with a regular moped. I'm hoping the enduro style tires will help with that. Plus having a bike I'm comfortable tossing around.

I'm still planning on doing all the same watercooling, although now I'll have to run antifreeze which sucks.

The 19" big wheel front end should be interesting.

I want to give a massive shoutout to Dos Cycles who have been saving my ass here all along. In addition to all the other small and large parts they've had in stock so far, they are providing me with a usable frame and spare stock rear end; just in case I can't get the kx80 rear wheel to setup properly.

Hoping the engine internals come soon so I can get that all wrapped up. Been spending time cleaning the inside of the cases.

Build it once, build it right.

Re: Mutant Manual Sachs Trike Build

bummer city

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