Building a Ht Motorized Bicycle or Three.
- Thread starter Theon
- Start date
Not sure you need a two stage baffle, but a two stage diffuser is worth considering,
mine was giving me a minor band in the mid and a second hard hitting band around 8000.
Then I belive a couple of inches of belly helps to broaden those bands.
The 30 deg baffle does make awesome power.
mine was giving me a minor band in the mid and a second hard hitting band around 8000.
Then I belive a couple of inches of belly helps to broaden those bands.
The 30 deg baffle does make awesome power.
Been having trouble trying to get photos up?
Think it's working now.
Sorry Dave I answered your last post, and I got called in to feed kids, ect and I took to long and it wouldn't accept my post.
Think it's working now.
Sorry Dave I answered your last post, and I got called in to feed kids, ect and I took to long and it wouldn't accept my post.
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Well I see you must have read Graham Bell's tuning guide.. If I remember right, he did mention that thing about the baffles in there. If you're looking for a certain powerband, the best way to do it is by slip fitting the baffle to the belly so you can adjust the distance of the baffle as well as swap out baffles set at different angles or even try some single stage/2 stage/3 stage or whatever that you think might work (still gotta do the math to get you in the ballpark) for your setup, then once you get one that hits right where you want it to, just simply weld it in, but if you want to multi purpose your engine for whatever reason you could always weld in a V band at the end of your belly so you can have the hard hitting narrow band baffle for racing and the more mild mannered "good all around" baffle for everyday use.
Typically doing the math and welding up a pipe will work, but every engine is slightly different and you can usually squeeze a little more power out or even widen the powerband a bit more by experimenting and fine tuning.
Oncce I get my other engine up and running I may do just that, weld up a pipe with v band fittings at the belly so I can change the belly length and baffle angles quickly and easily until I get it right where I want it, then make a copy of what works best for that particular engine, then I will have the v banded pipe for experimenting with and fine tuning future engine builds.
By the way, your piston and boost ports look good
Typically doing the math and welding up a pipe will work, but every engine is slightly different and you can usually squeeze a little more power out or even widen the powerband a bit more by experimenting and fine tuning.
Oncce I get my other engine up and running I may do just that, weld up a pipe with v band fittings at the belly so I can change the belly length and baffle angles quickly and easily until I get it right where I want it, then make a copy of what works best for that particular engine, then I will have the v banded pipe for experimenting with and fine tuning future engine builds.
By the way, your piston and boost ports look good
sorry dave and thanks for the reply. cheers
im pretty happy w what i have. nice entry and pull at 3600- 8000 w a straight pipe torque from idle to 2900. i have been having a blast. i have 6 hours on my jug allready.
seems theons got a nice motor! are u excited?
im pretty happy w what i have. nice entry and pull at 3600- 8000 w a straight pipe torque from idle to 2900. i have been having a blast. i have 6 hours on my jug allready.
seems theons got a nice motor! are u excited?
The new reed block I got from RSE last week for the Goat, after cutting my first one for the Mongoose is WRONG!.
The holes for the reed are at 30mm spacing, the old one had 32mm., This allowed near any walbro carb to bolt straight up as it does on any Model Aircraft reed block.
After trying all week to ring him, to see if it was just a stuff up. He pretended not to know what I was talking about for awhile, then told me he was using a different reed now and that was the new hole pattern and they were all like that?
It looks as though best option would be a couple of helicoils, but I don't yet have a 5mm kit.
I quite like the guy, but have been warned regarding his honesty.
It pisses me off because he knew what I was wanting to do with it when he sold t to me for $50, Just the block, with no mention of new reeds!
I may try filling the hole with JB and re tapping.
Otherwise the Goat Motor is ready to go together!
I tried to get a 5mm helicoil kit locally yesterday with no luck. I'd say it will be JB.
The holes for the reed are at 30mm spacing, the old one had 32mm., This allowed near any walbro carb to bolt straight up as it does on any Model Aircraft reed block.
After trying all week to ring him, to see if it was just a stuff up. He pretended not to know what I was talking about for awhile, then told me he was using a different reed now and that was the new hole pattern and they were all like that?
It looks as though best option would be a couple of helicoils, but I don't yet have a 5mm kit.
I quite like the guy, but have been warned regarding his honesty.
It pisses me off because he knew what I was wanting to do with it when he sold t to me for $50, Just the block, with no mention of new reeds!
I may try filling the hole with JB and re tapping.
Otherwise the Goat Motor is ready to go together!
I tried to get a 5mm helicoil kit locally yesterday with no luck. I'd say it will be JB.
The Goat is going!
It hammers! She's fast and loud. I have no muffler as yet on her but it will be needed.
I 've got great power all the way through the range, lacking a little just off idle but that's the price you probably have to pay for a strong kick above 7000 and pulling strong to just off 9000. I did get a little over 9k but power was starting to fade and I built this one for mid range.
I'm running a 44t sprocket, so she pulls hard and was scary fast offroad with multiple power bands.
A bit of vibration around 6000 unfortunately but bearable, smooth enough everywhere else.
Will try a few different rotors on her for different timing, and will have to give her a muffler, will also have to try her on the 36t sprocket and road tires!
It hammers! She's fast and loud. I have no muffler as yet on her but it will be needed.
I 've got great power all the way through the range, lacking a little just off idle but that's the price you probably have to pay for a strong kick above 7000 and pulling strong to just off 9000. I did get a little over 9k but power was starting to fade and I built this one for mid range.
I'm running a 44t sprocket, so she pulls hard and was scary fast offroad with multiple power bands.
A bit of vibration around 6000 unfortunately but bearable, smooth enough everywhere else.
Will try a few different rotors on her for different timing, and will have to give her a muffler, will also have to try her on the 36t sprocket and road tires!
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That thing looks Great!! if it runs as mean as it looks then you're doing good... Nice job on the auto tensioner too! Are you running that DLE 60 reed in that one? If you got a way to shoot a video, you should post one so we can hear it before you put on a muffler...
It does sound cool,
Will see what I can do for a vid, my camera might do it?
Still running the 55 reed. Havn't ordered a 60, not sure it will fit.
If I do a vid how do I put it up?
Will see what I can do for a vid, my camera might do it?
Still running the 55 reed. Havn't ordered a 60, not sure it will fit.
If I do a vid how do I put it up?
I just made a youtube account and uploaded it to there then posted the link in here... i took my vid with my phone camera and it did just fine... I'll need a better camera or a really safe way to mount my phone to the bike to take riding vids later tho... If you got a phone with a camera, most of them can do decent videos. Mine is a Samsung galaxy S5, but my old S2 did really good too then I just upload to youtube straight from the phone, but it uploads faster from the computer.
That's some good performance from the 55 reed... When I saw it on JNM's site I was thinking that reed would be too small to hit those kind of rpm's and still have good power. Now I'm tempted to get an RSE reed setup... do you think that reed box could be converted to case inducted fairly easily? or should I stick to the plan and make my own for the case inducted engine?
The RSE block would likely house a DLE60 reed in a case inducted set up.
It,s a neat looking block and what I've used for my case inducted project.
I wondered if the standard plastic block could be used?
I didn't notice any lack of top end that I would have expected from a piston port motor,
But a lot smoother low down than other motors of lower performance.
It,s a neat looking block and what I've used for my case inducted project.
I wondered if the standard plastic block could be used?
I didn't notice any lack of top end that I would have expected from a piston port motor,
But a lot smoother low down than other motors of lower performance.
Cool... yeah, usually if the reed is the right size it shouldn't affect the top but enhance the bottom...
I'm still planning on using the plastic block and making an adapter from the block to the case for mine as it's a very compact setup that way, even filling in between the bolt bosses behind the cylinder with the JB weld should work with the plastic block. The bolt holes for the plastic block are on the long sides tho so I may grind those holes off and make an adapter to sandwich the block into place. I did make a really simple adapter to connect the reed block to the intake and use a Tilly carb out of a 1/2" thick aluminum plate which I may try on the new piston port engine to see if it makes any difference.
Right now that engine is almost ready to roll and I got my new PW80 carb installed the other night, didn't have Any time this weekend to fill up the tank and fire it up with the new carb but I did work out a few more bugs that are keeping me from riding it like tack welding the front mount bracket and coming up with a way to secure the new pipe to the frame etc... I'll still need to pull the engine one more time to finish welding the front mount in but can get that done in a few hours when I get time again...lol
I also ordered an air filter boot for the new carb since the PW80 boot has a nice 90 degree bend right at the carb so I'll have room to put an air filter on. Right now there's no room between the frame and the carb to put a filter so I'm glad I found that piece. If I do end up getting an RSE reed box I'll have to make my own carb adapter so I can run the carb at an angle to miss the frame but it sounds like a good idea still.
I'm still planning on using the plastic block and making an adapter from the block to the case for mine as it's a very compact setup that way, even filling in between the bolt bosses behind the cylinder with the JB weld should work with the plastic block. The bolt holes for the plastic block are on the long sides tho so I may grind those holes off and make an adapter to sandwich the block into place. I did make a really simple adapter to connect the reed block to the intake and use a Tilly carb out of a 1/2" thick aluminum plate which I may try on the new piston port engine to see if it makes any difference.
Right now that engine is almost ready to roll and I got my new PW80 carb installed the other night, didn't have Any time this weekend to fill up the tank and fire it up with the new carb but I did work out a few more bugs that are keeping me from riding it like tack welding the front mount bracket and coming up with a way to secure the new pipe to the frame etc... I'll still need to pull the engine one more time to finish welding the front mount in but can get that done in a few hours when I get time again...lol
I also ordered an air filter boot for the new carb since the PW80 boot has a nice 90 degree bend right at the carb so I'll have room to put an air filter on. Right now there's no room between the frame and the carb to put a filter so I'm glad I found that piece. If I do end up getting an RSE reed box I'll have to make my own carb adapter so I can run the carb at an angle to miss the frame but it sounds like a good idea still.
Ok, I had to do it before going to bed, I put some gas back in the tank and tried out the new carb, it started up on the first pull and once the idle speed and mix was set up it idles soooo much better now and it revs out really nice too 
I'm happy with that so now I need to hurry up and finish welding up my mount brackets and make up a bracket or 3 to keep my new pipe in place... Damn I wanna ride this thing again... everything is starting to come into place so well now.
I'm happy with that so now I need to hurry up and finish welding up my mount brackets and make up a bracket or 3 to keep my new pipe in place... Damn I wanna ride this thing again... everything is starting to come into place so well now.
theon thats a beauty. the seat is holding it back two notches
» pipe is smooth poor elbow.
»wich fork?
»u did a adj plate mag? good good
»that is a different reed block than the americans buyer beware.
»theon the rings are not sealed yet. put 1 to 10 hours on it for breakin or blowby will be expected till seating. light load gentle throttle hand.... but its ur choice anyway.
i love the chain roller but please get a skateboard roller and swap it it for great happyness
» pipe is smooth poor elbow.
»wich fork?
»u did a adj plate mag? good good
»that is a different reed block than the americans buyer beware.
»theon the rings are not sealed yet. put 1 to 10 hours on it for breakin or blowby will be expected till seating. light load gentle throttle hand.... but its ur choice anyway.
i love the chain roller but please get a skateboard roller and swap it it for great happyness
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I have the 44t on for off road, It requires only short blasts! and has good compression braking.
The seat is old, but comfortable.
Not adjustable mag, that's where my deg wheel attaches.
RSE's more common reed block is a smaller 2 petal with a DLE30 reed.
This one seems a good size for this motor, not looking for more than 9000 RPM.
The rings, piston, and barrel are already half worn in, I gave the barrel a light scratch up, yet to do a compression check, but feels right.
Too wet to ride today and about time to go to work.
Only given her a few short bursts of High Rev WOT. and yet to fine tune the carb, still running her slightly rich. I like the popping!
She really comes on song sometime a bit above 6000 and vibrates a little at 6.
But pulls nicely along the trail all through the lower revs with a smooth power delivery till you hit 6500/7000 then she has a typical dirt bike powerband till 9K.
The seat is old, but comfortable.
Not adjustable mag, that's where my deg wheel attaches.
RSE's more common reed block is a smaller 2 petal with a DLE30 reed.
This one seems a good size for this motor, not looking for more than 9000 RPM.
The rings, piston, and barrel are already half worn in, I gave the barrel a light scratch up, yet to do a compression check, but feels right.
Too wet to ride today and about time to go to work.
Only given her a few short bursts of High Rev WOT. and yet to fine tune the carb, still running her slightly rich. I like the popping!
She really comes on song sometime a bit above 6000 and vibrates a little at 6.
But pulls nicely along the trail all through the lower revs with a smooth power delivery till you hit 6500/7000 then she has a typical dirt bike powerband till 9K.
Compression test gives me 160 PSI. Was hoping for 150-155 PSI. Close enough.
Have stuck a temporary muffler on her in the shape of an old standard pipe slipped to the end of my expansion chamber, much more socially acceptable.
The idle is a bit finicky and wants to idle high like a real race motor, figure I may have to reshape the tip of my needle a little.
I have a spare needle to play with.
After taking it for a ride with the temporary muffler it still goes hard and the noise is very acceptable. The motor still reached 9000 OK, but spat the slip on muffler fairly quickly.
Have the twin pipes apart to stuff, and will run with them.
Have stuck a temporary muffler on her in the shape of an old standard pipe slipped to the end of my expansion chamber, much more socially acceptable.
The idle is a bit finicky and wants to idle high like a real race motor, figure I may have to reshape the tip of my needle a little.
I have a spare needle to play with.
After taking it for a ride with the temporary muffler it still goes hard and the noise is very acceptable. The motor still reached 9000 OK, but spat the slip on muffler fairly quickly.
Have the twin pipes apart to stuff, and will run with them.
So the mufflers have cost me a bit of top end, but may just need to lean the carb out a fraction more?
Still got the vibes around 6000 which is a bit disappointing, don't think I'll get another RSE crank for my case induced motor.
I really want a Screaming Roo crank for the Mongoose, Dino claims to have had his motor to around 12000 RPM and still balanced?
He won't sell me a bottom end, as he says the top end weight is to critical to his 'perfect' balance.
So then looking at $300 for a motor, which I can't justify ATM.
Will have to keep going with the crank I have for now.
Still got the vibes around 6000 which is a bit disappointing, don't think I'll get another RSE crank for my case induced motor.
I really want a Screaming Roo crank for the Mongoose, Dino claims to have had his motor to around 12000 RPM and still balanced?
He won't sell me a bottom end, as he says the top end weight is to critical to his 'perfect' balance.
So then looking at $300 for a motor, which I can't justify ATM.
Will have to keep going with the crank I have for now.
