billet rods for the 2.8 Doodlebug and Briggs 3hp engines
you sed your cousen is working on the 2.5 and 2.8 hp predator engines and you woold be working on the 3hp. and i just noticed that the website afordable go karts is selling a ton of preformance parts for the 79cc and 99cc preditor engines but still no billet rods. they are selling a 79cc hopped up preditor and it mentiond using a billet flywheel but they didn't list it to sell separatly. maybe you can find a way to get some of those flywheels for your builds. and when your done with the rods, with AGK stocking all sorts of parts for these engines they may be willing to buy a bunch from you, so you shoold contact them.
Seems like a lot of expense and R&D for such a limited HP engine to me, I've never run a governor on a 3hp briggs due to the way I set up the throttles but never made enough revs to float the valves. I maybe see justification for the rods on the little predators but as you found out first hand the flywheel seems to be the big concern on the baby clone engines. Billet rods and flywheels just go together when we talk excessive revs on any small engine really. Also I wonder if the minibikes you are running are just too small for a good old briggs fiver or you are just intent on making the small engines not grenade under excessive loads. As far as the 2.8 lifan it seems an exercise in futility given all the other problems they are plagued with. I've sold parts off them to aid in a member getting one running for a kid, even gave a few parts and one complete 2.8 away. Too light to use as boat anchors so I figured parting em out was best plus it generated income. I've never seen a well performing 2.8 but that don't mean there have never been any. I watched my kids kill three after 6 hour days of riding normally and two were new. My Daughter now runs a 3hp briggs ungoverned on her DB and it's on it's fourth season of hard riding so I'm all for trying to build a hot little 3hp myself.
I found a small generator on big trash day on the side of the road powered by a 3.5hp briggs with weird intake/carb and weirder muffler, I opened it up and found that it had an aluminum flywheel on the horizontal shaft mill so I kept it. I want to get a camshaft custom ground for more lift and duration and cut the eyebrows and port the head. I have a nice OHV 5.5 briggs carb and 5hp briggs bowl type carb composite intake and will make as big a pipe as possible. My goal is more RPMs and HP with the less rotating mass the flywheel would provide. I also plan stiffer valve springs if I can source some. My reason is that I have a Stellar which is limited in engine height, I have a 1970 3hp with tons of compression that is a candidate but I have several 3.5hp mills I could use which flow better already. I will build a better 3-3.5hp briggs and I plan for it to rev past 5k wit the mods I am looking into, a rod with a less brittle dipper would be smart to use though. I'll watch what happens with your setup and decide which direction to go with mine. At least someone is trying to improve the small clone performance.
I found a small generator on big trash day on the side of the road powered by a 3.5hp briggs with weird intake/carb and weirder muffler, I opened it up and found that it had an aluminum flywheel on the horizontal shaft mill so I kept it. I want to get a camshaft custom ground for more lift and duration and cut the eyebrows and port the head. I have a nice OHV 5.5 briggs carb and 5hp briggs bowl type carb composite intake and will make as big a pipe as possible. My goal is more RPMs and HP with the less rotating mass the flywheel would provide. I also plan stiffer valve springs if I can source some. My reason is that I have a Stellar which is limited in engine height, I have a 1970 3hp with tons of compression that is a candidate but I have several 3.5hp mills I could use which flow better already. I will build a better 3-3.5hp briggs and I plan for it to rev past 5k wit the mods I am looking into, a rod with a less brittle dipper would be smart to use though. I'll watch what happens with your setup and decide which direction to go with mine. At least someone is trying to improve the small clone performance.
I know it seams like a lot of money but I'm just having fun ant thought I would share. Plus making parts for the small engines have always been talked about but never done. Next I'm working on a billet flywheel for the clones and a billet rod for the 3-3.5 Briggs. I'm 39yrs old and been building engines sense I was 10 and there had been a lot of things I would have to like seen happen. Now that my 12yr old has the same love for building that I had I got back into it along with a cousin of mine and we are trying to make it happen. I'm more of a moped/70's twin cylinder motorcycle freak and my son and cousin are the mini bike freaks. We are just having fun. So yes this is stupid to some but it's still mini bikes......
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Any updates to this stuff? Also since you have been looking into the rods etc, Just how doable would it be to use an actual billet rod as a sample to copy :shrug: I have an actual billet HS40 connecting rod that is NOS, I am going to verify if it will clear or not in a late model powersport H35/H40 this week. If it does in theory it would work in an HS40-50 and The powersport H35/40 and have the dipper in the correct location unlike the ARC rod is. I know the arc wont clear the case on a H35 but this rod appears to not be as chunky as the ARC on the the endcap.
A rod could be copied or made like the stock rod. I have a good friend that has a machine that can copy a part to get dimensions then he makes them from that. I have been busy lately with building up my Mopeds and spring cleaning but do have a 3hp Briggs rod to send him. What rod is it that you really want? Have a stock one already out?
This is the rod I have:
Its intended for the Tecumseh HS40, Tecumseh used it in all HS40's, HS50's and starting in the mid 80's some smaller HP "H" engines as well (the "H" cases did not have a clearance hump in the front of the case though like the HS engines did so thats why I need to verify this week when I have a 1994 H35 torn down for rebuild. I know that is an issue with the ARC made rod with straight down oil dipper that people use, but it is a bit larger on the bottom, this one is very close in size to the stock rod though so it may possibly work in that engine too. If that was the case It would be compatible with alot of engines, from 1968-200? whenever Tecumseh finally stopped production/went under.
I really need to start working on the engine I have that rod for soon, just started thinking its going to get lost forever once its installed in something so maybe if its machine copy-able or something like that maybe it should be done now. I wont even pretend to know what it would entail to make an actual rod thats going to be safer and stronger than the stock, the rod itself does not look too intricate, but to get the mating surface for the cap done :shrug: This I beam rod is weighing in at the same weight as the stocker 94 grams
Its intended for the Tecumseh HS40, Tecumseh used it in all HS40's, HS50's and starting in the mid 80's some smaller HP "H" engines as well (the "H" cases did not have a clearance hump in the front of the case though like the HS engines did so thats why I need to verify this week when I have a 1994 H35 torn down for rebuild. I know that is an issue with the ARC made rod with straight down oil dipper that people use, but it is a bit larger on the bottom, this one is very close in size to the stock rod though so it may possibly work in that engine too. If that was the case It would be compatible with alot of engines, from 1968-200? whenever Tecumseh finally stopped production/went under.
I really need to start working on the engine I have that rod for soon, just started thinking its going to get lost forever once its installed in something so maybe if its machine copy-able or something like that maybe it should be done now. I wont even pretend to know what it would entail to make an actual rod thats going to be safer and stronger than the stock, the rod itself does not look too intricate, but to get the mating surface for the cap done :shrug: This I beam rod is weighing in at the same weight as the stocker 94 grams
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