So the plastic engine mount is really just for maintaining the required spacing, not securing the engine to the chassis?

It's a mount, bolts the engine to the chassis. Spacing isn't critical with the shaft system, the engine just needs to be sitting on the chassis somewhere. I'm currently on vacation away from the rc stuff BUT I'm pretty sure I'm getting that new 3d printer I wanted which should do nylon and some other high temp polymers. I really think a plastic mount will work here. It's a small on road car with a small light weight engine. Maybe off road applications wouldn't be so forgiving to a plastic mount. Hopefully we'll see soon.

Hi there, was wondering if there is anyone with experience in fitting an 40FS on an Inferno GT available to answer some basic question about the engine mount plate? Thanks.
The only information I could find here dates back to 2013...

I don't know anything about the Kyosho Inferno GT, but I can tell you it's possible to make an adapter plate from a sheet of aluminum and some standoff posts, because that's what I did to install a FS40 in my HPI Bullet. There are pictures in this thread if you scroll back a little bit.

timjs Hi it’s Ben Weaver. So if I go with the buku brass clutch option and have the crank milled down to 7mm to fit a standard collet, which clutch nut / pilot shaft would I need? Also, could you link the correct buku clutch and any other available parts please? Thank you!!

Hey man. @fyrstormer this is the route you took if I remember correctly. Got any input here?

Buku's website is still up, although no one ever really knows if theyre still in business or not. Historically, they have poor communication. You'll place an order, hear nothing for a month or two, and the parts show up on your porch one day.
http://www.bukupower.com/

Yes, that's the approach I took. I had two crankshafts machined down to 7mm, and it worked, but one of them was very tricky because the indentation on the end of one of the crankshafts was slightly off-center and couldn't be used for mounting the crankshaft in the lathe. The machinist who did the work for me ended up making a clamp that could reach around the counterweight and grab onto the part of the crankshaft where the crank bearings normally sit, and then machined-down the end of the crankshaft to 7mm. I believe for the actual machining work he used a grinding bit rather than a cutting bit, since the crankshaft is made of hardened steel.

As far as the clutch is concerned, the BuKu brass flywheel combined with the brass-backed Komposite shoes and normal-stiffness springs (NOT the heavy springs BuKu recommends for use with brass-backed shoes) gets the job done great. It's possible that an aluminum flywheel might work as long as it's still fitted with the extra mass of the brass-backed clutch shoes, to keep the engine idling stably while allowing it to rev-up a little faster due to lower rotating mass, but I haven't gotten around to actually trying that combination yet.

The BuKu flywheel should come with its own collet. I'd tell you what kind of pilot shaft I used, but I honestly don't know; I just ordered a bunch and found one that fit close enough, then ground-down the backside of the pilot nut to make it the right length for the clutch bell to mate with the clutch shoes correctly, with about a 1mm gap between the back of the clutch bell and the front of the flywheel. The general type of pilot shaft I used is the kind intended for use with an old big-block nitro engine that just has screw-threads on the end of its crankshaft. I think the one I used was made by OFNA, and may still be found on eBay if you scrounge around a bit. Kyosho also made some, if I remember correctly. In any event, cutting the pilot shaft at one or both ends to get a perfect fit is going to be necessary, so make sure you have Dremel cutting wheels handy.

When installing the BuKu flywheel, you'll want to line the back of the flywheel with sticky aluminum tape, to prevent oil that inevitably leaks out through the front crank bearing from finding its way into the clutch through the spring-adjuster slots on the flywheel, and fouling the clutch shoes. This is something that requires periodic inspection to make sure the sticky aluminum tape is still firmly adhered and oil isn't sneaking its way under the adhesive, but it's a must to make sure the clutch doesn't get contaminated.

Hey man, where ya at? How serious are you about getting this project going?

[QUOTE=Pony;15637411]Guys been reading through the thread. Lots of great info. Trying to consolidate important stuff in on post. Missing lots let me know what and will add.

FS30 To car spec
Cam OSM45762010
Valve Spring x 2 OSM45760210
Intake Manifold OSM45269400
Carb Retainer OSM21481700

Other options
Complete OS26 Head OSM44104020
Compete Valve Assy x 2 OSM45760020

FS26 to 30 size
Liner OSM43003100
Piston OSM43003200
Ring OSM43003400
Pin OSM43006000
Gasket OSM22714100

FS40 To car spec
Cam OSM45262050
Valve Spring OSM45260250
Cylinder Head OSM45204150
Exhaust Nut OSM45169200

Other options
Compete Head OSM45204050



Flywheel
Heavy steel flywheel recommended for low idle.
Option 1
OS Drive Washer OSM 45208010
Standard Flywheel
Associated Clutch Nut 2312 (Drilled and tapped to ¼-28
Option 2
Get Crankshaft ground by machinist to 7mm Then use standard collet like Associated part 7618 and standard flywheel
Option 3:
Get crankshaft ground to 7mm by machinist, then use BuKu 34mm brass flywheel and BuKu BBK shoes with standard springs.”

I have everything to do option 1. I have the os drive washer and a drilled and tapped associated clutch nut for my 40scx. My question is by “standard” flywheel, do you just mean a flywheel that isn’t tapered to use a collet? Or will a collet style flywheel still work against the drive washer?

IMO, the biggest advantage to Option 3 is being able to fine-tune the clutch engagement. Shoehorning an OS 4-stroke engine into a surface RC is such a non-standard scenario that there are basically no purpose-made clutch parts that actually work as well as a normal 2-stroke nitro engine clutch, so having a highly adjustable clutch is the next best thing. And BuKu's Komposite shoes are damn near indestructible, even if you overheat them until the clutch bell is glowing red, so the tuning curve doesn't involve wasting money on ruined parts.

[QUOTE=rcpistonhead;16028953]Hey man I got your PM prior to your post being approved. You mentioned using a lathe? If you can, that's the best method so you can make your stuff exactly how you like it. That's how I do mine. As for the flywheel you can either use a collet style to fix it to the crankshaft (ideal) or you can use a drive washer to drive the flywheel with friction. While this WILL work, be aware that this is my first setup I tried and the "D" shaped "key" on the crankshaft was not sufficient. The crank eventually just spun through the flywheel and stripped it out while starting the engine on a starter box.
Edit: This was with my O.S. .62-V engine. I dont know what type of "key" your engine uses.

I am nearly complete with my 4 stroke USA-1 conversion. Just need to finish fabricating a mount for the 35mm electric fan and I have a different exhaust I made that I will put on. Otherwise it’s almost ready for the maiden bash. I tried posting photos with this post but apparently I don’t meet the criteria require to post photos yet 🙄

Awesome man! Can't wait. If you want, post something up on YouTube and just link it here. Looking forward to this!

She’s all done. Here’s my USA-1 conversion with the FS .40 S-CX. It’s a beast and is tons of fun to drive. The 4 stroke seems to love the 3 speed trans!

Yeah, I bet the 3-speed would work really well with a 4-stroke.