Supercharged 5hp Briggs Setup!

#22
I would think when you start to making some real boost in one of these little guys you would maybe need to machine a fire ring.
The VG 460 might be a good candidate for this.
By "fire ring", do you mean a literal fire ring like on a shoveled or panhead, or machining for an O-ring?
 

65ShelbyClone

Well-Known Member
#26
The stock gaskets and bolts would probably be fine for some serious power levels. I'd rather push out a gasket than run over a crankshaft.

Yeah, just a little over! But... I wonder how far you could get by underdriving the SC in a situation like that? There has to be a limit I'm sure.
I had the blower ratios figured for that engine a while ago. The 500 would have to be underdriven about 4.0:1 to make 10psi. Rotor leakage would be a bigger factor at such low speeds, but probably still work. My GX340 would only need a 1.75:1 underdrive by comparison.
 

delray

Well-Known Member
#27
The stock gaskets and bolts would probably be fine for some serious power levels. I'd rather push out a gasket than run over a crankshaft.
.
really, you can run over the crank. even with a billet crank? kind of had to believe. especially with big block GX honda. that's a lot to snap off.
 
#29
The stock gaskets and bolts would probably be fine for some serious power levels. I'd rather push out a gasket than run over a crankshaft.



I had the blower ratios figured for that engine a while ago. The 500 would have to be underdriven about 4.0:1 to make 10psi. Rotor leakage would be a bigger factor at such low speeds, but probably still work. My GX340 would only need a 1.75:1 underdrive by comparison.
Great info, thanks!
 
#30
What's with all the bench racing here? If you have built something, post it up in your own thread, otherwise, how about giving this young man his just due for a cool project?

I look forward to hearing an update @fallendiesels once you put a load to it!

 

delray

Well-Known Member
#31
Nice!
I’ve not done a lot with small engines, mainly Harley stuff... so when I hear “fire ring” this is what comes to mind:

View attachment 237858
yes, I have seen off set cylinder sleeves has a fire ring on small engines before.
information I posted on fire-rings also applies to fallendiesels project if you start to experience head gasket problems.
goodluck on your project. it will be interesting to see the final outcome...….
 

65ShelbyClone

Well-Known Member
#33
really, you can run over the crank. even with a billet crank? kind of had to believe. especially with big block GX honda. that's a lot to snap off.
It was a figure of speech meaning I'd rather pop a $5 gasket than break expensive hardware, although it has been known to actually happen.
 
#34
A local buddy is doing a Hansened Raptor right now. Plenum volume is really needed on a single or the fluctuations sap all the boost. Always pumping, drawing 1/4 of the time, ish.

I did a bottom end for Aussies that run 100cc and an AMR300 at over 120mph in a bike, air cooled 2v hemi chamber.

A wide band and EGT, with a nice Tilly seems the best for making it live while exploring the limits.
Dipper oiling, ugh. Generac may be a better SB base?

GL on it, regardless.
 

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