There She Blows

[bob58o]

I hope M10 x 1.25 x 15mm will work.

 

[bob58o]

And what do y’all think about carb size?

My plan was to use a 30mm (which I have) with the blower, but had a 21 or 22mm on this engine when running NA. I probably have a 24mm around here somewhere. They are all basically the same carb with different sized Venturis bored though.

 

[Denny]

30mm is too big. As it is it will be laggy with all the long runs of tubing.

 

[bob58o]

With the micrometer, 1.1877” to 1.1881”

It will take a bit of practice to refamiliarize with the mic, but the crankshaft seems to be acceptable.

 

[ptracker12]

Thanks for the photo's. Looks like the catch can collects from a fitting where the governor was. Just like you said! I would close off the crankcase fittings and run the catch can from the valve cover. Once your up and running and doing your tuning you can go from there. Obviously your going to have more pressure in the crankcase with a blower. This is just my conjecture from applying big engine stuff to a small engine. I could be fairly close or completely out to lunch.
If the engine isn't running lean you shouldn't have problems with burned exhaust valves. Just get your carb jetting to a correct ratio. I would start with a larger jet that's to rich and work down from there. A richer mixture causes a slower burn and cooler exhaust. Particularly important with an air cooled engine. This build is really out there, so it's going to be try this and try that until it all works. Right up my alley!

To maybe give you a better idea, on supercharged drag engines i would weld in a bung on a exhaust header collector at an angle facing away from the source of the exhaust, then connect that to one of the valve covers. The other valve cover would have no vent. No other ventalation in the crankcase. This would be a V8 of course. The movement of the air past the bung in the exhaust header would create a vacuum for the crankcase. Kind of like if you have a smoker in the car and you open a window, you can see the smoke being pulled out. Anyway, that would be all that was necessary.
Later they would run one vent from a valve cover to a vacuum pump and into the intake manifold. Cleaner and less emissions.

 

[bob58o]

I see Red Beard just published a 440cc draw through.

 

[bob58o]

My POS ring compressor tool doesn’t seem to do the job anymore. Anybody use one of these fancy ones? Now that I ordered it, I’m wondering if it will work with my head studs. I was hoping to not remove them, but after flex honing, there’s probably a bunch of nastiest in there? I’m sure I used some loc-tite.

2.756”

 

[BrownStainRacing]

My POS ring compressor tool doesn’t seem to do the job anymore. Anybody use one of these fancy ones? Now that I ordered it, I’m wondering if it will work with my head studs. I was hoping to not remove them, but after flex honing, there’s probably a bunch of nastiest in there? I’m sure I used some loc-tite.

2.756”

They work better then those ratchet types.

I've got 68mm and 70mm for the honda/clone engines.

If you used loc tite, jus heat the studs with a small torch to melt the loc tite.

 

[bob58o]

Well PB blaster, a torch, a few pullers with clamps with a pipe wrench… I don’t think the supercharger pulley budged and now it’s damaged.

There’s a key in there. Maybe there’s a trick to getting this off.

Im ready to try to cut it off. I figure I might be able to use the dremel. Maybe an oscillating multi-tool. I’ve never used the one I have and not sure if they make a tool to cut through a pulley.

 

[Denny]

That pulley needs to be pressed off like a power steering pump pulley.

 

[Master Hack]

My POS ring compressor tool doesn’t seem to do the job anymore. Anybody use one of these fancy ones? Now that I ordered it, I’m wondering if it will work with my head studs. I was hoping to not remove them, but after flex honing, there’s probably a bunch of nastiest in there? I’m sure I used some loc-tite.

Those are the best!

 

[bob58o]

Luckily, my gardening skills are just as bad as all my other skills.

I think my timing was off. I’ll see if the salsa garden sets fruit in the heat of August on my south facing balcony.

The Roma tomatoes seem to be doing ok. A few fruits going, a few flowers, so now I got it partially shaded.

The habanero and jalapeño are small and just started to bloom.

The onions are from seed and seem to be doing ok. I harvested some onion greens for a macaroni salad a few weeks ago.

The garlic was cloves from the grocery store. I put them in the fridge for a few months then planted them this spring. They did ok, then seemed to stall out. Leaves browning and thin stems.

Cilantro hasn’t sprouted yet.

 

[Denny]

What do you think we are, gokarts and gardening? Seriously though, nice garden.

 

[BaconBitRacing]

Hey Bob, do you make fresh salsa? If ya do I need some! Salsa is the best…

 

[bob58o]

Better Bikes and Gardens…

I’ve never made salsa before.

Also have never grown a tomato, a hot pepper, an onion, a garlic, or a cilantro.

Because this engine eats so much O2 in pieces on my floor, the garden is needed to replenish the atmosphere.

 

[bob58o]

So I watched Red Beard’s suck through supercharger video.

What stuck out to me?…

His talk about slide-style carbs getting the slides stuck because of the pressure/vacuum.

His idea was that a butterfly valve style of carb would be better option.

I believe I read about problems with those as well. Maybe the plate (butterfly vane thing) actually bending. I can’t remember these things. I’m old.

Perhaps a GX390 carb would work? I’ve used a 390 carb on a 212 before

 

[bob58o]

I think a standard gx390 carb is 21ish mm.

Perhaps if a butterfly carb is better, I need to learn more about motorcycle or lawn tractor carbs.

Otherwise I might need to relearn the air circuits on stock style carbs and see what kind of adapters would be needed for one.

Carburetor, 24mm Bored 3-Circuit Carb for GX390 & 420/440/460 Clones

We specialize in Honda GX120, GX160, GX200 and 6.5 Clone Performance for Karting, 1/4 Midget, Mini Bike, Mokai, Winch Boarding, Tractor Pulling, and Bar Stool Applications. Championship winning motors for QMA, USAC, BSP, AKRA, WKA, & ASN

www.nrracing.com

 

[bob58o]

While looking at the carb options and seeing the methanol ones, I remembered to start considering compression ratio.

After milling 0.035” off the head for an 18.4cc chamber and using the +0.020” connecting rod, the CR with a 0.040” gasket will still be around 10.4 : 1

Since the pulleys might deliver 11 psi of boost and the intake temps will be hot, I’m thinking alcohol is the answer.

 

[Denny]

Just remember you have to flow 2x as much methanol as gasoline to make a little less power. Methanol is also more highly corrosive than ethanol. And that stuff eats fuel lines and aluminum like nobody’s business. When I drag raced wi would have to flush the lines and tank with gasoline at the end of the day and still it ate stuff up.

 

[bob58o]

I guess I could try E85 since it’s widely available near me. The devil you know…

I’ll have to review what I looked at before concerning dynamic compression ratio and my cam choice. I know I used some calculators in the past but I think I had to use a best guess for the intake valve closing event timing.

Some calculators ask for 0.050” event timing.

I had been using 71 degrees After Bottom Dead Center as intake closing but don’t remember what calculator I was using.

280 lift
220 duration
104 intake centerline
111 lobe separation angle

The 280-0411 cam is a custom cam. I believe you can just rotate the gear to make the 102 intake centerline or a 106 intake centerline into a 104 intake centerline.

So I guess my cam splits the difference between the two standard 280 cam options