Need Measurement of a 6/1 'Roid

[quinnf]

Howdy,

Last February, I loaded Old Silver, the St-5 and the engine bed into my trusty '89 Toyota p/u and drove everything up to the wife's place in Gig Harbor, WA at 25 mpg!  I had installed AirLift airbags earlier for the trip and I've gotta say having the extra support in the back end made the truck drive like it was on rails.  Silver had been disassembled into crates since I had other projects going on that had to take precedence. 

Last visit to the wife's place, I got Silver put together and running (what a glorious sound it makes!), so I'm working on a starter.  I have a couple Gast 4AMs as well as a Toyota starter that I can use.  But in laying out the starter mount from 1100 miles away, I found that I need one measurement before I build it.

With a 6/1 sitting on a level surface, can anyone tell me what is the clearance between the bottom of the flywheel and that surface?  In other words, how much clearance there is between the flywheel and the flat surface the engine is sitting on.  As I recall, it's about an inch or two.

Thanks,

Quinn

[sailawayrb]

Hi Quinn,

I will check tonight after work.  However, judging by photo, I would guess it's closer to 1/2 inch.

Bob B.

[quinnf]

Thanks, Bob, I'd appreciate it.  I had fun unloading the stuff with a chain hoist from the back  of the truck.  Worked like a charm.  Give me a lever and I can move the world, and all that.  But after spending a couple of hours out there moving stuff around (remember this was February) I noticed that everything in the open garage had become coated with a thin layer of condensed water from my breath.  It was about freezing at the time.  Made me think expecting a soft rubber drive roller to get any purchase on the cold flywheel rim might be more than the coefficient of friction of 20A neoprene against wet cast iron at 0C might allow.  But I'll give it a try and see where I end up. 

q.

[Tom Reed]

Got 3/4" on mine.

[quinnf]

Tom,

Thanks for that.  Now I can make my drawing and calculate dimensions. 

Quinn

[sailawayrb]

Confirmed...0.75" with my 23.5" flywheels...and don't forget to account for the belt thickness if your design uses belt...

Bob B.

[quinnf]

Thanks, Bob.  Yes, it will.  I'm thinking I might have the drive roller bear on the belt to get better traction.  A year ago or so Surplus Center had starter generators and A/C clutches for cheap.  Sort of wish I had picked one up, but I had other irons in the fire at the time and didn't know when I'd be able to get back to the 'roid.  

I'm sort of having a hard time deciding which way to go.  I'm going to use pneumatic cylinders to actuate the decompressor and fuel rack closer, and engage the starter, so it seemed only natural that I should also drive an air starter with the compressed air.  However, I installed a glow plug for the times when temps drop below freezing and will be controlling it and the pneumatics with relays and solenoids, which will involve a battery, so it also seems only natural to use the Toyota starter, which will provide oodles of starting torque even in the cold, so I'm having a hard time making up my mind which way to go.  The air starter sounds great and has a cool factor that an electric starter just can't approach.  But the electric starter is more powerful and probably more reliable and capable of repeated start attempts . . .

[sailawayrb]

Yes indeed, design decisions and tradeoffs often go hand-in-hand...  I think once you commit to needing a battery in your design, an electric starter is the better choice.

I elected to go with an approach that would allow starting and also automatically shutting down in an emergency without needing any electrical power whatsoever.  I handled all my relay/solenoid logic (i.e., for monitoring gauges, emergency shutdown system and diesel/SVO/propane fuel system) by using a 12 VDC power supply which only becomes available after the genset is running and isn't required for shutdown (because an armed CO2 tank provides the required "power").  Of course, I don't have a glow plug or a starter, and this might be something I eventually regret if I have to start when it's very cold and as I get older.

Bob B.

[quinnf]

Well, I don't really NEED the battery, but I keep thinking that the system is mainly for emergency power so I need to plan for worst case.  That ice storm that knocked power out about 7 or 8 years ago in your neck of the woods left my wife and her nearly invalid mother isolated because of all the fallen trees, without heat, only because of no 120V power to run the furnace blower.  It got so cold the wife had to move her mum into a convalescent home, board the cats, and she slept/showered, etc. at the hospital where she works for something like 6 days until power was restored.  Should that happen again, I'd dearly love to configure Old Silver so that she could go out to the groj, push a button and have Silver thump to life.  She's already got a manual transfer switch permitted and installed at the panel, courtesy of the previous owners of her house, so that end is Kosher.

While I agree the 'lectric starter is probably the better road to stumble down, it's just that I really LIKE the sound the air motor makes starting the engine.  And it's so darn simple to go there, since the controls are all going to be pneumatic, anyway.  Springs will hold the decompressor cam and fuel rack closed.  Air pressure will retract the pneumatic rams against spring pressure while in "RUN" mode, sort of like what Bruce out in Arid-zona did.  So, should air pressure fail, or should the system fault some way or other, it's easy to dump air pressure via a solenoid (and disconnect relay for the genny) and shut everything down. 

So I'm still thinking on it.

q.

[vdubnut62]

Well then install both! Multiple backup systems never hurt.
Ron

[quinnf]

Don't laugh.  The idear has crossed my mind.   

q.

[sailawayrb]

So how do you ensure that you will always have air pressure and a charged battery when you need to start engine on a cold, powerless day?

Bob

[XYZER]

A set of jumper cables from the car will fix a dead battery......batteries are everywhere......my 6/1 won't run my real air compressor if I loose power. But if I lost power and needed air I have a real small compressor that it can handle for a flat...a big tank might kill it. Oh what a tangled web we weave......    

[vdubnut62]

Don't laugh.  The idear has crossed my mind.   

q.

I ain't laughing! If both were available, then by golly, I'd use 'em.
Ron

[quinnf]

Bob,

I figured I'd set up a float charger on the battery and the compressor I have there is tighter than a frog's arse.  However, I plan to wire it to an interval timer to connect it to the mains once/day for 5 minutes or so.  If the pressure switch calls for more air, then it'll start.  If not, it will just sit there. 

Knowing that solenoids inevitably leak, just like politicians inevitably lie, I'd put a ball valve on the output of the compressor, so the wife would have to turn it before hitting the START button.  I don't expect that would tax my wife's mechanical skills.  She's sharp, for a blonde.