Author Topic: Flat head hit and miss engine???  (Read 8850 times)

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Flat head hit and miss engine???
« Reply #15 on: February 13, 2023, 02:54:05 PM »
It's a brand new day, and just like Steve Earl, I've come back with brand new plan.        The flywheel is going to be 8" o.d. with a 1/4" web and a 1 3/4" dia. hub. No bolting. The "blades" are going to be 1 1/4" x 1/8" x 1 1/2". All is steel and all is welded. All mig welded. This size will cool the engine I am designing without any trouble.



Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Flat head hit and miss engine???
« Reply #16 on: February 13, 2023, 04:05:01 PM »
Beginning to get very, very weird, and yet it all fits and the crankshaft revolves without getting hung up. That base is made from a single piece of 4" square aluminum. It is tall like that to get clearance under the flywheel.


Online Laurentic

  • Full Member
  • ****
  • Posts: 310
  • Nr Yeovil, Somerset, England
Re: Flat head hit and miss engine???
« Reply #17 on: February 13, 2023, 11:29:44 PM »
Are there photos on this thread?  If so, I can't sse them, why is that, I'm logged in?
Chris

Online A7er

  • Full Member
  • ****
  • Posts: 272
  • Cornwall, UK
Re: Flat head hit and miss engine???
« Reply #18 on: February 13, 2023, 11:31:38 PM »
Brian,
I am not familiar with your concept of the exhaust/inlet ports being in the wall of the cylinder itself rather than in the top face of the block. As some youngsters would say, "what's that all about?". I do own a car with a side valve engine, and I have owned several others in the past, so valve in the top face of the block I am familiar with. It looks more like a two-stroke setup to me, or a sleeve valve system.
Lee

Offline vtsteam

  • Full Member
  • ****
  • Posts: 753
Re: Flat head hit and miss engine???
« Reply #19 on: February 13, 2023, 11:36:54 PM »
Are there photos on this thread?  If so, I can't sse them, why is that, I'm logged in?
Chris

Yes. Check that you aren't blocking imageshack.com, where they are hosted. If you're running Safari, check with an apple forum re. externally hosted images. Or switch browsers.
Steve

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Flat head hit and miss engine???
« Reply #20 on: February 14, 2023, 12:13:01 AM »
Hootchie Mama!!!--I even found room in there for a pair of gears and a cam and a tappet and a tappet guide. Still haven't got the faintest idea of how to turn this into a hit and miss but it's going to need all of these parts anyways.


Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Flat head hit and miss engine???
« Reply #21 on: February 14, 2023, 12:19:31 AM »
A7er--There are two or three ways of arranging the valves so that the cylinder head is flat with only a sparkplug in it. This cylinder head will get some cooling fins on it when I get around to it. I learned this nifty trick of bringing the ports into the side of the cylinder from Phillip Duclos about 10 years ago when I built the "Odds and Ends" hit and miss engine. The piston does not go up past the bottom of the port. The cylinder head has a 1" diameter protrusion on it that goes down into the cylinder to the top of the port.  :pinkelephant: :pinkelephant: :pinkelephant:

Offline Jasonb

  • Full Member
  • *****
  • Posts: 9467
  • Surrey, UK
Re: Flat head hit and miss engine???
« Reply #22 on: February 14, 2023, 07:11:38 AM »
You can even put the spark plug in the valve block as the ball hopper engines do (keeps them out the water)

Brian, as for how to make it hit and miss, shorten that exhaust valve, have that cream coloured bar pivot on the right side of the crankcase, fit a roller follower in the middle and have your governor latch work on the left hand end as it rises up to push the exhaust valve. The VJ Monitor has a similar arrangement but teh rocker is "L" shaped

Again ;look at many of the vertical hit and miss engines such as IHC, Monitor, Root & Van Dervoort

Regarding that rather tall crankcase, you could put the engine on legs or simply mount it on a wooded sled and let the flywheel overhang the side

Still interested to see a vertical section through that valve block as I'm not sure it will work as is, get that sorted first as it may affect other parts





« Last Edit: February 14, 2023, 07:31:38 AM by Jasonb »

Online Laurentic

  • Full Member
  • ****
  • Posts: 310
  • Nr Yeovil, Somerset, England
Re: Flat head hit and miss engine???
« Reply #23 on: February 14, 2023, 10:12:57 AM »
Thanks Steve, I will check that out.  The last post from Jason showed the photos OK, and previous threads from Brian showed photos of his builds OK too - not sure why this thread is different but it may be an Apple/Safari problem.hris

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Flat head hit and miss engine???
« Reply #24 on: February 14, 2023, 02:12:26 PM »
JasonB--Thank you for the wonderful pictures. There certainly may be something in there for me.---Brian

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Flat head hit and miss engine???
« Reply #25 on: February 14, 2023, 05:04:27 PM »
Jason--that cream colored bar is a tappet guide. It is fixed in position and the only purpose it serves is to guide the tappet.--thinking---thinking---What I have assumes the cream colored bar is fixed ad the red tappet is guided vertically by a hole thru that cream colored part. Do you mean to pivot that bar on the right hand side, with the tappet fixed in place in the cream colored bar? The hit and miss lever slides in under the left hand end of the pivoting cream colored bar to hold the exhaust valve open?

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Flat head hit and miss engine???
« Reply #26 on: February 14, 2023, 05:38:33 PM »
This is a cross section thru the engine at center. I have added the hit and miss mechanism between the flywheel and the crank case. I haven't yet decided how it's going to hold the exhaust valve open, but I'm closing in on it.


Offline Jasonb

  • Full Member
  • *****
  • Posts: 9467
  • Surrey, UK
Re: Flat head hit and miss engine???
« Reply #27 on: February 14, 2023, 06:20:00 PM »
Brian. Don't have a tappet, just a slightly longer valve guide.

Pivot the bar on the right

Move the cam nearer the engine ctr line

Have an adjuster screw and lock nut on the left end that contacts a slightly domed end to the valve

Far left end of bar has your latch plate to lock the bar in the up position (exhaust valve open) when missing

Would be less distance for the governor latch if flywheel was on the same side as intake & cam rocker, hence my early comment about not turning inlet and exhaust out towards the front - run straight out the sides

My photo is the opposite hand but gives the basic layout

Offline Jasonb

  • Full Member
  • *****
  • Posts: 9467
  • Surrey, UK
Re: Flat head hit and miss engine???
« Reply #28 on: February 14, 2023, 06:32:42 PM »
Although this one is working a pushrod upto the valve and ignitor you can see the action of the rocker and how it latches out. Ignore the L shaped lever on the left unless you want to use the bottom of the long crank case as a fuel tank and pump the fuel up to the carb which is what it is doing in the video

<a href="https://www.youtube.com/watch?v=GYMe522imaM" target="_blank">http://www.youtube.com/watch?v=GYMe522imaM</a>

Offline Brian Rupnow

  • Full Member
  • *****
  • Posts: 7575
  • Barrie, Ontario Canada
Re: Flat head hit and miss engine???
« Reply #29 on: February 14, 2023, 06:54:48 PM »
Jason--I'm clear on everything except the "follower". Does the cam act on the follower instead of the flat underside of the pivot bar?

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal