Cirrus V8 rotary valve engine build 2x scale up

[bazmak]

Well grasshopper congrats on your progress.A nice job you are at the stage I was and encountering the same problems
I too ran it for quite a while in the lathe and had a sticking valve.I think because its a long thin wall tube it not perfectly
concentric and straight.Dont know if honing will completely cure it.Also mu initial springs I also thought wer too strong
and I had plenty of leaks.So put it on the backburner/shelf and gave up for now .May try and resurrect it in the near future
Its a nice looking engine and looks great turning over by hand with the sump off.I have now goy into restoring Myfords
Please keep trying and posted.I like the belt drive.I too thought of it but did not think I had the room.CONGRATULATIONS

 

[davidyat]

Thanks for all the input. I never thought of the lathe. I secured the whole motor and put a cordless drill on the crank, filled the sump with enough oil so the crank would dip into it. Then zip tied the trigger closed and kept replacing the batteries when they died out. I'll next try the lathe and let it run a while. Great suggestion.
Grasshopper

 

[bazmak]

Found a couple of videos of running in in the lathe.I think it preferable not to fit the sump its easier to keep whttps://youtu.be/fxUKdic9https://www.youtube.com/watch?v=fxUKdic9WCQWCQatch and lubed

 

[bazmak]

/www.youtube.com/watch?v=LNFVb2GdPA8
Can you let me have some details and photos of the timing belt drive
I might get back into this.If you run it in the lathe with plenty of wd 40
its a mild abrasive and does mild lapping

 

[davidyat]

Barry,

Just got up. Later today, I'll get some pictures for you. Last night as I was getting to sleep, I may have had an Eureka moment. Something I may have overlooked. Will get back to you later today.
Grasshopper

 

[davidyat]

Barry,
Here are the pictures of the timing belt. Some background on what I did. I ordered a 0.500 inch brass tube and 3/8 inch steel tube from McMaster Carr for the rotary valve setup. The inner hole on the brass was 0.370 inch, which made reaming for the 3/8 rotary valve easy. After making the rotary valve, I lapped it in and silver soldered the end to close it up. The cogged pulleys were from Megadyne, 221 South Westgate Dr., Carol Stream, IL 60188 (630)752-0600 USA. Megadyne doesn't sell to the public, so I used Motion Industries, 4410 Sam Jones Expressway, Indianapolis, IN 46241 (317)248-2100 as the supplier who got the cogged pulleys and belts for me. I live near Indianapolis Indiana. The bore on the rotary valve pulley is 3/8 inch, 30 teeth, the crank pulley bore is 1/2 inch, 15 teeth and the idler pulley is 1/8 inch bore, 10 teeth. To get you started, here is the site for one of the pulleys I used. https://products.beltcorp.com/item/...ys-1-5-pitch-xl-pulleys-aluminum/15xl037-6fa6
You can see what this company has to offer. For the idler gear, I made the fixture, bored a 1/8 inch hole and tapped for a set screw to hold it. I had so many 1/8 drill bits, that I just snapped off the base on one and used it to mount the idler pulley. I would suggest if you do this, you can see that I have a very long set screw (one laying around) and found out it is very useful to put your thumb on it to take up the slack on the belt before tightening the assembly on the block. Also, Chuck Fellows pointed out to me to remember with this set up, the rotary valve is rotating the opposite direction of his. So when I was boring for the air inlets, I made sure of where cylinder #1 was at TDC, mounted the degree wheel with a pointer at 0 degrees and rotated clockwise every 90 degrees. I could look into the cylinder holes and made sure which cylinder was at TDC and drilled the air inlet at that cylinder with a jig I made to make sure the 1/8 drill was centered. I also had a spare cylinder
that I chopped off the top to find TDC of piston #1 with a dial indicator.

 

[davidyat]

Oh and yes I did have to put the 30 and 15 tooth pulleys in the lathe and remove some of the outer ridges to make clearance after mounting. I have about 20 or 30 thou of clearance between the two pulleys after installation.

 

[davidyat]

Well I tried a test run of the engine. A couple of exhaust pops and then the engine wouldn't turn and air was pouring out of #4 & 8 exhaust tubes. No matter how hard I tried to turn the crank, no go under pressure. OK, what did I do wrong? Started checking everything and got down to the rotary valve. Then I saw what I did wrong. After drilling 5 ports, somehow I got distracted and instead of following my prints and was using my eyes to see what rod journal was at TDC. BAD IDEA. The last 3 ports were totally out of whack. Lucky for me, I ordered way more steel tube for the inner rotary tube than I needed. Now it's back to the lathe to make another steel rotary tube. Thank God, I don't have to remove the brass bushing for the rotary valve and the SECOND ONE should be no problem. I do keep forgetting sometimes, one of my mottos, "Do you want to do it RIGHT the first time or RIGHT the SECOND time!!"
Grasshopper

 

[davidyat]

Wouldn't you know it, it happened on Halloween!!! As Dr. Frankenstein said when he shot the juice to the monster, "IT'S ALIVE, IT'S ALIVE!!!" The V-8 engine lives. When I made the CORRECT rotary valve, it works. Now my next problem. I have video of it running. One is about 1 minute, another about 22 seconds, taken with a Samsung camera capable of video. Then another about 20 seconds taken with an iPhone 7. Every time I try to upload, this site keeps saying the file is too big. They are MP4 files. I could really use someone like a 12 year old to take me by the hand and show me how to upload. HELP!!!
Grasshopper

 

[johnmcc69]

Congratulations Grassshopper!
Sorry I can't help with the video upload, by am looking forward to seeing it run.

John

 

[bazmak]

You have to upload videos to Utube and then put the link into your post.Cant wait to see it running

 

[davidyat]

OK, now to see if they will upload to youtube.
Grasshopper

 

[davidyat]

OK, let's see if this works. The video shows the engine running and not very fast. Later after I clean up the shop, I'll try some adjusting of the timing and see if that makes any difference.
Grasshopper

 

[bazmak]

That's great grasshopper.I will seak your advice when I get back to finishing mine

 

[ShopShoe]

That is nice to see running. I look forward to seeing it after your adjustments.

Thank You for posting,

--ShopShoe

 

[bazmak]

Don't forget it wont run fast unless you have a big air supply.* cylinders goes thru a lot of juice
Slow is good.how about a video with the sump removed,lets see the crankshaft you struggled with

 

[davidyat]

Barry,
You are so right about the volume of air the cylinders use. I have a small upright compressor tank and the engine (with a full tank of air) will activate the compressor to fill after about 9 or 10 seconds of quiet running. Unfortunately I can't show the crank running on air. In some of the previous pictures, you can see the idler pulley assembly is attached to the sump. No sump, no pulley. So what I did was turn the crank by hand for you.



Grasshopper

 

[davidyat]

Barry, I've put together an album of my build of the V-8. This is the title page you see first. I'd love to put your real name on it. I will understand if you still want Bazmak used. Thanks to all who helped me.
Grasshopper

 

[neil_1821]

Congratulations on getting it running! It always feels like a huge weight is lifted off your shoulders when they fire up.
Best thing for videos is to upload them to a YouTube account. If you’re struggling you could e-mail the videos to me in a zipped format and I can upload them to my channel and post the links for others to see. Just send me a message and I’ll try to help you.

 

[davidyat]

Thanks, Neil, I've made myself a youtube account and learned how to upload videos to them, then putting the URL in my replies. It works fine. You can see a couple of videos up above.
Grasshopper