Author Topic: Liney RV-2 - Four Heads Are Better Than One  (Read 3162 times)

Offline sshire

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Liney RV-2 - Four Heads Are Better Than One
« on: November 08, 2013, 04:12:11 AM »
Liney RV-2 - Four Heads Are Better Than One

Part 1 - Crankcase


I know. I know. It’s been 5 days since I’ve posted a new engine build, but I had to wait for Richie, my UPS guy, to bring a chunk ‘o 6061. After the double-wide RV-1, I’d had enough of those large parts and was itching to get into some 0-80 thread tapping.

If you’re not familiar with this Liney Machines engine, here’s a description from their website.

“The RV-2 is a four cylinder opposed style engine with gear driven valves and timing. The design is inspired by the internal combustion engines that power so many of today’s general aviation aircraft (and VW's!). The pistons are 3/8" with a 1/2" stroke driving a one piece aluminum crankshaft that rides in miniature ball bearings. The "RV" designation is for "rotating valve". The valve design incorporates a pinion gear on the crankshaft which times a one piece rotating valve.”

The plans are well done with one part per page (sometimes one part on two pages) and most have the drawing and a 3D line drawing of the part. Nice touch.

All metal was gathered. Mostly standard and I had nearly half of it in my stock. The only type I haven’t yet worked with is the 2011-T3 aluminum which is used for the one-piece crankshaft. Now, there’s yet another new thing. I’ve only done built-up crankshafts, so this should be an adventure.

A group portrait before most of it becomes chips.



Removing a piece of the 1.5x2” stock for the crankcase.



Squared up the 6061 with the face mill. I decided to treat myself and actually turned each of the 4 sided carbide inserts one turn. I had noticed a slight amount of roughness to the surface and looked at the inserts with a loupe. All four had edge chipping which was because I forgot to change from the aluminum finishing insert the other day when I had a piece of cold-rolled on the mill.



Hit this dimension bang on.



Now we have a square crankcase blank, most of which will become chips.



I marked out the block for my roughing cut so I have an idea where to stop. The aluminum roughing end mill went through the piece like it wasn’t there. The opening will be 1” deep.
Cuts were .100 per pass.





Halfway there.



After the roughing mill, I changed to one of my “good” end mills for the finishing passes. I define “good” end mills as the ones that are made in the USA and look like someone took the extra time with it. They also cut much more smoothly than my “everyday” Chinese imports. It also amazes me that I can actually get my hands clean when I finish in the shop.



Time now to put lots of holes in the crankcase. Between these holes for the con rods and the two for the crankshaft, there must be another 20 or so that will be drilled and tapped.



Locating edges and center for the crankshaft holes.



There is one hole at each end. The smaller one is .374”. Drilled undersized and reamed. The other end has a .75” hole. I used a series of drills to get to around .65. My largest is a Silver and Deming. I know that the S&D bits shouldn’t be used in a keyless chuck or you may need a 16” pipe wrench to get the chuck unlocked (DAMHIKT). The bit was put in a collet and drilling ensued.



When I was boring the 2” deep hole in the RV-1 valve block, I used my “import” brazed carbide on HSS shanked boring bars. CHATTER!!!. I cranked the Bridgeport’s speed down. I cranked it up. I increased the feed. I decreased the feed. I poured copious amounts of cutting fluid into the bore. I ran dry. An all around annoying experience.
I knew that the problem was the 2.5” boring bar flexing. After looking at various possibilities. HSS vs Solid Carbide shanks. Indexable vs brazed. Etc. Kennametal vs Criterion vs whoever.

I talked to these people. Very helpful. Made in Michigan. Set of 4 solid carbide .5” shank. Comes with 4 inserts, extra screw and wrench. $115.00. BTW, the Criterion set was $315.00.



I used the knee power feed and got the best finish I’ve ever had when boring with the Criterion head on the mill.







Tomorrow, all of the tapped holes and call the crankcase done.







« Last Edit: November 08, 2013, 04:17:48 AM by sshire »
Best,
Stan

Offline vcutajar

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #1 on: November 08, 2013, 12:31:43 PM »
Following you on this one also Stan. 

Vince

Offline b.lindsey

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #2 on: November 08, 2013, 01:16:31 PM »
Sure ain't no grass growing under your feet Stan  ;D. This will be another interesting one to follow!!

Bill

Offline Tennessee Whiskey

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #3 on: November 08, 2013, 01:55:17 PM »
You Know Stan, just like the rabbit said: "This won't take long, now did it"

Whiskey

Online Don1966

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #4 on: November 08, 2013, 06:51:36 PM »
Oh man! I turn my back for a few minutes and bang, Stan has another engine almost finished.  :lolb:  You don't mess around do you Stan? Great start there bud.  :ThumbsUp:

 :cheers: Don

Offline sshire

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #5 on: November 08, 2013, 09:17:41 PM »
The RV-1 has two cylinders, no heads, no con rods. The RV-2 has four of each.
Then there's this crankshaft thing which I assume I'll figure out. I've done offset cams on the lathe.  I'm thinking that this is just four of those on a string.
Then then was the fourteen 2-56 holes in the crankcase that I drilled and tapped this morning. I'm currently boiling the crankcase in alum to get the broken tap out of hole # 14.

Then, horror of horrors, my espresso machine refused to heat up. I get grumpy when I haven't had my morning double-shot of espresso.  I've got it in pieces on the kitchen counter awaiting a new heating element. (Good thing the Italians stock parts in Albany). And why would I possibly have a 30mm deep socket to remove it, anyway?

Not going to be a quick build like the RV-1. The fun never ends.
Best,
Stan

Offline b.lindsey

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #6 on: November 08, 2013, 09:34:42 PM »
Bummer of a morning Stan. It had to be hole #14 too didn't it?  I can relate to the lack of espresso as well. After changing positions here at the college, I switched over to a simple to use nespresso machine, which works well since I don't have a sink close by...same amount of caffeine and half the bio-breaks :)

Bill

Offline sshire

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #7 on: November 08, 2013, 11:22:37 PM »
Of course it was number 14, but as of a few minutes ago, I got the last of the broken tap out of the hole within threads intact. 90 minutes of simmering in a saturated alum solution.  :cheers:

My friends say I'm a lunatic about espresso just because I have a heavily modded Italian machine and roast my own beans.
They just don't get it.

Anyway, I'm aiming for a "done" on the crankcase tomorrow and maybe a start on the jugs.
Best,
Stan

Offline sshire

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #8 on: November 09, 2013, 02:41:05 PM »
I have this nasty habit of making sure I understand why an operation is done before I do it.
Either I'm totally off base here, missed something obvious or Doug forgot to put a note on the plans.

This is the crankcase drawing. The red arrow shows that 6 -#50 holes are drilled. The function appears to be mounting for the valve block. The #50 hole is the correct tap size for a 2-56 thread but no mention anywhere of tapping.

The blue arrow shows through holes to the cylinder mounting holes. These would appear to be used for a screw to hold the cylinders in position. However, there is no indication on the cylinder of a corresponding mounting location or hole. These are also a #50 drill size.

I'm stumped. If you've built this engine...HELP!!


Best,
Stan

Offline Tennessee Whiskey

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Re: Liney RV-2 - Four Heads Are Better Than One
« Reply #9 on: November 09, 2013, 04:51:59 PM »
Headed to the shed after lunch. I'll have a memory refresher. I know the cylinder retaining screws you're talking about. No there's nothing on the cylinder, the screws act as a type of set screw. I think I did mark the cylinders with the screw and then dimpled them.

Whiskey