V-4 Enging design

[walnotr]

I have been thinking about designing a V-4 engine roughly based on one I saw many years ago. Since I only saw it a couple of times and never disassembled I can only guess at the internals. Most of the crankshafts I have seen for four cylinder engines have the rod journals placed at 180 degrees. If the link for a YouTube video works, you will see the crank I've drawn with the rod journals placed at 90 degrees to each other. My question is, is this a feasible design? Of course there are still many things to work out.

Thanks

Steve C.

[ame=http://www.youtube.com/watch?v=vqYpPL6pNqA]http://www.youtube.com/watch?v=vqYpPL6pNqA[/ame]

 

[vlmarshall]

Is it a 4 -stroke? Won't it have a bit of a lumpy power output with the throws staggered like that? The animation is a bit too short and fast, to sort out an even firing order, but I see hit, miss, hit, miss, miss, hit, miss, hit, and back to the first hit again.

 

[Bernd]

VW's used 90% cranks and they ran. Just make sure you've got a flywheel to smooth things out.

Bernd

 

[mu38&Bg#]

An inline four is configured to fire every 180°. The V-4 could also be configured this way, but then it would be difficult to balance. And requires a multi plane crank, which have already considered for manufacture. A single plane crank uses less material and is easier to setup to manufacture.

 

[vlmarshall]

VW's used 90% cranks and they ran. Just make sure you've got a flywheel to smooth things out.

Bernd

Which VW? Not an Air-Cooled. They're 180 out.

 

[Bernd]

Which VW? Not an Air-Cooled. They're 180 out.

I think you caught me with my pants down on this one. Many years ago I rebuilt several of the aircooled ones. Now that I think about it, you may be right. The boxer engine aircooled is what I'm thinking. Don't know about the water cooled one. Never had one apart.

And here I thought I knew my VW engines, Sheeeeeeeeesh.

Bernd

 

[walnotr]

Thanks for the replies. This will be a work in progress at some point. I will be away from my machines for the next six months but will have a CAD program to play with in the mean time. I plan to work on the design and may be ready to start the build when I return. The original engine was in a race car a neighbor had back in the sixties. I only remember him telling me it was an air cooled Porsche V-4 with hemi heads. It was mounted in the car as a mid-engine with the trans axle behind it. Not much to go on. I have never seen or heard of one since. At any rate, it seems like it would be a challenge.

Steve C.

 

[vlmarshall]

Well, Porsche made a FLAT four for years, in the 914. A mid-engine air-cooled, with the transaxle behind the engine. Fun cars, my little brother had one. I've been a VW fan(atic) for all my life, and still have my '62 bug.

One day I'll build a model flat-four.

 

[Bernd]

Vernon,

I've driven aircooled since 1970. Switched to the water cooled when the Rabbit came out. First Rabbit was a 1976.

I built a dunebuggy back in '76 also. A full length chassi one. It is a T-tub. Cornered like a flat board. Still have the chassi and body, in seperate places. I've alway wanted to use the chassi to build a two seater but the full length of the wheel base. Maybe some day. Ya!

Bernd

Forgot to add this link. You're right, it is a 180% crank. (slapping forhead very hard)
http://www.appletreeauto.com/69mm-chromoly-crank-c-370-p-1-pr-3675.html

 

[BMyers]

Since we are talking VW's. I had 15 of them before I had a license. I will have to dig up pics of the rail buggy I built from 1" pipe. Hand bend ever tube, looked factory. Unfortunately, I sold the car to pay my first semester of college.

 

[vlmarshall]

Awesome. ;D

 

[Deanofid]

Since we are talking VW's. I had 15 of them before I had a license. I will have to dig up pics of the rail buggy I built from 1" pipe. Hand bend ever tube, looked factory. Unfortunately, I sold the car to pay my first semester of college.

So is the Myers like the one in the Myers Manx? Your name sure goes with the letters VW!

Had my share of Volkswagens too. All of them had flat engines and no radiator, as a VW should..
;D

Dean

 

[megalift]

It will work. Chevy's small block is 90*, they also made a 90* V-6. There was also some Chevy V-8s cut in half to make V-4s out of them for racing.

 

[walnotr]

Thanks Megalift, I had the original layout as a 60 degree engine and was having a hard time wrapping my head around the firing sequence. I have since changed it to a 90 degree engine and it is making much more sense. All the cranks I could find online were 180 degree designs so I was wondering if having the throws at 90 degrees would pose a problem. I guess the reason it may not be done on production engines is it too expensive to manufacture. The project will continue over the next few months and by the time I get back, there might be a workable design. If nothing else, I might learn a few new CAD tricks!

Steve C.

 

[Rustkolector]

Jerry Howell designed a very nice running V-4 gas engine. Unfortunately Jerry is gone, and will be missed greatly, but you might want to start with a set of his plans. It is a proven design, and you can go from there.
Jeff