Fusing two engines (welding) 3

[DOHC]

Hi,

I'm looking into fusing two exiting engines in to a V8 or V10, currently just seeing if there is a possibly way not that I'll be attempting it right away.
Could welding be strong enough to fuse two engines together practically and safely.

I've got two basic ideas,
All based off aluminium blocks for street use.

take two 4 or 5cyl engines and cut the lower end of the blocks at a 45 or 36 degree angle and weld the top parts together the lower part would need to be made custom for a custom crank shaft.

The other idea is to take two V6 engines and cutting them in two and connecting them in the middle running one crankshaft and set of camshafts.

I've heard and seen pretty big holes welded in engines but I'm still very sceptical that it would be practical for joining two engines.

Can anyone give me some more info on this? or other idea's.
Using a existing V8/10/12 isn't a option.

 

[Lou Scannon]

Well, this thread certainly didn't go where I expected, based on the OP. I'm not worthy!

 

[patprimmer]

My tip was a red flag within 24 hours as not professional or work related, but what the heck, it's been interesting.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[rmw]

This thread is so professional and serious that I forgot for a while that I wasn't reading in the Pub.

rmw

 

[yoyo133]

V-8 from a Suzuki? V-8 from a twin Ducati? v-12 from a Kawasaki 6cyl.? v-12 from a Honda CBX ?? Check out the Kneeslider..it's all been done and more WOW..

http://thekneeslider.com/

 

[RossABQ]

Anyone know if the blocks they are milling in these videos are based off production engines? Guaranteed if one of them would work for the OP, the cheapest path would be to offer to buy one of their demo's...

http://www.youtube.com/watch?v=QsmiIeAkE-o

http://www.youtube.com/watch?v=GU32Q6QXtWQ&feature=related

 

[izzmus]

For that matter, I've heard of a NASCAR block falling into the hands of a "civilian", who commissioned (Dart?) to produce a billet aluminum replica, with various alterations to suit his needs. Different heck height, allowance for a longer stroke, that sort of thing. The only things that really stuck in my mind were that the NASCAR engine's oiling system was described as "priority camshaft", which he had done away with as he wasn't going to be using flat tappets, and that it was done for ~$25k, which seems downright cheap, given all that had to be done.

 

[dtdynamics]

hey BrianGar im from ireland aswell and do some hobby casting of alu and machining.
your pattern making skills are top notch.
one thing i lack :-/
you got a website or anything i can have a look at?

 

[BrianGar]

DtDynamics, No no site yet, I must setup something sometime, Ive been meaning to.

Nice to see a fellow Irish man at it too, not many into it In Ireland..or anything else for that matter in the line of this stuff,
Perhaps we might meet sometime, you never know!

Brian,

 

[Mechaniac]

DOHC's stated desire to build a "Honda V8" remined me of this post I read on

http://www.speedtalk.com.

Larry is the real deal so I have no doubt that it's true. See his website for information about him, his company, and it's relationship with Honda,

http://www.theoldone.com.

Larry is the most tight lipped man in motorsports, so this may be the only mention of the V8 you'll find until it's official realease. It should be interesting to see.

Re: Favorite Non OEM Car Engine
by Larry Widmer » Sun Jun 20, 2010 4:39 pm

While it's months away, we are working on a Honda V8. It'll be using left and right-hand K series cylinder heads. Maximum displacement looks to be just over 5-liters. We have several international partners involved in the project.

Vernon

 

[Turborick]

Here is how we are joining 2 engines

http://bonnevillestreamliner.com/2000cc-v8-engine/

 

[gruntguru]

Wow. Looks like a lot of work - more of a U8 than V8. One of the (4cyl)engines has to turn backwards. A lot of potential for torsional vibrations in the coupling shaft. Looks like the cranks were just dropped any old place for the crankcase photo - the phasing looks stage. Are you planning simultaneous or alternate firing? That will probably have a considerable influence on TV's.

Engineering is the art of creating things you need, from things you can get.

 

[murpia]

Can I open this thread up to a discussion on how it might be possible to join 2 engines longitudinally?

E.g. create a V12 out of 2 V8s?

Also, if this is not feasible with a block, what about heads?

Regards, Ian

 

[HRHtex]

A V-16, you mean?

 

[BrianPetersen]

You can "join" them by having them separately mounted, with a coupling (or drive shaft) between them that is designed to absorb misalignment that will be present, provided that the end of the crankshafts that you are joining is capable of handling the drive torque. Where you are taking power out of the system requires consideration, too. Picture two normal auto engines with a flywheel on the end. Join those two ends with a drive shaft and take the power off via this drive shaft (between the two engines) and both engine's crankshafts see entirely normal loads (as if they weren't joined) - of course, this requires one of those engines to be reverse rotation as viewed relative to its own "local co-ordinate system". If you use the back end of one engine coupled to the front of the next - provided the front pulley is capable of taking the load - and you take power off the back of the second engine, then all the torque from the first engine passes through the second engine's crankshaft, which may or may not be okay. Torsional resonance is another consideration here.

It is certainly possible to overcome these issues if the system is properly designed, and it has been done many times.

 

[MikeHalloran]

Detroit Diesel used to sell longitudinally coupled engines for marine use, up to 24 cylinders as two V12s, at least.
They don't do it so much anymore.

One reason has to be the disproportionate difficulty of servicing the after engine's timing chain or gears.

In general you can't do it with stock engines because the usual crank nose drive is only good for something like 75 horsepower; so to start, the after engine needs a special crank, housing, balancer, etc., to carry the extra torque from the forward engine.





Mike Halloran
Pembroke Pines, FL, USA

 

[Turborick]

gruntguru
yea its more of a U than a V, gives more room in between for the future intercooler. We plan on even firing but can easily try other phasing. can you explain the potential for torsional vibrations in the coupling/output shaft? This motor will only see racing and dyno use so it will be apart quite often.

Rick Yacoucci Nebulous Theorem II #988
Fastest 4 cylinder Bonneville 2 way average 352.525 mph
Nebulous Theorem III #788 Fastest Unblown Flathead 280 mph

http://www.bonnevillestreamliner.com

 

[izzmus]

Mr. Halloran - Somewhere I recall seeing a twin engined dragster from the 50's or 60's that used two supercharged V8s mounted side by side.

The bizarre, couldn't-believe-that-worked part is that one engine was used for power takeoff and had a standard type flywheel and clutch. The other engine, however, was turned around, had a flywheel mounted to the crank snout, and the two flywheels' ring gears were meshed together!

Apparently they had a lot of problems, but their improvised engine coupler wasn't one of them.

 

[MikeHalloran]

Yeah, Mickey Thompson's four-engine LSR machine coupled the laterally paired engines by means of ring gear teeth, doubled up, and Dutch-pinned to the flywheels. It worked long enough, I guess.





Mike Halloran
Pembroke Pines, FL, USA

 

[BrianPetersen]

Turborick, in a 4 cylinder in-line engine, the crankshaft rotation speed is not uniform, because the pistons all reach maximum kinetic energy together (halfway down/up the strokes) and all reach minimum kinetic energy together (TDC/BDC). If you phase both engines to be simultaneous-firing then both engines will accelerate and decelerate simultaneously twice per revolution. If you phase them to be alternate-firing then one engine will be trying to accelerate while the other is trying to decelerate, and the difference between the two has to be accounted for *somehow*. Either you rigidly couple the engines together so that the full acceleration/deceleration loads can be transferred between the two engines without failure, or you very flexibly couple the engines together so that the slight phase angle differences between the two crankshafts can be accommodated without failure. Trouble with *that* is that every spring/mass system is associated with a resonance frequency. If you can assure that this frequency is either well below or well above the normal operating speed of the engines then it doesn't matter. If the resonance speed is within the normal operating speed range then it's going to be trouble.

I'm thinking it will be easier to make the engines simultaneous-firing so that you don't have to deal with this.

 

[gruntguru]

Turborick. Agree with everything Brian said, plus the fact that the coupling shaft introduces a "spring" between the two rotating "masses".

Engineering is the art of creating things you need, from things you can get.