This Noob Is Crazy!

[Guest Gollum]

I know this and other forums have rules about bashing newbies, but honestly I won't be offended if even the mods get a big angry with me for this, so consider this disclaimer half serious:

If you are a purist, please stop reading. If you are addicted to anything mechanical like me, read on.

So my first secret to admit, is that I'm not a rider, but a cage driver. :::dodges stones:::

So a little while back a friend of mine bought a... 98' I think VFR for very little as it wasn't in running condition. Once he got it running (open pipes) I was quite interested in the engine in these things as they sing quite a unique song, so I hit the books reading up about various V4 engines Honda has made and their various cylinder heads, crankshafts, etc.

A couple months down the road I was going back to a LONG time headache of mine, which is building an affordable flat plane crank V8 for that F1, or Ferrari V8 sound, but without breaking the bank. A guy on the main forums I'm on is actually going to build a LS1 with a flat plane crank, and might possibly end up milling the crank himself on a lathe from solid billet. So anyways, I was sitting there and then it dawned on me... The VFR has a flat plane crank. So I started looking at the ignition timing of the engines and figured out that if you had two engines stacked together, rotated the rear engine 180 degrees backwards in relation to the front engine's crank, then then rotated the left bank's camshaft on the rear engine you end up with EXACTLY the firing pattern used on the common flat plane crank engines out there.

Yum.

Insane idea? Sure, but it goes on.

So I was now more than ever looking in these engines as they seem to be one of the only commonly available V4 engine that has a 180 degree crank. I was originally thinking that I'd find a way to remove the transmission and plug up the block, and then mate the engines to a more traditional gearbox. Then I started doing some calculations and there just isn't a close enough ratio transmission available for a decent price that would really bring out the potential of these engines. Reving to 11k only to drop down to 6.7-7k after a shift just doesn't seem right.

So lately I've been looking into what it would take to machine the front snout of the primary shaft of the transmission. It looks like there's enough meat to work with, but it'll be hard to tell before I have an engine in my hands.

You might be thinking "there's no way those transmissions will hold the weight of a heavy car" and I was thinking the same thing too. But looking at the weight of the bike, and what Honda rated for cargo weight, it seems they rated it safe for around 950 pounds or so. I plan on having a curb weight of around 1700 pounds or so. That might be a bit optimistic, but 1850 would be a walk in the park to attain.

I'm also thinking that I'll probably run a very short rear diff in order to lighten the load on the engine/transmission even more, since I don't plan on the car going to 200mph.

I'd be keeping the tires relatively tame in fear of breaking something, probably around a 205.

200hp in anything under 2000 pounds makes for an exciting car that's fun to drive, and that's a fun starting point and what I'd plan on if I really do this. But my goals are even more sinister.

Once I'm able to prove my goals attainable (flat plane sound, 150+ wheel hp, less than $3,000 budget) then it's onto the next idea. Turbocharging. I'd hope to see around 350 wheel hp as a goal, though I'd stop once I see diminishing results for safety and longevity of parts. I'd probably run twin T25 or T3 turbines, I'm still calculating what I'd need. Most likely run a custom EFI setup by this point, make a custom intake manifold (plenum enclosing the stock ITBs), and I'd most likely be running ethanol to keep ping down.

I figure if there's guys making 160+ supercharged on pump gas, then there's no reason an intercooled turbocharged engine with ethanol or methanol shouldn't be able to knock on the door of 200 at the crank. More might be attainable, but I fear stock internals and transmission might be giving me problems at this point.

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.

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So yea... Do I qualify as nuts? Maybe. But it'd be a heck of a project.

I posted my thread in this section to get feedback regarding the technical side of what I'm trying to do. Obviously I'd be using machined billet steel for the couplers, obviously I'd have to make sure the engines don't rotate/move away from each other in any fashion. There's a lot of "duh" stuff that I've already got notes on. What I really need input about is what you people think are the limits/restrictions that I'll run into. Most will probably say "you'll fail, and I'll laugh" and I'll say "ok, but why do you think that, so I can avoid that mistake when the time comes?".

Oh and btw, I'm really liking VFR owners thus far. They seem like quite the awesome bunch of people. You're all more than welcome at by BBQ meets. :fing02:

Edited August 23, 2009 by Gollum

[VFR Capt.Bob]

I like your kind of crazy genius. I'm way out of my leaque to try and offer some oppinion on this. Make it happen and keep us informed. I've seen engines go for pretty cheap on Ebay and the like. Take lots of pictures so it's easier for some of us to follow along. Baron Von Fankenviffer I presume?

[kostritzer]

I love the sound of flat plane crankshaft V8's as well. Take a look at what Audi did with their V8 in the early 90's in DTM. They took their standard road car 90 degree crankshaft and "twisted it" into a flat plane crank! The rules said you had to use the original crankshaft, so they were definitely "stretching" 'em quite a bit!

The twin VFR is a neat idea, but balancing them would be very difficult. Powertech and Hartley have built flat plane V8's using Hayabusa and R1 cylinder heads, that would probably be the(expensive) way to go.

I've been tinkering around with the idea of putting the VFR engine into a small lightweight car sometime in the future. I would probably opt to turbo-charge it as that is the easiest way to make both horsepower and torque with an engine. Plus you have plenty of room in a car for all the plumbing compared to a bike! My advice to you is to put it in the lightest car you can find, a sub 1500lb car ideally!

[turtlecreek]

welcome....there has been some debate, but i think a V4 lover, even if just a cage, is welcome too!!

do a search on "torocharger" in this sight. that might help you too.

[Guest motorhead1977]

Really interesting idea!! BTW, Welcome here. Since your "ride" is still just a thought process no need to post a picture - yet. Some will shudder but how about setting your engine in a late 1970's Ford Fiesta or a similar vintage VW Rabbit or early FIAT 128? All are small, light and FWD so no need to make the power transfer direction changes RWD would require? I hope you can pull it off. I would love to see it all done. :fing02: :blush:

[Guest vthoky]

I like your kind of crazy genius. I'm way out of my leaque to try and offer some oppinion on this. Make it happen and keep us informed. {snip} Take lots of pictures so it's easier for some of us to follow along.

Yeah! What he said! This sounds like it'll be fun for you, and an online learning experience for the rest of us.

[SEBSPEED]

Welcome! I'd love to see you make some progress on this!

There's a guy here(hasn't been on in a while) that stuffed a 5th gen VFR engine in an older Mini, so the car part can be done.

Can you find a way to mate the 2 engines at the cases to join the cranks, and use the drive sprocket outputs as-is to turn a driveshaft with a double sprocket? That way the load of your vehicle will be carried by both transmissions, and you could even incorporate some kind of urethane cush drive like the bikes have on the (driveshaft sprockets) to reduce the initial hit of power. So, you'd mate the cases, and mount them together in a cradle which also supports the driveshaft(to keep distance constant), then run the driveshaft to a limited slip differential, and have a blast!

I definitely agree w/ Tom on using a nice light car, if you don't plan to make your own. Any compact car from the mid-late 80's, and early 90's should suffice.

As far as induction, I'd personally do a supercharger, to keep down on the headache of plumbing exhaust, but that's just me. If I had to use turbos, I'd use a smaller unit AND a larger unit to get boost everywhere instead of a big hit somewhere.

[2FAST4U]

For starters, welcome to the forum. You'll find a lot of very knowledgeable people here.

As crazy as you think your idea sounds, its all been done before. Some people have joined two Hayabusa engines at the crankshaft and put them in a car. Just last week I was watching a video on Youtube of a guy that custom made his own chopper with a turbocharged V4 Honda Sabre motorcycle engine.

We all like to see pictures. So even though your project is far from completed, show us what you've got so far!

[Guest trickster]

good luck car/ bike conversions can be really fun, (mine is a 68 mini, with a turbo busa motor the whole car is under 937lbs) and at 285hp it is a lot of fun (read 0-60 in under 4 fun). I think you might want to look to the R1 engine it will make more power and the new one is a cross plane motor (seen a r1 engine in a mini). Best thing is to just do a rear engine conversion on the small cars, and add an electric reverse.

a fiat 500 with a vfr motor would be very fun and be an easy conversion(relatively)

good luck I think you may have to up the budget a bit;)

[Guest Gollum]

Thanks for the warm responses thus far!

The car for this project is pretty much already decided, though not owned yet - Datsun 240Z. Stock weight is a heafty 2250, but I've personally witnessed what it takes to reach 1800 pounds, and there are guys out there in race trim running around 1600 pounds with a cage, and that's with the stock 400 pound engine + 80 pound transmission. This engine/trans COMBO should be under 350 pounds. So if I REALLY wanted to, I think 1400 might be an extreme stretch for a Z.

As far as progress thus far, unfortunately this is still all such a recent development for me, that I have too many other things that need to be done before this project gets going. But I can give a preview of my taste of things. Here's the dash I made one evening because I'd taken my dash out and needed to get my car back on the road. I only mounted the gauges I NEEDED, tach and boost! Oh, and that's stainless steel. :-D It's not a final dash of course, just something to get me by for now.

Regarding the engine mounting, I was thinking I'd design a slip yoke for the crank and transmission shafts. I'd build mount extensions off the block that then connected to and I-beam (probably chromoly steel) that connected mounts from both engines, effectively making a cradle for the engine side of the mount. The distance to the driveshaft would be kept constant by the mount in the car. I'd have to design my own mount cradle for the car side as well, but that's already been done about 1000 times in these cars. Any Ford 5.0 swap, Rotary swap, you name it needs custom mount work done in these cars.

I've seen toro's supercharger kit, and I HIGHLY respect the work that he's done. His work is what made the though of turbocharging a reality, not just a nice idea. I prefer turbocharging due to their dynamic power ability, which will allow just about anyone to drive the car without killing themselves. It also gives me the ability to tune lower pressure levels on the highway for economy and still squeeze some good gas mileage out of it (not that a MPG mark is a goal for this project).

Also, I obviously have heard about the hartley V8, and think it's awesome. But for the cost of that engine I could do this idea, buy the car, put in ready to go race suspension + brakes, get carbon fiber body parts, lexan windows, custom rims, and tires for several years... The cost just isn't work it to me. The guy I know who's going to go the LS1 route with his flat plane crank idea will probably have less than 10k or so invested and will easily produce over 400hp. I think he's actually shooting for 500hp. Oh yea, and it's going in a M3!

Oh, some of you might find this fun/interesting. This is some of my first 3d part modeling. It's a flat plane crank built to Ford 4.6 mod motor specs.

I'll try to get some pics for you guys in the next few weeks of the 240Z i hope to use for the project. It's conveniently sitting at a friends house garaged nicely. (don't tell the girlfriend, soon to be fiance!!!)

[Guest vfrrider]

Well, the H1 V8 makes about 285HP stock, and has a flat crank. 2.8L. So, already done for you.

See here: H1V8

Larry

VFRrider

[The Phantom]

Hi Gollum, welcome and all I can say is There Is A Gear Head God

This sounds like an amazing project and I reckon you're in with a good shot, given the knowledge you've demonstrated here.

The VFR has a flat plane crank. So I started looking at the ignition timing of the engines and figured out that if you had two engines stacked together, rotated the rear engine 180 degrees backwards in relation to the front engine's crank, then then rotated the left bank's camshaft on the rear engine you end up with EXACTLY the firing pattern used on the common flat plane crank engines out there.

When you say 'rotated the left banks cam' (and assuming I understand what you're proposing), do you mean lift the cam out of its journals, spin it laterally 180 degrees, and drop it back in again? If so then you are talking about VFR750 engines only, as they have the gear drive in the centre; the VFR800 moved the geardrive out to the side, so you can't do this with 1998+ motors. It's certainly do-able with 750s, giving what was dubbed the 'Twin Twingle' effect by the first guy I know to have done this, where the left bank fires both cylinders in sync, then the right bank fires both cylinders in sync. It's only achievable because the VFR fires the plug on every revolution (i.e. on both ignition and exhaust cycles) so you can swap them around ok.

It replicates what was done with Brit parallel twins back in the day, when you could get them to fire as a virtual big single, and when done it was called a Twingle.

OR do you mean running the rear motor backwards and setting the cam 180 degrees out to compensate (I'm fuzzy on this as it's not something I've considered).

Looking forward to seeing how this pans out... sorting a transmission will be a big one (Seb, linking two drive sprockets means linking/syncrhonising two shifters, which would be interesting, maybe a first!) and you'll probably need to use cooked spaghetti to model your exhaust system if you go with turbo(s)... but wiring and cooling should be fairly straightforward.

On turbo, a big plus there would be to ditch the eight carbs (and associated tuning headaches) and go with a couple of big simple carbs or something like a Motec FI system.

[kostritzer]

I'd love to see that mini with the VFR engine. Here's a Honda N600 with a VFR750 engine in it, wonder if they'll ever finish it?

http://hondan600.net/projects/n600pictures.html

[VFR4Lee]

Well, as long as your goals are sinister, and your means devious... :laugh:

[Guest Beaver]

You're all more than welcome at by BBQ meets. :laugh:

Sir, your double entendre has elicited a humoured response. Well played Gollum :laugh:

[Guest Gollum]

Regarding the engine setup again:

Ok, so I'd stack the two engines both facing forward, one in front of the other, so the transmissions are both hangout out to the left when looking at the front of the engines (I think that's the side the tranny is on). Now, spin the rear engine's crankshaft 180 degrees backwards, so #1 is 180 degrees away from firing. But now take that same engine's left bank, and just rotate the camshaft so that now the #1 cylinder is now 180 degrees past it's fire. Voila, Ferrari V8 ignition timing. This will give you a perfect LRLRLRLR firing pattern, with an ignition event every 90 degrees.

Regarding transmissions:

Yes, the thought was the pair the tranmsissions together to use BOTH, not just one. I'm not sure this has ever been done before. I can't imagine many other cases that there's a need.

Regarding balancing it all:

That will be a tricky one, but I'm not THAT worried about it, since there's hundreds of people out there that have used multiple engine setups. The most common is seen at tractor pulls. They pair up several huge big block engines and feed them all down to differentials that accept multiple inputs. In many cases they'll run 4 engines, 2 on each side. Each side will run a prop shaft from the front engine to the back engine, then the two back engines to a common diff. It's weird, but it works for them running thousands upon thousands foot pounds of torque, so I think I'll manage something.

To Larry:

As I mentioned, the Hartley V8 would cost more than my entire car project. It's a very awesome engine... but pointless for the everyday person like me, especially ones like me who are creative enough to find a much cheaper alternative.

I would love to be able to make my own custom block+crank like that though.

[magicman]

I very much love these ideas.

I know that you'll figure something out. There are lots of RC vehicles that run with dual motors. I mention that not to say it can (obviously) be done, but to point out that the motors all have a similar drive out put. A shaft to which you would mount a sprocket (or gear). There are many, many solutions out there, so take a scan through and you might find something inspirational. Heck, one of the local bike builders (now deceased) built a couple multi-motor bikes. http://www.toadscycle.com/customBikes.htm.

So, the layout you've described sounds more like you're going to build a W8 rather than a V8. I would actually suggest putting the motors side by side, both facing to the right (so drive output shaft would be pointing to the nose of the car). I would do as SEBSPEED suggested and just run both motors with normal sprocket outputs through short distance chains to a drive shaft with dual sprockets. That way they will both be turning the same direction, the same distance apart (which you would have to make adjustable to compensate for chain stretch). This would also allow you to install the motor(s) longitudinally in the right half of the engine bay with the outputs in line with the central drive shaft. This leaves space on the left half for your turbos/inter-cooler, battery (if not in the trunk), brake master and clutch master cylinders (remember, all these motors have hydraulically driven clutches).

Alternatively, you could mount them in the V8 configuration transversely (East-West) with the same gear/chain drives and a small diff in between. You would only have one motors width between the sprockets to fit it though. The output of the diff would lead to your RWD drive shaft.

If you REALLY don't like the sprocket idea, I'd suggest grabbing some shaft driven V4s. Such as from a Magna. You could set them up in the V8 formation, and have two output shafts coming out of the back of each block. Run them through their own hubs if you want, or into some diffs to convert them to turning your main drive shaft and that way you can basically lock them in place. I think that may be the easiest option. Especially with the Cam gear problem mentioned before. They also came in 1100s. :excl:

The problem you're going to encounter though is linking the cranks. If you don't, it would still run just fine. They wouldn't even need to be in the same gear (assuming you don't over rev one). You'd obviously lose that sound you were looking for though. So, keeping the motors running at the same RPM no matter what is going to be key. You'll also need to make sure that the clutches engage/disengage together to prevent undue stresses. Getting used motors, that'll most likely mean rebuilt clutch packs/springs/etc. Make sure everything is new, and theoretically it should all have the same specs and functionality.

As far as synchronizing the shifting, I would probably suggest either an electric or pneumatic type shifter. That way you don't need to worry about getting your linkages adjusted, or having them bend or any other similar problem. It would also eliminate the problem of trying to route the rods as well. You could just end up with a rally style, up/down quick shifter. That'd be pimp! And more importantly very easy to make electrically. The only hard part would be for putting it into neutral. But a separate button beside the shifter could be installed to command an only 1/2-2/3 push on the lever. Electric linear actuators aren't terribly expensive, and the Boolean logic would be super simple to convert into a small form factor relay based control module. Building that would also leave a ready to rock system to incorporate the electric reverse. If Neutral=True, then reverse can be engaged. Simple (the logic anyway).

Best of luck! Make sure you keep us up to date!

[Guest Gollum]

Those are some really interesting thoughts, well noted!!!

I was thinking of having them in a V8 configuration, longitudinally mounted in the bay. Ditching the sprocket of course. The transmission output already has a really nice make yoke style shaft that could easily be adapted to a custom driveshaft. If the two engines were stacked in a V8 then I just need to figure out how to machine the rear engine to accept the front engine's tranny output.

Next to the tranny issues, the crank connection should be CAKE. I definitely will be wanting to keep the firing as close as I can. I'll also obviously be making my own headers for this project. Equal length would be nice, but it will come down to what I have space for. Realistically even some Ferrari engines don't have equal length headers, just close enough. If I get within a 5-10% margin then that should be close enough for the "sound" to be there. And in order to not redesign/rebuild them once I go turbo I think I'm going to build them with turbo flange outputs and design a J-pipe to go down to make to a mid pipe, then when I add turbos I just add the turbos and a new custom J-pipe. Making headers is a PITA! Very time consuming and most likely will be the last thing done, therefor I'd be itching to get it on the road by that point.

Your ideas on shifting are intriguing to say the least. I was thinking I'd end up taking a mechanical linkage route, but that could get REALLY hairy if my tolerances aren't PERFECT. I was just figuring with not having ANY tranny in the transmission tunnel then I'd have plenty of room for a mechanical rod setup.

Slap shift for the win!

Oh, and S30 Z cars use a hydraulic clutch setup, so adapting that side should be easy. Obviously new, and most likely much stronger clutches will be in order for both engines.

Oh, I've had some friends suggesting an idea that I find pretty silly. Lets see what you guys think.

They're saying I should put one engine in front, and one in back, and make it AWD. Then if I still wanted the "flat plane sound" to find a what to eletronically pair the engines to the same RPM, maybe run them on the same coil setup, and run them through a common exhaust setup, that maybe exited out the sides. I think they're crazy.

Oh, someone mentioned carbs earlier. I was planning on going with the 02+ EFI engines. If I'mg going custom efi in the future it will make the transition easier. I just have to figure out how to work the VTEC solenoid. Might just end up being forced on all the time.

Edit: Oh yea, the magna seems like a great engine, but the crank has both of it's 2 piston journals at the same position. It will never offer a well balanced LRLRLRLR firing pattern unfortunately.

Edited August 24, 2009 by Gollum

[kostritzer]

Here's a pretty straightforward way to link up the two engines, gearboxes and all. Of course it doesn't turn them into a flat plane configuration, but it sounds like you can figure it out from there.

Twin Ducati's

[Guest Gollum]

That is REALLY sweet.

Running a midship setup isn't really an option for me, and I don't think it's smart to be running a chain all the way back from the front.

Though that does make me think...

I could still use something similar. Have the engines in the bay like I was planning, but run both sprockets out to a common rotating shaft and make that shaft run back to the transmission tunnel. Sounds easy when I think of it like that. Then I can even use stock sprocket parts, no modification necessary!

The only question I have, would be how compact I could make it all, and how much will I have to offset the engines to make room for that setup. I think I'll be fine, as the Z has plenty of room to work with, and since it's a bike engine I can fudge the rotation of the engine quite a bit.

You guys have already been a good help!

[magicman]

I would actually suggest putting the motors side by side, both facing to the right (so drive output shaft would be pointing to the nose of the car). I would do as SEBSPEED suggested and just run both motors with normal sprocket outputs through short distance chains to a drive shaft with dual sprockets. That way they will both be turning the same direction, the same distance apart (which you would have to make adjustable to compensate for chain stretch). This would also allow you to install the motor(s) longitudinally in the right half of the engine bay with the outputs in line with the central drive shaft. This leaves space on the left half for your turbos/inter-cooler, battery (if not in the trunk), brake master and clutch master cylinders (remember, all these motors have hydraulically driven clutches).

Alternatively, you could mount them in the V8 configuration transversely (East-West) with the same gear/chain drives and a small diff in between. You would only have one motors width between the sprockets to fit it though. The output of the diff would lead to your RWD drive shaft.

I could still use something similar. Have the engines in the bay like I was planning, but run both sprockets out to a common rotating shaft and make that shaft run back to the transmission tunnel. Sounds easy when I think of it like that. Then I can even use stock sprocket parts, no modification necessary!

The only question I have, would be how compact I could make it all, and how much will I have to offset the engines to make room for that setup. I think I'll be fine, as the Z has plenty of room to work with, and since it's a bike engine I can fudge the rotation of the engine quite a bit.

You guys have already been a good help!

That's basically what I was trying to suggest. You could either have the motor off to the side and hopefully you'd even have enough room so you only need the one stage of chain to have them hook directly into your drive shaft. If not you could have the motors only slightly offset and two stage it. They would run chains heading into the left side of the engine bay onto a dual sprocket shaft, and then from that shaft another stage would run back to your central drive shaft. That would allow you to center the motors a bit more, which would probably help in the header department too.

[Guest Gollum]

Yea, sorry I didn't get it the first time. ::doh::

I'm not sure a dual sprocket setup would be necessary, even if I kept the engines close to center of the bay. A driveshaft doesn't need to be perfectly straight, it's just important that your rotating planes are as perfect to identical as possible. Obviously you don't want your driveshaft pointing way the heck out of line, but I should have at least a little room to play around.

I could easily attach the dual sprocket shaft to the mount cradle I've got designed in my head. If all works out like I hope, the shaft would be tucked in very tight against the block, allowing me to keep the engine as close to center as possible. Then I can rotate the engine as needed to gain clearance for the exhaust on the bank opposite to the transmission.

Or... now that I've looked over the engine more. I could run a dual chain setup, with the third sprocket between the engines on the shaft the transmissions are running to. The secondary shaft looks like it could tuck in very nicely just under the oil filter, beside the oil pan. That would get me a very central output location and keep the engine still an entirely contained unit, so that no chains would need to be pulled to put in/remove the engine.

[magicman]

The sprockets are going to be your limiting factor for clearance. You've got considerably more mass to move, so getting your ratios right is either going to require some fairly large diameter sprockets, or a really low geared rear diff.

[Guest Gollum]

Well the stock sprocket reduction doesn't seem to be that much. Nissan diffs are all pretty short anyways. The common ratios START at 3.364, and those are harder to find. 3.9's are common, I even have a few. If I convert to a short nose diff (which I might) then I can go way up to 4.44 if I wanted to.

I might need help understanding the stock reduction though. In the service manual it lists a primary reduction, and a secondary reduction. Which is the chain setup, and what is the other? To me it looks like the transmission output sprocket is directly connected to the primary shaft, thus is a 1:1 ratio of whatever gear you're in.

Another gearing factor is that the wheels I plan on running will be under 24" tall, around 23.7.

[magicman]

That sounds like a good job for MS excel.

On the bike, in 6th, 100kph=~4500rpm. You'd probably want to go a bit higher, but probably not over 5800 for 100kph. Otherwise you're going to start to get a bit buzzy at speed. Stock gearing for that is 16:43 for the sprockets.

If I get a chance this afternoon, I'll see if I can break that down into a simple formula for you. It would of course take your tire size into account as well.

I'm guessing you'll go with the dual stage, as it would be more flexible, and also add some adjustment to gearing.