Has anyone done a VFR engine swap???

[thermoalex]

Hi i'm starting my winter project planing for my magna. Along with the CBR 600 suspension swap that I've started working on (thanks for all the great info Chokse), I would also like to swap out my engine for a VFR engine.  Winters in the Chicago area are cold and long so I have lot's of tinkering time.  I've seen some mid 90's VFR engines on ebay and they seem to be pretty inexpensive as far as engines go.  Has anyone here done the swap, If so any advice? 


Thanks
Alex

[Chokse]

Actually, the VFR engine swap is on my list for next winter.  I've got the VFR engine ready to go, but the bike has been down so long for the whole wheel and brake mod that I'd like to get a little riding time in during the summer and fall.  Once winter hits, I'll start working on the VFR swap and all it entails.  It is not easy and there are a lot of points at which one can really screw things up.  But, I'll take it slowly and hope for the best.  Maybe we can help each other figure things out a bit as we go along.

[thermoalex]

Sounds great, I've been searching around the forums to find some basic info like what year engines will work and what are the exact parts that have to be swapped along with the engine ie. wiring harness, ignition systems.  I haven't found very much yet, but I'll let you know what I find.

[Chokse]

I've found out most of the information needed for this swap, so I think I can help you.  It looks like you'll need the VFR crankshaft, crankshaft sensor, pistons and rods, cams and valves, wire harness, coils, CDI unit, and a couple of gears from the clutch side of the engine.  That's about it.  You can keep the Magna carbs, starter, engine case, transmission, cylinder heads, etc.  Apparently, you will have to do some major modifications to the VFR wire harness, and this seems to be the biggest issue with the swap.

[Chokse]

Oh yeah, you'll need a 94-97 VFR engine.  These years are the only ones that will work easily (relatively).  I'd love to do the 800 FI engine, but I don't think there is any way to get it mounted in the Magna and working properly.  I did find a big bore kit (840cc) for the 94-97 VFR engines that is about 600 Euros.  Pricey, but it would be cool.

[L J VFR]

I seen where one guy used the vfr bottom end and just put the magna heads on.  That way you could use the faux fins on the outside of the heads that come on the magna.  And plug the oil cooler lines on the vfr block.  Something about the dual coil set-up on the vfr had to be adapted as well.

Sounds pretty straight forward but I'm sure there is more than meets the eye with this conversion.

Oh, and I think you have to take the cams out of the vfr heads and put them in the magna heads.  IIRC

[thermoalex]

I agree very cool. Just doing some wishful thinking what if we had a donor VFR with the 800fi engine, and transplanted the single sided swingarm and engine.  This might make mounting the engine easier.

[Chokse]

You don't even need to use the VFR crankcase.  You can use the Magna crankcase and just put the VFR innards inside it.  The advantage is that your engine block serial number will still match the frame serial number (might make things easier with titles, insurance, etc.). 

The VFR 800 FI thing is just way too much work for any possible benefit.  I am certain the engine mounting points are at very different locations, the wiring would be a real bitch with the fuel injection, and I think it would be almost impossible to get the throttle bodies mounted correctly under the tank.  From my research, the stock Magna engine puts out about 79 HP, the 94-97 VFR engine puts out 105 HP, and the VFR 800FI engine puts out about 110 HP. 

Outside of the wiring, the 94-97 VFR engine is basically a "drop-in" installation and gives somewhere around a 15-20 HP boost (it will be lower than the VFR because of the exhaust).  Going with the 800FI, even if possible, would require a ton of extra work and money, and would only add an additional 5-7 HP.  At this point, you'd be better off getting a big bore kit for the VFR 750 engine.  It would probably give you that extra 5-7 HP and would cost far less in the long run.

[thermoalex]

You don't even need to use the VFR crankcase.  You can use the Magna crankcase and just put the VFR innards inside it.  The advantage is that your engine block serial number will still match the frame serial number (might make things easier with titles, insurance, etc.). 

The VFR 800 FI thing is just way too much work for any possible benefit.  I am certain the engine mounting points are at very different locations, the wiring would be a real bitch with the fuel injection, and I think it would be almost impossible to get the throttle bodies mounted correctly under the tank.  From my research, the stock Magna engine puts out about 79 HP, the 94-97 VFR engine puts out 105 HP, and the VFR 800FI engine puts out about 110 HP. 

Outside of the wiring, the 94-97 VFR engine is basically a "drop-in" installation and gives somewhere around a 15-20 HP boost (it will be lower than the VFR because of the exhaust).  Going with the 800FI, even if possible, would require a ton of extra work and money, and would only add an additional 5-7 HP.  At this point, you'd be better off getting a big bore kit for the VFR 750 engine.  It would probably give you that extra 5-7 HP and would cost far less in the long run.

Thanks for the hp info.  Other than the FI you really don't gain anything with the extra 50cc's.  The big bore kits i've seen were made in the UK and very expensive at today's exchange rates, I did find some old post on the VFR forum where someone made their own big bore kit for the engine.  At that point is reliability a question, because that's the one thing I love about Honda engines is that there bullet proof reliable for the most part.  Do you guy's think we would lose the reliability factor adding a big bore kit?

[Chokse]

I think if the big bore kit came from a reputable place and you had the polishing and honing work done at a quality place, you would be fine.  However, I don't think it would be a very smart idea to try and "southern engineer" something from spare parts.  Also, as far as I could find, that place in the UK is the only place selling a big bore kit for the VFR 750.

That being said, I'm not sure it is worth the extra cost.  You really need to consider price vs. performance gain.  I spent about $800 on all the wheel/brake stuff (new and used parts) for my brake mod conversion I am working on, and I felt that was justified.  Those brakes could very well save my life one day, and my life is worth more than $800... at least to me.  The idea of using better tires also factored into the safety issue and contributed to the justification of the price.

Like Tim Allen once said, "More Power!"  Yes, I'd like more power out of the engine and that's why I have the VFR swap on my "To Do" list.  For a while, I thought about having Dave Dodge do a complete rebuild of my engine with all the performance goodies.  I even called to ask about it.  Dave is a great guy and I love that he will stay on the phone with you and answer any questions you have, even if you're not buying anything from him.  He truly is a great guy and whenever possible, I try to throw my business to him.  However, his complete performance rebuild is nearly $5000 (eek) and brings the engine, according to Dave, to about 108-112 HP (depends on exhaust, air filter, and CDI unit).  That was just too much money and, since his rebuild used lots of custom made parts, meant that if anything ever broke, I would need to go through him for a replacement.  I'm sure he would give a fair price for replacement parts, but if he doesn't have any in stock, it could take weeks to get something (or, what happens when he retires?).

I figure the VFR engine swap will cost about $700 for a used VFR engine shipped to me, and another $100 for other miscellaneous parts.  Also, the swap requires no honing or polishing, which means with some basic tools, time, and patience, I can do it myself.  So, I can pay $800 and a few weekends of work for a boost to around 100 HP, or $5000 for a boost to 110 HP.  At some point you have to say the HP gain is not worth the extra money.  On a bike the size of the Magna, I can't see any reason to need more than 100 HP.  With that much power on a bike like the Magna, you'll be able to beat just about any cruiser out there in a 0-60, and maybe even keep close to a V-Max. 

This is just my personal view and I'm not trying to tell you what to do.  Who knows, maybe you are wealthy and can afford this.  If I were rich, I'd probably have Dave do the rebuild and not think twice about it.  But, alas, I am not rich and I do have to keep final costs in mind when doing these kinds of projects, and for me, the VFR swap could be justified, while things like a big bore kit or the DD rebuild could not.  I hope you don't think I am lecturing to you, but I don't want to see you piss away money for something that won't bring you a reasonable return on the investment.

[thermoalex]

Chokse, thanks for the input.  Trust me rich I am not, I love exploring options and thinking out the pro's and con's.  After all the info I definitely plan to stick with the straight up VFR swap since it is such a straight forward process it sounds like, plus 100hp would be a huge benefit for my bike.   Thanks again for all the advice. 

[TLRam1]

Once you guys get this figured out and do one write up an article and I will include this on the Magna FAQ section. This will be valuable information to those looking for a source of someone who actually went through the process.

[Chokse]

I have also heard you should stick with the Magna's carbs rather than use the VFR carbs.  Apparently, all models of the VFR came with a PAIR system.  Only the California model of the Magna came with a PAIR system.  I think it would be rather difficult to get the PAIR system carbs from the VFR to work properly with the non PAIR system engine on a Magna.  Anyway, I will give both sets of Carbs a try, but I have a feeling that it's going to be easier to use the Magna carbs and to just experiment with jetting a bit.

[JLeather]

Why do you need the crank/rods for the swap?  Are the pistons drastically different than the Magna's?  Different compression height or something?

[L J VFR]

Why do you need the crank/rods for the swap?  Are the pistons drastically different than the Magna's?  Different compression height or something?

The crank in the magna is a 360  degree design.   The VFR  runs the 180 degree crank design.