660 conversion

[maverick]

i can't find info... can somebody help a brother out?

[cad600]

We haven't had anyone do it here yet. Dru is on here and has done it, but his write up is on the Archives.

My understanding is that you can do it two ways:

1) FZR lower with YZF upper and a 3mm head gasket - you need conrods, cylinders, pistons, complete head, and carbs from the YZF
2) A complete YZF engine with a FZR crankshaft and a 3mm headgasket. This is accomplished by having new crank oil bearings made so it will sit and lubricate properly.

I recently had another idea as to how to do this. Take the YZF engine apart and send the crank to Falcon to have them redo the crank gernals to gain the stroke needed. This would alliveate the need to make new bearings. But it would be very expensive. The complete YZF option has an advantage of the transmission being a little stronger than the FZR. Now the YZF tranny is still the weak link in the conversion, but every little bit helps. Just don't run NOS through it if you do the conversion. Supposedly you will fry second gear each time you hit the button.

Does this sound about right Dru?

[j200pruf]

Hey cad are you talking about having them offest grind the crank? If so there is no way you would get an extra 60ccs doing that. And if your talking about having them weld up the crank and regrinding that way, you would jsut be better off putting an R1 motor in a FZR chassis as it would probably cost about the same.
Also if your are going to the trouble of building a stroker FZR/YZF motor you might as well get the big more kit from tts engineering in the UK for the YZF motor, that way you can get 720cc total

[cad600]

Hey cad are you talking about having them offest grind the crank? If so there is no way you would get an extra 60ccs doing that. And if your talking about having them weld up the crank and regrinding that way, you would jsut be better off putting an R1 motor in a FZR chassis as it would probably cost about the same.
Also if your are going to the trouble of building a stroker FZR/YZF motor you might as well get the big more kit from tts engineering in the UK for the YZF motor, that way you can get 720cc total

This is not true. APE and Falcon can both do the "Stroker" crank. But like I said, it is very expensive. They can do up to 6mm movement with the journals by cutting and rewelding them. The 660 needs 5.2mm of movement for it to happen. And unless your a good enough welder that NASA would hire you, I don't think there is really any way to get a R1 motor into a FZR6/4 frame. As for the 720, yes it is possible but I wouldn't want to pay for it. No one makes pistons for the YZF600 motor, all the piston kits available are for the R6 motor. The tts product is a base gasket from cosmic. So to do it you would need to find a company to make them. Personally, I think piston kits are a huge downfall. Most of them (for the FZR at least) create overheating problems. It also seams that the 660 is more reliable than the 619 or 630 kits as the three people I've talked to that have done it have no problems with their motors. The only thing I cann't deside on is weather or not I want to do the YZF based or standard FZR based build. I think the YZF tranny is a better option, but it doesn't fit in the FZR case and I don't know if the crank seals are worth the trouble to get only a small improvment in tranny longevity.

[diztroy]

2) A complete YZF engine with a FZR crankshaft and a 3mm headgasket. This is accomplished by having new crank oil bearings made so it will sit and lubricate properly.

I thought all that is needed to be done to fit the FZR crank in the YZF cases is too make a spacer on the rotor/flywheel side so that the YZF seal will work (as the FZR won't fit the YZF cases). Where'd you hear this about the bearings? Also I think most people perfer to use a 3mm base gasket and not headgasket.

The tts product is a base gasket from cosmic.

Are you saying their big bore kit is just a base plate spacer? What do you mean?

Also most piston manufactures will custom make pistons.....we have a member on yzf600r.com that bought 2mm overbores from JE for his YZF. Then you'll need to find someone to bore your cylinders and replate them....but JE probably does that too.

Thats interesting about the reliability issue...I'd never heard that before. Neat info!

[cad600]

The spacer for the fly wheel is propably what I'm reffering to as the bearing. It's kind of like a roller bearing for the conrod. It's just a spacer that allows the rod to spin on the rod journal but for the crank in the case. Again I have not done it, just talked to someone who supposedly has this way. He said something about a hole for the lubrication not being in the same place between the FZR and YZF and of course the different diameters. I don't have a YZF crank yet so I can not comfirm.

As for the tts item, if you look up the item it is just a base 63mm base gasket. It is not a piston kit. All of the piston kits they have are for the R6. I know that custom pistons can be done, but I don't want to know what it cost. I can imagine it is very expensive. Then you have the sleeves on top of it. But at the same time, no one just makes it as a kit (special order only).

Your right though about the gasket, most people do prefer to use it as a base not a head.

[diztroy]

Ok, thanks for the info, I'll havn't looked at the cranks and cases very close myself either, so I guess we'll both be looking into that.

I see what you mean about tts, I wonder why they don't list the pistons for the kit, but list the overbore gasket? And they don't even list kits for the FZR's?

But yeah, your right a big bore would be special order only, especially because the Nikasil replating required for boring the YZF cylinders (you can't resleeve a YZF600).

But back to the 660 topic, I posted some info on oldskoolyzf here, http://www.oldskoolyzf.com/forum/viewto ... 01&start=0
but keep in mind over there we are talking about putting a FZR crank in YZF cases.....but its got some neat magazine articles in it.

But here's some good info for using FZR cases on the archives, or just search "+660 +conversion"

http://www.fzrarchives.com/ipb/index.ph ... =30847&hl=
http://www.fzrarchives.com/ipb/index.ph ... =22010&st=

[SilverJS]

Guys,

I'd like to chime in as I've done loads of research on this myself.

Notwithstanding the oil inlet issue that was brought up earlier in the thread (I didn't know about that), this is the gist of what I've uncovered when attempting this :

1. The easiest way to do this, bar none, is FZR bottom end, YZF top end. Using the YZF600 bottom end in the FZR frame, with the stock swingarm/wheel combo, results in a sprocket offset of 1/2".
2. If, however, one insisted on using the full YZF engine and slap an FZR600 crank in it, a few more things would have to be considered :
- The crank seal is really a non-issue. SpeedWerks used to "make" a special seal allowing the YZF600 crank into the FZR400 cases for the vaunted 560 engine; I called them up a few years ago to ask for their secret (since 560s aren't the bomb anymore in racing circles), and the guy told me they simply went to a bearing shop and got the proper oil seal. So, the same would apply to using an FZR600 crank in YZF600 cases - easy as pie;
- Electrics from the FZR600 would have to be retained. That means the FZR600 flywheel, stator and stator cover (somebody once tried running a YZF600 engine with FZR600 stator cover - didn't work (no spark), as the stator offset was wrong), and of course CDI and accompanying wiring harness so the CDI can understand pulses sent to it by the stator (thanks Diztroy for pointing that out!);
- The next decision is con-rods : Using the (longer) YZF600 con-rods will require the 3mm spacer (I don't think the placement - top or bottom - makes a difference, but I'd be more inclined to put it on the bottom), or the FZR600 rods, which are the correct length, will have to have their small end bored 1mm, to 13mm. If you're going to modify crank journals and stuff and spend that kind of money, I suspect it would be easier to simply ask Carillo to build you a set of 4 custom con-rods, FZR-length, but with 13mm small end. Those will run you 374$ per item, thank you very much. =)
- The spacer is made by Cometic. They've actually got a part number for it - FZR base gasket, 0.125". =) 58$, as I recall.

Hope this helps.

Silver

[diztroy]

Silver, Thanks for adding that info.....I didn't know about the "SpeedWerks seal". I had wondered if a proper seal existed for using the YZF cases, so thats good to hear. If anyone gets the part number (YZF outer dimension with FZR inner dimension), please post it up, I'd really appreicate it!

I'll have to see if I have some spare seals laying around (cause I don't wanna pull apart a motor ) and get the part number/manufacturer off them.

[cad600]

I've actually got a FZR lower brocken apart in my garage right now. I'll see if I can find the measurements for the crank, but it might take me through the weekend to do it. I've also got a set of YZF cases in a box that I have yet to open. If I can get into it, I'll try to see what the dia is at the crank seal for a compairison.

Here is one question though. I've been planning on using a YZF for this and drop the FZR crank into it. If the seals are not that big of an issue - great. I thought there was another reason to use the YZF conrods - something about compression being a little off. But if I drop a FZR crank in it and attach the FZR strator wheel (flywheel) to it, will the thing work. SilverJS - you said the FZR cover will not work on the YZF because of incorrect offset for the strator itself. But would it have worked with the YZF cover and the FZR componites? I know that you would have to drill through the strator cover for the wires, but who cares? It's a dry strator and the one on my FZR has a big gaping hole in it anyway and still works. The other side to this is, is the YZF strator that much different in size than the FZR one that it can not be used with the FZR flywheel? I mean all it is is an electro magnet anyway.

[diztroy]

Cad, if you can just get the part numbers and manufacturer off the seals that should be good enough. Don't worry about taking measurements. We can look up the part numbers and it should give us the specs we need.

I think the reason most people like to use the YZF rods is because they are stronger. Here's a thread about that from the archives,

http://www.fzrarchives.com/ipb/index.ph ... =39881&hl=

As far as the stator/cover stuff, I've looked in great detail and posted something about it in the oldskoolyzf thread I linked too, here's the info,

If anyone is still interested in doing this I found out a little more information this weekend. I took the flywheels/rotors off the FZR600 motor and YZF600 motor. They definitly do NOT swap!! The cranks are both tapered, but the YZF600 taper starts bigger (~1.25 inch vs. ~1 inch). So this means the FZR600 flywheel/rotor must be used with the FZR600 crank. Also the stator covers are different; the YZF's is deeper and has a cutout for the stator wiring to go through whereas the FZR's stator wiring goes through the FZR cases. The stator and pickup coil is set back a little farther on the YZF cover then on the FZR cover. Also the teeth on flywheel/rotors to tell the ICU when to fire is different...3 on the YZF, 4 on the FZR. So you'll probably have to run the FZR ICU.

I guess what I'm try to say is that besides the FZR crank, the flywheel/rotor, stator cover/stator/pickup coil, ICU/wiring will probably also be needed for the swap with a slight modification to the stator cover or engine case to allow the wiring to pass through (I'd prefer to modify the stator cover).

So to better answer your question, you can use the YZF stator/cover/pickup coil, but the YZF stator won't fit into the rotor as far and you'll have to make a spacer for the pickup coil so it will line up with the timing teeth on the FZR rotor. So because the YZF stator isn't in the rotor as far it might not charge as well, but you could easily space it if needed.

However I think I'm just gonna use the FZR cover and notch it for the wiring. Six of One, Half Dozen of the Other, IMO.

[SilverJS]

OK - I see the electrical issue has been sorted out. To answer the other question that was brought up - YZF600 rods will raise the compression considerably, yes, since they are longer. That's why you need a spacer. In other words :

- YZF600 rods are longer, so they require spacer;
- FZR600 rods are shorter, so no spacer, but they need their small ends bored out 1mm to 13mm.

Your choice. dru86 had a GREAT thread on this in the FZR Archives, and some guy who races this conversion in mini cars chimed in with a bunch of superb info. He's raced both configurations highlighted above, with apparently great success. By all accounts, this is a joy of a little motor, with torque aplenty.

I had done all my research - and then asked Xian_83 (with the TRICK FZR683 that was for sale a month or two back), matter-of-factly, if he'd be interested in selling his engine. He was, and it is. =)))

To ME. =))))

Silver

[diztroy]

Dang! Nice score!

[cad600]

I was wondering who got the motor.

Yep, the electrical was about the only item I was not thinking of yet. Been looking at the post from Dru and Griffen for a while now. Had never seen the "oldschoolyzf" forum. That was very intriuging, thanks Diz.

I'll try to get the part numbers this weekend. Spent most of last night working on the build - you know how it goes.

[diztroy]

I Spent most of last night working on the build - you know how it goes.

Ok.......so then where's the update for your build thread?????

I don't have time to work on my stuff now....so I'm living vicariously through others, hehe.