Simmy's Naked Turbo Project

You are also invited to attend the CNYCC#16 In June.

we’ll line up ALL the 650rj’s for a group photo!

 

I thought you said #16 was all about 700X's.

 

I didn’t say it’s about any one model in particular.....

if there’s a bunch of X’s, we can line them up, too

 

My sidecar is an RJ with an X motor so would fit in the middle of a picture like that.
If you continue to host these I would sure like to make it out one day.
Your timing @hogfiddles is always the same weekend as our big vintage rally in Ontario, one day then.

Simmy's Naked Turbo Project continues;
Today I pulled the motor from the turbo parts bike I bought last year.
I started on this last weekend but left it for a week because one motor mount was completely frozen.
I started drilling it out today, then asked myself why am I F'ing around.
No one is ever going to build a bike from this frame so I just chopped it up to get the motor out.
I still have a corner of the frame to remove, at least now I can turn the motor upside down and keep grinding away.
I'm hoping this motor has a good bottom end, the gears all work anyway.
I have an 83 Seca 900 cylinder block & pistons but I also ordered a block and pistons from Luxembourg from an 88 XJ900
they should be here any day.
Using the 68.5mm bore with the Turbo stroke will make a 772.
The 67mm bore from the 83 900 makes a 738.
A 772 with 9 lbs boost should be really fast, it should bring the boost on sooner to.
If all I have to do is buy some top end gaskets, maybe some machining on the block to get the CR correct (8.2:1), then I can build a hot rod motor pretty cheap.
When I have this motor ready it's a weekend job to swap in the 772 and put my original 653T in storage.




One of the main bolts in the front is completely seized. The nut is off, the head is ground off and I pounded on with heat and no go.

WARNING!!!! Not for the squeamish, sorry XJ fans, another Turbo has left us, not much left on this carcass.


notice the 900 cases (in the middle). They have less material between the cylinders.
All the 650s and 750s have round holes, I think the 700N also.

The 900, 700/750X casings have the thinner ligament between cylinders.

 

My big bore kit arrived from Germany last week, finally got around to unpacking it.
Initial inspection looks great, the bores have no visible imperfections.
At first I didn't see any broken fins but there is a chunk missing below (above in the pic) the cam chain tensioner.
Can't see it making much difference and it won't be visible.



here's a pic of the OEM turbo piston - 63 mm versus the 68.5 mm piston from the Euro 891cc motor.
The turbo came with forged pistons. I'm controlling boost with the OEM actuator which limits the motor to about 9 psi by my observations.
I'm confident these cast pistons will survive the heat. Combining them with the 650 crank makes a 772.




I need help from someone who has the Yamaha service manual for the 891 .
I've copied the pages from my 83 XJ900 RK manual with the 853 motor.
Need to see if the piston clearance and ring gap is different.
I should probably compare the 650turbo to the standard 650 also to see if a turbo needs looser tolerances.

 

Hmm, couple of questions.
Are you sure the bore (and rods) clentrelines are the same for the 650 and 900 bottom ends? Ie have they widened the spacing to get everything in?
Secondly, why didn’t you keep the thing 900 cc? Just use the turbo scavenge pump etc? Sorry if I missed that further up..

 

bore centres for XJ650-900 and 85-88 FZ700-1000 are all the same.

I dissected my 900 motor and discovered some gouges in the main bearings, so that was going to require some new bearing shells.
Likely contaminates in the oil caused this.

I also discovered the Turbo has connecting rods with additional drillings and unique bearing shells to flow more oil.
Oil travels through the centre of the crank and feeds each of the connecting rods. You can see below the Turbo has big reliefs
in the bearing shells for a huge increase in oil flow.

I have a Turbo motor I hope will not need much in the bottom end.
I will need to inspect the usual weak points - ie; chain tensioner disintegration etc.
I can build a 772 cheaper than rebuilding my 900 motor.
And a 900 motor would never get the proper oil flow for turbocharging.
I thought about drilling the 900 rods but Chacal says the Turbo's bearing shells needed are no longer available anyway.

 

Oil cooling for the underside of the pistons...
Good that the centrelines are all the same though, makes life easier. Well done with this so far!

 

you are correct, the hole in the con rod is to direct oil to the underside of the piston to help dissipate heat.

 

I can send you the info from Haynes manual for the Euro engine, if you like.
Or can upload it and you download it from mediafire.

 

today I verified with 100% certainty all the casings fit together without any modifications (yet).
Below is the 891 block on 653Turbo cases


below is my test bench 650turbo head.
I'm using this to set my compression ratio.
It was the scrap head from the swamp motor.
I'm going to measure the combustion chamber volume.
Planning to set up a dial indicator for TDC, with the head cut I can put it right on piston 3.
I'll use #2 chamber for the measurements, #1 is already missing valves.
By greasing the rings of #2 it will hold fluid, you just monitor how much fluid it holds to the spark plug threads.
This gives you the actual combustion chamber volume.

increasing the bore from 63 to 68.5 leaves a sharp edge around the combustion chamber.
I'm concerned this would get overheated and maybe even cause pre-detonation.
I'm going to smooth it out with a rotary file before I take the volume measurement.


I scribed the chamber below showing the sharp edge to round off.
I have 2 other turbo heads,
once this is all figured out I'll make a head with all 4 chambers the same with a rotary file.
At this point I don't know if it will need more compression or less.
I need to get a new head and base gasket from the 891 for the measurement.

 

Simmy, you are doing some amazing work here.........

 

This is the donor motor below for the 772 project
I used the last of my WHIZ Loosen-All trying to free #2 cylinder.
I had this can for 30 years and I think my dad for 30 years before that. LOL.
I had a can of shoe polish which keeps a lid on #2 to keep the penetrant from evaporating.
I'll continue soaking it and pounding on it.
I suspected the motor was seized when I bought it but otherwise it wasn't weathered,
obviously stored inside.
When I pulled the spark plugs #2 was rusty, I knew then #2 was probably the seized cylinder.
The crank moves so once I get this block free I think this motor will work.
Except for a motor mount every fastener so far has come out.
The cams look good, that's one thing I didn't have spares for.




I'm getting ready to weld this nut to the motor mount bolt so I can reef on it.
I've never encountered this before.
That motor bolt is completely frozen in the motor.
I might be better off cutting it flush each side and just drilling it out.
You have to like working on old bikes to overcome this s#it.
I just keep convincing myself that a 772 Turbo is a necessity.

 

That's gotta be some potent stuff! (Has a skull and crossbones on it)

Careful with that, you don't want to break the case section off.
I would heat the crap out of it, and shock it with cold water a few times.

And like you said:

BTW, like the progress your making.
Tony

 

It will be a very important milestone in human progress.

 

I think so to but if only you could convince my wife LOL

 

I think you’re right, I’ve already heated and beat on it several times. What is required to break this free might be enough to break the mount. I’ll cut it close on each side and drill.
Good access and no hurry

 

It’s been 4-weeks soaking in pure penetrating oil with the occasional blow with a hammer and cylinder 2 is still seized.
This piston and cylinder is no value to me so next time I get a chance to work on this I will get it off. Thinking of just drilling into the piston so I can hammer a drift between the piston and cylinder wall.
The block is loose now, I can raise it about 1/2” by rotating the crank. The motor looks good but I suspect it was sitting a long time.

 

Do you have a proper torch? Why not just melt the piston out and clean up the bore with muratic acid afterward?
You'll need to use a pencil tip so you don't overheat the cylinder liner, but it should work faster than using a drill and drift, plus you can use the liner again.

 

all I have is a propane torch so that's not going to melt it.
I will try some heat before drilling though.
I just need to break the rings loose from the wall to get this block off.
The 891 block is going back on, this one goes into the scrap bin anyway.