Saturday 30 December 2017

The new TR1 motor - Assembling the longblock (part 16)

Last time we left off with the engine cases being re-assembled and the sealant hardening. On today's menu is the reassembly of what US-V8-engine builders would call the long-block. This post will also mark the end of the necessary and somewhat mundane section of the build and finally makes us progress towards the part where finally some provisions for extra power are made.

The main task this time is to install the timing gear and test-fit cylinders and pistons to assess the tolerances.

Timing is a lot easier, when all the timing marks are clearly visible. I have started to mark these with a bit of paint incl. the corresponding tooth to make installation of the flywheel easier.

The spring-loaded primary gear needs to be pre-loaded in order to mesh with the gear on the backside of the flywheel. Yamaha engineers conveniently placed a M6-hole in the gear, so you can lock the spring in place nicely.

After-reinstalling the gear on the back of the flywheel, I also painted the timing mark and the two adjacent teeth to make the installation a bit easier.

Before fitting the flywheel put on the oil-pump-chain, as you won't be able to put it on afterwards.

With the teeth marked in white it's fairly easy to time everything right.  

Once installed it is easy to pull out said M6 bolt.

The right side is a lot easier as you can clearly see what you're doing. 

The shaft of the primary gears is hollow bored and won't mind a bit of oil to lube the bushing of the gear nicely.

Of course I could just have fitted the later (larger) oilpump, before the flywheel, but as dozens of people have told me you can't do it, I took some photos showing how to do it. 

Always make sure you put in fresh o-rings on the oil-channels as a pressure loss would be incredibly hard to track...

As a lot of people pointed out, you can't sneak the oilpump past the flywheel. They are right. So you losen that one philips bolt...

... and install the back section of the oilpump into the cases.

I use medium loctite on these bolts, as they are only torqued to 10Nm.

Now fit the front section of the oilpump and you've got the oilpump installed without taking the flywheel off.

Gearshift selector installed on shifter drum.

Neutral switch with freshly annealed copper washer. (Hint: test it outside of the engine first. They rarely fail, but ...)

That's the 1100 outer clutch basket fitted.

The last section of this post is dedicated to installing the pistons and cylinders and assessing the tolerances as XV-pistons are notorious for sitting low in the bore.

Always grease up base-gaskets. Makes removal a lot easier and sometimes you're even able to save the gaskets for later use.

Pistons installed with fresh rings.

Cylinders were given a quick hone as their overall dimensions were quite like new (not bottle-shaped) and as such going for an oversize would have been a waste.

 Cylinder and piston installed ...

... and the rear one sits low at a whopping 1.3mm. The front one is "only" low by 1.1mm. Add 0.8mm for a compressed headgasket and this basically means: A lot of work to correct that.

Next up: Building a 9-disk clutch and then it's on to turning down the cylinders to get the squish right and then welding up the cylinder heads, which is where the power of this engine will come from.

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