The Dave Silvers (Hi-Level) Balancer Box....

B*gger, no internals, I`ll have to keep saving for another year for an overpriced original one...

There's a few more problems with them Dave, but nothing too bad and I think these have a place depending on what people want in their bike. But the M5/M6 is plain careless- and the "H" section ones are the same in this regard- they also have M6.....

Probably a deeper note as it has more volume than the "H" section. I'll compare some measurements tomorrow as it is not quite the same as a Honda item....

The 6mm holes could be plugged and 5mm threads inserted.If I needed a collector box I'd use one of these as I'm not too fussy on originalty

Don't think it would be too much of a job to open one up and install some internals, then tig back together. Might be an option if genuine ones become scarce.
I've only seen pics but I think it's simply two 25mm tubes bent at 90 deg with perforations on the outside radius.

Part 2 of this thread- a comparison with the Honda box.

I used Honda Part No 18310-413-013 to compare with the Hi-Level box. This Honda part was specified for the early "N" and "NA" versions of both the 250 and 400 SuperDreams- number was superceded to a 447 part for the "NB"'s and a few other model codes were used for the CM models and the later 450 range. But all essentially the same part except for the internal pipework.

Straight away the 2 boxes look to have slight differences in size and shape- but nothing that you would notice if you were only looking at one of them. Main difference is that the Hi-Level paint finish is more matt- and actually looks to be tougher than the Honda.





Again- only if you sit the boxes side by side would you notice any great difference. The Hi-Level box is not as deep for instance- it's the top one in the first photo below and the RH box in the other two photos. So when laid out on a table the boxes appear to sit different and the sockets not to line up- but its all cosmetic. I reckon when fitted you would be hard pushed to tell these boxes apart. Notice however that on the Honda box you can see spot welds in various places that are locating the internal pipework and baffles- there are none on the Hi-Level.






Again- there is nothing in any of the measurements I took that would cause any difficulty in the Hi-Level box being able to be fitted with only small adjustments. The overall length of the Hi-Level is 10mm longer at 260mm against the 250mm of the Honda. But all of this difference is down to the header inlet sockets being longer- if this caused a problem with lining up the headers- i.e. you could not get them far enough in before the collars hit- it would be easy enough to cut that extra 10mm off. You can see the difference in the photos above.

The centreline distance across the bike between the left and right sockets is exactly the same for both header and silencer ends for both boxes. However the 2 mounting brackets that fix the box to the bike- the Hi-Level brackets are 4mm less distance apart. Nothing that could not be fettled and jiggled to fit.

The diameter of the inlet sockets on the Hi-Level is 45-46mm against the Honda's 44-46mm- all fairly adjustable as the sockets are slotted anyway. Both boxes outlet sockets are within a mm or so with the Hi-Level at 50mm against the Honda's 49mm.

One difference which may mean a bit of tweaking is that the complex angles of the silencer sockets are slightly different. You can also see this in the photos above. The header inlet sockets are more-or-less straight on these boxes, but the way the silencers both angle up and splay out on these bikes mean the exit sockets end up at a strange offset. This is further complicated by the silencers themselves of course- as their inlet spigots are also at a complex angle. If you are using pattern silencers it all gets a bit complicated! Nothing that couldn't be adjusted when the system is fitted I think...


But now the bad news. As I said- the Honda box shows spot welds where internal stuff is fitted, and it's obvious when moving the boxes around for the photos that the Hi-Level box is much lighter. It's actually a full 1.40kg lighter at 2.13kg against the Honda's 3.53kg- a massive 50% lighter. And it's because the Hi-Level is just an empty box. In the Honda box it not only has the internal perforated pipes that direct the exhaust gases across the width of the box, but also other pre-formed plates to force the gases to follow a pre-designed path. Also- the gauge of metal used in the main construction of the Hi-Level is thinner- although the thickness of the tubing using for the inlets/outlets is the same. Honda box top- viewed from the silencer end and showing both the internal perforated pipe and the shaped baffles top and bottom. And then the empty Hi-Level box....






Also as I previously said- for some inexplicable reason on the Hi-Level box the heatshield mounting lugs have been tapped M6 instead of the correct M5 as on the Honda box. I know the comments above have said this can be fixed by plugging and then re-tapping with the correct size- I am not so sure this will be possible with the very slight difference between M5 and M6 threads. I think either the holes in the shields will need to be drilled out to suit M6 fixings, or the lugs ground off and replaced with M5 tapped items welded back on.


Conclusion?

I like the Hi-Level box as it adds some more choice. I would certainly fit it to one of my bikes in preference to those horrible "H" section boxes as it looks right. I think its pretty good value at 90 quid delivered. If I couldn't get the correct Honda box. I'm not sure the Hi-Level would last too long through a UK winter as it's pretty light construction. But we don't do the miles in the weather we used to. But.... you can still get really decent S/H Honda boxes which will also of course look right- and sound right and perform right. So the Hi-Level sits in the middle and I hope Silvers gets some more in.....

Great post that giving good comparison,reckon it will sound like the H section box?