The bike with the most room would be my 73 Eldorado or maybe the DR780 but I had thought of the Sunbeam if the boost was kept to something sensible like 4psi or less.
High drive ratio and low maximum engine revolutions for high torque.
The supercharger cost around US$141 plus post so was a spur of the moment thing.
If it could be mounted so it did not look to much out of place it might be viable, it is quite small but gains size when you hold it next to the engine block.
I had payed for it on a Sunday afternoon (eBay
) and it was at the door from Japan by 9:00am (DHL) on the Wednesday morning, I was still away at work so took some time to strip it when I flew back home, the rotors are some form of plastic and in great condition as were the bearings so a bonus.
Case and housings cleans and put back together.
I'm afraid with only 6 days at home motorcycles have been on the back burner for a bit, Spring is here so the weather is getting better so I will get more motivated as Summer approaches.
I had purchased all new parts to recondition the Sunbeams cylinder head quite some time ago but had had some concerns about the sealing face for the head gasket, old mate from its past had been there and there were signs of some heavy handedness in the form of some gouges etc.
The thought had been to fly cut the surface but it would be a large cut perhaps 1mm (0.040") as a minimum.
A welding repair perhaps another option with a light fly cut, anyway I had started by boring the old valve guides so they could be removed with little to no impact on the head itself.
As it turns out a cylinder head came up on UK eBay
, auction ending this week and looking to be in fine fettle, oddly only one other bidder so was lucky to get it for a little over $200 + post.It should be here by the time I return home in a few weeks.eBay
The pictures have been resized but were large and the casting including the all important gasket surface looks to be good.
That is about it unfortunately.
I had tried to contact one of the well known Sunbeam members in the UK about modifying the oil system for an oil filter but any emails return as if the address does not exist.
Having no oil filter is out of the question as was the same thing on my Eldorado, on the Moto Guzzi it was fairly easy to modify the engine block (as in links a page or so back in this thread) the Sunbeam is a little more tricky, some folk have diverted the oil at the rear crankshaft bush, this other member had it seemed machined a new oil pump outer plate that has a take off passage that goes off to the filter (and oil cooler) then back to the rear bush where it carry's on in its usual oil path.
With an oil filter a modern oil that does not hold contamination in suspension can be used, something like Mobil One V twin I hope.
The oil pump is just below the bore that takes the white metaled rear crankshaft bush so space to work with is at a premium, the original mod for this looks to be blocking the oil groove to take the oil away to a filter via the pressure relief port then bringing it back again to the upper passage that has a plug as standard, that may the way to go, we will see....