Forum

[simon]

I was considering it Alan but they are in perfectly good nick having done around 5 or 6 thousand miles with me and maybe the same prior, so they've proven their reliability. Big bearings too. I'll give it some thought and price them up over here but imperial bearings tend to be as expensive as metric ones are cheap so they may just get left where they are. What I am thinking about is an ally barrel and I will need new piston rings as even though it was a new piston 5 k miles ago there is substantial evidence of blow by. I'm interested in anyone's experience of the untested Indian ally barrels though. Don't care about the helicoiled threads as I can make my own proper steel inserts in a flash but would like to know about the tolerances and whether they are good enough?

[simon]

Your so right about the helmet Paul. I rode to the other end of the North Island on my old Ducati and it was almost stress free because a friend suggested ear plugs. Motor never sounded so sweet!

[Norm]

Simon,
We get a set of Jap mains over here for around $80

[simon]

And as I've just worked out they aren't imperial bearings. I've ordered the aluminium barrel and a new set of piston rings from our host and am looking forward to seeing how the change in cooling efficiency affects the high speed cruising potential. In the meantime I'll get the die grinder out and do a bit more fettling on the crankcase as the castings are woeful! should look fab even if it clanks like a JCB.

[Alan R]

--------- at least it will sound better than a THWAITES !! have a look at this }----- http://www.thwaitesdumpers.co.uk/mainsite/index.html -------------- I wonder if GRUNDA has seen this post ?? (goes and hides in cupboard !!)

[MadMike]

Simon in your original posting you state that you had found brass swarf in your oil. Before you rebuild, ar at least as part of the strip down process you MUST establish what it was and where it has come from, and then rectify the fault/failure and completely clean all cmponents and oil ways. Simply bolting on a nice shiny new barrel from our hosts coud result in you making a great lump of scrap metal if you do not correct the awarf making fault. Whilst you have established the lack of end float in the crank you have not identified the real cause of the problem that started this whole thread or threads.

[simon]

Yes MadMike the swarf was my main concern hence my head scratching. The only brass/bronze item I have found in the whole motor are the cam bushes and they are immaculate. The oil pump has been stripped and the oil ways all washed and blown out and nothing whatsoever has been found. Got me beat! The only thing I can imagine is that either the swarf was put un the oil tank by someone before I owned it or it was in the tray before I emptied the tank into it. Neither seems very likely I grant you. Moreover the fundament clank that the motor occasionally produces also seems to have no origin and to leave no damage. All a bit confusing really.

[Beezabryan]

MM & Simon, buggered if I can think why as the timimg gears run in an oil bath but the cams must have been changed or maybe just the bushes 'cos the Infamous Bullet 500 has all plain bearings in the timing chest. So far as I remember there is not a single piece of yellow metal anywhere in my 500 lump.

[simon]

Points for Beezabryan there! The cams have been replaced with the Hitchcocks Improved ones so do have brass bushes. I've found no solution to the swarf issue but think I might have finally discovered the source of the clatter. In giving everything a clean in kerosine prior to reassembly I noted that the inlet rocker was rather stiff. I pulled it apart to find that it has worn a patten in the shape of the cap which has an oil relief channel through the journal. I think this was locating itself and creating a clatter as the spring pressure overcame the resistance and slammed the tappets home. I've polished the rocker shaft with some 400 emery and it seems to rock freely with no notchiness now. Keep your fingers x'd for me. S

[Alan R]

Hello SIMON-------- reference your inlet/exhaust rockers }--- Are they the original iron ones along with the original rocker arm OR.. the later SAMRAT items with Aluminium bodies and re-profiled arms ?? When checking for free play clamp the two halves in your bench vice (This simulates them being bolted down in the cyl. head) and then check for rotation PLUS}--- ideally there should be NO side play BUT with oil coming through..It's also a good idea to open up the oilways and feed hole to allow an increased oil flow-rate (This will allow greater cooling etc.).. Remember with the Bullet ALL the scavenged oil from the sump goes up to the rockers before returning to the oil tank so a free-flowing system will keep the back-load on the scavange pump to a minimum.. I have heard it said that the SAMRAT rockers are a poor fit into the original push-rod end cap and that this gives a rattle sound---- but I haven't any experience of that myself..