Just doing one and found out that a BSA fork top bush will fit in the steel cage once the lip is removed. Then drill through the oil and peg holes and machine to fit your main bearing diameter.
I've been experiencing low oil pressure when mine warms up, a friend advised that I replace this bush,.the bike has a aftermarket high output oil pump,and heavy oil.on a hot day oil pressure dropped to 30psi...I'm thinking of pulling engine and teardown inspection this fall.this bike is Beautiful with fresh topend over haul,.I am the new owner.
vp23 is a bronze, not all bronzes are the same some bronzes can be mixed with lead or tin copper zinc, also other materials such as silicon, carbon, and so on the list is endless and all have different properties and applications, and the mix of different metals can and give the bronze all different colors that's why metals have a product number or code number you could look at it like a paint code hope that helps in any way
I would measure the journal and ream the bush to fit. The machined id of the bushes would be pretty hit and miss and if you ever need to fit another the journal might be too small.
hi you can't ream them steel backed bushes as there is not enough meat on them to do so plus all your doing is taking life off the bush, plus the journal always wears out oval so when the journal wears out its re ground back to round again to minus 10/20/ 30 and so on. i think you can only go to minus 50 on steel back bushes, then your looking at a solid bronze bush,and then that would need line boring and then reaming. hope that helps in any way.
@a65builder67 modern thinking is take the minimum off the journal to make it round and then bore the bush to suit to increase the life of the crank and preserve the strength not take it to -0.010 etc
@@grahamseward1388 hi you can't ream them vandervell vp23 steel backed bushes and if you try you will simply damage them the vp23 material will not stand it, the vp23 material has porosity properties and is designed to absorb carbon and other inperfection's floating about in the oil, also vp23 is a very very soft material and if you try to ream it will just close the metal and will wear very quickly, plus them steel backed bushes only come in 10s 20s 30s 40s and 50s and the vp23 material is only about 15 thou think
@@a65builder67 if you buy the +10 Bush it will stand a ream or hone, they don't make the steel backing +10+20 etc they are standard size. They had to machine them in the first place remember
@@grahamseward1388 well graham for one they are not machined they are rolled they are a split bush the steel is coated with lead bronze then the metal sprayed with vp23 material that material is sintered once that has been coated it is then rolled to the correct size which is a std size and then minus 10/ 20/ 30/ and so on and not plus 10/20, if i was you i would read up on vp23 sintered bronze which porous where can hold oil and micro particals such as carbon and other debris and that',s what gives it a good bearing material, bsa engineers were't idiots and them steel backed bearing where good for at least 30,000 plus miles also have a read up bsa a65 timing side bushes then you'll understand the meaning of plus/ minus in the engineering world. kind regards ps you can not ream or horn vp23 material it will get damage
I wouldn't put the bush in the crankcase Paul as it's easier to hone / polish in a lathe out of the crankcase. It could be slightly out of round after pressing into the steel backing. Also if the crank has 3 thou of wear on one side it will need at least 6 thou off the OD to clean up and make it round again, apologies if teaching you how to suck eggs
Thanks for sharing.
Just doing one and found out that a BSA fork top bush will fit in the steel cage once the lip is removed. Then drill through the oil and peg holes and machine to fit your main bearing diameter.
Enjoying this saga Paul, thanks for sharing👍
I've been experiencing low oil pressure when mine warms up, a friend advised that I replace this bush,.the bike has a aftermarket high output oil pump,and heavy oil.on a hot day oil pressure dropped to 30psi...I'm thinking of pulling engine and teardown inspection this fall.this bike is Beautiful with fresh topend over haul,.I am the new owner.
30 psi when hot, on a hot day would not worry me if the engine sounds and feels ok.
@@paulhenshaw4514 ok thank you sir.
Plan of Attack on- going then
What is the bush material metal? It appears copper or brass....................
It's a Vandervell vp23 insert, so classed as composite .
vp23 is a bronze, not all bronzes are the same some bronzes can be mixed with lead or tin copper zinc, also other materials such as silicon, carbon, and so on the list is endless and all have different
properties and applications, and the mix of different metals can and give the bronze all different colors that's why metals have a product number or code number you could look at it like a paint code hope that helps in any way
@@a65builder67 Ok very good. Thank you for your answer. It appeared to be brass, copper or bronze in appearance or some similar soft material.
@@AGEngineering Thank you for your answer here. Now I understand this bushing much better.
@@wayneroberts4144 your welcome Wayne and yes, your right vp23 is a bronze and is quite a soft material, take care with kind regards.
The inside of the P-B bush will also need spinning-out slightly as it's not a tolerance-engineered surface in there.
I would measure the journal and ream the bush to fit. The machined id of the bushes would be pretty hit and miss and if you ever need to fit another the journal might be too small.
hi you can't ream them steel backed bushes as there is not enough meat on them to do so plus all your doing is taking life off the bush, plus the journal always wears out oval so when the journal wears out its re ground back to round again to minus 10/20/ 30 and so on. i think you can only go to minus 50 on steel back bushes, then your looking at a solid bronze bush,and then that would need line boring and then reaming. hope that helps in any way.
@a65builder67 modern thinking is take the minimum off the journal to make it round and then bore the bush to suit to increase the life of the crank and preserve the strength not take it to -0.010 etc
@@grahamseward1388 hi you can't ream them vandervell vp23 steel backed bushes and if you try you will simply damage them the vp23 material will not stand it, the vp23 material has porosity properties and is designed to absorb carbon and other inperfection's floating about in the oil, also vp23 is a very very soft material and if you try to ream it will just close the metal and will wear very quickly, plus them steel backed bushes only come in 10s 20s 30s 40s and 50s and the vp23 material is only about 15 thou think
@@a65builder67 if you buy the +10 Bush it will stand a ream or hone, they don't make the steel backing +10+20 etc they are standard size. They had to machine them in the first place remember
@@grahamseward1388 well graham for one they are not machined they are rolled they are a split bush the steel is coated with lead bronze then the metal sprayed with vp23 material that material is sintered once that has been coated it is then rolled to the correct size which is a std size and then minus 10/ 20/ 30/ and so on and not plus 10/20, if i was you i would read up on vp23 sintered bronze which porous where can hold oil and micro particals such as carbon and other debris and that',s what gives it a good bearing material, bsa engineers were't idiots and them steel backed bearing where good for at least 30,000 plus miles also have a read up bsa a65 timing side bushes then you'll understand the meaning of plus/ minus in the engineering world. kind regards ps you can not ream or horn vp23 material it will get damage
I wouldn't put the bush in the crankcase Paul as it's easier to hone / polish in a lathe out of the crankcase. It could be slightly out of round after pressing into the steel backing. Also if the crank has 3 thou of wear on one side it will need at least 6 thou off the OD to clean up and make it round again, apologies if teaching you how to suck eggs