Post by beerbellykelly on Dec 18, 2013 0:34:44 GMT
see the same q,s asked many times over the years-I WILL ADD TO THIS AS TIME ALLOWS-
here,s how i like things done,we,ll gloss over the basics and keep it AIRCOOLED ,but most of the info and tech apply to all ICE,s
clean-surfaces , mating faces must also be flat-CHECK THEM-threads all good and clean-CHECK-hd STUDS/STRAIGHT CUTS/THRUST WASHERS ETC-CHECK MEASURE AND CHECK alighnment /matched pairs AGAIN BEFORE YOU INSTALL-
everything in order-plan the stages before you build your motor and have all the parts and equipment you,ll need to hand-read the manual
race list-make a note of every tool you need during the strip down of your motor-this will be your pits tool kit plus a few-
prep-everything weighed [if req] and fettled , ready to go-
CHECK ALIGNMENT check rotation check everything-
plenty of tea-coffee beer cake
If an engine has reached its time for a rebuild or you are planning more power a few basics will save you time and help you choose your parts-
rebuild for average street use-first thing i always check is the oil filter-slice the metal caps off with a stanley knife and pull open the paper element-read it like a book-grey sludge is normal -clutch residue and general combustion scuzz-lumps of alloy are worrying and shiney brass coloured or magnetic shards are cause to investigate-IF your motor is clean and has passed a leakdown test - save money and leave it be-streetbikes DO NOT suffer quite as hard a life as racers-
IF you have a big bore kit or want to force induct or increase the power by a good margin or you are going racing-you WILL need to START AT THE BOTTOM-
the engines we deal with are roller bearing big ends and ball bearing mains , as opposed to plain bearing [on the mains and big ends] of later designs,this requires a pressed up crank [like a two stroke ] - suzuki welded some of these cranks as standard - but just enough to deal with stock power-START AT THE BOTTOM-
make no mistake building an old engine to deal with bigger horse power and increased torque is never cheap-BUT ITS WORTH EVERY PENNY!
you can go and spend the thick end of £12-1500 on a competition crank in europe,more if you want a custom american version-decide if your pocket can hack it and spec your crank-
factory seals,and gaskets or cometic -gaskacinch , kbond , moly paste-loctite thread stud lock
on a race motor we send the transmission to a specialist set up for just this-we use very special bearings and cannot fault them in both racing on the great white dyno at bonneville or lapping the isle of man-we
use the same people each time-
i have two old dot punches welded onto parts of bar to hold my cylinder heads when disassembling-it keeps the mating surface away from harm and makes life real easy-which is my lifestyle choice-
cylinder head re-working is a massive subject , and everyone knows best-we just use the same guy , and i have a long standing simple rule-if they dont have a flow bench and cant show us a printout of before and after -they wont ever see one of our heads-
another friend of a friend has a combustion dynamommeter-this helps in cam design -we like people with such hobbies and interests.
cams-again everyone knows best and this is possibly a bigger subject than even head design-established practice has long been what works on track , but what use is that to me if i wish to use a readily available BBturbo from a modern production car on my 20 year old motorcycle ?
well for many years the answer was always use the stock cam-a turbo engine likes the least amount of overlap [valves closed longer] as it reduces to an extent the backpressure [where the exhaust gasses back up to such a degree that intake charge area is reduced-] some tuning houses way back offered turbo cams but most builders went with went with stock-
the thinking in this area has been around for at least 15-20 years , and with the advent of the modern high effciency turbochargers would seem , for race use at least somewhat outmoded-
while racing at speedweek in 2012 i got to spend a bit of time in the pits with the poteet & main team-they helped a friends team out and we got to talk turbos-the fabulously named KENNY DUTTWEILER-does the fastest turbos there is-he had this to say-
on the older turbos , especially stuff like that rayjay you mentioned it was common to see 1:5-2:1 back pressure ratios-some manufacturers even quoted the ratio!-on the units we use and those that are generally available for competition , back pressure is in fact less than boost pressure ! -due to the higher back pressure ratio of the old turbos we would see some tuners [mainly on car engines] using a cam which closed the exhaust valve earlier , this was easliy achieved with a wider lobe separation angle [LSA]
this is where the older wide LSA theory came from ?
here,s how i like things done,we,ll gloss over the basics and keep it AIRCOOLED ,but most of the info and tech apply to all ICE,s
clean-surfaces , mating faces must also be flat-CHECK THEM-threads all good and clean-CHECK-hd STUDS/STRAIGHT CUTS/THRUST WASHERS ETC-CHECK MEASURE AND CHECK alighnment /matched pairs AGAIN BEFORE YOU INSTALL-
everything in order-plan the stages before you build your motor and have all the parts and equipment you,ll need to hand-read the manual
race list-make a note of every tool you need during the strip down of your motor-this will be your pits tool kit plus a few-
prep-everything weighed [if req] and fettled , ready to go-
CHECK ALIGNMENT check rotation check everything-
plenty of tea-coffee beer cake
If an engine has reached its time for a rebuild or you are planning more power a few basics will save you time and help you choose your parts-
rebuild for average street use-first thing i always check is the oil filter-slice the metal caps off with a stanley knife and pull open the paper element-read it like a book-grey sludge is normal -clutch residue and general combustion scuzz-lumps of alloy are worrying and shiney brass coloured or magnetic shards are cause to investigate-IF your motor is clean and has passed a leakdown test - save money and leave it be-streetbikes DO NOT suffer quite as hard a life as racers-
IF you have a big bore kit or want to force induct or increase the power by a good margin or you are going racing-you WILL need to START AT THE BOTTOM-
the engines we deal with are roller bearing big ends and ball bearing mains , as opposed to plain bearing [on the mains and big ends] of later designs,this requires a pressed up crank [like a two stroke ] - suzuki welded some of these cranks as standard - but just enough to deal with stock power-START AT THE BOTTOM-
make no mistake building an old engine to deal with bigger horse power and increased torque is never cheap-BUT ITS WORTH EVERY PENNY!
you can go and spend the thick end of £12-1500 on a competition crank in europe,more if you want a custom american version-decide if your pocket can hack it and spec your crank-
factory seals,and gaskets or cometic -gaskacinch , kbond , moly paste-loctite thread stud lock
on a race motor we send the transmission to a specialist set up for just this-we use very special bearings and cannot fault them in both racing on the great white dyno at bonneville or lapping the isle of man-we
use the same people each time-
i have two old dot punches welded onto parts of bar to hold my cylinder heads when disassembling-it keeps the mating surface away from harm and makes life real easy-which is my lifestyle choice-
cylinder head re-working is a massive subject , and everyone knows best-we just use the same guy , and i have a long standing simple rule-if they dont have a flow bench and cant show us a printout of before and after -they wont ever see one of our heads-
another friend of a friend has a combustion dynamommeter-this helps in cam design -we like people with such hobbies and interests.
cams-again everyone knows best and this is possibly a bigger subject than even head design-established practice has long been what works on track , but what use is that to me if i wish to use a readily available BBturbo from a modern production car on my 20 year old motorcycle ?
well for many years the answer was always use the stock cam-a turbo engine likes the least amount of overlap [valves closed longer] as it reduces to an extent the backpressure [where the exhaust gasses back up to such a degree that intake charge area is reduced-] some tuning houses way back offered turbo cams but most builders went with went with stock-
the thinking in this area has been around for at least 15-20 years , and with the advent of the modern high effciency turbochargers would seem , for race use at least somewhat outmoded-
while racing at speedweek in 2012 i got to spend a bit of time in the pits with the poteet & main team-they helped a friends team out and we got to talk turbos-the fabulously named KENNY DUTTWEILER-does the fastest turbos there is-he had this to say-
on the older turbos , especially stuff like that rayjay you mentioned it was common to see 1:5-2:1 back pressure ratios-some manufacturers even quoted the ratio!-on the units we use and those that are generally available for competition , back pressure is in fact less than boost pressure ! -due to the higher back pressure ratio of the old turbos we would see some tuners [mainly on car engines] using a cam which closed the exhaust valve earlier , this was easliy achieved with a wider lobe separation angle [LSA]
this is where the older wide LSA theory came from ?