421LC Project - Sneak Preview of Initial Results
Mar 18, 2020 22:53:17 GMT 1
midlifecrisisrd, Tobyjugs, and 2 more like this
Post by muttsnuts on Mar 18, 2020 22:53:17 GMT 1
So its been a while since posting anything, just been mega busy as usual, but this evening I decided to progress the 421LC project a bit further.
My original target was to build an engine that would do mid to late 60's bhp and approx 40ftlbs of torque, after a lot of testing and tweaking and a few top end strip downs and adjustments being made, I think I am about there.
One side affect I wasn't expecting is how the engine will perform 2 tasks pretty well, with the right pipes on it becomes a rev monster and pushes over 71bhp, but with the correct designed pipes for it on, it is pushing 65+bhp, but with huge mid range.
One graph shows how it compares to a stock LC doing 40bhp, and the other graph shows how just swapping the pipes transforms the engines characteristics, which is an unexpected bonus, although I doubt the crank would have a long life being revved that hard all the time !
To help refresh peoples memories, I started building a 4mm stroked, 68mm bore one off LC engine a few years ago, so this is a stock looking motor in its entirety, it uses a custom crank that fits straight into the crankcases without machining and has relined barrels that have been taken out to 68mm
I still have work to do on it, but having pretty much hit my target, I am pretty happy with it, so I'll probably put the bike together and get some miles under its belt to see how reliable etc it will be
I know the gearbox is going to need some attention soon, so doing some miles on it before stripping it down is probably a good idea anyway
No doubt I'll play with it a bit more and hopefully squeeze some more out of it once its got a few miles under its belt
Watch this spsace......
My original target was to build an engine that would do mid to late 60's bhp and approx 40ftlbs of torque, after a lot of testing and tweaking and a few top end strip downs and adjustments being made, I think I am about there.
One side affect I wasn't expecting is how the engine will perform 2 tasks pretty well, with the right pipes on it becomes a rev monster and pushes over 71bhp, but with the correct designed pipes for it on, it is pushing 65+bhp, but with huge mid range.
One graph shows how it compares to a stock LC doing 40bhp, and the other graph shows how just swapping the pipes transforms the engines characteristics, which is an unexpected bonus, although I doubt the crank would have a long life being revved that hard all the time !
To help refresh peoples memories, I started building a 4mm stroked, 68mm bore one off LC engine a few years ago, so this is a stock looking motor in its entirety, it uses a custom crank that fits straight into the crankcases without machining and has relined barrels that have been taken out to 68mm
I still have work to do on it, but having pretty much hit my target, I am pretty happy with it, so I'll probably put the bike together and get some miles under its belt to see how reliable etc it will be
I know the gearbox is going to need some attention soon, so doing some miles on it before stripping it down is probably a good idea anyway
No doubt I'll play with it a bit more and hopefully squeeze some more out of it once its got a few miles under its belt
Watch this spsace......
