Originally Posted by
motomanpat
How new is this engine? Did you buy it brand new and you are having this issue? If it is used at all it could be the rod. In my Vspec I had a similar problem but it was at about the 2 gallon mark.My rod started going away(I didn't know it at the time) and I was having a really hard time getting my low end to be right but it still ran and was pretty good down the straight but it kept stalling out and then I started tuning the mid,still no good! After that I went to a playday and was still having the same tuning issue so I started tuning again and then I heard a pop and it locked up. The bottom of the rod where the copper bushing is was totally trashed.
Not sure if this is the same issue but if your motor has been used at all then it is something to think about since you still have pinch. Hope that helps!!!!!!!!!!!!!!!
Originally Posted by
Jonro
Ok i pulled the engine down again and yes there is allot of play between the rod and crank pin. The brass bit in the rod is almost worn away, how can i tell if just changing out the rod for a new one will help or if the crank pin is worn too much also? The engine still has good top end and good compression so is it normal for the rod to wear so quick?
I also have a MRT GRP that has close to the same amount of wear on the rod end but it runs like a swiss watch, so eh i duno... I don't know weather ill bother with this engine as i could end up replacing the rod and it wont fix a thing.
Ok first and foremost I would like to let you know that in the original V-Spec the connecting rod does not have a lubrication hole going to that bushing add that to the break in process which is pretty hard on the rod.I have also heard that it is a good idea to replace the rod after break-in
. You need to get a Vernier Caliper and measure the crank pin in a few different spots to see how out of round it is. I can't remember but I think it needs to be no greater than .01 difference between all measurements(Maybe someone could chime in with the correct tolerance) If it is still within the Spec the crank is still useable. I would suggest to you that if it is in spec and you decide that you want to buy a rod buy a Speed rod as there is a lubrication hole going to the bushing! So how does the backplate look? Heavy scoring?