Knocking RV8
Posted: Wed Feb 13, 2008 9:06 am
I am looking for some advice from those more experinced in the RV8 than I am. I have more or less finished installing a RV8 in my TR7, it is basicallly a standard carbed SD1 unit. I purchased the engine second hand and partilly stripped it before installation, I thought I had struck gold as it was very clean inside and virtuallly everthing looked like new (it is also painted the blue which is usually used by re-conditioners), I didn't remove the crank or pistons but did check a couple of bearings.
I now have it all back together and on on start up it sounds great, the problem is when it gets hot, after a long idle where it has beeen cycling on the electric cooling fan (90deg C cut in) a heavy knocking starts, it can be stopped by pulling the plug lead off on cyl 2 on the LH side and it goes away when the engine speed is raised above idle. I have also removed the sump and checked the big ends which look fine, removing the plug lead on the other cylinder which shares the crank journal has no effect.
My thoughts are it must be a piston / con rod issue possibly the piston is upside down or damaged, my plan is to finish the rest of the installation (mainly modifying the bonnet to clear the carbs), fit an oil pressure gauge and drive it to see if the issue is evident under load.
Has anyone any other ideas / thoughts?
Kevin
I now have it all back together and on on start up it sounds great, the problem is when it gets hot, after a long idle where it has beeen cycling on the electric cooling fan (90deg C cut in) a heavy knocking starts, it can be stopped by pulling the plug lead off on cyl 2 on the LH side and it goes away when the engine speed is raised above idle. I have also removed the sump and checked the big ends which look fine, removing the plug lead on the other cylinder which shares the crank journal has no effect.
My thoughts are it must be a piston / con rod issue possibly the piston is upside down or damaged, my plan is to finish the rest of the installation (mainly modifying the bonnet to clear the carbs), fit an oil pressure gauge and drive it to see if the issue is evident under load.
Has anyone any other ideas / thoughts?
Kevin