The saga continues
.....
The end is almost in site, after blue printing the bottom end and moving the notches for the shell bearings :evil: , the PAR rods are good into the engine again.
Simon, thanks for your help with ARD, I got my mechanic mate to speak to them rather than me (a pretend mechanic) and he said they were very helpful and useful 8)
However, the con rod side clearance is too big! It 0.533mm, 0.033 out of tolerance :x
At this point the saga changes course. Though we've not built the engine and checked all the tolerances, the writing is on the wall for the gap size but it might be that PAR have done the right thing :shock:
Both my mechanic and ARD felt this would be "okay" though not ideal and we should just build the engine. Not happy with that as an answer I've done some digging.
There is a school of thought that for race engines, the side slearance should be 0.4-0.7mm. Many US sites engine building sites talked about this for their V8
This increases the amount of oil around the bearings and causes more splash. The disadvantage is that you get more splash and you are taking oil away from elsewhere in the engine. Also at low engine revs you might find the oil pressure is way too low and you can get knocking
But... when the oil pressure is higher you will get better lubrication and cooling of the piston.
With the Sunny being a road car, Nissan will have a side clearance that is lower to ensure you don't get any knocking at idle but up to 0.5mm you're probably okay. The PAR 0.533 is right at the top end of what you could get away with on a road car. The wider side clearance is meant to be better at high revs which is exactly what my car has been built to do.
Have PAR done something right at last :shock: :shock:
Any thoughts?