Hi, firstly can i say congrats to administrators for giving people like me access to such a great resouce such as this forum.
righto to the problem.
The rb26 in my r32 gtr has developed a knocking noise starting at 2200-2400RPM and increases in noise intensity to 3000RPM.
At idle the engine there is no miss, no noise showing no sign of a fault.
I have changed oil, pulled out the cams, compressed each valve individually and put it all back together to eliminate any issues with cam timing however the noise is still there.
The noise was first noticed after doing several 1/4 mile runs on the g-tec. I had a wideband installed during the runs to ensure mixtures were ok as the engine had been rebuilt about 2000km's before (by myself). The turbo's were running standard boost. There was no noticable noise to indicate a failure, the noise was only noticed when i left to go home.
the noise is a solid noise at 3000 almost sounds like it is in the inlet side of the head.
I havent yet changed the cam timing to ensure it is not valve knock. The engine turns over by hand fine with no noticable issues. On inspection of the cams there was no noticible sign of an issue, aside from a wear mark on no 6 exhaust base circle but checked clearances and was fine.
i have heard big end knock before (the reason for the rebuild) and i dont believe it is the issue.
The list of mods for stage one
- JE forged pistons,
- ARGO rods with arp bolts,
- Jun oil pump,
- Calico coated main and big end bearings,
- Tomeii cams type B and valve springs,
- Tomeii head and manifold gasket set,
- Aftermarket split dumps,
- Garrett GT2560 turb's
- new r33 crank
- head oil restrictor
- tomeii sump baffle
- modded oil return line to sump
- turbo blankets and manifolds heat wraped
- Ross Harmonic balancer
- ARP head and mains studs and bolts
if anyone has come across this issue before and knows what it may be can you please enlighten me as it has me puzzled mostly due to the inconsistancy of starting at 2200 ie a valve knock would be heard at idle, so too would a big end failure. I am maybe thinking it might be an issue with a peice of ancillary equipement on the engine - not explored.
thankyou for any future help.