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I eventually found a replacement at a wreckers just north of Sydney about an hour's drive from where I live. These LS1 conrods are as scarce as rockin' horse you know what!
Che70velle I was concerned mainly about getting the old pin out. I was worried it might be mis-shaped and therefore difficult to press out, hence the suggestion to cut it and press the ends in. I've dropped it off at the engine shop that originally pressed the pins into the pistons for me and I will let the figure it out.
I've also ordered a new set of injectors. I resisted the temptation of ordering a cheap set off ebay as I've read nothing but bad stories about mismatched injectors, etc. I purchased them from a reputable supplier who has assured me they are genuine Bosch injectors. Hopefully, should have them tomorrow.
I eventually found a replacement at a wreckers just north of Sydney about an hour's drive from where I live. These LS1 conrods are as scarce as rockin' horse you know what!
Che70velle I was concerned mainly about getting the old pin out. I was worried it might be mis-shaped and therefore difficult to press out, hence the suggestion to cut it and press the ends in. I've dropped it off at the engine shop that originally pressed the pins into the pistons for me and I will let the figure it out.
I've also ordered a new set of injectors. I resisted the temptation of ordering a cheap set off ebay as I've read nothing but bad stories about mismatched injectors, etc. I purchased them from a reputable supplier who has assured me they are genuine Bosch injectors. Hopefully, should have them tomorrow.
Cheers,
Greg
All good man.. Didn't realize you were down under haha. Shipping might have been a bitch on that one!
Engine is all back together now with the replacement conrod. Guess what, the original problem is still there!!!
It runs great when I first start it up. Then once its warmed up, it starts smoking like a chimney, and running roughly. I checked the oil - no sign of coolant there. I checked the coolant, no sign of oil there. I pulled the plug from the cylinder that had the bent conrod replaced and stuck my inspection camera in. Looks fine. Can see small traces of what appears to be oil on top of the piston but I assume that's the oil I used to lubricate the cylinder before I stuck the piston back in.
I'm starting to run out of ideas. Could it be a crook O2 sensor making the mixture too rich once it goes into closed loop? Would that cause the smoke I'm seeing? Help!
Greg
PS> I can hear a slight cavitation noise coming from the fuel pump but not sure if its significant?
I tracked both O2 sensors as well as the AFR (Air Fuel Ratio). I've included a snippet of the graph below.
The AFR remains constant at 15% which seems unusual ? I would expect it to be changing quite rapidly in response to the changes in the O2 sensors.
Both O2 sensors start out at around 400 mV and track each other for the first 45 secs. At that point the right O2 sensor (blue trace) starts falling to around 400mV. If I rev the engine I can see the right sensor respond by increasing in voltage by about 200mV but the left sensor only increases by around 20~30mV. I would expect both sensors to track each other fairly closely however the right sensor wants to settle at around 300mV and the left sensor at 650mV. The right sensor is responsive to changes in rpms but the left sensor seems very lazy and doesn't respond much to rpm changes.
The leaky fuel injector was on the left side so I suspect that possibly unburnt fuel has contaminated the left O2 sensor.
The graph below was taken at t= 285 secs to t = 310 secs. The engine should have been well and truely in closed loop by this time.
I'm thinking the reason for the smoke was due to residual and rough idle could be contributed to fuel delivery. Do you have a fuel pressure gauge installed to monitor PSI when running?
Yes I was thinking initially the smoke was due to some residual fuel in the exhaust but there is a lot of it and it doesn't seem to be abating (although last time I started it there wasn't any smoke?). I have a fuel pressure gauge installed and it is steady at just under 60 psi (I think for an LS1 it should be 58 psi) so close enough.
Its just that the waveforms for the two O2 sensors are so different. I expected they would closely match.
I've ordered a new set of O2 sensors (genuine Bosch). Just waiting for them to come in.
Also I've installed a new Bosch fuel pump which hopefully will stop the cavitation problem. I had a high flow knockoff 044 installed previously which probably contributed to the cavitation. This one has about 60% the flow rate of the 044 plus it has a 15mm inlet port so I'm installing a 5/8" inlet hose as opposed to the 1/2" I had previously.
I've just installed the new O2 sensors. This seems to have fixed the problem! No more rough idling and hesitation on acceleration. The waveforms of the new sensors appear to be switching the way I expected them to:
The new sensors I confirmed as genuine Bosch as the box had the hologram on it with the security code. I checked the security code on the Bosch website and it confirmed them as genuine.
Now for the next problem. I noticed that even though the coolant got up to 200 deg F, the thermostat had still not opened. Its only relatively new, so I'd be surprised if it is faulty. Could I have an air bubble in the system - would that cause the problem? Any suggestions on how to troubleshoot the problem appreciated.
I installed a high flow water pump. I've read that this may cause the thermostat not to open. Could this be the cause? Apparently I should install a high flow thermostat that opens with the flow.
Can someone recommend an appropriate thermostat to install ?
I installed a MotoRad stat in my C5 Corvette many years ago. With a DeWitts radiator, I've had no problems cooling a built LS7. If I were you, that's the brand I'd look for. I'd go with a 180° model.......
Motorad thermostats are not so common in Australia. I think the one I need is the 456-180. Tridon has a similar stat with model no. TT456-180 which seems to be equivalent to the Motorad one. (well looks identical in both pics and same specs).
I came across a Mr Gasket stat model no. MG4364 which has the following description:
"These high performance thermostats are designed to resist large variations in coolant pressures that occur at high RPM's where coolant temperature and coolant pressure fight for control of the thermostat keeping it from opening at it's designated temperature. The balanced HP Thermostat features all brass and copper construction, and opens at the right temperature regardless of engine RPM."
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