4.6 stroker issue
Posted: August 3rd, 2016, 10:28 am
Hi everyone guys,
this is my very first post here, i've been looking on the net to find suitable info but i didn't find that much so i hope to get the attention of someone that went through a similar problem.
A buddy just built a 4.6 stroker using an '88 XJ block, cast# AMC8933002665, '92 YJ HO head, piston part #IC944KTM-030, '88 XJ connecting rod and a '3727 crankshaft, there are a lot of more performance parts like Comp Cam camshaft, floowkooler high flow water pump etc, 62mm throttle body, JBA headers, '00TJ intake, 24 lb fuel injectors etc etc ,so... engine was running find during the very first test drive,coolant temp was just over the 210 F but steady, driving in the freeway temp was fine as well and even less than that then, he told me that pushing a little bit more on the gas pedal and hit the 4000 RPM coolant temp increased a little bit more but everything seemed just fine until he heard the engine knocking pretty bad, idle was pretty rough so he turned it off.
So, he took the engine apart and found four seized pistons, crankshaft and bearing were just fine, so we think is not an oil pump related problem, double checked the clearance pistons/cylinder that is correct to the manufacturer recommendations, rings have the right gap, water pump impeller is ok, same thing for the oil pump, so looks like that everything was fine ,there's nothing but the seized pistons.
My concern is about air trapped in the coolant system that made the temp sender to act funny, coolant temp was way higher than the one the gauge was telling and the engine just overheated so bad.
The interesting thing is that all pistons were seized on the driver side.
Another concern was the water pump, if i'm not wrong XJ's water pump has a different rotation compared to the TJ so i thought the impeller might turn in the wrong side but my friend told me they checked that too and pump is ok.
Do you guys have any suggestion, feeling, advice, tip or idea about that? Any help would be greatly appreciated, i'll try to attach some pic of the piston that might help you out.
this is my very first post here, i've been looking on the net to find suitable info but i didn't find that much so i hope to get the attention of someone that went through a similar problem.
A buddy just built a 4.6 stroker using an '88 XJ block, cast# AMC8933002665, '92 YJ HO head, piston part #IC944KTM-030, '88 XJ connecting rod and a '3727 crankshaft, there are a lot of more performance parts like Comp Cam camshaft, floowkooler high flow water pump etc, 62mm throttle body, JBA headers, '00TJ intake, 24 lb fuel injectors etc etc ,so... engine was running find during the very first test drive,coolant temp was just over the 210 F but steady, driving in the freeway temp was fine as well and even less than that then, he told me that pushing a little bit more on the gas pedal and hit the 4000 RPM coolant temp increased a little bit more but everything seemed just fine until he heard the engine knocking pretty bad, idle was pretty rough so he turned it off.
So, he took the engine apart and found four seized pistons, crankshaft and bearing were just fine, so we think is not an oil pump related problem, double checked the clearance pistons/cylinder that is correct to the manufacturer recommendations, rings have the right gap, water pump impeller is ok, same thing for the oil pump, so looks like that everything was fine ,there's nothing but the seized pistons.
My concern is about air trapped in the coolant system that made the temp sender to act funny, coolant temp was way higher than the one the gauge was telling and the engine just overheated so bad.
The interesting thing is that all pistons were seized on the driver side.
Another concern was the water pump, if i'm not wrong XJ's water pump has a different rotation compared to the TJ so i thought the impeller might turn in the wrong side but my friend told me they checked that too and pump is ok.
Do you guys have any suggestion, feeling, advice, tip or idea about that? Any help would be greatly appreciated, i'll try to attach some pic of the piston that might help you out.
