Rod bearing clearance
02-18-2019, 05:45 AM
#1
Rod bearing clearance Need a recommendation. What clearance do you guys run on rod bearing.
Generally it’s .001 per inch of rod journal dia.
The engine I’ll us is a std LS3 block, flat plane crank with 3.00” stroke, Honda 1.885” journal.
Nothing fancy, NA around 540hp
Will rev approx 8500 rpm.
The recommendation I got is 0,0028in ,just seems to me it’s a little too much.
What do you say?
Generally it’s .001 per inch of rod journal dia.
The engine I’ll us is a std LS3 block, flat plane crank with 3.00” stroke, Honda 1.885” journal.
Nothing fancy, NA around 540hp
Will rev approx 8500 rpm.
The recommendation I got is 0,0028in ,just seems to me it’s a little too much.
What do you say?
02-23-2019, 08:05 PM
#3
TECH Junkie
How are you going to go about performing your measurements?
Water cooled engine still or something track only will no cooling?
I personally would shoot for 0.0020" to 0.0022" ...with the smaller Honda size journal at your predicted max engine speeds.
What are your measurements for your main bearing clearance thus far.
You do not want the main bearing clearance and the rod bearing clearance to be wildly different...
What weight oil were you planning on? Or did you want a recommendation?
Stock rod journals measure @ 2.0990" to 2.1000". Even then 0.0028" is just a bit loose for me spinning 8500 RPM unless using 15w40 oil.
Water cooled engine still or something track only will no cooling?
I personally would shoot for 0.0020" to 0.0022" ...with the smaller Honda size journal at your predicted max engine speeds.
What are your measurements for your main bearing clearance thus far.
You do not want the main bearing clearance and the rod bearing clearance to be wildly different...
What weight oil were you planning on? Or did you want a recommendation?
Stock rod journals measure @ 2.0990" to 2.1000". Even then 0.0028" is just a bit loose for me spinning 8500 RPM unless using 15w40 oil.
02-23-2019, 08:09 PM
#4
TECH Junkie
Also to spin the engine at those speeds, you will need some serious oiling or go dry sump to keep the engine alive.
Do not throw a Melling or other off the shelf high pressure oil pump on the crankshaft and just call it a day.
Oil flow drops drastically when these engines spin 6000-6500 and faster. Be Warned!
Do not throw a Melling or other off the shelf high pressure oil pump on the crankshaft and just call it a day.
Oil flow drops drastically when these engines spin 6000-6500 and faster. Be Warned!