New AMC 360 Installed - couple questions
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- Location
- Plumas Lake, CA, USA
- Vehicle(s)
- 1974 CJ5 ~ Fresh built AMC 360 - SM420 - D20 - D30F with upgraded 30 spline shafts and knuckles & D44R - 4.27 Gears - ARB Lockers F/R - All chrome molly axles - on 33's - YJ 4" Lift Spring Conversion
Hi all,
So finally got the 360 finished up and in. She's running good and strong.
Two concerns - let me know your thoughts on these all. Like to bounce around some ideas...
1 - Still running a bit on the hot side. I have a new flex fan, 180 degree thermostat, new cooling hoses and "shouldn't" be anything wrong with the radiator. Now I'm not running a shroud, but never have and never had any problems with the temp... I am running the temp sensor that came in the new intake still, so not positive on accuracy yet. Next to check. Main question - is it normal for a fresh rebuild to run a little hotter than normal during break in? I assume with stuff starting to "clearance" itself out in there and piston rings seating it would be a little more friction than the old tired 304 had... It's running about 220 - 225 degrees F.
2 - At idle, when I advance timing to 12 degrees per the DUI HEI unit instructions, the engine "stumbles" intermittently... Not really a miss at all, but hard to explain. Shakes a second like a miss would, but thermo temp reading confirms at least not a constant miss, and at higher RPM, or increased timing advance it gets better. I think I have it set at 14 degrees advance @ idle. I'm slightly worried this is too much, though I know some high performance engines run much more than that...
Random mentions for both:
I am still running my MC2100 carb on a adapter to the edlebrock 4 barrel performer intake. Too little fuel maybe? Running lean causes additional heat right? Too little fuel at idle may stumble a bit? Haven't done the calculations, but the carb was right (maybe slightly high) for the 304 CFM - probably a bit low for a 360...
Haven't even re-adjusted carb mixture screws yet really. set them about a 1/2 turn richer than I was running them on the 304.
I do have the shroud for the fan / radiator, just needs adjustment for fitment again, and never needed it even while on rubicon on 100 degree + days before...
Let's see what you all think. Questions on set up etc let me know.
Thanks for looking
So finally got the 360 finished up and in. She's running good and strong.
Two concerns - let me know your thoughts on these all. Like to bounce around some ideas...
1 - Still running a bit on the hot side. I have a new flex fan, 180 degree thermostat, new cooling hoses and "shouldn't" be anything wrong with the radiator. Now I'm not running a shroud, but never have and never had any problems with the temp... I am running the temp sensor that came in the new intake still, so not positive on accuracy yet. Next to check. Main question - is it normal for a fresh rebuild to run a little hotter than normal during break in? I assume with stuff starting to "clearance" itself out in there and piston rings seating it would be a little more friction than the old tired 304 had... It's running about 220 - 225 degrees F.
2 - At idle, when I advance timing to 12 degrees per the DUI HEI unit instructions, the engine "stumbles" intermittently... Not really a miss at all, but hard to explain. Shakes a second like a miss would, but thermo temp reading confirms at least not a constant miss, and at higher RPM, or increased timing advance it gets better. I think I have it set at 14 degrees advance @ idle. I'm slightly worried this is too much, though I know some high performance engines run much more than that...
Random mentions for both:
I am still running my MC2100 carb on a adapter to the edlebrock 4 barrel performer intake. Too little fuel maybe? Running lean causes additional heat right? Too little fuel at idle may stumble a bit? Haven't done the calculations, but the carb was right (maybe slightly high) for the 304 CFM - probably a bit low for a 360...
Haven't even re-adjusted carb mixture screws yet really. set them about a 1/2 turn richer than I was running them on the 304.
I do have the shroud for the fan / radiator, just needs adjustment for fitment again, and never needed it even while on rubicon on 100 degree + days before...
Let's see what you all think. Questions on set up etc let me know.
Thanks for looking