Post by PictureChasers on Oct 24, 2005 1:36:06 GMT -5
We have already paid to completely rebuild this engine, and it still cooked, so we are taking no chances & replacing everything. This block has n :oow spun bearings twice so it's not my favorite piece of metal. The rods were resized but we suspect there are at least 10 things that caused our failure in 5 month old engine. We had head planed, new valve stem seals and valve grind. I wanted heads polished but they are pretty much streamlined, they are not quite like an old dodge.
We are installing a mechanical oil pressure guage this time since that seems to be the big issue with failures. A mechanic talked me out of it last engine, so this engine I am following my gut! Also I believe a second water temp guage is simple thru block heater hole.
We changed our oil at 50km, 200km, 1,000km, and 2,000km, then every 2-3,000km with 20W-50W Castrol GTX or other brand name, Subaru oil filters. We check oil every fill and neither of our Justy's lose much. Our Subaru built one leaked a bit. Our Justy friend used aviation gasket cement on our stock Justy and it doesn't leak a drop.
Our potential failure cause list, please comment as we are planning our new engine. Keep in mind that I trust the machine work at Paul's explicitly. I will likely take this new motor work there.
Oil Pump - It was brand new so we didnt replace it, now I have learned that it was likely ruined when the original bearings packed it in
Timing Chain set - Same thing, were brand new so we left them in, both on Subaru's advice
Oil Pressure guage - Could have prevented failure I bet
Sloppy assembly - Subaru waited for a month, then rushed to assemble it.
Timing - was off 10.5 degrees
Piston Rods - Were resized and de-stroked by .002 inches, my Justy expert cringed, but they were slightly bent
Head glass beaded - I thought it was great idea, but my Justy friend again does not like glass beading, saying it's difficult to get all glass beads out. Heads were pressure washed afterwards in a spinning steaming machine with some solvent or something. These guys build many race car engines, so I think the glass beading was a good idea.
Pistons - They looked fine, but I asked Subaru mechanic 3 times to order them, he talked me out of it. I just figured that they were only $150, on top of an job that cost over $2,000 with Subaru labor.
Plug Wires - Original Subaru items were not replaced, our Bosch Platinum plugs had a burn mark on one of the wire ends, but the electrodes were beautiful
Fuel pump or filter - We learned just before spun bearing that it was running lean, likely fuel pump or filter
RPM - I drove for 9 hours at 120-140km/h, 4-4,500RPM, but everyone here says that with oil pressure that should be no problem. Temp guage ran at bottom third. Car packed it in a month later doing the speed limit
Catalytic Converter - I do NOT think it was the Cat. This car hauled ass, I dont run them hard, but at high speeds where limits & safety permits.
Crankshaft - turned nice at .020 inches (is that how you write 20 thou?), with Clevite bearings
Plastigage - I suspect that Subaru doesn't have any
Balance - Machine shop said it was not worth balancing, anyone balanced a Justy engine? Or other soobies? I dont want power, I want smooth reliability. Will it help, or make the parts TOO light/weak.
Genuine concern for engine - This engine was built by a Subaru dealer trying to get us out of their hair, the next one will be hand built lovingly by me!
Any other causes? Please post them but this is what I have learned so far... Any machine work advice GREATLY appreciated! I am not concerned with machine costs, I want the best engines possible within reason. Machining is cheap insurance in my opinion.
Any other tips to improve LONGEVITY and RELIABILITY are very welcome on our journeys. I'm not sure about the turning up the oil pressure relief valve screw trick? I like the idea of an external oil filter, but I think maintaining pressure is more important on these little engines.
We are installing a mechanical oil pressure guage this time since that seems to be the big issue with failures. A mechanic talked me out of it last engine, so this engine I am following my gut! Also I believe a second water temp guage is simple thru block heater hole.
We changed our oil at 50km, 200km, 1,000km, and 2,000km, then every 2-3,000km with 20W-50W Castrol GTX or other brand name, Subaru oil filters. We check oil every fill and neither of our Justy's lose much. Our Subaru built one leaked a bit. Our Justy friend used aviation gasket cement on our stock Justy and it doesn't leak a drop.
Our potential failure cause list, please comment as we are planning our new engine. Keep in mind that I trust the machine work at Paul's explicitly. I will likely take this new motor work there.
Oil Pump - It was brand new so we didnt replace it, now I have learned that it was likely ruined when the original bearings packed it in
Timing Chain set - Same thing, were brand new so we left them in, both on Subaru's advice
Oil Pressure guage - Could have prevented failure I bet
Sloppy assembly - Subaru waited for a month, then rushed to assemble it.
Timing - was off 10.5 degrees
Piston Rods - Were resized and de-stroked by .002 inches, my Justy expert cringed, but they were slightly bent
Head glass beaded - I thought it was great idea, but my Justy friend again does not like glass beading, saying it's difficult to get all glass beads out. Heads were pressure washed afterwards in a spinning steaming machine with some solvent or something. These guys build many race car engines, so I think the glass beading was a good idea.
Pistons - They looked fine, but I asked Subaru mechanic 3 times to order them, he talked me out of it. I just figured that they were only $150, on top of an job that cost over $2,000 with Subaru labor.
Plug Wires - Original Subaru items were not replaced, our Bosch Platinum plugs had a burn mark on one of the wire ends, but the electrodes were beautiful
Fuel pump or filter - We learned just before spun bearing that it was running lean, likely fuel pump or filter
RPM - I drove for 9 hours at 120-140km/h, 4-4,500RPM, but everyone here says that with oil pressure that should be no problem. Temp guage ran at bottom third. Car packed it in a month later doing the speed limit
Catalytic Converter - I do NOT think it was the Cat. This car hauled ass, I dont run them hard, but at high speeds where limits & safety permits.
Crankshaft - turned nice at .020 inches (is that how you write 20 thou?), with Clevite bearings
Plastigage - I suspect that Subaru doesn't have any
Balance - Machine shop said it was not worth balancing, anyone balanced a Justy engine? Or other soobies? I dont want power, I want smooth reliability. Will it help, or make the parts TOO light/weak.
Genuine concern for engine - This engine was built by a Subaru dealer trying to get us out of their hair, the next one will be hand built lovingly by me!
Any other causes? Please post them but this is what I have learned so far... Any machine work advice GREATLY appreciated! I am not concerned with machine costs, I want the best engines possible within reason. Machining is cheap insurance in my opinion.
Any other tips to improve LONGEVITY and RELIABILITY are very welcome on our journeys. I'm not sure about the turning up the oil pressure relief valve screw trick? I like the idea of an external oil filter, but I think maintaining pressure is more important on these little engines.