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I recently rebuilt my 455 again because I cracked an intake runner, so decided to freshen everything.Long story short I have turned the crank for the 2nd time and am having the block magnafluxed along with the crank cause sumpthin aint right!! I put the eng. together carefully after having the cylinders re honed, and the mains aline honed,(for the 2nd time @ 2 different shops.) and after about 1 hour of road time my oil pressure dropped off suddenly. I changed the oil and cut the filter to find lots of copper in it!! Pulled the eng. and #3 & #4 mains were gone with damage to #2 and #5. Rods were good.I am running about .0028 to .0031 on #1 thru #4 mains and .0038 on #5. and about .0028 to .0030 on the rods. I have a new M22hv Melling oil pump with a .250 shim.(No I'm not sucking the pan dry), Cam bearing restrictors and restricted push rods. The motor made about 500hp before the rebuild and I haven't really changed anything except the heads!! They are large valve C heads with a little porting and a Comp Cams hydraulic roller. My static compression is the same as the old heads @ 9.2:1 and I'm running the same Diamond Pistons. Oh, and to complicate things even more, after all this I was getting light smoke from the exhaust at idle like the rings weren't seated!! NOW IF YOUR READY, THIS IS THE 2ND TIME THIS ALL HAPPENED (rebuilt,installed,ran,broke,did it all again)
Any Ideas greatly appreciated!!
How much oil pressure do you have when it starts, when hot?
I'll ask the obvious first, did you clean the oil passages in the crank etc really well? Can you see clear evidence of an align hone, any pinching of the bearings? New bolts, studs? All other passages cleared with brushes etc.?
Cam fit well? Any binding in the pump?
Last edited by cutlassefi; October 18th, 2012 at 06:14 PM.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by chasman414
I recently rebuilt my 455 again because I cracked an intake runner, so decided to freshen everything.Long story short I have turned the crank for the 2nd time and am having the block magnafluxed along with the crank cause sumpthin aint right!! I put the eng. together carefully after having the cylinders re honed, and the mains aline honed,(for the 2nd time @ 2 different shops.) and after about 1 hour of road time my oil pressure dropped off suddenly. I changed the oil and cut the filter to find lots of copper in it!! Pulled the eng. and #3 & #4 mains were gone with damage to #2 and #5. Rods were good.I am running about .0028 to .0031 on #1 thru #4 mains and .0038 on #5. and about .0028 to .0030 on the rods. I have a new M22hv Melling oil pump with a .250 shim.(No I'm not sucking the pan dry), Cam bearing restrictors and restricted push rods. The motor made about 500hp before the rebuild and I haven't really changed anything except the heads!! They are large valve C heads with a little porting and a Comp Cams hydraulic roller. My static compression is the same as the old heads @ 9.2:1 and I'm running the same Diamond Pistons. Oh, and to complicate things even more, after all this I was getting light smoke from the exhaust at idle like the rings weren't seated!! NOW IF YOUR READY, THIS IS THE 2ND TIME THIS ALL HAPPENED (rebuilt,installed,ran,broke,did it all again)
Any Ideas greatly appreciated!!
Chasman
How far is the oil pickup off the pan? I will assume the engine was put together clean. I allways run an accusump for insurance. Radius hitting the bearing edge?
Last edited by VORTECPRO; October 18th, 2012 at 07:56 PM.
did you put the rods facing the right direction, caps etc. with the bearing notches facing the right direction. Where the pistons assmbled properly when they where pressed in ,what where the clearances, I had a shop once assmble 3 pistons @ss backwards. thank god i pulled the engine apart before it ran. The shop actually pointed it out to me when i decided to go with diffrent pistons., that came down to how i marked the rods the ones i gave them to swap ( 3 where bent ) i was focused on the way the piston notch faced and was not paying attention to the location of the bearing tang or notch. Just tossing some possiblities out there to get the juices going.
I would ask if the big end of the rods were resized/trued? Very important. Was crank checked for straightness? I put together a 425 and after about 3000 miles it started knocking. Very faint. I pulled crank and found ugly rod bearing. Took the crank back to shop and they said it was bent. I guess they can grind a bent crank and give it to you to install...or it was dropped after machining!?
How much oil pressure do you have when it starts, when hot?
I'll ask the obvious first, did you clean the oil passages in the crank etc really well? Can you see clear evidence of an align hone, any pinching of the bearings? New bolts, studs? All other passages cleared with brushes etc.?
Cam fit well? Any binding in the pump?
I had a good 40lbs cold at idle and 20lbs hot at about 900 rpm.I scrubbed every crack crevice and gallery with bore brushes and power washed everything! Yes the aline hone was done 1st time by a local machine shop then checked and re done by LSM Eng. when it was found to be wrong the first time and you can plainly see the hone marks, plus it was re checked by LSM after the crash along with everything else for straightness, ETC. No problems were obvious. All new studs and gaskets etc. What do you mean by pinching of the bearings? Cam fit perfectly with new bearings, ran the pump to prime and it worked smooth and oiled well.Everything turned smooth as silk!!!! Ive read that the #4 main webs can crack so we are magnefluxing the block and the crank.
How far is the oil pickup off the pan? I will assume the engine was put together clean. I allways run an accusump for insurance. Radius hitting the bearing edge?
The pick up is 3/8" off the bottom of a Moroso 7 Qt. pan with baffles. Engine was spotless. I ran virtually this exact same engine for 4 years with No problems at all.I'm not familliar with Accusump?Do you mean crank radius hitting the main bearings?
did you put the rods facing the right direction, caps etc. with the bearing notches facing the right direction. Where the pistons assmbled properly when they where pressed in ,what where the clearances, I had a shop once assmble 3 pistons @ss backwards. thank god i pulled the engine apart before it ran. The shop actually pointed it out to me when i decided to go with diffrent pistons., that came down to how i marked the rods the ones i gave them to swap ( 3 where bent ) i was focused on the way the piston notch faced and was not paying attention to the location of the bearing tang or notch. Just tossing some possibilities out there to get the juices going.
Yes the rods were double checked before disassembly,The piston rods are full floating Eagle H beam.I've been through that with stock rods,cost an engine!Which clearances ?Thanks
I would ask if the big end of the rods were resized/trued? Very important. Was crank checked for straightness? I put together a 425 and after about 3000 miles it started knocking. Very faint. I pulled crank and found ugly rod bearing. Took the crank back to shop and they said it was bent. I guess they can grind a bent crank and give it to you to install...or it was dropped after machining!?
Yes the rod big ends were all checked and were round and proper size.Crank has again been turned -.020 on the mains and of course any wobble would have shown then.I've never heard of being able to grind a bent crank and still come out bent, I have heard of dropping cranks and bending them BUT I'm no expert!! We have tried to triple check everything, with nothing obvious to be found yet but I do appreciate the suggestions, (I will ask about grinding a bent crank). Thanks, Chas.
Did the oil have a fuel smell to it? Any chance the carb is running too rich and washing down the cylinders and also thinning the oil?
No funny smells or colors or even metal in the oil (It was all in the filter),The oil was still green (Brad Penn 20w50)and amazingly clean!!I run an o2 sensor and the car is running the same ratio it was prior to rebuild (12.5 to 13.5:1)I don't think that was a problem (at least it never was before with the jetting I'm running)But that is something I will double check next time to see if I'm spilling fuel out somehow, Thanks, Chas.
Believe it or not that was 4 engines ago. What I didn't say in that post was that I race the car a lot. In fact 400 runs a year is my average and that's only during the summer here in Mi. I usually rework the eng. every 800 runs or 2 years.What we believe the problem was then was simply abuse. When you constantly turn 6000 rpm with a more or less stock 455 lower end and crank you will probably have bearing wear. I posted some pics of old bearings.
In 2014 I put a girdle between main bearings #1,2,3 &4. That stopped almost all wear. I also changed to Brad Penn 10w30 instead of the 20w50 I had been using and that helped. I also stopped using restrictors except for restricted pushrods.
I did a rebuild this past winter and added Edelbrock aluminum heads. They are worth every penny.
Thanks for your interest.
October 18th, 2012, 04:14 PM
I recently rebuilt my 455 again because I cracked an intake runner, so decided to freshen everything.Long story short I have turned the crank for the 2nd time and am having the block magnafluxed along with the crank cause sumpthin aint right!! I put the eng. together carefully after having the cylinders re honed, and the mains aline honed,(for the 2nd time @ 2 different shops.) and after about 1 hour of road time my oil pressure dropped off suddenly. I changed the oil and cut the filter to find lots of copper in it!! Pulled the eng. and #3 & #4 mains were gone with damage to #2 and #5. Rods were good.I am running about .0028 to .0031 on #1 thru #4 mains and .0038 on #5. and about .0028 to .0030 on the rods. I have a new M22hv Melling oil pump with a .250 shim.(No I'm not sucking the pan dry), Cam bearing restrictors and restricted push rods. The motor made about 500hp before the rebuild and I haven't really changed anything except the heads!! They are large valve C heads with a little porting and a Comp Cams hydraulic roller. My static compression is the same as the old heads @ 9.2:1 and I'm running the same Diamond Pistons. Oh, and to complicate things even more, after all this I was getting light smoke from the exhaust at idle like the rings weren't seated!! NOW IF YOUR READY, THIS IS THE 2ND TIME THIS ALL HAPPENED (rebuilt,installed,ran,broke,did it all again)
