Connecting Rod Side Clearance
#1
Connecting Rod Side Clearance
355 just went back together and in for the 2nd time and the oil pressure still seems so-so. Rod & main clearances are tightened up by .0005" to about .002 to .0025. Now running a Canton HV oil pump with standard pressure relief spring. OP is about 50 at 6500 RPM. If I recall my Eagle crank and Eagle H beams had a good bit of side clearance as received from Eagle. Could this be where my oil is going? What are reasonable limits for side clearance. Oh yea, 10W-30 Mobil 1
Thanks
Steve
Thanks
Steve
#2
Re: Connecting Rod Side Clearance
Originally Posted by SABLT194
355 just went back together and in for the 2nd time and the oil pressure still seems so-so. Rod & main clearances are tightened up by .0005" to about .002 to .0025. Now running a Canton HV oil pump with standard pressure relief spring. OP is about 50 at 6500 RPM. If I recall my Eagle crank and Eagle H beams had a good bit of side clearance as received from Eagle. Could this be where my oil is going? What are reasonable limits for side clearance. Oh yea, 10W-30 Mobil 1
Thanks
Steve
Thanks
Steve
Put some descent oil in it and see 20/50 maybe.
Side clearance won't effect pressure if ya have volume..It effect's how much oil is thrown on the cyls and splash but not to much at holding the oil in the brg. I have run as much as .020 and it didn't drop pressure.
#6
Re: Connecting Rod Side Clearance
Now running a Canton HV oil pump with standard pressure relief spring. OP is about 50 at 6500 RPM
If things are loosey-goosey the first place it'll show up is your oil pressure when idling hot. Idling at say, 800-900 fully warned up what kinda pressure are you seeing? 5? 15? 25? 500?
BTW- maximum side clearance for a SBC is .025" measured by pushing the rods apart and inserting a feeler gague between them. Really you want it more like .015. Loose clearances betwen the cam journals and cam bearings is another source of oil volume loss that is sometimes overlooked, often when replacement cam bearings are installed in place of factory original units.
Last edited by Damon; 06-16-2005 at 01:35 PM.
#7
Re: Connecting Rod Side Clearance
Originally Posted by SStrokerAce
.015 is a good number to shoot for?
Did you measure what you have?
Did you measure what you have?
Last edited by arnie; 06-17-2005 at 08:00 PM.
#8
Re: Connecting Rod Side Clearance
Clearances were in excess of .020". Probably closer to .025". Why would Eagle do this? Is there a fix to close up these clearances?
I guess the only downside to running 15W-50 M1 would be a couple of HP loss - yes?
Steve.
I guess the only downside to running 15W-50 M1 would be a couple of HP loss - yes?
Steve.
#9
Re: Connecting Rod Side Clearance
Only good way is to go in there are re-grind the fillet radius larger on the cranks.... Or make wider rods. If the rods are .940" wide on the big end, then it's the crank.
The .025" is ok, it's a little loose but I wouldn't worry too much about it your not going to kill yourself there.
Bret
The .025" is ok, it's a little loose but I wouldn't worry too much about it your not going to kill yourself there.
Bret
#10
Re: Connecting Rod Side Clearance
Originally Posted by SStrokerAce
Only good way is to go in there are re-grind the fillet radius larger on the cranks....
Originally Posted by SStrokerAce
.... then it's the crank.
#12
Re: Connecting Rod Side Clearance
Originally Posted by SStrokerAce
If you grind the rod journal smaller you can enlarge the fillet radius....
I hope you are not telling me you can, or expect to 'ride' on the radius of the crank journal.
Last edited by arnie; 06-18-2005 at 04:12 PM.
#13
Re: Connecting Rod Side Clearance
Arnie.... the larger the radius the more it narrows the width.... which will take down the side clearance. Think about this one a little more.
Eagles cast cranks have a .093 radius and the forged ones are .125, the larger the radius the narrower the rod journal
Bret
Eagles cast cranks have a .093 radius and the forged ones are .125, the larger the radius the narrower the rod journal
Bret
#14
Re: Connecting Rod Side Clearance
Hmmm, apparently you are not aware where the side of the rod makes contact with the crank journal.
See the edit above:
I hope you are not telling me you can, or expect to 'ride' on the radius of the crank journal.
You testing me? This is crank tech 101.
Originally Posted by SStrokerAce
Think about this one a little more.
I hope you are not telling me you can, or expect to 'ride' on the radius of the crank journal.
You testing me? This is crank tech 101.
Last edited by arnie; 06-18-2005 at 04:24 PM.
#15
Re: Connecting Rod Side Clearance
Originally Posted by SStrokerAce
Eagles cast cranks have a .093 radius and the forged ones are .125, the larger the radius the narrower the rod journal.
Sure, the novice makes the mistake once, and he then learns. However, for the experienced to fall victim to this, is well.... unforgivable.
Last edited by arnie; 06-18-2005 at 04:41 PM.