Box Stock

Crankshaft end play

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bxbuilt2

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How much end play should the 69730 predator crankshaft have? Is more or less end play better for performance?
 
not really better for performance unless your end play is basically none and you open it up a little. Some end play is neccesary, just dont want it to be excessive. I dont like to see any more than .003"
 
Weddle Racing said:
not really better for performance unless your end play is basically none and you open it up a little. Some end play is neccesary, just dont want it to be excessive. I dont like to see any more than .003"
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I agree , I like just enough clearance to avoid friction between the main bearings.
 
Get a thinner gasket. How much does it measure? How are you measuring it. Be careful .003" cold, may be too tight when engine is hot.
 
I have had 2 blocks that with the thinnest gasket I could find,And choices are very limited,Had to shim between PTO brng and sidecover to get .005 clearance ..Cold. ,The Excessive clearance threw the cam timing off enough to bother me.. I have .002 shims
 
Thanks for the replies. I am measuring .020 end play with a dial indicator on the end of the crank. I have installed the ARC billet dual bearing side cover and a stock side cover gasket. I put all 4 shims that come with the side cover on the crank and .020 is the end play I ended up with. Who's got some thin side cover gaskets?
 
I do not feel that .003 or .005 as others have said is enough. They have much more "clone" small block experience than I however. I would think they would get a little snug at temp. but like I said, I don't truly know. The ones I have messed with had more. Good luck.
 
jsstump#70 said:
I do not feel that .003 or .005 as others have said is enough. They have much more "clone" small block experience than I however. I would think they would get a little snug at temp. but like I said, I don't truly know. The ones I have messed with had more. Good luck.
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'Like'....."Loose", but Not excessive!
 
jsstump#70 said:
I do not feel that .003 or .005 as others have said is enough. They have much more "clone" small block experience than I however. I would think they would get a little snug at temp. but like I said, I don't truly know. The ones I have messed with had more. Good luck.
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I agree with you Jeff, I like .010 to .020 Myself.
 
Sorry guys, i did not mean to put .003, that should have read that i dont like to see any more than .030, sorry for the confusion. Thats exactly why you shouldnt reply to posts on here when half asleep lol
 
.030" Really ? Ya'll do realize that when the crank walks so does the rod journal and the flywheel . If U ever see unusual marks on the side of your rod journal, it prolly from "crank walk". JMO
 
.010" is is where you should shoot for. Weddle check your alarm clock .030"???? You should shoot for .004 to .005" rod side clearance and enough crank end play to to prevent binding between the bearings when at temp.

This will only work for the SA and opens as your BSP will not allow modifications. It has been a long time since I did this and don't intend to repeat it, but it is a very enlightening experiment.

Assemble an old block with side cover, gasket and only the crankshaft installed, make certain everything turns as freely as you can make it. spin the crank a few times note how easy it turns and how long it spins. Place this assembly in an oven at 350* remove it and recheck the spin of the crankshaft. I found that the bearing bores pinched down on the steel bearings enough to bind the races against the balls. We actually had to right a rule specify that the bearings were not allowed to be pulled out of the bores by hand. Builders were sanding the blocks out so far the bearings would fall in and out.


This is not stated to tell you it is permissible, you better check your rules, and the rule writers need to specify in regard to this. Don't start bashing the clone or the rules it is a simple fact this would be beneficial in any bearing captured in Aluminum in any brand of engine.
 
Kart43 said:
.010" is is where you should shoot for. Weddle check your alarm clock .030"???? You should shoot for .004 to .005" rod side clearance and enough crank end play to to prevent binding between the bearings when at temp.

This will only work for the SA and opens as your BSP will not allow modifications. It has been a long time since I did this and don't intend to repeat it, but it is a very enlightening experiment.

Assemble an old block with side cover, gasket and only the crankshaft installed, make certain everything turns as freely as you can make it. spin the crank a few times note how easy it turns and how long it spins. Place this assembly in an oven at 350* remove it and recheck the spin of the crankshaft. I found that the bearing bores pinched down on the steel bearings enough to bind the races against the balls. We actually had to right a rule specify that the bearings were not allowed to be pulled out of the bores by hand. Builders were sanding the blocks out so far the bearings would fall in and out.


This is not stated to tell you it is permissible, you better check your rules, and the rule writers need to specify in regard to this. Don't start bashing the clone or the rules it is a simple fact this would be beneficial in any bearing captured in Aluminum in any brand of engine.
Click to expand...

'Like'....:)
 
Don't like. Metal expandes as it's temperature goes up. Think about what happens when you heat up the sump cover to install a bearing, the hole become s larger and the bearing slips in. The interal clearance of the bearing will be reduced if the sump cover is cooled, placed in the freezer.
Jim
 
silverback said:
Don't like. Metal expandes as it's temperature goes up. Think about what happens when you heat up the sump cover to install a bearing, the hole become s larger and the bearing slips in. The interal clearance of the bearing will be reduced if the sump cover is cooled, placed in the freezer.
Jim
Click to expand...
Food for Thought, I agree with the freezer vs sidecover....ETC. theory; BUT..IN the Oven Everything Heats at the Same Time
 
silverback said:
Don't like. Metal expandes as it's temperature goes up. Think about what happens when you heat up the sump cover to install a bearing, the hole become s larger and the bearing slips in. The interal clearance of the bearing will be reduced if the sump cover is cooled, placed in the freezer.
Jim
Click to expand...

Yea I guess what I did to investigate must have all been in my mind, and the test method is invalid because somebody hypothesizes otherwise.

Remember the crank shaft expands, both races, and the balls expand, they are constrained in a bore, the crankshaft and bearings will absorb more heat than the thin side covers so I wonder which may expand more.
 
astrowrench said:
Food for Thought, I agree with the freezer vs sidecover....ETC. theory; BUT..IN the Oven Everything Heats at the Same Time
Click to expand...
Put the bare block and sidecover in an oven at 350- 400 degrees face down and they will fall out.P.S. remove your crank bearings first, this will turn them blue and is probably not good for a bearing you are going to use.
This is a quote from another post, this works because aluminum expands more than steel per degree of temperature rise.
Jim
 
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