Crank Reluctor Clearance Help

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Nov 4, 2011 | 08:55 PM

o1Z0sick

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Racer

Joined: Sep 2009

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From: Houston

Crank Reluctor Clearance Help

This has been bothering me for a few days so I took a few pics in hope of some guidance. What is the accepted clearance between the #5 main cap and the crank reluctor wheel? I have a hair over 0.011" clearance as checked with a 0.011" feeler gauge. I checked run-out and it is 0.020" (within the 0.028" max spec). The block is a new LS3 and the crank is a K1 with a 24x wheel. The engine was built by a reputable LSX shop in Houston.

What bothers me the most is that to install this wheel (as per precision engine) there is a 0.007" interference fit with the crank and when heated to 450*F it slides right on. Will thermal expansion of the #5 block main or cap main cause a problem? Any help would be great before running a bad wheel screws up my brand new block.

Last edited by o1Z0sick; Nov 6, 2011 at 11:08 PM.

Nov 6, 2011 | 11:17 PM

o1Z0sick

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Racer

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From: Houston

Anybody check this before?

Nov 7, 2011 | 08:52 AM

CHJ In Virginia

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From: Shenandoah Valley Virginia

I would get on the phone to the builder ASAP before you go any farther with the assembly.

Nov 8, 2011 | 01:50 PM

o1Z0sick

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Racer

Joined: Sep 2009

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From: Houston

Quote:

Originally Posted by CHJ In Virginia

I would get on the phone to the builder ASAP before you go any farther with the assembly.

It is proving very difficult to get a response from them and I am not just the only one. To me, CUSTOMER SERVICE is really what makes or breaks this hobby.

Does anyone else have their engine on the stand? Can you check this dim for me?

Nov 8, 2011 | 02:36 PM

cdkcorvette7

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From: Oak Hill Virginia

No idea... free bump. Good idea getting info before proceeding. You definitely need to talk to someone who's done this before...

Nov 8, 2011 | 03:09 PM

lucky131969

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From: Dyer, IN

Quote:

Originally Posted by o1Z0sick

What bothers me the most is that to install this wheel (as per precision engine) there is a 0.007" interference fit with the crank and when heated to 450*F it slides right on. Will thermal expansion of the #5 block main or cap main cause a problem? Any help would be great before running a bad wheel screws up my brand new block.

I'm not sure I understand your concern here. The interference fit, is between the ID of the reluctor, and the OD of the crank. If the reluctor is heated, this facilitates installation, and then becomes secure as it cools. When the crank and reluctor are heated(at the same rate during engine operation), it will stay in place......because there is no disparity in temperature.

I would not be concerned about the CTE, as much as how you are taking the measurement. Have you incorporated your crankshaft end play measurement?

Nov 8, 2011 | 07:16 PM

o1Z0sick

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Racer

Joined: Sep 2009

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From: Houston

Quote:

Originally Posted by lucky131969

I am referencing the clearance or gap between the main cap and reluctor wheel. If the main and wheel both expand at temperature they move closer together making the clearance smaller.

The measurement is taken with the crank pushed back, end play is 0.004".

Maybe this is the way GM designed it to fit, but damn that's tight IMO.

Nov 8, 2011 | 07:41 PM

lucky131969

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From: Dyer, IN

Quote:

Originally Posted by o1Z0sick

Ok. Speaking strickly to an LS1/6 crankshaft, that end play would be considered good. So you have a minimum clearance of .011, and a maximum clearance of .015. If you look at the sensor pickup, the window is narrow. It does not take much deflection in the reluctor to cause problems. Even in the event that the surfaces did make contact, they are well lubricated. Take not of some of the other clearances in the engine......like the crank counter weights to the block.