What is an ideal rod bearing clearance for a slant? I am finishing up the mock up of my hydro motor today and will be checking this measurement before it all comes back apart.

I am using k1 rods which specify measuring bolt stretch to determine how tight the rod bolts are is this necessary for mock up? It would seem to me that you do not want to stretch the bolts until final assembly.

The factory spec is .0005"-.0015". I think .001" is good for a street engine. .0025" is max spec before reconditioning.

The rod bolts will stretch a certain amount without permanently distorting. So long as they aren't permanently stretched it's fine.

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Joshua

For a regular street engine, set at 0.0015". I set my high performance motors at 0.002" my latest K1 cast cranker is at 0.0025".

Lou

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Home of Slant6-powered fun machines since 1988

I only measured one rod bearing this weekend- it measured .0020-.0025. I am going to check a couple more though, as it was tough to get a real good reading on the plastigage.

I do plan on this engine spinning 4000+ rpms at times and it may also see a turbo one day. So far all the clearances have checked out good for the crank and rod bearings, and the valve train looks right in spec also. I think this will really be a zippy little motor