TT_Vert

iTrader: (12)

The odd thing is, the other rod on this journal is at .00175" or so. I got this motor second hand, the block was new, the reciprocating assembly had a few thousand miles on it if I recall correctly. Can I get an oversized bearing to compensate for this? The journal on this rod looks perfect w/o any scoring either. I'm stumped as to why one rod would be like this.

Thanks

Dave

streetlegalls1

iTrader: (15)

.006,Pull the crank,bring it to a machine shop and have it checked,it could be egg shaped,don't try to guess this one out.

TT_Vert

iTrader: (12)

ok and if it is NOT egg shaped, what will I do to resolve this? Isn't .006" too large to fix w/ an oversized bearing?

Thanks
Dave

streetlegalls1

iTrader: (15)

You can get an over sized bearing and take up the clearance,check the rod or rods also.hopefully u have a reputable machine shop handy that can answer the mystery

Tony Mamo @ AFR

iTrader: (13)

Measure the crank journal....it might be within spec. It could be a rod that is out of spec....a much easier situation to deal with.

Just my .02....

Tony

KCS

iTrader: (20)

What are the actual measurements of the journals and bores?

For a 2.100" pin, the rod big end housing (without bearing) should be no smaller than 2.2247" and the crank pin should be around 2.9990" or so.

What you could do is get some Clevite 663-10 (745-10 for 2.00" pin) rod bearings, measure the ID of the bearing torqued in the rod, and have the crank ground to a number that would achieve your desired clearance, say .0022"-.0028"

Double check to make sure it's really .006" clearance before you go doing anything reall drastic. Make sure the rod bolts are properly torqued/stretched to spec, everything is clean with acetone or laquer thinner, and the right bearings are in the right locations. As far as I know there isn't a bearing out to take up about .003", and it probably wouldn't be right to have to do it on just one rod.

Hope that helps. Let us know what you find.

TT_Vert

iTrader: (12)

i went ahead and took another rod bearing from a rod that had a good clearance and put it in the bad (or so I thought) journal and sure enough i'm at .002". Must be a bad bearing. I'm going to replace all the rod bearings and recheck their specs. If the crank bearings are at .0015" should I Just leave them? I see no scoring in any bearings or surface..

Dave

TT_Vert

iTrader: (12)

new clevite 77s .010" over got me to .020-.030" on all rod bearings. I used plastigauge so I cannot get any more accurate than that. All mains were at .0015". Hopefully all goes well from here on out.

Dave

KCS

iTrader: (20)

I hope you mean .002-003" clearance because .020-.030" is WAY too much. A good general rule of thumb is .001" clearance for every inch of shaft diameter. I'd shoot for .0022-.0025" on the rods and .0025-.003" on the mains.

But I think plastiguage tends to read tight...