My machinist is scaring me

[90T04]

Is it not common practice to resize a new set of rods to attain your desired clearance? My crank is fine, doesnt need any machining, so I plan on just putting it back in as is, with a set of standard clevites and new eagle rods. I told him the clearances that I want my main and rod journals set to and he looked at me like I was freakin frankenstein. He told me that the only way to set the clearances was to turn the crank 10 thousandths and put in a set of 10 thousandths bearings. Am I missing something?

 

[IJ.]

Ummm no it's not normal but is done from time to time....

Correct way is Rods are sized xx + or - the bearings are installed, rods are torqued in a rod vice then micced.

Crank pin is measured and depending on this size it's either Ground or linished to get the desired clearence.

Where this falls over is if trying to reuse an already machined crank to fit xx bearings, some shops will resize the rod BUT and this is where in my opinion it falls over is you end up with too much crush on the bearings and it deforms them from round.

Toyota get around this by having many select fit bearing sizes so you can juggle the set to get correct clearence and crush.

 

[90T04]

Okay awesome IJ, that is exactly what my machinist told me about the bearing crush becoming excessive. So I take it when people here talk about having clearanecs all within half a thousandth they are linishing each journal individually to attain a specified diameter?

 

[Doward]

When I had Maloof machine my bottom end, he set everything up per each and every bearing. They came back number for where they had to go.

 

[90T04]

When I had Maloof machine my bottom end, he set everything up per each and every bearing. They came back number for where they had to go.

Yea I read about your machine work Doward. I just wish I was a little closer to that area and I might consider having him do mine too. Sounds like a top notch type of shop. The shop I have my engine at right now mainly does sprint car engines, so while I am not concerned about the performance aspect, he has not done a whole lot of import motors. He does have a good attitude though and is willing to work with me and my demands. When I mentioned RA specs he took me back a showed me a V8 block that I could almost see my reflection in the deck surface.