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Crankshaft grinding


JamesP

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Hi,

 

I'm after a bit of advice on having my crankshaft machined. Just wandering if anyone knows of a good machinist to take it to in the Devon area?

 

Also where would the best place to get new bearings from?

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i would hold out on buying new bearings untill you have your crankshaft reground, there is a required clearance between the bearings and journals, also possibly cheaper to buy 2nd hand.

 

I did spot an ebay company a few months ago who collect and also supply the required bearings. i'm in noway affilliated with the company, i was looking into rebuilding an engine alittle while ago.

 

http://www.ebay.co.uk/itm/CRANKSHAFT-GRINDING-NISSAN-300C-300ZX-350Z-MAXIMA-NAVARA-3-0-3-5-V6-ALL-YEARS-/161920955252?hash=item25b33db374:g:diQAAOSwZjJU8DOd

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i would hold out on buying new bearings untill you have your crankshaft reground, there is a required clearance between the bearings and journals, also possibly cheaper to buy 2nd hand.

 

I did spot an ebay company a few months ago who collect and also supply the required bearings. i'm in noway affilliated with the company, i was looking into rebuilding an engine alittle while ago.

 

http://www.ebay.co.uk/itm/CRANKSHAFT-GRINDING-NISSAN-300C-300ZX-350Z-MAXIMA-NAVARA-3-0-3-5-V6-ALL-YEARS-/161920955252?hash=item25b33db374:g:diQAAOSwZjJU8DOd

 

Thanks for the reply. I know I need the crank ground before I buy bearings but haven't seen many places I can buy from. I've seen a few companies selling more performance orientated bearings but I'm only after fairly standard ones as I don't want to be spending huge sums of money on them.

 

Thanks the the link I'll have a look at that, could be handy if they supply the correct bearings I'll need as well.

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Look for a machine shop/engineer that does a lot of engine work, they will have all the data on what the crank should be ground to in order to accept the correct manufactured bearing shells,which are all made to a std size, that way you shouldn't need to check the clearance.

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I've heard that the crank on a vq can't be reground because of the material it's coated in? Worth reading into. I took my bottom end into the engineering company and they measured and ordered the bearings for me. I think nissan have 7 or 8 different size bearings to choose from but not sure how big they go.

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I've heard that the crank on a vq can't be reground because of the material it's coated in? Worth reading into. I took my bottom end into the engineering company and they measured and ordered the bearings for me. I think nissan have 7 or 8 different size bearings to choose from but not sure how big they go.

 

Cant say i have seen anything about the VQ crank being specially coated, it could be Nitrided but most forms wont preclude grinding, yes a decent engineering company that is used to crank grinding will grind the journal to the tolerances for the manufactured oversize bearing, which means it will fit and have the correct crush tolerance when fitted without ever having to use plastiguage or similar.

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I've heard that the crank on a vq can't be reground because of the material it's coated in? Worth reading into. I took my bottom end into the engineering company and they measured and ordered the bearings for me. I think nissan have 7 or 8 different size bearings to choose from but not sure how big they go.

 

Cant say i have seen anything about the VQ crank being specially coated, it could be Nitrided but most forms wont preclude grinding, yes a decent engineering company that is used to crank grinding will grind the journal to the tolerances for the manufactured oversize bearing, which means it will fit and have the correct crush tolerance when fitted without ever having to use plastiguage or similar.

I can't quite remember what the reason was tbh, maybe I've misunderstood or they were talking about wear on the block that holds the bearings or something, either way I'm just glad my crank wasn't worn

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I'm trying to do a bit of research about it and so far haven't seen anything that says it can't be done. Mine isn't in too bad condition, only 2 conrod journals have some slight marking but just about bad enough for it to need doing.

 

I'm just trying to see if anyone has used a machinist that's good. I'd rather go to someone that's recommended if I can.

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