Discussion
Can anyone recommend whether this journal is usuable, or whether it should be reground. Other than the slight pitting shown (it's not deep, but you can detect it with your fingernail), it's in good order and measures within spec.
(Click on the image for a larger version)
Thanks
Matt
(Click on the image for a larger version)
Thanks
Matt
Edited by MattYorke on Sunday 16th January 23:04
Because of the extensive coveage area of the pitting it's a regrind rec from me too ;-)
If you want to avoid oversize shells etc, it might be possible to have it recovered by a metal spray job before the grind op??
(if it was just a small area, you might have got away with a very light emery job to ensure there were no high spots, but, over that area i think you are asking a bit much of the oil film)
If you want to avoid oversize shells etc, it might be possible to have it recovered by a metal spray job before the grind op??
(if it was just a small area, you might have got away with a very light emery job to ensure there were no high spots, but, over that area i think you are asking a bit much of the oil film)
No one is going to put their neck on the line and say polish it over and give it a go as I suspect you already know. Whether it would in fact work ok is another matter. I'd be happier with a bit of pitting on mains than big ends.
What no one has mentioned though is that the crank looks very like a nitrided EN40B one to me which means you could be grinding through some or all of the nitriding if you have it done. However it's not practical to have it nitrided again without redoing all the mains as well. Still, cast iron and EN16 cranks are soft enough and still work ok so I guess you live with it.
Whatever the engine is I'd be tempted to take it to a specialist in that type for an opinion. It's not easy to judge from photos.
What no one has mentioned though is that the crank looks very like a nitrided EN40B one to me which means you could be grinding through some or all of the nitriding if you have it done. However it's not practical to have it nitrided again without redoing all the mains as well. Still, cast iron and EN16 cranks are soft enough and still work ok so I guess you live with it.
Whatever the engine is I'd be tempted to take it to a specialist in that type for an opinion. It's not easy to judge from photos.
It's a lunati pro series crank, so by the time I pay for 2 way shipping, it'd be not far off the cost of a new one. I have asked Lunati about grinding these cranks previously (this motor is one of triplets) and they said it's quite common to not re-nitride them after a 10 thou regrind, although it is preferable.
I guess I could do the whole lot, all bearings & journals, but I'm very reluctant to remove metal that doesn't need removing.
I guess I could do the whole lot, all bearings & journals, but I'm very reluctant to remove metal that doesn't need removing.
MattYorke said:
It's a lunati pro series crank, so by the time I pay for 2 way shipping, it'd be not far off the cost of a new one. I have asked Lunati about grinding these cranks previously (this motor is one of triplets) and they said it's quite common to not re-nitride them after a 10 thou regrind, although it is preferable.
I guess I could do the whole lot, all bearings & journals, but I'm very reluctant to remove metal that doesn't need removing.
Don't regrind the mains, just re-nitride and lap them.I guess I could do the whole lot, all bearings & journals, but I'm very reluctant to remove metal that doesn't need removing.
In for a penny, in for a pound. 
I've been using/planning to use Roland Alsop for all the machine work, but don't think he can do nitriding, and I don't know anyone who can. Can anyone make a recomendation of who could therefore do the crank for me. Within about 100ish miles of farnborough, hants, ideally.
I've been using/planning to use Roland Alsop for all the machine work, but don't think he can do nitriding, and I don't know anyone who can. Can anyone make a recomendation of who could therefore do the crank for me. Within about 100ish miles of farnborough, hants, ideally.
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