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Opinions On Bearings

JustinP

By JustinP,
in Engines & Forced Induction

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JustinP Mentor

JustinP

Posted
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:)

I will be assembling the engine (under the watchful eye of my dad!). The place doing the machining and balancing has recommended King, I was originally thinking ACL.

Seeing as 2 very experienced people on here have recommended one and the other I guess they must be pretty even!

Another quick question, seeing as Nissan builds the engines with graded bearings why do people not have issues when using non Nissan standard size bearings? Or are the differences between journal measurements on the crank tiny (and if so why do Nissan bother with grades bearings?)

Thanks :)

Hmm, what a conundrum. Now you'll have to start a thread on who's opinion is the best opinion. My advice would be to ask your engine builder, if you are the engine builder, then it won't matter

The Dan Grand Master

The Dan

Posted
Posted

:)

I will be assembling the engine (under the watchful eye of my dad!). The place doing the machining and balancing has recommended King, I was originally thinking ACL.

Seeing as 2 very experienced people on here have recommended one and the other I guess they must be pretty even!

Another quick question, seeing as Nissan builds the engines with graded bearings why do people not have issues when using non Nissan standard size bearings? Or are the differences between journal measurements on the crank tiny (and if so why do Nissan bother with grades bearings?)

Thanks :)

There is a whole thread on this only a few weeks back. Explains everything

The Dan Grand Master

The Dan

Posted
Posted

As long as your clearances are ok and you are using a tri-metal bearing you will be fine. The bearing is not going to be a point of failure and if you were going to be pushing the limits of either manufacturer then building it yourself is probably not the best option.

Even the bi-metal bearings are ok in things mildly tuned - Nissan had no trouble with them

T04GTR Grand Master

T04GTR

Posted
Posted

that is the propper way of doing it. and besides, if its got oil they wont ware out. its only if there is an oiling problem it wont matter what is in there.

i personaly have found the tollerances with SOME acl race series bearings to vary as much as 1/2 thou.

NDC is a very good brand aswell.

The Dan Grand Master

The Dan

Posted
Posted

that is the propper way of doing it. and besides, if its got oil they wont ware out. its only if there is an oiling problem it wont matter what is in there.

i personaly have found the tollerances with SOME acl race series bearings to vary as much as 1/2 thou.

NDC is a very good brand aswell.

:thumbsup:

From memory NDC make the factory Nissan bearing don't they?

And yeah, have sent a few sets of ACL back myself but only because we didn't like more than 0.0001 variation.

The Dan Grand Master

The Dan

Posted
Posted

i line hone then fit bearings to each journal then measure it. we then grind / linish crank to get exact clearances on each journal.

We have found that linishing the crankshaft to achieve an exact measurement will actually do more harm than good. Of course you can generally always take off 0.0001 without too much trouble but anything more than that will make the journal not round any longer and create a wave effect over it. Sometimes it is better to have that small variation in clearance rather than the wavey journal, but once again 0.0001 is generally considered ok for a linish if you absolutely had to.

STATUS Grand Master

STATUS

Posted
Posted

We have found that linishing the crankshaft to achieve an exact measurement will actually do more harm than good. Of course you can generally always take off 0.0001 without too much trouble but anything more than that will make the journal not round any longer and create a wave effect over it. Sometimes it is better to have that small variation in clearance rather than the wavey journal, but once again 0.0001 is generally considered ok for a linish if you absolutely had to.

in over 50 done that way weve never had an issue so i will keep doing the same thing :P

The Dan Grand Master

The Dan

Posted
Posted

in over 50 done that way weve never had an issue so i will keep doing the same thing :P

Whatever works for you. I wasn't telling you to change, I was only providing an educational viewpoint for the readers of this thread. Most good engineers can do 0.0001-0.0002 without too much of a problem but go 3 tenths or 4 and the journal WILL become out of round and uneven across the face. Whether that equals engine failure or not, I'm not sure, as there are so many different reasons an engine can fail but I do know that an out of round journal is worse than 1 tenth in clearance

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