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Crank cross-drill necessary?

I'm rebuilding a sedate 2.7 for street use and have been reading all the posts regarding crank cross-drilling and bearing grooving to enhance oiling for the center rods.

I am planning to do the oil bypass mod and am also installing a later oil pump for increased capacity. Is the cross-drilling really necessary for a street motor (never revving past 6k, if even that)? Is it better to groove the crank journal or the main bearing?

I do see the benefit of making sure the oil system is as good as it can get, but am wondering if this is approaching the point of diminishing returns.

Thanks for the help.

Old 07-02-2011, 08:30 AM
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You do not need to cross drill your crank. That is for racing engines. If you ae building a 2.7 I think the oil bypass is already done.
Old 07-02-2011, 08:34 AM
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I forgot one bit of info - I am starting with a early 2.4L 7R mag case (and that's why I'm clearancing the case for the larger oil pump and doing the bypass mod).
Old 07-02-2011, 09:03 AM
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Un bolt the steel studs and install dilivar. You dont need to case save the 73 7R case because it has never been stressed or overheated.
Bruce

This isnt where it belonged...
Bruce

Last edited by Flat6pac; 07-02-2011 at 05:41 PM..
Old 07-02-2011, 09:06 AM
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We cross drill every crank but most would say that it is not necessary.
We always install CaseSavers in mag cases and only use Supertec head stud kits.

I wouldn't use a Dilivar stud in anything not even a lawn mower engine.
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Old 07-02-2011, 02:59 PM
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You must install case saver as Henry stated. Crossdrilled crank is not needed below 7500 RPM. Read all the threads on Headstuds to help you decide on them.

-Andy
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Old 07-02-2011, 04:09 PM
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Thanks for the info.

I am definitely planning on head stud inserts and am avoiding dilivar. My only question was whether to proceed with the crank cross-drilling for a street motor.

(I have looked at the Supertec stuff - very nice!)
Old 07-02-2011, 07:35 PM
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Quote:
Originally Posted by fanaudical View Post
My only question was whether to proceed with the crank cross-drilling for a street motor.
Its not necessary for engines that do not exceed 7300 RPM. This includes most street engines that are not run continously above 7K.
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Old 07-02-2011, 09:26 PM
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Got it - Thank you very much, Steve!

Old 07-02-2011, 09:36 PM
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