Does a new GM LS1 block need machining?

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Sep 14, 2014 | 01:19 PM

kristov

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Does a new GM LS1 block need machining?

http://www.summitracing.com/int/part...1166/overview/

When buying a block like this - does it need any kind of machining (decking, boring etc.) or can you just start assembling it with new parts?

It will be used to rebuild a stock LS1 with a bad block.

Sep 14, 2014 | 01:40 PM

Fat Jesus 808

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Yes, they are shipped at 3.890" bore. Ls1 bore is 3.898"

Sep 14, 2014 | 02:04 PM

kristov

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Quote:

Originally Posted by Fat Jesus 808

Yes, they are shipped at 3.890" bore. Ls1 bore is 3.898"

Thanks!

What about decking the HG-surface?

Sep 14, 2014 | 03:33 PM

Fat Jesus 808

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That should be machined alredy, but might as well have it checked and make sure its flat

Sep 14, 2014 | 04:06 PM

00SlvrSS

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I advise anyone that buys a block "fresh" gets it machined totally and build according. There's nothing like knowing your clearances and decking for a little more quench and know you have a straight line hone done.

Sep 14, 2014 | 06:17 PM

Fry_

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Would be better off with a LS2 block only $229 more and already has freeze plugs and cam bearings installed

Sep 14, 2014 | 06:36 PM

Pbeyer2010

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$1000 seems like a lot for a block that has to get machined anyway. IMO i would look for a good used LS1 block for a few hundred bucks and have that machined... my $0.02

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Sep 14, 2014 | 07:08 PM

redtan

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Quote:

IMO i would look for a good used LS1 block for a few hundred bucks and have that machined... my $0.02

Yeah if you're going to do all that work you might as well save some money and get a used block. The whole point of buying new is not to have to all that work. A used block after proper machining is going to be just as good as new given that it's in good condition.