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Align this, Align that! What does GM have against dowel pins?

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Old Jul 22, 2016 | 05:17 PM
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Default Align this, Align that! What does GM have against dowel pins?

I'm getting ready to install my LS1 in my 240SX, and am looking into replacing the rear main seal and oil pump. But I have to admit I was taken back by this notion that the rear main seal carrier and oil pump need to be properly aligned. Every engine I have worked on had dowel pins to properly line up these parts. But the LS series apparently doesn't? What's with this? I would think that it would have been a no-brainer to have dowel pins to make sure these parts are properly lined up.
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Old Jul 22, 2016 | 05:37 PM
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The rear main is no big deal. Never aligned an oil pump in my ls1, just installed.. no issues.

The ls1 should seem to you like a Neanderthal could work on it. In contrast working on Nissan engine bays/engines is like, why'd they put this here, why'd they put that there, you can't get to this because this is in the way..a ******* nightmare compared to most GM cars and engines.
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Old Jul 22, 2016 | 06:06 PM
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Originally Posted by Launch
In contrast working on Nissan engine bays/engines is like, why'd they put this here, why'd they put that there, you can't get to this because this is in the way...
Nissan is the absolute WORST car in the world to work on. They just cram stuff in there, even when it doesn't have to be done that way. Not only that, but they make some stuff intentionally hard. For instance, on the 240SX, the bolts that hold in the steering box point UP!

As for working on cars, most of my experience is with Honda. Hondas are SO simple they might as well call them Fisher Price. Toyota is a little more complicated than Honda, but not too bad. As for the LS1, it's certainly a simple engine. But it would still be nice if there could be dowel pins to take out the guesswork (and/or need for special tools).
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Old Jul 22, 2016 | 06:50 PM
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I can see why they don't put dowels on either end of the engine, If the block is line bored for any reason the dowels would be off. Even a line hone could throw off the oil pump alignment by a few thousandths. An aftermarket crankshaft may be different than stock also. You do want to shim the pump before tightening it down to prevent premature wear. Same reason not to have dowels to locate seals but not as critical as the oil pump.
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Old Jul 31, 2016 | 02:52 AM
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it's simpler than that. it would cost extra. maybe 2 dollars a block? over a million blocks thats a nice little christmas bonus.
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Old Aug 1, 2016 | 03:03 AM
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Originally Posted by truckdoug
it's simpler than that. it would cost extra. maybe 2 dollars a block? over a million blocks thats a nice little christmas bonus.
Good point - IIRC they are at over 3m engines now. Most successful EFI V8 every conceived.
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Old Aug 1, 2016 | 05:37 PM
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Originally Posted by truckdoug
it's simpler than that. it would cost extra. maybe 2 dollars a block? over a million blocks thats a nice little christmas bonus.
That might sound like a good reason but I doubt that is the actual reason. Everything is automated so the cost isn't likely to be even close to $2 a block to pay for and install them, Dowels bought in bulk probably cost them less than $.10 a unit.
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Old Aug 5, 2016 | 12:42 AM
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Originally Posted by LLLosingit
I can see why they don't put dowels on either end of the engine, If the block is line bored for any reason the dowels would be off.
And seeing as the LS SBC is the most commonly rebuilt engine in motorsports today...

no dowels for you.
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