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402 ls2 bottom end help

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Old 10-12-2012, 02:49 AM
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Default 402 ls2 bottom end help

Ok, this will be my last bottom end thread I swear. After deciding on the pistons and rods setup with the stock crank, I figured I'll just kick myself for not doing a 402 build since I'm buying pistons and rods anyway. So I decided on these pistons and rods
Wiseco 4.005" -3cc flat tops with 1.110" compression height
scat I beam 6.125" rods .927 pin

That will work really well with the ls3 heads and gm .054 gaskets I already have. Going for 10.8:1 and 69cc heads.

So my question is which crank? I'm looking at the callies compstar, manley pro lightweight, and scat regular weight 4.000" stroke crank. What is the weight of the callies compstar? The manley is 50-52 lbs.

Also I have a noob question. How is the reliablity of a 402 stroker? I know that the rods side load the pistons more, so does this hurt the max mileage you can get on a 402? I really want a super reliable setup that will last at least 80K, but I would expect to get 120k on a well put together motor. Is this a realistic expectation on a motor like this?

And my cam is a 226/234 .598/.612 114+2 LSA which is very small for a 402. Will that cause any problems? I can is still rev this out to 7K rpm with no problem?

Thanks again everyone,

Ryan
Old 10-12-2012, 07:54 AM
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You need to get the right piston for a stroker application bud.
What is the correct piston that you have?
If you have scat rods just get a scat crank, you might also need to clearance the block for the stroker as well. BUT PLEASE don't be discouraged! Your doing the right thing so you won't regret it later. Trust me lol
Old 10-12-2012, 10:15 AM
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Ryan, there are a few cranks out there, and we recommend a Scat LS Series Forged Competition Crank if you are looking for overall performance and longevity. This crank will have a weight of 48 lbs and will have no fitment issues with the rods you were looking at. There are 2 options for the connecting rods- Scat I Beam rods and Scat H Beam rods, H beam is the stronger of the two. The Wiseco LS Forged Pistons you will need are Wiseco K464X05 and will be compatible with the 4.00 stroke, 6.125 rod length. I plugged your 402’s set up into our Compression Calculator and it should produce a 10.73:1 ratio. We recommend the use of Wiseco piston rings for the 402 LS you are assembling and they are sold for a single piston so you would need a set of 8. Taking all this into consideration with the specs of your cam you are correct that it is on the smaller side. This engine combination should make a great street/strip setup providing lots of torque, drivabilty and should pull hard to 6700 RPM.
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Old 10-12-2012, 10:27 AM
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http://www.texas-speed.com/p-903-tsp...-assembly.aspx

Consider buying it as an entire kit rather than piece by piece. We can save you more money this way! Of course we can balance the assembly for you so it will be ready to drop into the machined block (after filing rings obviously)!
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Old 10-14-2012, 04:02 PM
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Thanks for all the responses. I dropped the motor off at lamar walden friday and they actually get a really good price on a callies compstar crank. Also they can get the h beam callies rods for what I was looking to pay for the i beams. So now I have the compstar crank, h beam rods, and wiseco pistons. I can wait to fire this thing up and bring it to the dyno.
Old 10-15-2012, 11:56 AM
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Originally Posted by derotoredFD
Thanks for all the responses. I dropped the motor off at lamar walden friday and they actually get a really good price on a callies compstar crank. Also they can get the h beam callies rods for what I was looking to pay for the i beams. So now I have the compstar crank, h beam rods, and wiseco pistons. I can wait to fire this thing up and bring it to the dyno.
Sounds like a good combo to us. Keep us in mind if you need any other items for your build.
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