402 LS1?

In the next year I want to perform a LS1 swap into my pickup and i have a couple questions concerning possible upgrading. Although i probably wont have the funds this year, what would i need to have it built with to withstand a sts turbo in the near future. My question is how difficult and how much would it cost to rebuild a stock low mileage LS1 into a stroked 402 forced induction capable engine? My ultimate goal is 400-450 rear wheel horsepower and i figured a 402 ls1 and a sts turbo at around 7 psi would do the job. Going along with that, is the LS1 motor the best way to go about this or is a 6.0 engine better? Any help and opinions good or bad would be greatly appreciated.

i would say the lq4 6.0 would be the best, but i don't know maybe this will get others to post a reply. also if you want around 400 to 450 horsepower you might as well just go all motor, because the sts will put up to around over 500 but i think that would be even better than 450 just my opion, good luck with this.

An LS1 will require being resleeved to make it a 402. The cost of resleeving will be tremendous. You're better off buying an LS2 block that is already 4" or buying a L92 block that is 4.06" and having an even larger engine. The LS2 block is about the same cost as an LS1/LS6 block. The L92 will cost you about $300 additional due to the work they do inside the block to control displacement on demand(dod) and variable valve timing.

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 08&#58;20 AM) [snapback]77874[/snapback]</div>

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An LS1 will require being resleeved to make it a 402. The cost of resleeving will be tremendous. You&#39;re better off buying an LS2 block that is already 4" or buying a L92 block that is 4.06" and having an even larger engine. The LS2 block is about the same cost as an LS1/LS6 block. The L92 will cost you about &#036;300 additional due to the work they do inside the block to control displacement on demand(dod) and variable valve timing.
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Thanks for the replies guys. I was told the ls1 could be stroked to a 402 without resleeving thats good infromation to know. How large can an ls1 be stroked, 383? As for the horsepower numbers more is obviously better i was just shooting for 400-500 rear wheel in the end. i will look into the l92 or ls2 block and see what i can find. im going to have around 4-5 thousand to build a motor so i would like to go the easiest and best way possible.Thanks

All the aluminum blocks have a max overbore of about .010". The 97 and 98 LS1 don&#39;t even allow that much according to what I&#39;ve read. 402 is typically a 4" bore with a 4" stroke. 408 would be with a 4.030 overbore.

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 11&#58;17 AM) [snapback]77884[/snapback]</div>

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All the aluminum blocks have a max overbore of about .010". The 97 and 98 LS1 don&#39;t even allow that much according to what I&#39;ve read. 402 is typically a 4" bore with a 4" stroke. 408 would be with a 4.030 overbore.
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Interesting i didnt know that. How hard would it to be to rebuild a stock ls1 into like 10 psi forced induction capable? The stock ls1 is 350 horse right, and i believe the turbo can give up to 15 psi so wouldnt a rebuilt LS1 with a turbo kick out somewhere in the 500 horse range. Thanks.

Take a stock LS1, bore it plus .010", add ARP bolts/studs to the stock rods, mains and heads, put forged pistons in it with increased pocket sizes in the pistons to drop compression or add 317 casting 6.0L heads to drop the compression. Run 10+ lbs of boost and you&#39;ll be easily 500+ hp at the rears. Talk to Billy or Allen and they can put you together a game plan.

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 11&#58;40 AM) [snapback]77886[/snapback]</div>

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Take a stock LS1, bore it plus .010", add ARP bolts/studs to the stock rods, mains and heads, put forged pistons in it with increased pocket sizes in the pistons to drop compression or add 317 casting 6.0L heads to drop the compression. Run 10+ lbs of boost and you&#39;ll be easily 500+ hp at the rears. Talk to Billy or Allen and they can put you together a game plan.
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That sounds good, not too overly complicated. What are good forged piston brands and such in your opinion, i really dont know because I did a internet search and get thousands of possibilities from a ton of different places. Will this engine run ok on the lower compression without the turbo for a while, or should i wait till i have it all to install it? Also, with this setup and proper maintenance how many miles do you think the engine would last, if possible i would like this setup to last 100k miles if possible and have it get me through college, but if not i guess thats ok. Its going to be my daily driver so im not going to be racing it everyday, but occasionally i may take it to the track. Thank you for all your help, its greatly appreciated.

You&#39;ll want to buy a boost controller so that you can run 5-7 lbs every day and boost it up at the track. It should last a good long time. There are quite a few good forged pistons out there. Wiseco, Probe, Mahle, Ross....only to name a few. Be sure to do your research and call the manufacturer and talk to their customer service rep about your application before dropping the coins on a set. You&#39;ll also need good quality rings, most are around &#036;200 a set unless you go extreme with a very nice set of total seal gapless rings. Be sure when you buy bearings for the engine that you buy nothing that isn&#39;t coated. An extreme use engine needs everything it can get towards lubrication. Calico makes nice coated bearings and they aren&#39;t that much more expensive than stock units. They start with popular brands of bearings and then apply their proprietary coating to the bearing surfaces. Go check out their website and read up on the benefits. You might even consider getting the piston skirts coated to reduce friction.

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You can run the engine without a turbo without any problems. You can also run additional timing with the low compression engine to gain some of the lost performance caused by the lower compression. Most LS1 type engines can&#39;t handle but about 24 degrees of timing before they ping but with the low compression you&#39;ll easily be able to pull about 28 degree or more. I don&#39;t think Calico will coat your pistons for you but you can ask them. You can do a little research on the net to find places that will coat the pistons for you. You may be even able to get the company that supplies the pistons to you to have them coated before shipping them out. Speed Pro and Mahle both sell a coated piston. Do some research and don&#39;t be afraid to call or email the manufacturers for more information.

Sounds good i will do those things. How many horse is the engine going to put out do you think in the low compression form? If its a significant drop couldnt i buy normal not dished pistons for the buildup and use the stock heads and then later put on the 6.0 heads? Which is better, dished pistons with stock heads or stock pistons with 6.0 heads? Thanks

You could use the stock heads with flat top pistons and then when you go turbo you can swap the 317 casting heads and then put the turbo on it. For what it&#39;s worth, there are guys running the stock compression LS1 heads and pistons with turbo but they have to limit the amount of boost to about 5 lbs max.

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 04&#58;23 PM) [snapback]77925[/snapback]</div>

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You could use the stock heads with flat top pistons and then when you go turbo you can swap the 317 casting heads and then put the turbo on it. For what it&#39;s worth, there are guys running the stock compression LS1 heads and pistons with turbo but they have to limit the amount of boost to about 5 lbs max.
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I may have to do that. If im gonna spend 3-4 thousand for a turbo im gonna use most of the boost it can make. You can set it on two modes and i think i will run 7psi and 12psi but i may change my mind. What would the hp numbers be on the low comp engine if i had the dished pistons until the turbo? If its not very much i will do that and save the money of having someone have to swap the heads and buy the different heads when i install the turbo.

I would build it with the dished pistons and not worry about the power loss. Once you start worrying about it, that means it&#39;s time to go turbo and 317 heads. The lower the compression you start with, the higher boost numbers you can build safely once you put the turbo on it. I&#39;ve seen guys run 8:1 compression and run 30 lbs of boost. More boost means more combustible fuel/air combination and more HP potential. Look at the power numbers they get out of a turbo&#39;d Honda or Toyota, that is possible only by building huge amounts of safe boost. That is possible by running low static compression, boosting it to the max and supplying a steady safe amount of fuel. Don&#39;t forget you will need some big injectors to replace the stock units. Budget money for that, a speed density tune and a good fuel system(one fuel pump per fuel rail, you&#39;ll need aftermarket fuel rails for that, or something like one of Aeromotive&#39;s A1000 pumps).

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 04&#58;51 PM) [snapback]77927[/snapback]</div>

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I would build it with the dished pistons and not worry about the power loss. Once you start worrying about it, that means it&#39;s time to go turbo and 317 heads. The lower the compression you start with, the higher boost numbers you can build safely once you put the turbo on it. I&#39;ve seen guys run 8:1 compression and run 30 lbs of boost. More boost means more combustible fuel/air combination and more HP potential. Look at the power numbers they get out of a turbo&#39;d Honda or Toyota, that is possible only by building huge amounts of safe boost. That is possible by running low static compression, boosting it to the max and supplying a steady safe amount of fuel. Don&#39;t forget you will need some big injectors to replace the stock units. Budget money for that, a speed density tune and a good fuel system(one fuel pump per fuel rail, you&#39;ll need aftermarket fuel rails for that, or something like one of Aeromotive&#39;s A1000 pumps).
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30 Psi, good lord thats a lot of boost. So with the bigger injectors and the new fuel pump am i going to have any gas mileage at 5-7 psi of boost?

I have heard of some of these guys on here picking up fuel mileage once they went turbo from stock. The larger injectors are really only going to make a difference at power levels greater than stock. The O2 sensors will keep the fuel mixture appropriate for normal driving times. You&#39;ll only lose mileage if you can&#39;t help but have your foot buried to the floor all the time just to hear the turbo whine. You need the injectors and pump to supply more fuel when boosting it. You don&#39;t want to put too much air and not enough fuel, major lean condition and soon a dead engine.

Yeah i know to upgrade the injectors and fuel pump but i didnt know about the fuel rails. Ill probably install some 42 pound injectors for it. That should supply enough fuel. I know this build isnt for fuel mileage but hopefully under normal driving conditions when everything is done i will get 15 mpg. If not oh well but 15 mpg would be good. Another question i have is regarding the transmission. I have the 4wd version of the 4l60e and was thinking about having it rebuilt to hold the new horsepower. My question is if the camaro 4l60e already stronger and easier to build up. If this is so i could just get that with the ls1 and have the output shaft switched with my 4wd one. I just dont know if there is a difference between the two?

I am not 100% sure but the internals of the 4wd 4L60E should be the same as the 2wd version. The only diff should be the output shaft. I would take your tranny down and have it rebuilt while you have the engine out. Get billet 1-2 and 3-4 apply pistons from Superior, they will help keep power applied solid to the band while applied. Tell the builder NOT to add frictions or plates to the 3-4 clutch pack, have him install the 3-4 clutch pack from a 4L65E transmission(BorgWarner preferably).

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 31 2006, 07&#58;14 PM) [snapback]77943[/snapback]</div>

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I am not 100% sure but the internals of the 4wd 4L60E should be the same as the 2wd version. The only diff should be the output shaft. I would take your tranny down and have it rebuilt while you have the engine out. Get billet 1-2 and 3-4 apply pistons from Superior, they will help keep power applied solid to the band while applied. Tell the builder NOT to add frictions or plates to the 3-4 clutch pack, have him install the 3-4 clutch pack from a 4L65E transmission(BorgWarner preferably).
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Ok that sounds good. How many horse do you think this is going to hold safely?

damn guys...whens the wedding? Red, you need to start charging a consulting fee. That is of course after I had already asked all these questions. :laugh: