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Leftover parts turned into a wallet friendly, 428hp iron LS1

Leftover LS1: A stack of castoff parts leads to a budget-friendly, fuel-injected 428hp LS engine!

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One man’s trash is another man’s treasure is a phrase that fits well here. It all started with a friend that was going to stroke an LS1 he had for a project. His plan was to add some new Scat rotating parts and Trick Flow heads, and stuff the 383 LS1 into his race car. Solid plan. However, that meant he had a sizable pile of old parts left over. This, of course, got me thinking.

Now, for the most part, used parts out of an engine with 90,000 miles on it don’t have a very high perceived value. Why? Well, because new and shiny parts must make more power, right? Well yeah, but they also cost a lot more of your hard-earned cash. The engine ran fine before it was torn apart so this gave me an idea. Why not take those parts and figure out a way to turn them into a fairly strong wallet-friendly mill? My friend sold me the used parts for $300 and, to be honest, I think he was just happy to have them out of his garage. Not that I considered that a great deal, but after digging around on Craigslist for a bit I found similar deals out there; 853 heads for $200, truck heads for less, rotating bits for a couple hundred dollars, and so on. Think about it, how many strokers have been built? How many stock parts have been removed during the process? All those parts are just hanging out in dusty corners and storage bins just waiting to be put back into action.

So I had most of an LS1, which meant the next trick was to find a block to stuff it all into. Finding a used LS1 block really wasn’t the best option. If the bores weren’t perfect I would have to hone them, which would negate using the stock 3.898-inch bore pistons, and if I changed the pistons I would have to rebalance the assembly, costing even more money. It was then that I remembered Summit Racing was running a smokin’ hot deal on ready-to-rock 5.3L LS blocks. Yep, for $300 I had a strong, certified 5.3L block nearly perfect for my LS1 castoff parts. Now, of course, the 5.3L block came with 3.780-inch bores, so there was some cost to bore it out to fit the LS1 slugs, but in the end I had a block for just over $600. The iron block is heavier than its LS1 cousin, but it was cheaper and perfect if a little boost is ever added.

The rest of the build just involved cleaning up the 853 heads (early LS1), getting some new Clevite bearings and rings, and picking up some gaskets. To up the power of our leftover LS1, we sourced a new bumpstick from Comp. We could have tossed in a huge cam and went for a glorious dyno number but we figure an engine like this would get grafted into a street-driven Chevy so we practiced some moderation and grabbed a cam that would make good power and still have great street manners. We bought the cam in kit form so it came with new lifters, springs, retainers, locks, and valve seals. And since they were in a kit, it was a bit cheaper than a la carte.

We decided to test the combo with the stock LS1 intake, since that’s the lowest cost option, and also with a higher flowing intake and throttle body from FAST. Why? Well, the early LS1 intakes were some of the worst from GM so we knew going the stock route would leave a lot of power on the table. To be honest, if you’re set on going the stock route you would be better off with a truck intake even if they’re fairly ugly. But we had the LS1 intake, so we gave it a go. We then found out what spending $1,300 on a 92mm FAST intake and matching throttle body would add to the equation. It turned out that the gain was a pretty good return on investment, even when the power numbers with the factory LS1 intake were strong enough for most people, and quite a bit more than stock, for an LS1 or even an LS2. We did some quick math and figured that you could realistically build this engine for under $2,900 (with the stock intake system) from pan to throttle body, not counting an ECU, harness, and some of the other bits to make it run. In this age of $10,000+ engines, that’s what we call a bargain. Of course, the final cost of a build like this comes down to how cheap you can score the used parts for, so get out there and see if you can figure out a way to turn someone else’s trash into your treasure!

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1. This is what inspired this project; the leftover guts from an LS1 stroker project. Every time an engine is stroked there’s a stack of good parts left languishing in some storage shed or shop corner. When you find these parts they can usually be bought for cheap since they are perceived to have little value, but we know better. The crank stroke, 3.622 inches, is shared with the 5.3L LS engines found in countless GM trucks and SUVs.

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2. Of course, the block the guts came out of was used for the stroker project so we needed something to stuff all the parts into. Now, we could have tried to find a used LS1 block, but they aren’t real common so we decided to make one from a 5.3L block (a 4.8L block works, too). This choice was made easy since Summit Racing had them cleaned, checked, and ready to rock for just $300.

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3. The 5.3L block came with a bore of 3.780 inches, too small for our used LS1 pistons so a trip to the machine shop was made and the bores were punched to 3.898 inches, the stock bore of a factory LS1. The machine shop bill set us back $322.

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4. Utilizing the stock LS1 bore was advantageous since it let us reuse the stock hypereutectic LS1 flat-top pistons and the powdered metal rods they were attached to. This is the best way to roll since trying to remove the pressed in pin often ends in broken parts. Since the parts all came from the same engine, we didn’t need to have the rotating parts balanced, saving more cash.

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5. This engine was destined for street duty so we wanted a cam that would make good power yet retain excellent street manners. The Comp cam (PN 54-414-11) we slid in was a 216/220-deg. duration at 0.050-inch, 0.525/0.532-inch lift, and a 114 LSA stick. A bigger cam would make more power but we were going for balance. We also needed an LS cam thrust plate from Summit (PN 150106) to secure it in place.

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6. Now, we could have saved money and reused the stock LS1 lifters but our cam came in an upgrade kit (PN K54-414-11) that included new lifters (PN 850-16) and springs for a smokin’ price so we splurged a bit. After coating them with some Driven Engine Assembly Grease we dropped them in place using the factory lifter trays.

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7. Since the LS1 had only 90,000 miles on it the stock crank was in great shape, but we had the machine shop polish it before setting it into the 5.3L block with a set of new Clevite main bearings (PN MS2199H). For the rods we used Clevite rod bearings (PN CB-663P).

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8. After installing fresh LS1 rings, we popped the piston/rod assemblies into place. Remember, the dots on the pistons always face forward.

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9. After a fresh coat of black paint we had our iron LS1 short-block together. The original timing chain sprocket was paired with a new chain from Summit Racing (PN SME-143012).

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10. We did need four head dowels (PN NAL-12570326) from Summit since the originals left with the stock LS1 block. For head gaskets we went with a dependable and affordable Fel-Pro set (PN 9284 PT).

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11. In our case, we ended up with the 853 heads left over from the LS1 stroker project. Not the best heads out there but a decent head and we often see them on Craigslist for $100-$150 a pair. We simply cleaned ours up and secured them in place with a set of torque-to-yield fasteners from Summit Racing (PN SUM-910210). Do some porting and there’s a few more ponies to be had.

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12. The LS1 ran great when it was in the car and had excellent oil pressure. So we simply cleaned, inspected, and installed the original pump.

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13. The blocks that come from Summit (or from Chevrolet) ship missing all of the various plugs and bits needed for it to run. The good news is that companies like Comp (PN 251) and Summit Racing (PN SUM-G1584) offer plug kits for reasonable prices. The Summit kit is nice since it comes with a new oil restrictor (also referred to as a barbell or dog bone).

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14. When it comes to the oil pan what you use will be based on what you plan on stuffing the engine into. In our case, we had a C6 Corvette oil pan system laying around, so we used it. If you don’t have a GM pan that will work for your project then Holley makes a few that would be perfect for transplants into classis Chevys.

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15. For around $200 we were able to get new 1.7:1 rocker arms for our engine. They paired up nicely with the upgraded springs that came in our Comp cam kit. If you have stock rockers you could use them as is or install a trunnion upgrade kit.

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16. And that brought us to this stage, an iron LS1 long-block. At this point we had about $2,100 into the build, way cheaper than a new LS1. This is where you can go several different directions. Given that it’s an iron block it would be good-to-go for a little boost or a small shot of nitrous. And there are scores of aftermarket intake options in addition to used car or truck cathedral port options from GM.

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17. Of course, the cheapest option for us was to run the stock LS1 intake and throttle body that was originally on the LS1. However, it’s one of the worst performing intakes GM made, even if the price was right. A better option would be the LS6 version from later LS1s, LS2s, or even a truck intake if you the necessary hood clearance and aren’t put off by how unattractive they are. The LS1 intake had the stock fuel rails and 26-pound injectors. This whole setup can be had for cheap on the used market since none of the parts are considered all that desirable for those looking to maximize power.

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18. A better looking, and performing, option would be a 92mm FAST intake (PN 54039B). The downside is cost, but it will make quite a bit more power over the stock LS1 or even the LS6 GM version.

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19. Of course, the new intake worked best with a matching 92mm FAST throttle body (PN 54091). The three-bolt LS1 throttle body is too small to be effective on the 92mm FAST intake and, besides, it won’t even bolt up to the four-bolt intake flange. We went with new parts, but used throttle bodies are easy to find if you’re looking to save cash.

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20. Just to make it look complete, we tossed on a leftover LS3 water pump and a set of Hooker exhaust manifolds. The great thing about LS engines is just about any water pump from any LS variant will bolt up to any other variant so there are a ton of affordable ways to skin the proverbial cat. Also, some of the later GM cast-iron exhaust manifolds flow pretty decent and can be found dirt cheap if you look around a bit.

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21. One bit of good news was that our stock LS1 fuel rails and injectors work perfectly with our slick 92mm FAST intake manifold, saving us cash.

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22. So, if you were pinching pennies how much power could you get from the GM LS1 intake? Well, in the interest of science we decided to find out.

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23. The answer was 428 horsepower at 6,100 rpm and 417 lb-ft of twist at 4,700 rpm on the dyno with Hooker LS swap headers. Considering what we’re working with these are stout numbers and a bit more than what even LS2 engines put out from the factory, all on a relatively tight shoestring budget. Even after 6,100 rpm the power held well and, combined with the excellent low-end torque, this is the perfect low-buck option for your street-driven project.

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24. Of course, for those with a few more coins jingling around their pockets, more power can be had with the FAST intake and throttle body that we mentioned earlier. But, how much power will the extra cash get you?

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25. The answer would be 26 hp! Yep, when run with the same oil and coolant temps the iron LS1 churned out 457 hp and 439 lb-ft of torque! More than just the gain in peak numbers was how the FAST intake made more power everywhere across the pull, most notably in low- to mid-range torque. Compared to many bolt-on parts that’s a pretty good bang-for-the-buck addition. Either way you decide to go, this engine would be a great and affordable way to get an LS mill under your hood!

Sources

Don Lee Auto
Cucamonga, 91730
909-989-1573
www.donleeauto.com
Summit Racing
Akron, OH
800-230-3030
http://www.summitracing.com
Westech Performance
Mira Loma, CA 91752
951-685-4767
www.westechperformance.com
Holley
Bowling Green, KY 42101
866-388-5120
www.Holley.com
Chevrolet Performance
888-924-9147
www.chevroletperformance.com
Fel-Pro
Southfield, MI 48034
800-325-8886
www.felpro-only.com
Competition Cams
800-999-0853
http://www.compcams.com
Clevite
662-893-2860
mahle-aftermarket.com

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