LM7 need help picking parts for 500+ hp N/A build.
05-13-2014, 09:03 PM
#1
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LM7 need help picking parts for 500+ hp N/A build. Ok I am a complete noob on motor building so please take it easy on me.
I manage a body shop and one of my mechanics in our GM service shop said he would be happy to put my engine together for me. I already have a 5.3L LM7 engine out of a 2002 Chevy Silverado. It had a 109K miles on it and ran fine when I pulled 5 years ago and has been sitting on an engine stand since.
My goal for this motor is to be in the 450-550hp range naturally aspirated for of course the least amount of money possible. I am going to be putting this into a 68 short wide bed chevy truck I am currently restoring as a dedication to my brother who just passed away in February.
I would like to maintain the fuel injection and have an engine that is reliable with good street manors as I plan to cruise this truck plenty and drive it to the shows.
So what is the most common and economical way to achieve my goals, remember I work at a GM dealership so I get employee pricing on GM parts, but other then that fact I don't care what brand as long as they are of reputable quality.
I manage a body shop and one of my mechanics in our GM service shop said he would be happy to put my engine together for me. I already have a 5.3L LM7 engine out of a 2002 Chevy Silverado. It had a 109K miles on it and ran fine when I pulled 5 years ago and has been sitting on an engine stand since.
My goal for this motor is to be in the 450-550hp range naturally aspirated for of course the least amount of money possible. I am going to be putting this into a 68 short wide bed chevy truck I am currently restoring as a dedication to my brother who just passed away in February.
I would like to maintain the fuel injection and have an engine that is reliable with good street manors as I plan to cruise this truck plenty and drive it to the shows.
So what is the most common and economical way to achieve my goals, remember I work at a GM dealership so I get employee pricing on GM parts, but other then that fact I don't care what brand as long as they are of reputable quality.
05-14-2014, 02:27 AM
#2
450 will be tough to achieve, you can get close with some really expensive parts..
Max effort you'll need 1 7/8 longtubes
Fast 102 intake
Aftermarket heads (trickflow 215's I like, but they're are many different brands)
Custom cam to match these mods and the rear gear ratio you plan to run..
^^^ this is if you want to achieve 440-450 range, it's a close estimate..
If you want 370-410 hp range then a custom cam and ported 243 heads with a ls6 Intake will be a cheaper route..
Either route should warrant at least a new ls6 ported oil pump, new lifters, new timing chain and new lifter trays!
It's scary how expensive it is to chase the last 30-40 hp in a NA engine build!
Search for 5.3 NA builds or call a couple sponsors up to the >>>> right of the screen and most will be able to gameplan a build within your budget!
Max effort you'll need 1 7/8 longtubes
Fast 102 intake
Aftermarket heads (trickflow 215's I like, but they're are many different brands)
Custom cam to match these mods and the rear gear ratio you plan to run..
^^^ this is if you want to achieve 440-450 range, it's a close estimate..
If you want 370-410 hp range then a custom cam and ported 243 heads with a ls6 Intake will be a cheaper route..
Either route should warrant at least a new ls6 ported oil pump, new lifters, new timing chain and new lifter trays!
It's scary how expensive it is to chase the last 30-40 hp in a NA engine build!
Search for 5.3 NA builds or call a couple sponsors up to the >>>> right of the screen and most will be able to gameplan a build within your budget!
05-14-2014, 08:25 AM
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450 will be tough to achieve, you can get close with some really expensive parts..
Max effort you'll need 1 7/8 longtubes
Fast 102 intake
Aftermarket heads (trickflow 215's I like, but they're are many different brands)
Custom cam to match these mods and the rear gear ratio you plan to run..
^^^ this is if you want to achieve 440-450 range, it's a close estimate..
If you want 370-410 hp range then a custom cam and ported 243 heads with a ls6 Intake will be a cheaper route..
Either route should warrant at least a new ls6 ported oil pump, new lifters, new timing chain and new lifter trays!
It's scary how expensive it is to chase the last 30-40 hp in a NA engine build!
Search for 5.3 NA builds or call a couple sponsors up to the >>>> right of the screen and most will be able to gameplan a build within your budget!
Max effort you'll need 1 7/8 longtubes
Fast 102 intake
Aftermarket heads (trickflow 215's I like, but they're are many different brands)
Custom cam to match these mods and the rear gear ratio you plan to run..
^^^ this is if you want to achieve 440-450 range, it's a close estimate..
If you want 370-410 hp range then a custom cam and ported 243 heads with a ls6 Intake will be a cheaper route..
Either route should warrant at least a new ls6 ported oil pump, new lifters, new timing chain and new lifter trays!
It's scary how expensive it is to chase the last 30-40 hp in a NA engine build!
Search for 5.3 NA builds or call a couple sponsors up to the >>>> right of the screen and most will be able to gameplan a build within your budget!
So it sounds like 400's is a more realistic goal for what I want to do...
05-14-2014, 12:24 PM
#5
You can get a custom specd cam that will make more power than the ls6 cam while maintaining good drivability.. If that's what you want..
You could even keep the truck intake manifold instead of an ls6 intake and still make good power..
05-15-2014, 12:51 AM
#6
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So what are some good cam choices/suggestions?
05-15-2014, 01:12 AM
#7
I usually point noobs toward my build. It has a lot of pages on why I selected what I selected and what some of the trade-offs are.
https://ls1tech.com/forums/generatio...ger-parts.html
I would say the best thing to do is punch the 5.3L out to a 3.9" bore and run a 4" crank for a 383. Then you can go a little wilder with the cam and heads and still have a nice driver... and it will make good power and torque. Getting 450rwhp out of that would be easy.
https://ls1tech.com/forums/generatio...ger-parts.html
I would say the best thing to do is punch the 5.3L out to a 3.9" bore and run a 4" crank for a 383. Then you can go a little wilder with the cam and heads and still have a nice driver... and it will make good power and torque. Getting 450rwhp out of that would be easy.
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05-15-2014, 05:55 AM
#8
450 will be tough to achieve, you can get close with some really expensive parts..
Max effort you'll need 1 7/8 longtubes
Fast 102 intake
Aftermarket heads (trickflow 215's I like, but they're are many different brands)
Custom cam to match these mods and the rear gear ratio you plan to run..
^^^ this is if you want to achieve 440-450 range, it's a close estimate..
If you want 370-410 hp range then a custom cam and ported 243 heads with a ls6 Intake will be a cheaper route..
Either route should warrant at least a new ls6 ported oil pump, new lifters, new timing chain and new lifter trays!
It's scary how expensive it is to chase the last 30-40 hp in a NA engine build!
Search for 5.3 NA builds or call a couple sponsors up to the >>>> right of the screen and most will be able to gameplan a build within your budget!
Max effort you'll need 1 7/8 longtubes
Fast 102 intake
Aftermarket heads (trickflow 215's I like, but they're are many different brands)
Custom cam to match these mods and the rear gear ratio you plan to run..
^^^ this is if you want to achieve 440-450 range, it's a close estimate..
If you want 370-410 hp range then a custom cam and ported 243 heads with a ls6 Intake will be a cheaper route..
Either route should warrant at least a new ls6 ported oil pump, new lifters, new timing chain and new lifter trays!
It's scary how expensive it is to chase the last 30-40 hp in a NA engine build!
Search for 5.3 NA builds or call a couple sponsors up to the >>>> right of the screen and most will be able to gameplan a build within your budget!
My build is 11.25:1, Trick flow genx 205s, comp xe275hr w/ 1.82 rockers, and an edelbrock intake.
Seen an 11:1 motor with a trick flow cam practically the same specs go 499hp through an ls6 intake...
05-15-2014, 08:39 AM
#9
499 at the engine or at the wheels? There's a huge difference in at the wheels... only a handful of LS1s have ever hit 500 at the wheels (let alone 5.3s). And they are with heads much better than the 205s, a lot more cam than that, and a lot more compression than 11.25:1...
05-15-2014, 10:19 AM
#11
You take a 5.3, put in a max the **** effort cam spec'd for a single plane intake, run a bad *** set of worked over MAST 215cc or TFS 215cc or AFR 215cc heads with lightweight valves and a spot on valve train setup, and run a Super Victor intake with a 4150 TB (no elbow), I think you'll be well over 450 rwhp. Maybe not 500 rwhp, but pretty close.
11-11-2015, 11:37 PM
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This coment makes me want to go for it. My build is based off of the project track rat 5.3 build. but mine is with a 3.80 bore 11.8:1, harlen sharp roller rockers and a lsxrt port matched and lightly ported intake and ported ls2 tb. Tfs 205 top end kit with the 220 224 575 split tfs cam. Their build made 496 I belive at the crank. I'm hoping for 530-540 at the crank with this street cam a more aggressive cam should net around as much as 575 580 at the crank. I may be a little high on the last estimate. I'm running a fully built 4l65e and custom converter. Yes with a auto tranny I will fall short of 500 at the wheels but with a stick and decent clutch, a do-able build on pump gas.
11-12-2015, 12:57 AM
#15
TECH Veteran
I would personally go the 383 ci route.
More torque at a lower rpm over a standard 5.3!! Torque is what moves you..... horsepower is to brag to your buddies about.
More torque at a lower rpm over a standard 5.3!! Torque is what moves you..... horsepower is to brag to your buddies about.
11-12-2015, 08:17 AM
#16
I think the best bang for the buck would be to just bore the cylinders to 3.898" and drop in a stock LS1/6 rotating assembly. Put a decent 22x/23x size cam in there and let it eat. With an LS6 intake and some decent headers, you would be around 400whp/400ft-lbs.
11-12-2015, 10:16 AM
#17
TECH Addict
On a budget, throw the ls6 heads and intake on it, with a custom grind cam. With a good exhaust and a good tune, you should have a really fun truck.
If you have a little extra coin, then I would use the heads you have now as cores for any of the various cnc ported factory castings offered by any of the vendors on this site. Don't go crazy, but you can set yourself up with trunion upgraded stock rockers on cnc ported heads that flow 300cfm for less than two grand, probably less than $1500 if you are a careful shopper. The cnc ported factory heads with upgraded trunion stock rockers, ls6 intake, custom cam, good exhaust, and good tune will be north of 400 at the wheels.
As for adding displacement... First off, say goodbye to your budget.
Couple things to remember, you don't have to overbore the block to add a stroker crank. A 4" crank in the 3.78" bore makes a 359ci stroker. Wiseco makes the pistons, I believe you can find the whole kit with forged k1 crank and rods.
Secondly, if you do overbore the block, nothing guarantees that it will pass the sonic check. And you could have just paid money to ruin your engine.
I'm not against overboring an iron block, just something to think about.
You can use your stock crank, pick up some JE forged 3.905" x 1.175" pistons, and some eagle 6.25" forged rods, all for about $1000. That's a pretty stout iron 5.7 combo on a budget.
The above iron 5.7 with the cnc ported heads, good exhaust, custom cam, and good tune will be capable of producing some good power, and would provide an excellent platform for boost, if you so desire.
If you have a little extra coin, then I would use the heads you have now as cores for any of the various cnc ported factory castings offered by any of the vendors on this site. Don't go crazy, but you can set yourself up with trunion upgraded stock rockers on cnc ported heads that flow 300cfm for less than two grand, probably less than $1500 if you are a careful shopper. The cnc ported factory heads with upgraded trunion stock rockers, ls6 intake, custom cam, good exhaust, and good tune will be north of 400 at the wheels.
As for adding displacement... First off, say goodbye to your budget.
Couple things to remember, you don't have to overbore the block to add a stroker crank. A 4" crank in the 3.78" bore makes a 359ci stroker. Wiseco makes the pistons, I believe you can find the whole kit with forged k1 crank and rods.
Secondly, if you do overbore the block, nothing guarantees that it will pass the sonic check. And you could have just paid money to ruin your engine.
I'm not against overboring an iron block, just something to think about.
You can use your stock crank, pick up some JE forged 3.905" x 1.175" pistons, and some eagle 6.25" forged rods, all for about $1000. That's a pretty stout iron 5.7 combo on a budget.
The above iron 5.7 with the cnc ported heads, good exhaust, custom cam, and good tune will be capable of producing some good power, and would provide an excellent platform for boost, if you so desire.
11-12-2015, 12:28 PM
#18
turn it into a 383 and never look back.
383 cubes will provide the torque to get that truck rolling. Good set of heads (243s with some work might get you there) to let it breathe and control it with a factory PCM. Contact a few vendors for recommended cam choice and compare before you buy one.
383 cubes will provide the torque to get that truck rolling. Good set of heads (243s with some work might get you there) to let it breathe and control it with a factory PCM. Contact a few vendors for recommended cam choice and compare before you buy one.
11-12-2015, 12:31 PM
#19
TECH Veteran
turn it into a 383 and never look back.
383 cubes will provide the torque to get that truck rolling. Good set of heads (243s with some work might get you there) to let it breathe and control it with a factory PCM. Contact a few vendors for recommended cam choice and compare before you buy one.
383 cubes will provide the torque to get that truck rolling. Good set of heads (243s with some work might get you there) to let it breathe and control it with a factory PCM. Contact a few vendors for recommended cam choice and compare before you buy one.
11-12-2015, 01:17 PM
#20
TECH Veteran
One of the highest combos I've seen with a stock bottom end made 483 horses and 440 ft lbs. It features tfs 205 heads, a tfs camshaft and a fast intake (truck version).
Expensive top end there.... not cheap at all.
Then I seen a test where a 224 cam made 440 horse at the crank using stock heads (LM7). Loss a lot of low end torque tho compared to other smaller cams that was tested.
Expensive top end there.... not cheap at all.
Then I seen a test where a 224 cam made 440 horse at the crank using stock heads (LM7). Loss a lot of low end torque tho compared to other smaller cams that was tested.
