Figured out why our engines suck!
05-04-2010, 10:32 PM
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Figured out why our engines suck! We only have a 3.78" bore! Very shitty.....
Valves are very shrouded and with our large stroke these aren't really good rev motors either. Plus, high RPM's won't really fill theses dinky cylinders very well, do to smaller valve size's. Yes.. there are 5.3's out there that scream.
Borexstroke
283 Chevy 3.88"x300"
305 Chevy 3.736"x3.4803"
302 Ford 4"x3.00"
327 Chevy 4"x3.25"
326 Pontiac 3.875"x3.75"
Anything under a 4" bore is garbage. Ford's 302 and Chevy's 327 really rock for small cubed motors. We could debate these engines flaws too, I know!
Valves are very shrouded and with our large stroke these aren't really good rev motors either. Plus, high RPM's won't really fill theses dinky cylinders very well, do to smaller valve size's. Yes.. there are 5.3's out there that scream.
Borexstroke
283 Chevy 3.88"x300"
305 Chevy 3.736"x3.4803"
302 Ford 4"x3.00"
327 Chevy 4"x3.25"
326 Pontiac 3.875"x3.75"
Anything under a 4" bore is garbage. Ford's 302 and Chevy's 327 really rock for small cubed motors. We could debate these engines flaws too, I know!
Last edited by DavidGXP; 05-04-2010 at 10:34 PM. Reason: spelling
05-04-2010, 10:56 PM
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Doing it will mean that I'm about to force feed this ***** *****. I just need a little more $$$
Seriously... thinking about this engine has left me with wanting more. We have excellent heads, and I wanna use them dammit. Sick of 5.0's LS1's and other V8's with simmilar mods wooping my ***!
Seriously... thinking about this engine has left me with wanting more. We have excellent heads, and I wanna use them dammit. Sick of 5.0's LS1's and other V8's with simmilar mods wooping my ***!
Last edited by DavidGXP; 08-07-2012 at 11:12 PM.
05-04-2010, 10:57 PM
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Remember how much horsepower the older engines made? It was pretty rare to find an engine of our size (325ci) making as much HP as ours from the factory, and if they did , they were fairly radical and had poor idle and manners and got 10 mpg. Our engines do pretty good for 3.78" bore. The heads flow pretty well and computers help them run efficiently. Doesn't take very much to make 1 horsepower per cubic inch, which used to considered fantastic years ago
05-04-2010, 11:01 PM
#5
Remember how much horsepower the older engines made? It was pretty rare to find an engine of our size (325ci) making as much HP as ours from the factory, and if they did , they were fairly radical and had poor idle and manners and got 10 mpg. Our engines do pretty good for 3.78" bore. The heads flow pretty well and computers help them run efficiently. Doesn't take very much to make 1 horsepower per cubic inch, which used to considered fantastic years ago
I'm with you, our engines are FAR from terrible.
05-04-2010, 11:10 PM
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Yep... I made a come back comment about these cars and engines not to long ago stating the same. Put these heads, cam and intake on a 4" bore motor that's the same size, and feel what happens! The stroke is good for torque, but for raw power, a little more bore with a little less stroke would be better IMO.
I not trying to compare old engines to new, I'm just trying to compare the bore sizes of similar engines. It would be cool if GM really did make the 5.3 a 327. Guess we're more of a 326 Pontiac.
I not trying to compare old engines to new, I'm just trying to compare the bore sizes of similar engines. It would be cool if GM really did make the 5.3 a 327. Guess we're more of a 326 Pontiac.
Last edited by DavidGXP; 05-04-2010 at 11:37 PM.
05-05-2010, 12:08 AM
#7
Yep... I made a come back comment about these cars and engines not to long ago stating the same. Put these heads, cam and intake on a 4" bore motor that's the same size, and feel what happens! The stroke is good for torque, but for raw power, a little more bore with a little less stroke would be better IMO.
I not trying to compare old engines to new, I'm just trying to compare the bore sizes of similar engines. It would be cool if GM really did make the 5.3 a 327. Guess we're more of a 326 Pontiac.
I not trying to compare old engines to new, I'm just trying to compare the bore sizes of similar engines. It would be cool if GM really did make the 5.3 a 327. Guess we're more of a 326 Pontiac.
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05-05-2010, 07:47 AM
#8
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There really are only three viable options...
Turbo...
Bolt ons...
Engine swap...
If you want to have a lot of power n/a you need a bigger engine....
Buy an LS1/2/6 block, modify the crank, and swap the accessories over.....
Either enjoy her as a DD, make her breath harder, or put a bigger bore engine in it. I think an LS1/2/6 would work well.
Turbo...
Bolt ons...
Engine swap...
If you want to have a lot of power n/a you need a bigger engine....
Buy an LS1/2/6 block, modify the crank, and swap the accessories over.....
Either enjoy her as a DD, make her breath harder, or put a bigger bore engine in it. I think an LS1/2/6 would work well.
05-05-2010, 10:13 AM
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you are right the small bore is the down side to the 5.3 but with an LS6 intake, headers, big cam and maybe some head work you can make 450hp, that's not too shabby.
another way to look at it is to compare your engine to the LT1 or L98 or even the old 5.0's, it's clearly a winner.
another way to look at it is to compare your engine to the LT1 or L98 or even the old 5.0's, it's clearly a winner.
05-05-2010, 12:41 PM
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There are some pretty stout 5.3s, as you mentioned. My 2007 Tahoe ran strong, especially for a 4400 lb truck. While you make a valid point that our bore size isn't the optimum for power, I think that the main reason our LS4s aren't very strong is because the intake and exhaust are compromised in the name of FWD packaging.
For the record, the LS1/LS6 is only a 3.90 bore, only .12 larger than the 5.3. Few people would say that THEY suck!
I think that, with a proper intake and exhaust, these motors will make similar street power to 5.7 LS1s. Sure, the LS1 will always be able to make more maximum power due to it's inherent size and bore-stroke combos, but on the street, a properly modded LS4 should not be too far behind.
I'll be curious to see what you think after you do your LS6 intake.
For the record, the LS1/LS6 is only a 3.90 bore, only .12 larger than the 5.3. Few people would say that THEY suck!
I think that, with a proper intake and exhaust, these motors will make similar street power to 5.7 LS1s. Sure, the LS1 will always be able to make more maximum power due to it's inherent size and bore-stroke combos, but on the street, a properly modded LS4 should not be too far behind.
I'll be curious to see what you think after you do your LS6 intake.
05-05-2010, 01:15 PM
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you are right the small bore is the down side to the 5.3 but with an LS6 intake, headers, big cam and maybe some head work you can make 450hp, that's not too shabby.
another way to look at it is to compare your engine to the LT1 or L98 or even the old 5.0's, it's clearly a winner.
another way to look at it is to compare your engine to the LT1 or L98 or even the old 5.0's, it's clearly a winner.
05-05-2010, 01:38 PM
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LT1s feel stronger because all of the torque is down low. When I drove my first LS1 (a 2000 Z28) car, I thought it felt weak, even compared to a bolt-on L98 Trans Am I once had. Then I nailed it on the freeway on the way home from the dealer, and was shocked. It pulled HARD all the way to 5500 RPMS...A place where the LT1 is out of breath.
The lesson for me is, linnear torque across the whole powerband doesn't feel as strong as peaky torque at low RPMs, assuming the same max torque. It definitely affects SOTP feel.
The lesson for me is, linnear torque across the whole powerband doesn't feel as strong as peaky torque at low RPMs, assuming the same max torque. It definitely affects SOTP feel.
05-05-2010, 02:15 PM
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LT1s feel stronger because all of the torque is down low. When I drove my first LS1 (a 2000 Z28) car, I thought it felt weak, even compared to a bolt-on L98 Trans Am I once had. Then I nailed it on the freeway on the way home from the dealer, and was shocked. It pulled HARD all the way to 5500 RPMS...A place where the LT1 is out of breath.
The lesson for me is, linnear torque across the whole powerband doesn't feel as strong as peaky torque at low RPMs, assuming the same max torque. It definitely affects SOTP feel.
The lesson for me is, linnear torque across the whole powerband doesn't feel as strong as peaky torque at low RPMs, assuming the same max torque. It definitely affects SOTP feel.
I love the LS1 feeling. The first LS1 I drove was a C5 vette and I was amazed that through every single gear, the car pulled evenly and smoothly.
When I drive the monte, it is the exact opposite of the LS1...its like a FWD LT1 that doesn't sound as good. All the power of the LS4 comes on like a sledge in first gear, but 2nd and 3rd combined with a poor flowing intake and a poorly designed exhaust for a V8 makes for a lazy powerband. I can tell that this engine makes some power, but the FWD transaxle set up is not conducive to great performance.
05-05-2010, 03:59 PM
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LT1s feel stronger because all of the torque is down low. When I drove my first LS1 (a 2000 Z28) car, I thought it felt weak, even compared to a bolt-on L98 Trans Am I once had. Then I nailed it on the freeway on the way home from the dealer, and was shocked. It pulled HARD all the way to 5500 RPMS...A place where the LT1 is out of breath.
The lesson for me is, linnear torque across the whole powerband doesn't feel as strong as peaky torque at low RPMs, assuming the same max torque. It definitely affects SOTP feel.
The lesson for me is, linnear torque across the whole powerband doesn't feel as strong as peaky torque at low RPMs, assuming the same max torque. It definitely affects SOTP feel.
05-05-2010, 05:55 PM
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LT1's are torque monsters! My cousin had a 95 T/A with the LT1 and it was a real tire smoker! It wasn't all that impressive on the freeway but on the street it was a different story.
LT1's have a 4.00" bore and is a true 350/5.7L. as most of us know. Those engines were extremely choked up from the factory with small heads and cam.
I can't wait to get my intake on, I need to hurry up and get back home from duty, Im still stuck in Cali. with no car to drive.
LT1's have a 4.00" bore and is a true 350/5.7L. as most of us know. Those engines were extremely choked up from the factory with small heads and cam.
I can't wait to get my intake on, I need to hurry up and get back home from duty, Im still stuck in Cali. with no car to drive.
05-06-2010, 12:36 AM
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The GM Gen III/IV heads rival 80's NASCAR heads in terms of flow. The LS-series heads have a 15-degree valve-angle, way more vertical than the original small-block and LT1 motors. This allows for a shallow combustion chamber and lets the air/fuel burn more efficiently and completely. There are many more reasons that make a 5.3 desirable, but i'm sure you get the picture.
In the end, there's a lot more to the equation than just bore and stroke.
05-06-2010, 01:01 AM
#17
Quoted for truth.
The GM Gen III/IV heads rival 80's NASCAR heads in terms of flow. The LS-series heads have a 15-degree valve-angle, way more vertical than the original small-block and LT1 motors. This allows for a shallow combustion chamber and lets the air/fuel burn more efficiently and completely. There are many more reasons that make a 5.3 desirable, but i'm sure you get the picture.
In the end, there's a lot more to the equation than just bore and stroke.
The GM Gen III/IV heads rival 80's NASCAR heads in terms of flow. The LS-series heads have a 15-degree valve-angle, way more vertical than the original small-block and LT1 motors. This allows for a shallow combustion chamber and lets the air/fuel burn more efficiently and completely. There are many more reasons that make a 5.3 desirable, but i'm sure you get the picture.
In the end, there's a lot more to the equation than just bore and stroke.
05-07-2010, 06:31 PM
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With a proper tune and catback exhaust, this engine is plenty stout. I've had chevy 305HO, Ford 5.0 302, Chevy 350 L98, Pontiac 350 LT1, and 3.8l supercharged GTPs, and this LS4 is probably one of the most responsive engines of them all (maybe the 302 Ford was meaner). This is not a bad setup at all, considering it's a 300+ horsepower V8 in a FWD car that keeps up with many of the other RWD V8s out there. I'm not dissapointed at all 