Help estimating HP
#1
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I just got my 5.3L back from the engine shop that I am going to put into a kit car that I building (a Factory Five Daytona Coupe). This is going to be a track car mostly, so we put some money into some reliability mods that didn't add power, but should help with the longevity of the engine. The builder didn't have a guess on the power so I wanted to see what you all thought.
Here is what I got:
2004 5.3L bored .020" over
stock 706 heads with 2.00" SS intake and 1.59" SS exhaust valves
stock rockers
flat top pistons with -4cc valve reliefs
Calculate compression to be 10.0:1
Comp cams LS1 277Lr HR-113 cam
(227/235 @ .050, .614/.621 lift, 113 deg lobe separation)
98 LS1 intake and stock ported TB
85mm MAF
1 3/4" shorty headers into a dual 3" exhaust (no cats)
planned redline of 6500 rpm
Here are some of the reliability mods:
nitrate coated crank
forged rods and pistons
dual valve springs
LS7 lifters
Comp cams rocker trunion kit
ported oil pump
Thanks
JC
Here is what I got:
2004 5.3L bored .020" over
stock 706 heads with 2.00" SS intake and 1.59" SS exhaust valves
stock rockers
flat top pistons with -4cc valve reliefs
Calculate compression to be 10.0:1
Comp cams LS1 277Lr HR-113 cam
(227/235 @ .050, .614/.621 lift, 113 deg lobe separation)
98 LS1 intake and stock ported TB
85mm MAF
1 3/4" shorty headers into a dual 3" exhaust (no cats)
planned redline of 6500 rpm
Here are some of the reliability mods:
nitrate coated crank
forged rods and pistons
dual valve springs
LS7 lifters
Comp cams rocker trunion kit
ported oil pump
Thanks
JC
#3
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What you have will work, and work good...but look for a deal on an ls6 intake and port, or pick up a ported stock throttle body...I'd also ditch the MAF and run an SD tune( this will give you a crisper throttle response).
I am also guessing you are going to be running a manual tranny so that will give you less drivetrain loss.....I'll guess 450 at the crank and closer to 380-400 at the wheels. If you don't have the heads on yet get a little bit more milled off of them to bump your compression up to around or just over 10.5:1.
Sounds like a sweet project, so we need pics
I am also guessing you are going to be running a manual tranny so that will give you less drivetrain loss.....I'll guess 450 at the crank and closer to 380-400 at the wheels. If you don't have the heads on yet get a little bit more milled off of them to bump your compression up to around or just over 10.5:1.
Sounds like a sweet project, so we need pics
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#4
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I would tend to agree with what the other guys said. Pick up an Ls6 style intake and you should see 400/385 at the wheels. If you can grind the casting flash out of the intake runners and smooth and polish them and have a good valve job done on them and that will give you mabey 20 more HP. Plus its cheap the minor porting can be done by you with a Die Grinder or Dremel and the valve job will cost less than $250.
#5
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Well if I get 400-450 at the crank that is what I was aiming for. The car will only weigh 2500 lbs when it is done so that should be a good power to weight ratio.
Mark: you are correct, manual transmission
Gunslinger: The engine shop did a valve job with the new valves and ported the area in the head for the bigger valves.
I agree on the LS6 intake. I just couldn't find one in my price range. This one will get me going and I'll keep an eye open for a LS6 one.
Here are some pictures.
This is the kit when we picked it up from the factory
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_5410.jpg)
Junk yard motor
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_5358.jpg)
The machine shop layed out all the parts for us before he assembled it
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_5518.jpg)
Engine back together
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_1744.jpg)
The headers have to dump forward for the side pipes
Mark: you are correct, manual transmission
Gunslinger: The engine shop did a valve job with the new valves and ported the area in the head for the bigger valves.
I agree on the LS6 intake. I just couldn't find one in my price range. This one will get me going and I'll keep an eye open for a LS6 one.
Here are some pictures.
This is the kit when we picked it up from the factory
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_5410.jpg)
Junk yard motor
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_5358.jpg)
The machine shop layed out all the parts for us before he assembled it
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_5518.jpg)
Engine back together
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_1744.jpg)
The headers have to dump forward for the side pipes
![](http://i250.photobucket.com/albums/gg253/jkrueger485/Daytona%20Coupe/IMG_1743.jpg)