5.3L Truck Motor Cam-only
#1
5.3L Truck Motor Cam-only
I figured that since so many guys are using these 5.3's in swap vehicles and putting cams in them, that it would be cool for everyone to see exactly what a 5.3 with a cam can make to the tires. While it may not be the most impressive numbers or set-up in the world, it is merely just for reference and for those interested to see what they can do.
To start, this vehicle is a 2001 C5 Z06 Corvette that the LS6 it came with grenaded itself and was taken out of commission. The owner could not find a suitable replacement for a cost he found reasonable and he had plans to supercharge it anyways with an A&A kit. This brought up the idea of, "why not just put a 5.3 in it, they LOVE boost!" So we decided to swap a 5.3l engine in it!
2001 C5 Corvette
-LM7(5.3 w/ dished pistons)
-Stock 862 truck heads
-LS6 intake manifold
-Tick Performance LS1 Stage 1 Blower Cam 226/234 .598"/.612" 115+3
-ARP Head Studs
-LS9 Head Gaskets
-Pinned crank pulley for future A&A S/C kit
-Long Tube 1x7/8" headers
-Factory air box and paper filter
-Off Road X-pipe
-Factory Cat-back exhaust
Dyno Graph with SAE correction factor applied:
To start, this vehicle is a 2001 C5 Z06 Corvette that the LS6 it came with grenaded itself and was taken out of commission. The owner could not find a suitable replacement for a cost he found reasonable and he had plans to supercharge it anyways with an A&A kit. This brought up the idea of, "why not just put a 5.3 in it, they LOVE boost!" So we decided to swap a 5.3l engine in it!
2001 C5 Corvette
-LM7(5.3 w/ dished pistons)
-Stock 862 truck heads
-LS6 intake manifold
-Tick Performance LS1 Stage 1 Blower Cam 226/234 .598"/.612" 115+3
-ARP Head Studs
-LS9 Head Gaskets
-Pinned crank pulley for future A&A S/C kit
-Long Tube 1x7/8" headers
-Factory air box and paper filter
-Off Road X-pipe
-Factory Cat-back exhaust
Dyno Graph with SAE correction factor applied:
Last edited by Sales@Tick; 03-13-2013 at 10:57 AM.
#3
What this means is that a 5.3 piston spends the same amount of time at top dead center and bottom dead center as any other LS engine with a 3.622" stroke and 6.098" rod length. When I hear guys say that 5.3's need teeny tiny cams it just drives me nuts! If that piston is spending the same amount of time at TDC and BDC as any other LS engine with that length stroke and rod, why would you need to hold the valves open for a lesser amount of time or shut them sooner on a 5.3? The answer is you wouldn't.
Now, because they are smaller in cubic inch it does mean that they need a little less cam, but not 15-20 degrees in duration like some guys (and self proclaimed experts alike) say that they do.
Hope this helps to enlighten you and anyone else reading this.
#6
TECH Junkie
iTrader: (51)
Thanks for posting this. I was wondering what a 5.3 would make at the wheels. I wonder how this 5.3's power would compare to a LS1 with this setup just to see how valuable cubic inches are.
Ricer math time, add a 2% gain to match the LS1 compression of 10:1, that would take 351 to 358. I would think a LS1 with this setup used would be around 390rwhp. Just a guess though. Roughly a 30rwhp difference for the 25 less inches.
Ricer math time, add a 2% gain to match the LS1 compression of 10:1, that would take 351 to 358. I would think a LS1 with this setup used would be around 390rwhp. Just a guess though. Roughly a 30rwhp difference for the 25 less inches.
#7
See above paragraph on stroke and rod length. Piston spends the same amount of time ATDC and ABDC as a LS1/LS2/LS6 etc. They will all peak at the same RPM because the piston spends the same amount of time on the intake, compression, power and exhaust stroke. Therefore the operating range for a given camshaft will be nearly identical.
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#8
makes perfect sense. 5.3 is to 5.7 is to 6.0 is to 6.2. Generally each of the bigger pistons will net 20-30hp. Not to mention the LM7 is 9.5 SCR. Also consider there's negative overlap and the fact it carries to 6.5K is pretty sweet. Should be killer with the blower. Especially with 300ft/lbs at 3K right now!!
#10
makes perfect sense. 5.3 is to 5.7 is to 6.0 is to 6.2. Generally each of the bigger pistons will net 20-30hp. Not to mention the LM7 is 9.5 SCR. Also consider there's negative overlap and the fact it carries to 6.5K is pretty sweet. Should be killer with the blower. Especially with 300ft/lbs at 3K right now!!
No problem! I knew this would enlighten a lot of guys doing this type of swap. On average we see a 20-30rwhp gain with those heads.
#12
Thanks for the information. Based on that info on the PRC heads, which heads do you think would work best with that cam and a single s480 on a 5.3 in that relative price range?
#14
Moderator
iTrader: (9)
Martin,
I can't argue the piston speed with the same stroke and rod ratio. Things I think reflect the differences and food for thought.
Although stroke/rod ratio is the same, bore is different. Which means:
There is more volume to fill for the 5.7, 6.0, 6.2
Same sized valves means the larger bore can breath more easily due to the unshrouded valve.
I believe that as the cyl volume increases (5.3 to 6.2) if the same heads are used, a bigger cam would be required to keep the same peak as there s not enough duration to fill the cyl adequately. 5.3 to 5.7 not so much. At some point the valve is not causing a restriction as bore goes bigger.
Am i wrong in saying the smaller bore motor suffers with the bigger cam in the lower rpm. The small 5.3 bore won't pull the same vacuum as a 6.2 wearing the same top end.
I can't argue the piston speed with the same stroke and rod ratio. Things I think reflect the differences and food for thought.
Although stroke/rod ratio is the same, bore is different. Which means:
There is more volume to fill for the 5.7, 6.0, 6.2
Same sized valves means the larger bore can breath more easily due to the unshrouded valve.
I believe that as the cyl volume increases (5.3 to 6.2) if the same heads are used, a bigger cam would be required to keep the same peak as there s not enough duration to fill the cyl adequately. 5.3 to 5.7 not so much. At some point the valve is not causing a restriction as bore goes bigger.
Am i wrong in saying the smaller bore motor suffers with the bigger cam in the lower rpm. The small 5.3 bore won't pull the same vacuum as a 6.2 wearing the same top end.
#15
Martin,
I can't argue the piston speed with the same stroke and rod ratio. Things I think reflect the differences and food for thought.
Although stroke/rod ratio is the same, bore is different. Which means:
There is more volume to fill for the 5.7, 6.0, 6.2
Same sized valves means the larger bore can breath more easily due to the unshrouded valve.
I believe that as the cyl volume increases (5.3 to 6.2) if the same heads are used, a bigger cam would be required to keep the same peak as there s not enough duration to fill the cyl adequately. 5.3 to 5.7 not so much. At some point the valve is not causing a restriction as bore goes bigger.
Am i wrong in saying the smaller bore motor suffers with the bigger cam in the lower rpm. The small 5.3 bore won't pull the same vacuum as a 6.2 wearing the same top end.
I can't argue the piston speed with the same stroke and rod ratio. Things I think reflect the differences and food for thought.
Although stroke/rod ratio is the same, bore is different. Which means:
There is more volume to fill for the 5.7, 6.0, 6.2
Same sized valves means the larger bore can breath more easily due to the unshrouded valve.
I believe that as the cyl volume increases (5.3 to 6.2) if the same heads are used, a bigger cam would be required to keep the same peak as there s not enough duration to fill the cyl adequately. 5.3 to 5.7 not so much. At some point the valve is not causing a restriction as bore goes bigger.
Am i wrong in saying the smaller bore motor suffers with the bigger cam in the lower rpm. The small 5.3 bore won't pull the same vacuum as a 6.2 wearing the same top end.
The LS1 Stage 1 Blower cam(226/234 115+3) has an intake valve close event of 45 degrees after bottom dead center. Here is my LS1 Street Heat Stage 2 cam(231/238 113+3) in a 4.0" bore LS2 engine with stock cylinder heads and a stock LS2 intake with the same 45 degree after bottom dead center intake valve close event and look where it peaks...at the exact same RPM. The 799 heads on the LS2 actually have a 210cc runner versus the 190cc runner on the 5.3 engine. The 799 heads also have a 2.00" intake valve versus a 1.89" intake valve on the 5.3 heads.
And the 5.3 graph again:
When two engines have identical runner length like the 5.3 and this 6.0 now in comparison, and they have the same intake valve close event along with the same rod length and stroke, they will peak at the same RPM's. Bore does not play hardly any factor in this equation. It is a very common misconception, but it is hard to wrap your brain around at first.
Last edited by Sales@Tick; 03-17-2013 at 02:06 AM.