Whats your thoughts on this swap?
Whats your thoughts on this swap? Well I've had fun with the 5.3, but I think its time to move on.....SO I have a buddy of mine who gave me the pistons and rods out of his 5.7, same rods nad piston I have in my 5.3.....Pro LS summit pistons and rods. I was thinking about putting the ported 243's off my 5.3 and going with a little smaller cam, and a touch more compression (9.8:1 vs 9.3:1 ....iirc). The main objectives are: hopefully equal or more power but better economy and I'll send the pistons off to be coated because the piston slap noise drives me insane when the engine is cold. I have a summit ghost cam right now, 222/233 on a 115 lob sep....I was looking at the ls6 power max cam (204/222 112 lob sep). My reasoning is I think the 5.7 will make more "cruising" torque with the samller cam, more compression and bigger displacement....possibly picking up fuel mileage. Thoughts?
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https://youtu.be/d-yBFW-T9go
here's my Power max 204/222 112 LSA spinning inside my LQ4 that I stuffed with 4.0662" Silvo-Lite LS3 pistons and topped with stock #706 heads. I can't wait to Auto X with it again next year. I've run a lot of the smaller lower lift stuff over the years and this is by far the best One I have tried. excellent valve events for efficiency and tourqe. Honestly it doesn't feel any weaker up top than the 226/230 112+4 it replaced given my restricted intake and exhaust with this setup
here's my Power max 204/222 112 LSA spinning inside my LQ4 that I stuffed with 4.0662" Silvo-Lite LS3 pistons and topped with stock #706 heads. I can't wait to Auto X with it again next year. I've run a lot of the smaller lower lift stuff over the years and this is by far the best One I have tried. excellent valve events for efficiency and tourqe. Honestly it doesn't feel any weaker up top than the 226/230 112+4 it replaced given my restricted intake and exhaust with this setup
what kind of rpm does it turn? its a 6.2?
I wouldn't bother unless you get compression up over 10:1, plenty of boosted guys running around with 10.4, 10.9, etc
I don't think coating alone is going to solve your piston slap problem, especially for very long as all those shamwow coatings wear off.
That said your going to spend more than you will ever save in increasing "MPG", more CI is going to use more fuel. Sounds like you need an 11:1 4.8L and run more boost
I don't think coating alone is going to solve your piston slap problem, especially for very long as all those shamwow coatings wear off.
That said your going to spend more than you will ever save in increasing "MPG", more CI is going to use more fuel. Sounds like you need an 11:1 4.8L and run more boost
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YES it's basically an iron LS3 flat top bottom end (11.8:1) static) with stock 706 heads on top, LS6 intake, and f body manifolds. I need to check the cranking compression for you all as I'm sure it is through the roof. I have the rev limiter set at 7200 even though I have 2.73 gears because when I auto-x the car I just leave it in first gear and let it eat. It probably sees 6 - 6,500 normally racing and it will hit the rev limiter rarely and only if I'm being particularly unsympathetic. It gets the same gas mileage in this car as my old 4.8L l did in the same car with a 212/218 115 + 0. This is the 11th LS engine combination I have tried in 20 years and it is by far My favorite. Cruising torque does not even begin to describe the power max, it should be the stock starting point cam in every ls engine ever lol, as far as I'm concerned every cam on the market has too late of an IVC now considering everything I have tried. If it's an easy enough for you just put the PowerMax in your 5.3 and I think you'll be happy enough You're missing so much bottom end with that wide LSA long duration high RPM piece that you don't need because you have a turbo right? The valve events are "the engine" and everything you bolt around that, well it just compliments it.
I wouldn't bother unless you get compression up over 10:1, plenty of boosted guys running around with 10.4, 10.9, etc
I don't think coating alone is going to solve your piston slap problem, especially for very long as all those shamwow coatings wear off.
That said your going to spend more than you will ever save in increasing "MPG", more CI is going to use more fuel. Sounds like you need an 11:1 4.8L and run more boost
I don't think coating alone is going to solve your piston slap problem, especially for very long as all those shamwow coatings wear off.
That said your going to spend more than you will ever save in increasing "MPG", more CI is going to use more fuel. Sounds like you need an 11:1 4.8L and run more boost
There are coatings that quieten the piston slap. i built a drag engine for an atv a couple years ago and it had bad piston slap at idle (max power cylinder and cp piston was sized from max power wrong) so I did some research and found there is a coating for forged piston noise. Je actually puts this coating on some of their pistons. So I sent the piston off and had it coated. There is a break in process that allows a run in of a pretty think coating to size itself to the bore. It definitely did the trick as the motor was completely quiet when it went back together. been getting beat on for a couple years now.
https://www.enginebuildermag.com/201...-technologies/
(pump gas 93) when I had like 10.8:1 compression, it would clatter at 11 psi and 11 degrees of timing. Now I have 11 degrees at 22psi.......no clatter...been together for. I dunno...a couple years now?
I already have the engine, I have the pistons and rods. I probably wont balance it this time because the 5.3 didnt even need to be balanced. So I'll need to buy a cam, head gaskets, and bearings and rings. Then I can sell the cam I have (I actually have two cams I can sell) and maybe even sell the 5.3 shortblock. And I'm sure the 5.7 will make more power anyways.
YES it's basically an iron LS3 flat top bottom end (11.8:1) static) with stock 706 heads on top, LS6 intake, and f body manifolds. I need to check the cranking compression for you all as I'm sure it is through the roof. I have the rev limiter set at 7200 even though I have 2.73 gears because when I auto-x the car I just leave it in first gear and let it eat. It probably sees 6 - 6,500 normally racing and it will hit the rev limiter rarely and only if I'm being particularly unsympathetic. It gets the same gas mileage in this car as my old 4.8L l did in the same car with a 212/218 115 + 0. This is the 11th LS engine combination I have tried in 20 years and it is by far My favorite. Cruising torque does not even begin to describe the power max, it should be the stock starting point cam in every ls engine ever lol, as far as I'm concerned every cam on the market has too late of an IVC now considering everything I have tried. If it's an easy enough for you just put the PowerMax in your 5.3 and I think you'll be happy enough You're missing so much bottom end with that wide LSA long duration high RPM piece that you don't need because you have a turbo right? The valve events are "the engine" and everything you bolt around that, well it just compliments it.
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So that cam will pull to 7000 in a 6.2? If thats the case, I'm sure it'll pull that high with a smaller engine. I thought about just swapping cams an see how it does, but i was trying to kill two birds with one stone and put a bigger engine to make up for lost power from the smaller cam and eliminate the piston slap i have.
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He already has that cam and he's tired of it It's got a 43° IVC It's not efficient and it's too big and wide for a 5.3L and his goal of low engine speed fuel efficient "cruising torque". please read the thread before you post in it. We are trying to build engines in here not sell camshafts I'm so tired of this crap
If youre going to go through all the trouble to go to larger cubes, why go from a 5.3 to a 5.7. Go 6.0 or 6.2 or a 383, make the change impactful. You'll make more power NA, more power at less boost, better throttle response for a heavy GTO, and still get good gas mileage.
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im with ddnspider. why bother sticking it halfway in? get a crankshaft and put as many cubes as you can. its going to cost a few more dollars and be the exact same time and effort.
or leave the 5.3 alone.
or leave the 5.3 alone.
There are coatings that quieten the piston slap. i built a drag engine for an atv a couple years ago and it had bad piston slap at idle (max power cylinder and cp piston was sized from max power wrong) so I did some research and found there is a coating for forged piston noise. Je actually puts this coating on some of their pistons. So I sent the piston off and had it coated. There is a break in process that allows a run in of a pretty think coating to size itself to the bore. It definitely did the trick as the motor was completely quiet when it went back together. been getting beat on for a couple years now.
https://www.enginebuildermag.com/201...-technologies/
(pump gas 93) when I had like 10.8:1 compression, it would clatter at 11 psi and 11 degrees of timing. Now I have 11 degrees at 22psi.......no clatter...been together for. I dunno...a couple years now?
I already have the engine, I have the pistons and rods. I probably wont balance it this time because the 5.3 didnt even need to be balanced. So I'll need to buy a cam, head gaskets, and bearings and rings. Then I can sell the cam I have (I actually have two cams I can sell) and maybe even sell the 5.3 shortblock. And I'm sure the 5.7 will make more power anyways.
https://www.enginebuildermag.com/201...-technologies/
(pump gas 93) when I had like 10.8:1 compression, it would clatter at 11 psi and 11 degrees of timing. Now I have 11 degrees at 22psi.......no clatter...been together for. I dunno...a couple years now?
I already have the engine, I have the pistons and rods. I probably wont balance it this time because the 5.3 didnt even need to be balanced. So I'll need to buy a cam, head gaskets, and bearings and rings. Then I can sell the cam I have (I actually have two cams I can sell) and maybe even sell the 5.3 shortblock. And I'm sure the 5.7 will make more power anyways.
That's odd you have so much clattering, I do FI on stock LS2/LS3 stuff regularly and they don't knock their brains out on pump gas especially not on 11PSI.
If youre going to go through all the trouble to go to larger cubes, why go from a 5.3 to a 5.7. Go 6.0 or 6.2 or a 383, make the change impactful. You'll make more power NA, more power at less boost, better throttle response for a heavy GTO, and still get good gas mileage.
while I do agree with you, the reasons are this: 1) I have a nice 5.7 sitting on the stand that was the original engine in this car….and I have a set of free forged pistons and H beam rods for it. 2) I’m trying to spend the least about as possible 3) I’d like to use what I already have 4) if I put a 6.0 or 6.2 then turbo size becomes a factor. Then I just create a huge snowball effect that I don’t care to get involved in. The turbo I have now will work with what I want to do.
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I think the 5.7 will be a good compromise. It’ll make just as much or more power. Smaller cam, shoukd get better fuel mileage and idle lower.
and I forgot. The smaller cam will probably be noise wise, quieter.
Last edited by Kfxguy; Nov 17, 2021 at 10:46 AM.
I'm aware of the coatings, I see faint marks of what's left of the coating when tearing down engines. Better to machine the block properly for the piston rather than rely on a coating.
That's odd you have so much clattering, I do FI on stock LS2/LS3 stuff regularly and they don't knock their brains out on pump gas especially not on 11PSI.
That's odd you have so much clattering, I do FI on stock LS2/LS3 stuff regularly and they don't knock their brains out on pump gas especially not on 11PSI.
I dunno, I broke a piston adding one degree of timing to that. It didn’t like it. I also think this 5.7 block has a lot less wear than the 5.3 block in the car.
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I think the funniest thing to me about this thread is I also have a nice old 5.7L bottom end lying around that I don't know what to do with 🤣
Do both, The cam is very cheap and easy to change Right now and if You are in this forum weighing in on stuff you should be able to change one yourself imo and it will provide you the economy You are looking for now. Then in your spare time you can build a gigantic *** LS engine like everyone else is suggesting I agree it's awesome there's no replacement for displacement and I love my 376.28" engine, However it shouldn't be a rush to complete it. Also once you've run this cam and seen the cam card to compare it with the one you have now for the cam you're running it will all make sense to you, also you'll have a better idea of how to math out your big engine and it will perform exactly the way you want.
having a turbo makes things more complicated than just stuffing a huge engine in. Like said above, the turbo is just big enough for what I have and almost marginal for the 5.7. I’m already running into back pressure problems. I’m changing the exhaust housing to remedy this but if I go bigger engine, I’ll have to go even bigger turbo and I just don’t have the room to do that. It’s already a very tight fit. I’m stuck with what I have unless I decide I want to cut the car up, which I’m not.
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having a turbo makes things more complicated than just stuffing a huge engine in. Like said above, the turbo is just big enough for what I have and almost marginal for the 5.7. I’m already running into back pressure problems. I’m changing the exhaust housing to remedy this but if I go bigger engine, I’ll have to go even bigger turbo and I just don’t have the room to do that. It’s already a very tight fit. I’m stuck with what I have unless I decide I want to cut the car up, which I’m not.