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Ly5 5.3 - H/C issues - lethargic and down on power

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Old 10-05-2019, 08:33 PM
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Default Ly5 5.3 - H/C issues - lethargic and down on power

Looking for some input. Got an ly5 in a 73 camaro
i built for my wife. Every since day one, something has been off. The car has been increasingly difficult to tune, makes no upper rpm power, and is just very disappointing in general. I’ve had dozens of cam only and h/c ls cars, as well as multiple boosted cars. I’m no stranger to the game and the results. The car has the following mods.

73 camaro
5.3 ly5 24x reluctor
862 5.3 ported heads
mamo ported ls2 Intake
custom grind flow tech inductions cam 227/232 .630/.625 on a 111
.660 springs / stock timing set
dod delete
4400 Jakes performance stall/80e
3.73 8.8 rear

car made like 275hp on a dyno jet.
car seems to make good power down low, but just drags through the rpm range up top, seems
to run good, no missing or hesitation, 12.7 afr and 27* of timing. Had a hell of a time with getting the idle tuned in.

I built this car from a running 305/th350 car to a ls swapped ready to go car in 3 days. I just installed the cam dot to dot and sent it. I have a buddy coming over Monday to put a degree wheel on it and see if things are screwy there, as I believe the cam to be very advanced causing my issues.

Today i removed the engine and pulled the heads to
have them decked and ls1
valves installed. I noted ptv contact on the intake valves on all 8 cylinders. I noted the cam was indeed installed dot to dot. I compared the cam gear and the crank gear key way to dot relationships and they all showed the same. If it’s not a cam ground way off on accident, I’m at a loss. It should not be having ptv issues, and it should run considerably harder than it does. Ran a 13.9@103 last weekend. Any ideas?








Old 10-05-2019, 08:55 PM
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Valves are not bent, so it’s not a compression loss causing it
Old 10-06-2019, 03:37 PM
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Interested to see what the degree wheel says. It sure sounds like it's off. I once had one nine degrees advanced on the grind. It was torquey as hell but was done by about 5200 rpm
Old 10-06-2019, 05:48 PM
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Originally Posted by Cwarta
Valves are not bent, so it’s not a compression loss causing it
If your valves hit the pistons they are bent. Maybe ever so slightly, but they are bent.
Old 10-06-2019, 10:31 PM
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Originally Posted by Darth_V8r
Interested to see what the degree wheel says. It sure sounds like it's off. I once had one nine degrees advanced on the grind. It was torquey as hell but was done by about 5200 rpm
agreed, and sounds about like mine. Tire fryer down low but no pull up top

Originally Posted by ironmanLS1
If your valves hit the pistons they are bent. Maybe ever so slightly, but they are bent.
i checked them in my lathe with a dial indicator
Old 10-07-2019, 07:59 PM
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Well I noticed that the exhaust valves had hit the pistons, all 8 and all 8 look identical. Originally I had thought they were from the intake valves, but I wasn’t paying attention, as it was the exhaust valves. So I had a friend come over who builds engines and does all of our blown big blocks and such and put a degree wheel on the engine. We checked the intake side first, and the cam card calls for a 109* intake lobe centerline and we got 115.75 after checking it twice. We went to check the exhaust side and there isn’t a centerline listed on the cam card.

My other question is, everything I’ve read says that when you advance the camshaft you gain ptv clearance on the exhaust valve. Yet I’m having interference issues, which is why I’m wanting to check the exhaust side. If the exhaust side is also advanced the same amount I’ll just get an adjustable timing set. If it’s not I assume I’ll have to buy a new cam shaft.
Old 10-07-2019, 08:55 PM
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By your description my first thought was cam timing. Best I can tell from what you said above it's 6 degrees off. Also, I'm not familiar with that cam gear I guess because that dot you show isn't what I'm used to. I'm used to a tiny circle dot being the alignment dot.

If you don't find it there look at a possible exhaust restriction, may be allowing it to make power till it hits a certain amount of flow then chokes

Last edited by 00pooterSS; 10-07-2019 at 09:02 PM.
Old 10-07-2019, 09:03 PM
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Originally Posted by Cwarta
Well I noticed that the exhaust valves had hit the pistons, all 8 and all 8 look identical. Originally I had thought they were from the intake valves, but I wasn’t paying attention, as it was the exhaust valves. So I had a friend come over who builds engines and does all of our blown big blocks and such and put a degree wheel on the engine. We checked the intake side first, and the cam card calls for a 109* intake lobe centerline and we got 115.75 after checking it twice. We went to check the exhaust side and there isn’t a centerline listed on the cam card.

My other question is, everything I’ve read says that when you advance the camshaft you gain ptv clearance on the exhaust valve. Yet I’m having interference issues, which is why I’m wanting to check the exhaust side. If the exhaust side is also advanced the same amount I’ll just get an adjustable timing set. If it’s not I assume I’ll have to buy a new cam shaft.
If you're at 115 on the intake side vs a 109 intended centerline, cam is retarded seven degrees, so exhaust PTV is reduced or completely eliminated. So sorry, man. You pulling the heads to verify valves are not bent?
Old 10-07-2019, 09:16 PM
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Originally Posted by Darth_V8r
If you're at 115 on the intake side vs a 109 intended centerline, cam is retarded seven degrees, so exhaust PTV is reduced or completely eliminated. So sorry, man. You pulling the heads to verify valves are not bent?
Ahh, that makes more sense. I have a new set of valves in the heads now, so we are good on that
Old 10-07-2019, 09:48 PM
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Anyone see my post above about the dot on the cam gear? I've never seen that dot as being the alignment dot. Is it a gear I'm not familiar with or the wrong dot?
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Old 10-07-2019, 10:35 PM
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Originally Posted by 00pooterSS
Anyone see my post above about the dot on the cam gear? I've never seen that dot as being the alignment dot. Is it a gear I'm not familiar with or the wrong dot?
Thats a gen 4 cam gear with the timing marks in the cam gear, they all look like that
Old 10-08-2019, 07:06 AM
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Originally Posted by 00pooterSS
Anyone see my post above about the dot on the cam gear? I've never seen that dot as being the alignment dot. Is it a gear I'm not familiar with or the wrong dot?
That does look like a strange looking cam gear. Obviously thats the correct dot but I wonder if its some kinda Chinese gear that is not drilled correctly?
Thats doesnt look like any Gen4 cam gear ive seen, its 3 bolt and doesn't have the 4 raised points for the cam sensor that would be in the timing cover on a gen 4..
Old 10-08-2019, 10:42 AM
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Originally Posted by Ls7colorado
That does look like a strange looking cam gear. Obviously thats the correct dot but I wonder if its some kinda Chinese gear that is not drilled correctly?
Thats doesnt look like any Gen4 cam gear ive seen, its 3 bolt and doesn't have the 4 raised points for the cam sensor that would be in the timing cover on a gen 4..
Its a 24x cam gear, would be c on this chart. It was ran with thenfront timing cover and cam sensor on this engine, it’s a gm gear.


Got the exhaust centerline numbers back, it’s supposed to be 113 and it’s 107.75.

so is the intake retarded and the exhaust advanced?


Old 10-08-2019, 11:01 AM
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Ahh okay it's 3 bolt 1x swap gear. They definitely don't all look like that, that's a very specific swap gear.

Sounds like that cam was cut WAY off.

I think I'd make that cam into a lamp and get a cam from a reputable company. I've never heard of flow tech inductions and would be real weary of a company that doesn't check their work. If they don't have very good quality control I would be concerned about proper hardening etc.
Old 10-08-2019, 12:00 PM
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Originally Posted by 00pooterSS
Ahh okay it's 3 bolt 1x swap gear. They definitely don't all look like that, that's a very specific swap gear.

Sounds like that cam was cut WAY off.

I think I'd make that cam into a lamp and get a cam from a reputable company. I've never heard of flow tech inductions and would be real weary of a company that doesn't check their work. If they don't have very good quality control I would be concerned about proper hardening etc.
Its not a swap gear, it’s the gear that comes factory on any 24x motor with the front timing sensor, such as a 2005/6 gto.

FlowTechInductions aka Ed Curtis has been around a very long time, and ya an awesome reputation. I specifically asked him to drop ship the cam to me from his grinder as I was in a huge hurry to get it done for my wife’s graduation so she could take her car. Ive bought over 20 camshafts from Ed, and all performed excellent. No doubt this cam would have never made it to me if I had let Ed perform his normal routine. Ed has asked me to recheck all of my finding one more time as it sounds like he’s highly skeptical of the exhaust numbers I got, so I’ll be rechecking that. I ordered an adjustable timing set to to fix the issue, if it’s not both retarded and advanced. So hopefully I was off on my numbers. We will see
Old 10-08-2019, 05:11 PM
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My bad. Not a swap gear. Just a weird duck. I didn't realize they did 1x with front mounted cam sensors, guess it was a short time period they did weird **** in the middle of the gen3/4 change over.

And gotcha on Ed Curtis, recognize that name didn't recognize the other.

Last edited by 00pooterSS; 10-08-2019 at 05:36 PM.
Old 10-08-2019, 06:05 PM
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Originally Posted by 00pooterSS
My bad. Not a swap gear. Just a weird duck. I didn't realize they did 1x with front mounted cam sensors, guess it was a short time period they did weird **** in the middle of the gen3/4 change over.

And gotcha on Ed Curtis, recognize that name didn't recognize the other.

Yea limited run for sure, I use them a lot in my swaps so it seems super common for me lol!

I rechecked my numbers and got this.

116 intake lobe centerline, supposed to be 109.
106.5 exhaust lobe centerline, supposed to be 113.

Equals out to a 111.5 LSA which the cam card calls for a 111.

Is the exhaust lobes advanced and the intake lobes retarded? Or are the exhaust lobes the opposite? Not sure what to think here and I strewed around too long getting Ed the new numbers, now I gotta wait till tomorrow lol.
Old 10-08-2019, 08:04 PM
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Both are retarded. When you retard the cam, the intake moves away from TDC. The exhaust moves toward TDC
Old 10-08-2019, 09:07 PM
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Originally Posted by Darth_V8r
Both are retarded. When you retard the cam, the intake moves away from TDC. The exhaust moves toward TDC
I ordered a billet double roller for it that’s adjustable, hopefully it will do what I need.
Old 10-10-2019, 04:21 PM
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With the new 9 way adjustable timing set on A2 I got it to 109.75*, target is 109. Should be good


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