LS2 intake on LS1 problem
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Joined: Jul 2020
Posts: 85
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From: Tennessee
LS2 intake on LS1 problem
Hello everyone,
So, got a ported LS2 intake I'm putting on my build for my 99 FRC and it will not sit down as it should. Do I need different vent tunes or Valley cover...both not sure what's going on I thought it would go right on. I tried my stock LS1 intake and it sat down just fine no issues. Thanks for any helpful advice.
So, got a ported LS2 intake I'm putting on my build for my 99 FRC and it will not sit down as it should. Do I need different vent tunes or Valley cover...both not sure what's going on I thought it would go right on. I tried my stock LS1 intake and it sat down just fine no issues. Thanks for any helpful advice.
Drifting
Joined: Sep 2009
Posts: 1,862
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From: Prescott, Arizona
2000 and earlier C5's had rear head coolant air bleed ports and the steel air bleed piping from them to the front ports routed under the intake manifold. The air bleed piping then connected to the throttle body with a hose. This piping may be interfering with the later manifold sitting down in the valley far enough to bolt up and seal. Check this, you may be able to relieve some of the ribbing on the underside of the manifold so it sits down or need to relocate the rear to front air bleed piping using 1/4" heater hose and fittings around the back side of the passenger side head, then Tee into the air bleed hose from the front ports which leads to the top right of the radiator.
Race Director
Joined: Oct 2004
Posts: 12,861
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), there was only a very slight "witness" mark on the intake webbing from the steam pipes. Maybe the LS2 intake has less clearance, IDK. Anyway, Jim993 is right. Use some wet, slow drying paint, like house paint, and brush some onto your steam pipes. Then, while the paint is still wet, carefully sit the intake in a reasonably close-to-installed position. Remove the intake, view the paint on the intake bottom, and remove material where the paint left a mark. Helluva lot cheaper than a new aftermarket $600-$1,000 intake!! My .02.....
Thread Starter
Advanced
Joined: Jul 2020
Posts: 85
Likes: 2
From: Tennessee
Before going to that expense, try to get what you have to work. I once had an LS6 intake on my 4 steam piped LS1 in my 2000 C5. I didnt even need to trim the webbing under the intake. This may vary from one engine to another. When I pulled my intake to change a bad oil sender (imagine that!!), there was only a very slight "witness" mark on the intake webbing from the steam pipes. Maybe the LS2 intake has less clearance, IDK. Anyway, Jim993 is right. Use some wet, slow drying paint, like house paint, and brush some onto your steam pipes. Then, while the paint is still wet, carefully sit the intake in a reasonably close-to-installed position. Remove the intake, view the paint on the intake bottom, and remove material where the paint left a mark. Helluva lot cheaper than a new aftermarket $600-$1,000 intake!! My .02.....
), there was only a very slight "witness" mark on the intake webbing from the steam pipes. Maybe the LS2 intake has less clearance, IDK. Anyway, Jim993 is right. Use some wet, slow drying paint, like house paint, and brush some onto your steam pipes. Then, while the paint is still wet, carefully sit the intake in a reasonably close-to-installed position. Remove the intake, view the paint on the intake bottom, and remove material where the paint left a mark. Helluva lot cheaper than a new aftermarket $600-$1,000 intake!! My .02.....
Race Director
Joined: Oct 2004
Posts: 12,861
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When new products are introduced, like the LS1 was in 1997, from that moment on, bean counters scramble furiously to make the product even cheaper to manufacture, and TRY to keep the functionality equal to the original. They ALWAYS succeed in making it cheaper. They aren't always as successful with the functionality part. Keep your 4 corner steam setup, if possible. Personally, I think you can make the manifold work. That said, I hope whoever ported it did a HELLUVA job, because the LS2 intake is NOT on everyone's short list of top LS intakes!! Best of luck to you......
