Return On Invetsment

[93Ext5.7ltr]

Hi,

I was considering adding a FAST 90 and NW 90 along with flycutting for changeover from G5X2 &.595/.605 lift) on 114LSA to G5X3 (just a tad bigger) on 112LSA. I'm currently spinning the engine to 6100rpm. Was considering (here's why the flycut is important besides the larger cam) spinning the engine to 6500rpm....

Safe enough? What do you guys think about how much HP this addition would add to the current setup (see sig).

Thanks for the input/advice.

[RedHeartbeat]

Save your money and buy STSSilverados turbo kit. For $3000 you'd be seeing 12's before too long.

[93Ext5.7ltr]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 2 2006, 09&#58;16 PM) [snapback]75181[/snapback]</div>

Save your money and buy STSSilverados turbo kit. For &#036;3000 you&#39;d be seeing 12&#39;s before too long.
[/b]

Hi RedHeartbeat....I thought that idea was done? I mean 59cc heads w/ a turbo is gonna murder the engine with the compression ratio I already have. I don&#39;t see being able to put a gasket on thick enough, that will hold well enough? Am I wrong?

[RedHeartbeat]

Cometic can build thicker gaskets for you to drop compression. They will build them whatever thickness you need.

[1slow01z71]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 2 2006, 11&#58;32 PM) [snapback]75191[/snapback]</div>

Cometic can build thicker gaskets for you to drop compression. They will build them whatever thickness you need.
[/b]

.060 is the biggest they make even then it wont drop it low enough for a good CR for a decent amount of boost. If oyu go any bigger(.060 is pushing it anyway) you are risking blowing a headgasket out even with head studs and tq&#39;ing them 10-15 ft-lbs over.

Are your AFR&#39;s milled? I believe the combustion chambers on the AFRs have alot of meat on them that you could port out.

On the original quesiton I wouldnt bother with all the trouble just for a bit bigger cam.

[RedHeartbeat]

.060 is the commom commercially available size. They will make whatever you require.

Check their custom section at....
http://www.cometic.com/custom.aspx

They make a .120 thick gasket for the factory s/c Dodge Magnums. Shouldn&#39;t be an issue to do the same for an LSx engine.

If the desire strikes you to go FI, then you can just swap pistons for some with a deep relief to drop compression and still use your heads as they are. That or you could sell your whole engine as an assembly, buy a stock 6.0L and swap them out and add the turbo.

[1slow01z71]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Dec 3 2006, 01&#58;50 PM) [snapback]75219[/snapback]</div>

They make a .120 thick gasket for the factory s/c Dodge Magnums. Shouldn&#39;t be an issue to do the same for an LSx engine.[/b]

Crappy 10 head bolt design comes to mind.

I didnt know they made supercharged magnums.

Ill put it this way go over to tech and see what the head asket thickness is that everyone uses and look at the threads with .060 head gaskets where someone tried to take a short cut and killed a combustion chamber on a head and had to either buy a new one or get it welded and resurfaced.

[Defunct SO]

yep, I just ordered .074 for a customer.

Just curious, why only spin to 6100rpm?

[RedHeartbeat]

I imagine the real issue would be how the head gasket is used. In stock form to FI, I think a thick gasket would be very safe. I don&#39;t think a very thick gasket would be as good for a Nitrous application, depending upon what the material is they place in the center of the gasket. Cometic also has the new design head gaskets that have a gas filled ring around the cylinder.

Personally, if I were to do something for that big heavy truck to make it go faster I would swap in some forged FI pistons and then turbo it. Pistons and rings, new conn rod bearings, GM head swap gasket set and ARP head bolts or studs should cost close to &#036;1000 for parts and then add the turbo kit cost. For under &#036;400 you can add forged rods from Eagle. Maybe someone on here can get you what-a-bargain on a set of rods and pistons already match balanced.

[farmtruc]

how much compression is that engine at, the ls2 has 10.5 and i have a customer pushing 10psi with it, runs damn good.

i say go for it. unless you&#39;re at about 11.0, but 5psi will still be badass.