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Compression, cam and intake advice

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Old 03-09-2016, 01:50 AM
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Default Compression, cam and intake advice

First post. It's long but I wanted to be thorough. It's also posted on another couple forums.

My project is a C1 Corvette restomod. I'm the replacing the frame with a hand built chassis from Corvette Correction that uses C4 suspension and an LS3 motor. I'm not modifying the tubs of the car so max tire width I can get is limited so traction will be a challenge. The car is being built to be a driver and not a race car but there is a certain sound I am looking for. The car belonged to my father and was his daily driver/weekend racer and had a pretty good cam in it, closed chambered heads and at least 11:1 compression. I remember what the car sounded like when I was a kid and I would like to replicate that as much as possible. I have a spec sheet that was found in the car of the cam but I am not sure how to read it because it does not have all of the measurements I am used to looking at to tell the size. I did have one builder look at it and he said it was a big cam but didn't tell me the details I was looking for. I have attached a pic of the sheet.

On to my question.

Disclaimer: My build is a little difference, I am not looking for max HP. This is about sound and cosmetics, please keep that in mind when commenting.

In a nutshell what I want is a 11.5:1 LS3 with a heavy lope cam and sheetmetal intake.

I procured a donor LS3 and 6 speed from a 2015 SS Camaro and I want to modify it to get the sound and look I want. Honestly the stock 430 hp is plenty and changing the cam is really going to up the hp, it's almost like a side effect to me because I really could not care about adding any additional hp. I want to switch out the cam to get the sound I'm looking for as well as at least change the springs in the heads. If a head swap is required I am ok with that but would rather not spend the money if I do not have to. I was thinking something in the .550 to .650 lift range with about a 108 LSA to get the lope I am looking for. I am not an expert on cams and these parameters I came up with are based on cam sounds and reviews/dyno sheets of other people's cams. I considered getting the crate LS3 525 hp motor with the larger cam but I listened to one and it wasn't the sound I was looking for. The stats on that cam are .525 on both sides and a 110 LSA. I want a sheetmetal intake purely for the looks. I do not want to same looking intake as 90% of all the other LS motors. I realize that there are several manufactures out there that make sheetmetal intakes but I have no intention of buying an intake for $2500. To be honest I'm thinking about going with this one. http://www.ebay.com/itm/111832604942 I have read up on these and understand they are knockoffs and the quality might be lower and not produce for max air flow but since I am not trying to squeeze all the hp I can I don't see why it wouldn't fit my needs. I also understand that a lot of these eBay intakes tend to have a lot of slag so I will have to pay attention to that. Other than milling the heads, getting smaller chambered heads or thinner gaskets I do not know how to get to the 11.5:1 I am looking for. Lastly I was thinking about getting a Holley ECU and replace the stock unit to provide more programmability but I am not sure if that is necessary and again if I do not need to spend the money then I'd rather spend it somewhere else.

Again what I want is a 11.5:1 LS3 with a heavy lope cam and sheetmetal intake. Not trying to squeeze all the ponies I can.

1. How do I get to 11.5:1?
2. What cam gets me the sound I am looking for?
3. Sheetmetal intake options. Not spending $2500.
4. Holley ECU needed or not?
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Old 03-09-2016, 11:42 AM
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no point for 11.5 - 1 if you don't want more power imo ... and get a small cam and have it specd on like a 109 lsa
Old 03-09-2016, 12:01 PM
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Originally Posted by Mavn
no point for 11.5 - 1 if you don't want more power imo ... and get a small cam and have it specd on like a 109 lsa
I agree withe the statement about 11.5 but without it I won't get the same pop from the cylinders I and looking for and I remember as a kid.

What would a small can be in your opinion? .550?
Old 03-09-2016, 01:11 PM
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Originally Posted by Dads62
I agree withe the statement about 11.5 but without it I won't get the same pop from the cylinders I and looking for and I remember as a kid.

What would a small can be in your opinion? .550?
Ls motors aren't like SBC. Get a BTR stage 2 -3 - or 4. mill the heads a bit and call it a day!
Old 03-09-2016, 02:10 PM
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Originally Posted by Mavn
Ls motors aren't like SBC. Get a BTR stage 2 -3 - or 4. mill the heads a bit and call it a day!
I'm not opposed to milling the heads. If I went with a stage 3 or 4 cam how much should be milled to keep the valve clearance safe? Would the intake need to be modified also?
Old 03-09-2016, 02:29 PM
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The stock displacement LS3 that just went into my '95 Impala just dyno'ed 450hp/400tq at the wheels.

This was through a ported LS3 heads that were not milled, 10.8:1 compression, stock LS3 intake and a Lingenfelter GT1-1 cam (NOT their GT-11 cam). Oh, it has a nice lope as well


More compression is not needed for the 'pop' you're looking for.....and a sheet-metal intake will suppress low end power and their power advantages over a stock intake will only be seen above 5500 RPMs. IMO, a waste of good mod-money if you're not building a race-stroker motor.

As for 'cams'.....the lobe lift (you mentioned .550" to .650") really has very little to do with the cam's performance characteristics. It should only be considered when selecting valve-train components or if you're looking to take advantage of high-lift airflow capabilities of ported heads.

Much more focus should be placed on duration and overlap which is directly related to valve opening & closing events.

My recommendation to you.....contact CamMotion and/or Brian Tooley Racing; you can Google them . Let them know what you have, what you WANT, and find out from them what can best get you there.

BTW.....what car is this engine gonna go in to?

KW

Last edited by KW Baraka; 03-09-2016 at 02:41 PM.
Old 03-09-2016, 03:33 PM
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Agree with KW, call Kip @ CAMMOTION or Brian @ BTR have them
Spec for you, with the money saved I would look at the Borla
Induction, Independant Throttle Bodies, looks like a classic
Set of Webers from back in the day! With Electronic controls
The best of both worlds. I would not put a sheet metal intake
Especially one of questionable quality on a cool rest-mod.
Holley EFI on a Single Plane intake would be my second choice.
Good Luck.



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