LS1 Racing

iTrader: (15)

I'm thinking about doing a cam swap on my LQ4 setup. Right now, I have the stock, dished pistons with 243 heads milled .026 topped by an LS6 intake I also have long tubes into true duals. My camshaft is a GM Hot Cam. Don't laugh, as this combo made 439 RWHP/372 lb-ft through my T56 on an eddy-current dyno.

Now, I was thinking about just swapping an LS3 top-end and doing the cam later, but it based on my current setup, I *think* the LS3 top-end will only net me about 25 HP with this cam. Since I want instant gratification, I'm thinking about doing a cam now and the LS3 stuff later.

Question is, if I want to make more than 25 additional RWHP with my current heads/intake setup, which cam will get me there and how much power could I expect to make over my current Hot Cam?

Two things to note: I don't have the funds to do the LS3 setup and a cam swap. Also, since my heads are milled .026, I have to be careful about PTV clearance.

Any opinions would be greatly appreciated!

Baconz28

I'm doing a iron 6.0 block with ls3 internals. Even if it was a stock 6.0 block bottom end like you have I would still do the ls3 top end. I'm using the ls3 heads on my motor along with a lightly ported ls3 intake with a 92mm nick williams throttle body to match it up. I called Brian tooley and he spec me out a 229/244 on a 113+3 cam.

LS1 Racing

iTrader: (15)

I'm eventually going to do the LS3 top-end, but I want to see what I can do to max out my current combo, which is limited by the Hot Cam.

I just want to know what direction I should be looking in for a cam, and what kind of gains I can expect over and above the Hot Cam.

Baconz28

Call Brian tooley and tell him your goals and mods. He never upsets a customer.

KCS

iTrader: (20)

I would port the 243's. You should easily gain another 25whp, spend about the same amount of money, and not have to take a hit in compression with the larger LS3 chambers.

LS1 Racing

iTrader: (15)

After doing a little math, it looks like I'd be going from 10.6:1 with my current setup to 10.1:1 with LS3 heads milled .040. A half-point of compression is going to cost me between 6 to 9 HP at the power levels I'm at, which would be around 465-470 RWHP. I think I can live with that, as I will be adding a cam either way to benefit from the improved airflow of the LS3 package.

But this is getting the cart before the horse. My original question still stands, though I will also reach out to Brian Tooley for some recommendations.

Baconz28

I talked to brian on the phone about his ls3 cams. I think it's his stage 4 cam that makes around 500 to the tire.. only reason I didn't get the cam I'm kinda scared of the ptv issue

vaethshuxun

I just want to know what direction I should be looking in for a cam

LS1 Racing

iTrader: (15)

So, after several conversations with Jim @ CalSpeed, I decided to go with the Comp Cams LSr 273Lr HR12. Here are the specs:

Duration: (I) 223, (E) 231, lift .610, .617 LCA 112

This is a bit more potent than my Hot Cam, but without making drivability worse than it is now. We're going to be milling the heads .040, but even with this cam, there won't be any PTV issues. I know I'm probably leaving 10-15 HP on the table by not going bigger, but I want to leave some margin of error for PTV, as well as retain some street manners.

Based on this combo, I expect to be around 480 RWHP/420 TQ when it's all done, which isn't bad when you consider the total cost of the swap will be about $1500 after selling off my LS6 parts and Hot Cam.