So I�m building a lq4 for my s10 and was wanting 450-500 whp N/A. Would prefer to stay away from doing bottom end stuff besides a cam obviously. Didn�t know if someone could point me in a nice direction to get the power I�m looking for by doing too end work and a cam that�ll work with what I�m wanting and maybe a recommendation on a stall I should run. It�s a street/strip truck so don�t really mind if the stall is big. I bought 799 heads for it also. Thanks in advance

 

That is a lot of rwhp for a dished piston. You are going to need to get a better set of heads or those 799s ported and milled. You might need to fly it your pistons because of PTV. You are going to need a large cam. Many of the active vendors will help you with you goal but 450-500 wheel is on the upper end of what the combos can make on 6.0s with the LQ4 pistons.

A friend of mine just put down 450 wheel on an LS2 with prc stage 2 243 heads and a 23x/23x cam. He made around the range of 11:1 compression but the LS2 has flat pistons for the extra compression.

Get a 4000 stall from a reputable company like, Yank, Circle D, or PTC. You won't regret it. I love my big stall.

 

I planned on getting a stage 3 btr cam or a comp cam 231/239 .617/.624 and to mill and port the 799 heads with upgraded pushrods, springs, and lifters. But I heard that if you mill and port the heads that it limits your cam options. That�s what I was concerned on.

 

When it comes down to it, you are going to have to check PTV when you start milling the heads, using thinner head gaskets, or you'll need lower your expectations about the rwhp. You'll get a bump in compression from the smaller chambers of the 799 head, 64cc vs the 317 72cc. I used a compression calculator and it said the LQ4 with the dished pistons of 6.7cc would be about 10:1 compression ratio. There might be some additional room to mill the heads or use the thinner gasket, but I'd call BTR to see what you can get away with.

I decided against any milling/thinner gaskets on my build because I just didn't want to get into measuring pushrod length and checking PTV. I'm not a very experienced mechanic and I basically can follow directions well lol.

 

I think it's a tall ask on a stock bottom LQ4. Can it be done? Yes, but it'll cost you. Cost and driveability/reliability should always be part of the decision process. Honestly, if it were me and I was dead set on keeping the bottom end stock, and I wanted 450-500, I'd look at supercharging or turbos to get there. Just my $.02. I'm sure there are plenty here that will tell me I'm wrong.

 

sounds like a max effort build, youre going to have to pay attention to every last detail. the lq4 pistons are going to be a hindrance.

 

Leave it stock and boost it with an ebay GT45 cheapo. Decap inj etc etc. Sloppy type build

Your asking for pain of you want 450-500 out of that motor sbe NA it will be an undriveable turd or cost a fortune as mentioned. Or adjust your goals to 400whp and you'll have it done in a weekend all in less than a grand

 

I have yet to have LQ4 dynoed, but the LS1 that was in my car dynoed 410 to the wheels with the build below. I did nothing more than swap the LS1 short block for an LQ4 short block. All of the parts were swapped. Loss of compression but increase in CI should be close to a wash.

243 heads CNC machined 65.5cc with 2.04/1.575 valves
234/238 .612/.612 112+4 cam
LS6 intake
42lb/hr injectors
Pacesetter 1 3/4 LT headers, no cats, catback
Built 4L60E with 3200 stall

 

I think it will be lower because of the piston difference/compression ratio difference. Report back! I'm interested to know

 

Compression will be important

If you're balling on a budget get a valve job done on those heads, it will open up quite a bit more power, more than milling them for compression will. Get the bowls blended too. Should cost you maybe 500 but you'll have some damn good heads at that point. Mill a bit off of them. Like .020 to get in the neighborhood of 62-63 cc. Get .045 head gaskets from ws6 store. You're gonna wanna bump compression but don't have to go crazy with it, be better if you did but be fine if you don't. Getting the heads to 63 with .045 gaskets puts you at 10.5:1
Or find 706 heads instead and bolt those on for 10.75:1. I'd want to be close to 11:1 at least. But you're gonna need to watch for valve clearance.

What you could do is order your cam and set your heads on with the used head gaskets and measure and see how far you can cut the heads then go from there. If you can get the heads down to 59 cc and run the .045 gaskets that would get you to 11.0
Those pistons are kinda killing you, they kill off right at 1 point of compression. But 1 point wont make or break your setup, just helps.

Look at the titan 5 for your build. Do a 4000-4400 stall and a FAST 92 or 102 intake, or sheet metal intake like a sniper intake or a holley high ram. With the last 2 intakes you'll lose some low end with that setup but who cares it's going in a S10 with a 4k+ stall. So just find one of those that meets your budget.

If you're not on a budget you'll be able to get to the 450-500 but start with pistons and better heads.

 

I would bypass the 799s, sell them and put the money into a set of 5.3 heads, as other mentioned, you can get these milled a bit and get down to 59-60 CC, then you'll be into the high 10s to 11:1 compression. I think $1000 or so gets them CNCd and larger valves installed. I believe this route will give you less concern with PTV clearance, since the chamber is already small to start, the valves aren't as close to the bottom of the head as they would be in an 243/799 or 317 head milled to the same size. The compression will help with running a larger cam.

I have never dyno'd my combo, I'd like to this year. My LQ4 is a mish-mash of parts I had laying around... stock 317 heads, but they have been CNCd (chambers are still 72cc), 223/231 0.637/0.617 cam, TBSS manifold, 92MM Warr TB, no MAF (Holley Terminator X running SD), some 1-7/8 headers and good exhaust. Runs strong, and I've never felt that it lacks any low-end that some complain about. I have a Yank 3200 and 4.56 gears (heavy-ish 1971 GMC).

I am thinking about grabbing a set of 5.3 heads and a bigger cam to swap on sometime this year.

 

Milling also changes flow and the flow curve.
you can sink the valves in the seats to help ptv.if ported right wont hurt flow. So what ever you do. Get them flow checked afterwards

 

Instead of a hp goal do you have a et goal?

 

Hoping to have it to a tuner in the next few weeks, I'll get some dyno numbers then.