It's no problem at all. If you've ever been a gear head, you'll find working on these engines isn't difficult at all.

I ran a 228/230 cam with my AFRs milled to 62cc, and I utilized a .040 gasket. This gave me 11.34-1 CR, and a tight quench of .032-.033 to ward off any chance of detonation. I never ran anything but pump 93 and at 28 degrees peak timing, it never had any issues with knock.

I dyno'd 446/411 on one dyno, where on another "higher reading" dyno that had previously gave me 9rwhp higher readings, would have put me at 455rw, all with the stock LS6 intake and smallish cam by todays standards.

The time in my SIG was run with the car de-tuned by 16rwhp (that's another story in itself).

 

I hear ya. I'll loosen up and dive in beyond routine maintenance eventually. I still have fond memories of being able to literally sit inside the engine compartment of my Cuda while working on it. Then again, it was a rolling brick in comparison to my WS6.

 

AFR heads ,talk to Tony or PAT-G.

 

i agree with some of the previous posts. I would go with a better set of heads, degree the cam and go with a fast. An aftermarket set of heads would be the best choice for higher dyno numbers but i have seen some prc ls6 headed cars in my area do some damage on the streets with that cam..goodluck with this hope you meet your goals!!!

 

Thanks man. The next step is always difficult when you don't know EXACTLY WHAT was done WHEN by the previous owner.

 

Dan-
There seems to be some good advice going on here.
I might have missed it but I didn't see exactly what your goals were.

I was glad to hear that you loved the car. Saying you thought it ran like a raped ape, and gave you great drive-ability
.
That was one of the reasons I went with a 228/228 cam on a 114LSA.
By today's standards, that's a pretty street-able/ small cam with a pretty small lift.
Non the less, even with this small cam, to put down over 430rwhp with the setup is pretty stout. Yes, that was achieved with offroads pipes (not the cats you are running now) and the cutout/dump wide open, but it needed all the breath it had to put those numbers down with a small cam.

It's easy to see that once you put the off-roads on and open the dump you will easily see the 420-425 mark. If your goal is simply another 20 hp, I would simply go with a MUCH more aggressive cam. With a great tune, you can still make a beast cam have pretty good drive-ability especially in an M6 can.
Going from the current cam to a much more aggressive cam can easily yield another 20HP.
I wouldn't swap the heads until I saw the numbers on the new cam.
Doing a cam on an LS1 car is much easier than you might be used to on the older stuff. You don't even need to remove the intake manifold.

Once you pick out a new cam, have your offroads pipes on, cutout/dump open and a fresh tune, check out the numbers. If you are not pushing close to 450, then think about the heads.
Again, I am not sure what your exact goals are. At the time, I was happier with 430+hp and amazing drive-ability, rather than a more impressive Dyno Graph and idle, stalling issues etc.
You are on the right track. Have fun with it.

 

Thanks for the reply CJ. My "goals" and "concerns" are two separate things and I will PM you about that. Bottom line, as we discussed early on, the more I know about what was done and when it was done to the car, the better off I will be with regard to where I go from here.

 

Hey Dan-
If you want to get max. flow out of your current heads I would definitely go with a more stout cam. With your current cam your lift is only at .568 .568 (Int/Exh) The heads flow great to over .600-- check it out

From the benchflow-
Flow numbes: Intake
.200 .139
.300 .198
.400 .250
.500 .282
.550 .292
.600 .302

That's pretty impressive lift at .550 and .600
If you ran a stout cam with a lift in the 590's you would see a large improvement.

 

I'd check out a ported Fast 92. That will surely net you some gains.

 

To be on the safe side you might consider upgrading your fuel system. Just to contrary a stroker kit might work better on a driver. What rear gear are you running?

 

Thanks CJ. I'm going with your advice and swapping out the cam since there has already been a lot of effort put into flow. Time to start researching cams with a 590-ish lift. The fun never ends!

 

What is the combustion chamber size on these heads? What is the installed gasket thickness? Did you ever do the SCR/DCR calcs to figure out where the combo stands currently?

I have never seen a setup like this make anywhere near the claimed 438rwhp on the Dynojet I tune on. This link shows the car the way it came in the door with the tune that was on it vs. some WOT re-tuning that we did: https://ls1tech.com/forums/12790217-post1.html The tune had a very abusive WOT timing arrangement the way Dan received it.... a flat 32 degrees across the board. The knock sensors were totally disabled by the previous tuner and the car definitely knocked all over the place the way it came in. It made the most power with the timing down around 26deg moving up a hair up top as expected.

I don't mean any disrespect, just telling you my experience and what I saw.

 

If the engine was hot and ran through CATs, then I'm not surprised at all that it knocked when loaded on the dyno. The previous tuner may have been working under different conditions.

It's really hard to tell anything about the fueling (dyno-scan) from the first run, so I can't say anything about that. It may very well have been a bad tune.

If it was me I would supe-up the heads some more, and take care of several small details to get things more optimized.
If I wanted a large boost in street power (not dyno #'s), I'd build a modest stroker around 370 - 383 cubes.

If you just care about dyno numbers, then your best way to go is the cam & head upgrade, but that's not me.

 

I think you should post dyno graph from previous owner cause 440 rwhp with that set up (cats or not) is


Dan, don't forget if you get a radical cam the drive ability is going to suffer.


Tune was HACKED

 

No conditions justify this.

It was an unloaded sweep. The cal had the VE and MAF table stock (hello, heads and cam car) and the IFR looks like the letter W rather than a line. The PE was less than 1.0 down low and looked like a range of mountains. Timing was a constant 32deg from .60g/cyl to the end of the board from 2500-up and the same was copied to the low octane table.... that's on top of having the knock sensors deadened completely out.

Obviously, none of this is the previous owner's fault at all, nor am I implying such. The car appeared to be exceptionally clean when Dan got it and he has kept it in that condition.

 

CJ (previous owner) will chime in shortly here. All I can add is that he had it tuned with off-road pipes (no cats) and the dump pipe wide open. I can also say that the car idled fine and ran fine including getting an average of 27.5 mpg driving 875 miles back to VA from Chicago. After Frost did some minor tweaking it did seem to have better throttle response but there were a few new oddities that seemed a bit strange- gas mileage seems to have suffered and for whatever reason the voltmeter is randomly pulsing all over the place. I'm not saying this was a result of the tweaking done while on the dyno but there are still some quirks left for me to work out.

Thanks to everyone for their input and keeping things civil.

 

+1000

There are two ways to achieve 450rwhp with 346 cubic inches. One way requires a very stout cam and supporting valvetrain to spin the engine fast enough to move the required air. The better option for a "fun street car" is to get a known good set heads that will flow the air at more reasonable speed, and pair them with a cam the makes power at lower engine speeds but can hold on to the curve upstairs.

One last thing, it sounds like the combo in question here may have a cam that is a bit limited in potential (.568 lift). I would suggest that a more modern profile at similar .050 duration could make 10-15 more rwhp, and the right VE's and compression should gain some low end as well.

 

What casting # are the heads?

 

241 "ported by afr"

 

No wonder the current owner is confused....

If the heads are indeed ported stock castings, the only way to know for sure what you have to work with would be to have them independently flowed. A well ported set of heads could possibly produce those numbers, but truth in advertising has long been a problem. Building the combination around too many unknown variables may only lead to disappointment down the road.