BigBoyWS6

Howdy all.
Its a 390ci fully forged Callies crank/rods and Diamond flat top pistons. Its getting pulled out of the car because the oil pick up tube fell off into the oil pan a couple days ago. While its out I'll get the Holley Terminator X and its new engine wiring harness. And I'll have a local machine shop re-hone the cylinders, re-ring it for high boost and all new bearings. I want to put a new top end on it while I'm at it also because what I have now is OLD *** LS1 heads, LS6 intake and stock ported TB.

Its 410 RWHP now. I'm figuring maybe 80-100 HP gain with new top end and cam.

Maybe all LS3 stuff? And of course a new cam for the boost.

Planning either an F1-A-94 or possibly F1-X.
The rest of the car is ready to go.
Thanks.

imma_stocker

iTrader: (19)

Cathedral ports favor low-mid rpm power. Rectangular ports favor mid to high rpm power. Rec port heads need 4.00 bore MINIMUM but do better with larger bores due to some valve shrouding. Also with rec port heads you will need to triple check piston to valve clearance. Might need pistons with LS3 valve reliefs.

What's the bore/stroke of that 390?

BigBoyWS6

4.030 x 3.825

I think I’m going with TFS 220 cathedrals w/ ca625 studs. A guy has a 383 cube iron LS with these heads and he just ran a 7 second 1/4 mile pass. I may just go ahead and use the identical turbo he’s using also so it’s the proven HP that can be made with those heads and this turbo that I’m interested in.

I have zero interest in drag racing……only roll racing.

He’s making 1280 RWHP so I should make that, or more.

BTR Trinity intake and a 92mm TB was also the idea.

A shop just found my 4L80E broken wire in the harness issue so next week I’ll start this ball rolling.


This is the turbo he’s using, it will fit my kit perfectly, so it might be my choice. Pic attached.

wannafbody

iTrader: (2)

I'd wait till BTR releases their canted valve heads later this year.

BigBoyWS6

What could the gains be over using TFS 220 heads, all else being the same?

Also, any idea of what they might cost?

I mean, I’ll be able to surpass the limits of what my iron 4-bolt block can handle with TFS 220’s so how much better should I really shoot for with this 390ci….?

I know of a brand new LSX block that I’m hoping to secure so I’ll be able to take the step into the 6-bolt world later. Then go for bigger power with a 427ci.

wannafbody

iTrader: (2)

BTR claims the cathedral ports will flow 360 cfm. That's outstanding. As to how much power they'll make with boost, I'm not sure.

Kawboom

The best bang for the buck is probably ported stock castings of some sort. The heads you have are actually pretty good but sending them to a proper machine shop for CNC porting and valves is a lot cheaper and gives you a lot better set of valves and springs than any budget aftermarket casting.

BigBoyWS6

My heads are custom built and modded LS1 heads, but they were made back in 2002 by Agostino Racing Engines. The intake valves are oversized, they’re ported, new dual springs and CHE trunion upgrade, new titanium retainers.

But they only flow 304 cfm @ .650. That’s terrible.

Lots of power left on the table. Just think N/A what the RWHP increase would be with a 360 cfm head and new can to match. Maybe 100+ HP……right….?
So 200+ increase under 15-16 psi of boost.


People have told me to just put the ca625 studs in and keep these heads to save $3,000. See what it makes.

BigBoyWS6

A couple aftermarket heads now flow more than 360cfm. Are the BTRs better for other reasons than just flow?

Kawboom

No, upgrading your heads will not gain 100hp going from that head to a 360cfm head. That stated 304CFM at .650 lift is right in line with a Stage 2.5 CNC ported cathedral port head from Texas Speed or a Stage 2 head from Total Engine Airflow. You can find videos of heads of that caliber making 600 horse on the dyno on a 408 without too much cam, so that head is not your restriction, its 70cfm better than the stock heads and those were fairly good for a stock casting. For comparison the AFR 245 barely flows 360 at .700 lift, and thats for engines up to 450ci and needs a big bore. If you're small bore it's not even an option, and in dyno comparisons they don't out-power the cheaper heads until you get to big engines or big RPM.

If you have the stock 76mm throttle body that may be your restriction point.

I would freshen the heads and make sure they're in good shape, and run them. Spend the big money on something else.

BigBoyWS6

I guess the only problem is my heads don’t have a thick deck.
The T6 kit and turbo I’m using can easily make 1300 RWHP.

You think my current heads along with a bigger TB and BTR intake can support that turbo?

Wont back pressure be quite high?

Cant even find flow numbers for the TFS 220 Cathedral heads, they don’t list them anywhere.

Kawboom

You know what dude, you do whatever you want.

Based on this thread and others you've started you're either messing with us or you're beyond help. One thing is for sure, you will run into a bunch of other problems before you make power to deform or crack the deck of your factory heads.

BigBoyWS6

Yea....just messin around.....I have a lot of time on my hands.

G Atsma

Spend it elsewhere, please...

imma_stocker

iTrader: (19)

Must be nice to be rich.

gnx7

iTrader: (28)

LSA or LS9 heads are made from a better grade aluminum, rotocast (shaken while molten), weigh 2lbs more each than other production heads, and have additional webbing cast into the rocker arm boss area. They will metal fatigue less than heads that aren't designed for forced induction. A stock LS3 intake manifold will make 1200rwhp and have great power from idle up to 7000rpm (I run one). Beyond that it hits an airflow wall and just holds on to peak (actually around 6600-6700rpm it hits a flow wall). That would be my suggestion.

Katech will port them for $499.... plus a bunch of other tear down/clean/reassemble fees. Or just have someone give them a quick hand port. (Bo White)
https://katechengines.com/i-30497878...ls9-heads.html