Advanced Induction

iTrader: (2)

Outlaw/Taner - We have yet to determine what to do for a reasonable all out configuration. The 215cc 23deg version will likely be best for most guys wanting an 11.5-12:1 383-396 that exhibits excellent drivability and manages to make power to 7k or more depending on valvetrain. A larger version is something I'd personally like to do, but we need to determine if there is really a good reason to do it. It will be done once we determine what would be a significant & safe improvement over the 215cc 23deg head.

Serious business requires a serious top-end . We have (on the shelf) a set of reverse cooled AllPro raised runner 23deg heads, but have yet to produce masters in them. They would be an option for someone who wouldn't revise their shortblock, but we may just sell them as-is. If one is willing to go through the expense of going to a purpose built top-end, then I can not imagine staying with any of the 2Xdeg heads. We had considered putting a racier LT specific package together by altering existing 13deg setups, but do not know what kind of demand there is for something like that.

Regarding compatibility, there is still hours of mockup to be done. Everything should work fine, and anything we sell typically has additional machining beyond porting for that very reason anyhow. I am certain the end-product will be something ready to bolt-on and run.

Have a nice Christmas, guys.

GIZMO

iTrader: (8)

FYI. Buyers of any head with decreased valve angles may have to change pistons or cut new valve notches if the are running a lot of cam. That said, these heads are a move in the right direction for serious LT1 builds.

Beaflag VonRathburg

iTrader: (176)

They are a move in the right direction. The results are quite nice. We'll see if pricing is as well. Hopefully, they will continue the trend and keep working down the valve angles and raising the runners.

joelster

It would depend on the price, i'm sure. I have seen a few sets of converted sbc heads, and it is not rocket science by any means. A 13 degree head will not be a cheap starting point no matter what. That will also require offset rockers, offset lifters, etc......I made a thread titled "Brodix?" and I think the best bet would be their 18 degree heads which allow all of the valvetrain components of a 23degree setup.

I think I am speaking for a lot of guys here, when I say that we need a bolt-on head/intake package that can flow over 330cfm (at least), support an easy 550+ N/A hp, and cost $2000-$2500. If someone were to develop a 13 degree setup with heads that cost $3000, shaft rockers that add $900, lifters that run $500, headers that run $600 a custom intake that runs $1000, the grand total would cost more than a VERY strong LS1 motor, which is simply unacceptable.

Abdullah

iTrader: (2)

i want to buy these AI CNC'd 21* TFS LT1 heads for my 1996 impala SS. i want a proper shaped, a proper crossectioned area with high velocity and good flow numbers ports and as small sized ports as possible. i'm waiting for these heads.

96capricemgr

iTrader: (1)

You know they have multiple customers at that level at the wheels with their 200cc ported stock castings and factory pcm or the 215cc Trickflow.

joelster

Yep I am aware of that. Very impressive indeed. The only thing is that those are maxed out. They have taken those castings as far as possible. What if they started with something that flows 320 out of the box? Like the Brodix 18 degree head. That would put you right at the limit of the factory pcm, then if you decided to take it even further with an aftermarket EFI controller, the head would have enough meat in it for additional porting to get you near or over the 350cfm mark, into SB2.2 territory.

Someone needs to sell a top-end package that includes a converted set of SBC heads with a single plane, fuel rails, and an elbow.

GIZMO

iTrader: (8)

Dumping the factory PCM should be the number one modification on a high HP small block build. The factory PCM is maxed out on un-ported LT1 heads (trust me).

GIZMO

iTrader: (8)

It seems to me that the aftermarket is going out of it's way to produce good LT1 heads. What is needed is a bolt on intake. Maybe if everyone stopped putting down Edelbrock on this sight they would consider making an LT1 specific open plenum intake?

N2OMIKE

iTrader: (3)

I was in the lot today but they were closed

engineermike

I want a 2 valve head that performs like a 4 valve head. Tons of low and mid-lift flow, and big power gains using small camshafts and reasonable rpm. I see a lot of guys wanting 320 cfm at .700 lift, which doesn't interest me in the least. I want 250 cfm at .300 lift. Oh yea, and a 64 cc chamber too...

joelster

250cfm at .300"?

That is asking A LOT. Just browsing through my Brodix catalog here and seeing which heads fit that bill....hrmm...here's one that's pretty close:

Brodix KC 13 flows 239cfm at .300", and also 370 at .800", it is ONLY$3952.50 BARE and requires a $800 intake manifold, special headers, shaft rockers, .180 offset lifters, etc....oh and it has a 283cc port, which probably wouldn't have the best low rpm street manners, lol.

They make a 15 degree head that is close also, and quite a bit cheaper, but the special parts will kill you in the wallet.

The LT1 market doesn't really need another 180ish-cc head that flows in the 250-270 range. We already have the TFS 195, the GM LT4, the Dart 180, AFR 195, plus Ai ported stuff and LE ported stuff. Give us a bare head that flows well over 300 that bolts right on without any special stuff. LSx stuff does that all day long, and has good street manners too, so don't say it isn't feasable.

engineermike

250 cfm at .300 is difficult on a 2v head, but not impossible. The LS7 heads get pretty close straight from GM.

The thing is that you don't need a 260 or 280 cc port to get good low lift flow. A 210 cc port is fine, but you have to maximize the valve size (along with some other bowl and chamber tricks). The valve is the main restriction in the port at low lift, so the larger the valve, the more curtain area you have. The KC13 and LS7 heads have good low lift flow largely because of the huge 2.18" and 2.20" intake valves.

The large, high runners help get you top end power that most of us will never need, mainly due to streetability issues with the cams required, limitations of the stock EFI system, and limitations of a hydraulic roller valvetrain.

With good low-lift flow, you get power in the midrange (<6500 rpm) where most of us need it, and don't have to sacrifice response or spend $$$ on special intakes, shaft rockers, valve covers, headers, etc...

fuel

iTrader: (13)

engineermike and joelster you both have good ideas. dont forget a matching lt1 single plane intake to match.

GIZMO

iTrader: (8)

Keep in mind that the LS7 head is designed for a 4.125 (+) bore. The limiting factor on LT1 will be the Max. 4.060 bore. You could of course sleeve the block, but how many are willing to do that? Which goes back to my first issue. The main reason that their are so few fast N/A LT1's on this site is that everyone insists on running the factory PCM (even in non street applications). Small blocks like rpm's.

Beaflag VonRathburg

iTrader: (176)

You guys are saying pretty much what I said on page 1.

People get too caught up in havings small intake runners. It doesn't hurt, but it is not neccesary to have small runners to maintain port velocity. I want to see a true large runner casting that will support power in a wide range of applications.

I also want to see the LT1 aftermarket step up in valve sizing and down in stem diameter. There's no purpose what so ever to run an 11/32 valve with the wide variety of 8mm LS stuff out there. 8mm valves cost the same and there's tons of good spring packages out there that cost less and perform better than most of the stuff that is currently commonly being used. There's no purpose to having a 2.02 intake valve with a 4.03 bore or a comp 918 with a steel retainer on an 847 sized cam.

If someone made something like a 230cc as cast head that flowed well out of the box, had enough meat to be opened up for larger engines, with options for a multitude of valve sizing, and a revised valve angle that worked with current technology it would sell like hot cakes. I really think trick flow taking a humongous step in the right direction with slightly moving the valve angle on these heads. I just want to see someone make the next step.

engineermike

True about the LS7 head, but you can easily fit a 2.2"+ valve in a 4.000 bore as long as you put them in the right place. Back in the day, I ran a TFS Twisted Wedge with 2.02/1.6 valves on a 305 (3.74" bore). Yes, the valves were somewhat shrouded by the bore, but it still made more power than 305-specific heads with smaller valves.

+1

Grr

iTrader: (2)

ive been saying this since the l92 stuff came out. 230+cc runners from the factory with perfect idle and emmissions. the small port/velocity stuff is pretty much bullshit when you see the factory moving in that direction. give me a goddamn large runner head so i dont have to convert SBC heads

T/A KID

iTrader: (12)

The runner on the L92's are actually 260. I am no head guy, but from my understanding its about the shape of the port in key areas. A lot of the time people get too worked over on runner size, when thats only a small portion of making a good set of heads. From memory the L92's have a 2.1X intake valve, thats pretty damn big IMO.

I say a larger runner head, with a smaller valve angle (21 is better than what we have had) with large sized 8mm valves would be awesome.
We can actually change the valve angle of any head, the question is how much can we go on a given head without having to change up pistons, etc.

engineermike

Problem with the SBC and LTx is that you can add runner volume, just not where you need it. The low runner roof and pushrod location limit the size in those areas. Add size in other areas and you don't get any gains, and in some cases you get losses. That's why the big cc heads move over the pushrod and sometimes even use offset lifters so they can enlarge the port in that area.