Are there any alum. cylinder heads out there that can be easily converted to reverse flow cooling for an LT1? The reason I ask this is because I'm looking for a flow range of about 325-330 cfm at .600-.700 lift on a set of 14-15 degree angle heads. I'm shooting for a SR cam in the 7000-7400 rpm range. I know extensive porting on a afr 220 23 degree head will usually have flow # around 295-300 @ .600... But I'm looking for a bit more. I know this will cost alot extra to have a mech convert it over but who has done this? I remember someone with a set of Pro-action heads doing this for a relatively small amount. Any opinions or comments apreciated.
-Tony

 

You need to talk to Bret about doing this. I believe most people use Brodix heads for this project.

 

Aren't the SB2.2 heads of the 15* variety??? Isn't Mindgame running those???

 

sb 2.2 heads would be ridiculous ... watch out LS1's !

 

Yes Mindgame is, I belive with a small cam & 15* heads he's running 530rhwp easy, LSWHA?

 

SB2.2's are 11* if I remember correctly. And no Mindgame isn't running them.

 

Yep, the 2.2 is 11º with a 4º cant towards the bore centerline. Very different head in comparison to the 18 and 15º. The 15 GM head is actually built from the 18º casting. By the way, I use the GM 15º casting (the 615) not the Brodix.

Horsepower is actually close to 570 at the rear wheels. Don't know exact numbers now... been a lot of tuning going on with this engine since it left the dyno. Most of that tuning has been in an effort to get the thing down the track quicker. So it may be lower or higher than first dynoed.

Tony,
Are you building a stroker? What displacement were you looking to build? NA or nitrous? Projected output? Track, street/strip car? More info = betta.

-Mindgame

 

If I were you, I'd get some 215RR or 227 AFRs and have Advanced Induction port them.

www.advancedinduction.com

Mike

 

mindgame what did you end up paying for the heads + work done to them?

 

Hey krispy, follow this thread and go to post #35. I covered as much as I can in that post. Overall, I've probably got over 10k in these heads. Frightening I know, but that's from the time that I purchased them til now. They've had two different sets of titanium valves in them at one time or another. That's about $2300 in itself.
I run lightweight SS valves in them now, but they've had alot of work put into them over the years.

-Mindgame

 

Mindgame, whats your opinion on the TFS 18* SBC heads?
they need offset lifters and some other special valvetrain items

 

My Dad and I have a set of Pro Action 235's (23*) that flow real close to 330 CFM @.700, and are alot cheaper than what Mindgame has invested, they have been converted to use on an LT1, but he will put out 50-70 more HP on the same engine combination all else being equal, even though he only has me by 20 or so cfm. That is a huge amount of air in a NA application. West Coast Cylinder head can do the conversion for ya.

BTW, An AFR 227 would be hard pressed to flow 330 cfm, the portwork and valvetrain required to run them would be as much or more than we have in our heads and valvetrain. Just something to consider.

IMO a GM LT4 head in the hands of the right porter can be a killer street head, with the right combination and intake manifold, some serious power can be had with these, something else to consider.


David

 

Any true 18º head is going to need an offset lifter and rocker shafts to work. You'll also need "special" pistons. WRT the TFS heads... I just don't know. To me they're 18º heads, I don't know all the things a guy who works with the heads would know like... how durable the castings are (hardness/softness) whether or not the port requires a lot of work or not to get an accepted shape. I'm just a programmer who's spent a lot of money in order to pick the brains of the guys who do know.

I can give you the names of some guys who could tell you though if you're interested? Are you finding some good deals on these TFS heads? May also want to look at the Brodix 18X for a stroker app. They can use a good deal of 23º hardware (they're a hybrid head) which cuts down on the cost.

Another thing to keep in mind about airflow as measured on a flowbench is that.... it's way below the depressions seen on an actual engine. The straighter that line of sight (port entry to valve) the better things are gonna be when the airflow gets high. So, cfm for cfm, the angle race heads have the advantage. That's the whole point in raising the roof and using a larger radius along the short side.

-Mindgame

 

True, but i'd like to see what those 23*ers flow vs Mindgames 15* ones at say .400 lift... That would tell more.

 

More info: Looking to build a 396. expected power output 550-560rwhp@ around 6,700-7,000rpms. The application of nitrous will most likely be in the far future on this motor. No more than a 250-300 shot. Intended use: Will go to the drag strip very seldomly. Just to get an idea of what the car runs. Most of this cars time will be spent on road race events. It will be driven on the street on the the weekends. I don't mind a little maintenance(SR setup) for some extra ponies. I am willing to invest up to $11,000 JUST on the motor, not any accersories. I can assemble the heads, install the heads, intake, and the motor myself. just need the bottem end built buy a professional.