Hi Folks,

I normally hang out in the C2 section but you C3 guys are the real gear heads in CF. I am looking at a generation one 396" small block stroker to replace my original 327" for street use. The LS series heads seem to be the hot ticket for modern engine builds, but I want to keep an old 350 4 bolt main as a base block.

What head recommendation do you advise for my build? I'm looking at a hydraulic roller cam, and an all forged assembly with approximately 10.5 to 11.0 compression. I also run a 5 sp. with a 1:1 3.36 final. Obviously, I'm looking for strong street performance with decent drivability at a max rpm of 6300 or so. My '64 also has factory air which I intend to keep. I've also been toying around with installing an Inglese cross ram with sidedraft Webers for induction but that's for another story ($$$$$).

Any ideas would be appreciated.

 

Little confused on what you're doing, as mentioned LS. Gen I small blocks vs LS, are light years different, and nothing interchanges. World Products, does make a crossbreed block, that's Gen I down low, and LS on top. LS7 heads flow best out of the box, with 6.2 L-92 heads, not far behind. We're talking 360 cfm intake for the LS7's, and 330 for the L-92's.

 

Thanks. Did not know about the World products block option. I'm not familiar with the latest generation engines (LS), but always hear about how well their heads flow.

I really wanted to find out what aftermarket gen. 1 head flowed (almost) as well as an LS series head. Need some real world experience from you gear heads out there.

 

Comparing a 15deg head to a 23deg head is hardly fair, you need AFR 227's, 235's, 245's the bigger heads AFR has out now. A ~15deg Gen 1 small block head will smoke any LS head, comparing apples to apples.

 

Go with AFR

 

Yeah, but then you're comparing a $3000 pair of heads to an $8600 pair of heads.

 

Motorhead

You know i'm old tech.

Brodix at there catalog prices has an LS series head they call the BR7. The as cast version (262 runner obviously for larger buids) package price for two of them $1733.62 ( package in brodix terms means complete,valves,springs,retainers for hydraulic roller cam in this case, 155 seat, 405 open) it flows as cast .400 = 294, .500 = 334, .600 =360, 650 = 364 two complete heads as cast for 1733.62 with this strong of flow numbers.

Then they have two complete 264cc runner with 100 percent cnc for $3022.10 .400 = 303, .500 = 343, .600 = 369. .650 = 376.

Then they have a 273 runner 100 percent cnc two complete heads $3022.10
.400 = 286 , .500 = 344. .600, = 381, .650 = 409, .700 = 416.

Same price 264 or 273 take your pick both are 100 percent cnc.

The brodix prices are catalog. summit will most likely be a little cheaper.

A little chief dart with a 300 runner having to go to extreme lifts can only do 440 cfm. It would cost well past $ 8000.00 with headers to set it up.

The BR7 uses standard LS7 components. No special anything.

Pistons = standard. rockers = standard, lifters = standard, headers standard. 100 percent LS compatible. minimum bore 4.125.

 

I got some alum dart heads from competition products for $1200.most sbc are 23* valve angle.

 

AFR 245's flow 350cfm for about 2 grand so who is paying more ?

 

My bad, the ported LS7s are $2400. 403 CFM. Exhaust side is only 246 though. (which is probably one reason why the LS motors typically run pretty significant splits)

 

Yeah they are they are the greatest head and engine ever built, a 427ci C6Z06 with your badass 15 deg heads can't even make more power than my ancient Gen 1 427ci with 23 deg heads I built in my basement.

By the way show me the link to the $2300 LS7 heads that flow 403cfm, is the the $2300 how much it cost to port them ? Or is that for one head ?

 

Who makes the $2300.00, 403 cfm head GM ?



Motorhead the LS7 uses a 12 degree head.

( PER 2 ) should mean two heads.

PKG (package ) in brodix speak means complete,


The AFR 245 heads on AFRs web site cost $2524. You are forced to buy a shaft system to use it. It flows 250

The BR7 ( PKG ) ( PER 2 ) brodix 262cc as cast heads flow 364. Two complete heads $1733.62. It uses standard inexpensive LS7 rockers.


$2524 plus lets say $ 1000.00 for a shaft system your forced to run $3524.00 to run the afr 245 head and nobody really needs a shaft system for spring pressures of a hydraulic roller cam.

It would cost roughly twice as much money to run the 245 afr head.


The 100 percent cnc 264 or 273cc (STS versions cost) $3000.22 ( PKG ) ( PER 2 ) 264 flows 376 the 273 flows 416.

If you want them bare 262 as cast 1100.18 ( PER 2 ). STS BR7 264cc 100 percent cnc $2363.18 ( per 2 ) STS BR7 273 100 percent cnc same price bare ( PER 2 ) $2363.18.

This is strait out of the 2012 brodix catalog or you can go to www.brodix.com

 

AFR 235cc heads flow 340cfm and use conventional rockers. Not a big difference between the old relic 23deg head and the new fantastic LS head which again is 15degs, 20cfm difference and the AFR's are much cheaper and again comparing a 15deg head to a 23deg head isn't even close to fair and you bolt them straight on to a Gen 1 small block

 

Assuming that you will be running carburetion, I'd recommend AFR 195 Eliminators. Although the runners are smaller than others have recommended, the smaller cross section will help keep fuel atomized at the lower rpm you mention. And, since you claim 6300 rpm max, your will have plenty of flow from these heads, far exceeding the flow from stock cast iron heads.

You might also check with AFR Tech for their recommendations.

 

There are upsides to LS motors and downsides. I weighed all options and went with a Dart SBC 427. One of the big factors was using an 8 stack efi. The Inglese was around $5k for the SBC. An LS 8 stack or cross ram can run $8k-$10k.

My next build will use an LS motor as they make more hp cheaply. For the same price as my 427 with 565hp, I will use a LSX 454 with 725hp. An LS can be configured to look like a traditional engine. In my comparison I am factoring the use of efi in the SBC. If you stay with traditional carb they are very reasonable. For some ideas check out ultrastreet.net to see all the engines available. From their engine combinations, you can also get a good idea as to what parts to select if you are going to build it yourself.




What you cannot do is mix and match from Gen 1 parts to Gen 4 other than a few hybrid set-ups. An LS will be cheaper to buy and more expensive to install.

 

The original LS1 series engines were 15 degree. The LS7 is 12 degree.

 

MotorHead - I'm not trying to take anything away from your build or what you've done. I think you have an awesome motor, an awesome car, and definitely respect the talent you've put into building your engine. I hope someday to be able to do something like that myself.

I am, however, also very realistic. Maybe it's because it's political season in the U.S. right now.

That said, that stock LS7 is running a cam that doesn't even touch the cam you've got in your small block. 211/230 on a 120 LSA.


That's a cam + headers + cold air LS7 dyno. For some reason the cam guys keep their grind data secret (and I'm not going to spend $550 on a cam to start measuring things), but the shop says duration in the mid 240s intake/mid 250s exhaust. I'd imagine the LSA is a bit more on the conservative side (112/114) in order to help the computer idle.

It's interesting to note from that graph that headers + intake push it to 490rwhp / 461 RWTQ.

The heads these things have from the factory are pretty damn monstrous.

 

The LSA is 113, the cam is $450, not $550 and we keep the actual specifications "secret" (as you put it) because unscrupulous tuners flagrantly and blatantly copied our cams in the past. At least this way, those "tuners" have to buy a cam first if they want to copy it.

As a FYI - stock GM LS7 heads are awesome.

Stephen

p.s. Below is our slightly smaller cam - same deal - 2006 Z06 Vette, CAI+headers+Mayhem II cam. Look at the torque curve. We have found that bigger is not always better with the LS7 heads.

 

450-ish rwtq @ 2800 rpm????

Insanity. lol I should put one of these in my TRUCK.

 

Shark Racer you and I know each other and I respect your knowledge, our "arguments" aren't really mean spirited rather more of a conversation and exchange of ideas of what we each like and don't like, although at times can seem a bit more than that.

I am always interested in learning things and yes i do like the carbed LSX 454 but with the motors I build I see no reason to go to an LS based engine. That could change in future but it would have to look more old school than the way some of them look now. A carbed LS7 would be nice too.