engineermike

And intake side. 210's flow waaaaay better on the intake than 195's out the box.

Mike

95Bird

MG..here is some more info for your database. this is myaverage across all 16 ports.

lift int. exh.
.200 121.9 101.3
.300 176.9 132.0
.400 216.8 153.3
.450 231.9 160.2
.500 242.4 165.7
.550 238.5 169.8
.600 230.8 172.4
.650 229.8 174.3
.700 227.9 175.6

I had a runner CCs of 177. My cam specs are 255/263 654/628 110 ls. compression was around 12:1. I dynoed 427 427 dyno (cut/past link) on pump gas and 439.7 439 dyno on race gas. You can see that in the first dyno I still had some low end tunning issues..but overlook that. All dyno runs were made through a 9" and 4.71 gears so I would guess 15-20 rwhp down from a stock rear end with 4.10s from what I have seen other cars loose from a 9". So what do you make of this. Car ran what was in the sig. I think this is the perfect example of how peak flow doesn't show the potential of a head to make power and illustrates that there are so many factors to come into play when making power . Oh...the heads were pretty inconsistant when you got over .450 lift. My best port flowed 249 at .500 then dropped off like the average shows.

Oh..hehehe..it made 502/535 on a small 75 shot pulling 4 deg of timing.

Cody

Thats awsome !!!!!!!!!!!!!!!

Elysian

For a while I was considering doing what you did: a 383/396 with converted GEN 1 heads. Mostly I was interested in retaining the LT1 fuel injection hardware (which, as far as I am concerned, pretty much negates the advantages of any carbeurated SBC1). Now that I have AFR 195's with a bunch of $$$ spent on porting, I'll use them on my current motor. I actually have a Chevy 400 smallblock (4.18 bore) with splayed mains just waiting to be put together. Only trouble is, with a 400 block I would end up turning off the spark side of the LT1 computer and using some kind of a distributor - or - going to an Accel setup ($$$) that would completely replace the functional aspects of the opti-spark (granted, the opti is known to be a POS anyway). You've pretty much talked me out of replicating your route to making power. GEN 1 w/ an Accel system or something like it is probably the way to go. I was just trying to do things cheaply. But like you said - making big power isn't something for the faint of heart anyway.

Van

Hey Bret, Those wouldn't happen to be the numbers you got after you had those TrickFlow heads done would they?

Mindgame

Hey Tim, thanks for the numbers. Your car is definitely strong. Like you said... it aint in the peak numbers. I think having a strong motor is maybe 50% of the battle in cutting low ET's. If you look at that Stock Elim. LT1 crowd, they're going low tens with maybe 400-420hp at the rear wheels. When you've got the car setup dialed in such that you can cut consistent 1.4 second 60' times, hey it don't take much to run those ET's.

I'm running the Moser/Auburn 9" with 4.11's. I know the 9" loses a little to the 12-bolt on the mechanical efficiency but I'm thinking that it's just a couple of percentage points.... like 12-13% vs 15-16%. I have engine dyno numbers along with a couple of dynojet graphs. I'll have to pull them up to see what the actual losses were.

Elysian,
Stick with the gen1 idea. If you want to break down the costs a little more we can do that. I've been running numbers on the two builds and don't mind sharing what I've come up with if you're seriously interested.

Good luck.

-Mindgame

Elysian

Mindgame: I wound be interested. Like I said, I already have a block. I haven't had it checked out yet, and I've heard that Chevy 400 blocks have a tendency to "crack," so I'm a little concerned about that. But assuming the block can take it, that's one expense down.

Rotating assembly: forged or billet crank? "Knife-cutting," I believe, is the term used for making the crank more aerodynamic - is it worth it? Gen 1 rotating assemblies are cheap relative to what the Gen 3 guys are paying. Still, I figure it would run about $2500 to balance and assemble.

Next, I would be interested in what you think of BRODIX 15* or 13.5* heads? Their 285cc 13.5* heads flow in the neighborhood of 400cfm. Look kickass.

http://www.brodix.com/2004_Catalog/19-20.pdf

On a ~430-440ci smallblock, ~280-290cc heads would be drivable? Right now, I have a mail order tune on a 350 with some ~203cc AFR LT4's and a 233/239 .569/.577 110lsa cam . . . all this works out to a moderately lopey idle and shifting around 6800-7000rpm. If the 430-440ci smallblock setup with these heads could have similar street manners, I could live with it. I figure it would be easy to dump $3000 into a good set of heads.

It seems like anyone serious about making power would also be committed to going solid roller. I'm not exactly certain what would be required for 13.5* / 15* valvetrain materials. I know non-standard rockers can run some dough.

Sheet metal intake? Thinking this would be somewhere in the $2000 range and would require some careful thought put into design time. A GEN 1 intake could be used, but I think you'd run into some hood clearance issues with a carb-style throttle body that, in the end, might not save you much $$$.

Naturally, you're probably stuck with making your own headers - maybe $1500-$1800 if done in stainless.

Accel EFI? FAST? Other? I am uncertain exactly what these cost to set up, but I know the forced induction guys use them pretty routinely.

Mindgame

Before all the affordable aftermarket blocks came around we (racers) were using the 400 blocks and pushing alot of power through them. They can be made to withstand some hp, but the machining is expensive. You're correct, they do have a tendency to crack in the main web area, especially the 4-bolt blocks. Now we're talking about putting a crank with 1/4" more stroke in there so you can see a potential problem.
There are lots of tricks to strengthening the block. One is to plug the deck's large coolant holes..... tap, plug and redrill. That was to help strengthen the deck surface. Most engine builders would also grind large fillets at the main bulkheads to try and strengthen the block in that area. As you can guess, we're running into a lot of machine work.... the price is going up!

You could sink $1000-1200 (easily) in the machine work or you can look for an $1800 block that is beefier in all the critical areas, has improved cooling and is fully machined, ready to go. That machine shop bill is something alot of people miss when thinking this out.... "Should I use my old block (needs machining) or should I buy one of those new expensive blocks (fully machined)??".

I wouldn't want to throw the 4" stroke crank in an old block. If I were going that route I'd just stay 3.75.

Forged or Billet?

Forged is fine for anything you could hope to do NA. If you want to build a 700 hp street engine and throw a 200hp shot of nitrous on it... billet might be a good choice.
Knife edging is a good thing. Makes the couterweights more aerodynamic and cuts down on drag. If you're going to go that far, why not use one of the oil shedding coatings too? This stuff is all a matter of budget... knife edging and undercutting (lightening) are nice options but most of your high end forgings are going to have this or at least it'll be "optional".

You would need a shaft setup for either of those options in heads.

That 13.5º head you mention.... I don't know anyone who's worked with it. Good friend of mine owns a circle track race engine build shop. They have a great deal of experience in porting the Brodix 12/15/18º heads but I have yet to hear of any consideration for that 13.5. I don't doubt they've thrown it on a few engines but it's a mystery to me.

I don't know what your goals are but the Brodix 18X might be a good choice for you. I think one of Mark Stielow's many builds from a year or so ago used the 18X and a wimpy solid roller (434 build). Made, I think, ~625hp and well over 500 lbs-ft. I believe that one spun 6300rpm but I'll try to find exact details if you're interested.

How much hp is it going to take to make you happy? That's the real question. But 650-675 is something I feel is easily attainable from a moderate 434/18X build. That saves you some money too.

A FI intake is going to be a bit more than that, figure ~$2500 for the intake with fuel rails installed. Then you need a throttle body.... so 3k is a good guesstimation.

You can pick up the older gen Accel stuff for really good prices these days. It's plenty powerful enough and I like the Gen6 interface. Whatever you can get a deal on... Accel or Fast is nice to work with.

-Mindgame

Denny McLain

Speaking of Trick Flow.....

I believe a couple of sets are being ported locally here in Dallas. The rumor I hear is an easy 300 cfm out of them.

Anybody heard anything more? Being you can order them direct from Summitt for about a thousand less that AFR heads, this may be the deal of the decade for us LT guys.

I've had quite a number of heads reflowed and 285 cfm is the most I've personally seen when they were flowed in front of you. Not sure how many of these 300 cfm heads actually exist.

Again.... this is just holding my ear to ground listening for hoof beats and drums so if someone has any real information.... please share it.

Van

Mindgame, PM'd you.

Mindgame

Interception.

-Mindgame

galopin

Here's an article on the Mark Stielow engine Mindgame is talking about:

http://www.popularhotrodding.com/eng...0305em_mmouse/

400 CID
15 degree Chapman GM Heads
610 HP @ 6800
526 T @ 5500


Elysian,

I think you might be overestimating how much runner volume you need. I am working on a plan for a 434 SBC with either raised runner 23 degree heads, or 15/18 degree heads. I'm looking for a 6200-6500 RPM peak and 625-650 HP. I called Chapman Racing and they suggested their Edelbrock 18 degree heads with a 247cc raised seat with a csa of 2.58. Mike Chapman said I should look for runner volume between mid-to-high 240s and a csa of 2.58-2.6. They cost $3500-3600 fully assembled (I think he said $2400 bare, but don't quote me on that).

Here are the flow numbers:

.2 -- 157/114
.3 -- 228/180
.4 -- 278/213
.5 -- 317/240
.6 -- 338/248

Mindgame

That's one of the other motors Stielow had built. Wasn't too impressed with that one. Think he's even built a canted valve 396 (650hp) motor since then. I get more life out of my tennis shoes.

No, the one I was referring to used a GM 18º head. Sorry... thought it was the 18X. That engine was built around the tall deck Rocket block (434 ci). Some specifics...

·10.5:1 static comp
·mild solid roller 242/248 110ºlsa
·Todd McKenzie ported GM 18º heads 343 cfm @.600 (that's all the info)
·6.125 rod length
·Callies "stealth" crank
·Arias pistons (4032) 1/16-1/16-3/16 rings
·CSI water pump
·GM 18º (579) cast intake manifold
·Force Fuel Injection throttle body, accel 36# injectors

615hp @ 6000rpm, 574 lbs-ft @ 4500rpm

A mild one.

-Mindgame

galopin

I like that 434. I could find a place for it between my fenders.


Regarding the Mule--it's engine isn't as mild as it use to be:

http://www.camaros.net/cgi-bin/forum...c;f=2;t=008754

I think the car was initially suppose to be a twin-turbo, but Nelson Racing Engines couldn't meet the deadline, so it remained NA.

Mindgame

And people tell me I've got the HP bug bad! Hell... everyone and their grandmother has gone turbo. Too easy.

The intake setup on that one is pretty slick... still using the kinsler stacks I guess.... I like it.

Oh well, he'll have another bullet in there before that one finishes break-in. Hang around for the swap meet.

-Mindgame