I got the flow numbers back for my sb2's that I had converted for reverse cooling. The motor is a 396 with real good parts. Second Street Speed is doing the machine/assembly. I know there are some guys in here that have experience with these heads. Please tell me what you think. I thought they're a little light on top end flow compared to what I've seen but the mid lift numbers seem inline. They came from Petty Enterprises.

Intake Exhaust
.100 87 69
.200 162 110
.300 237 146
.400 292 190
.500 325 225
.600 351 240
.700 372 250
.800 379 262

These numbers are @28". 2.15/1.60" valves with an intake seat angle of 45 degrees. Test bore was 4.030" No pipe for the exhaust.

The SR cam spec'd for this motor and ordered from Cam Motion is: 269/279 @.050" .720/.680 113 lsa .020 hot lash.

The car is road raced and run at the strip. There is a direct port fogger capable of a 400hp hit in place. Trans is a G-force T-56. Rear gears are 3.91's.

Opinions? Let the brain trust flow. Thanks.

 

That's [EDIT] disturbing.

Whatcha trying to do? Die?


Mike

 

Ah, well, I'd like to keep all my limbs intact, but hey whatever happens happens. In any case, I'm trying to build a true dual purpose machine. It was last year but I decided that I couldn't make the kind of power I wanted with heads available to the LT1 and if I was going to go to the trouble to convert a set, I thought I'd skip over the 18 and 15 degree stuff and go sb2. I want to go faster than 9.44 with the 6sp I'm sure taner will chime in here. I also want my father to be able to go to some road course events with it, so...

Anyone else. I'm interested in opinions about the setup. Thoughts on what might not work, etc..

 

i dont even wanna know what that engine costs.

snap some pics for us !

 

It's not as bad as you might think. I got the sb2's used from a place in the Carolina's. True, Oliver billet rods are not cheap and neither is the specialized valetrain components that are required but it's the way to make power. I'm hoping for 750 flywheel on the motor and 1050 on the hit. I think this is about the limit for a porperly built/hardblocked LT1. Even then I won't hit it with that much spray all the time. 200 for most events with the big hit reserved for special occaisons.

I don't have any pics yet but will post some when they get here. Should have the intake in about two weeks. SB2 spider with BIG fuel rails, an NX direct port setup with billet rails and a 1250cfm polished accufab tb. Can't wait to see it.

 

Dave, all I can say is "holy sheit".

Rich

 

Awesome.

What are you doing for headers? Lemon's or some other custom builder?

Dave

 

Dave,

Arte you gonna run that down at Maple Grove in the spring? I wanna come and watch.

Steve

 

g'luck dave, going sb2.2 is definitely the way to go faster, i guess i am too stupid to leave this 23 degree stuff lying on the shelf. those numbers are killer!!! i still think there is something to be said about doing it with the 23 degree stuff. g'luck on beating that 9.44, shouldn't be a problem for ya! but keep this in mind, i had issues on that pass, and alot of us plan on going faster each year.

i didn't touch the bottom end this winter, no need to , except for that billet core thingy that lifts the pushrods the folks at Cam Motion are pretty thorough, and their customer service is good! as far as the top end goes, new headers, heads ported, and a sheet metal intake. i think the 3 most important changes will be camshaft, intake and heads ported in that order. i will say that your camshaft is a bit more radical than mine

23 degree heads for ever, lmao!!!! i think if i ever ditch the bottle I will go that way as well. that is one way to make some real power all motor! maybe we'll meet up at the track sometime next year? if you ever head to Ohio, and goto Norwalk let me know. that is the best track I have ever been to!

 

Based on the flow numbers, a NA engine should be able to make 775 hp.

 

YEEEESSSSSSS!!! WHo did the LT1 conversion? Aftermarket engine management?


David

 

Hmm, back to the drawing board for me I suppose. Had plans for a direct port/SB2.2 setup next year.

I know you can get more than 1000hp out of a filled LT1. I would think you'll be in the 800-900hp range on nuts and in the 1100-1200 range on the gas.

Guess I'll stick w/ these sorry 23* heads like Taner.

 

Damn, those are some insane #'s. (I had no idea sb2.2's flowed that well)

What are you doing for engine management?

 

45 deg seats aren't always used on a SB2.2 head, but that would explain why the top end numbers are not as high as some that are out there. That and the 4.030" test bore vs. a 4.125" test bore that is normally used on a Sb2.2 casting for flow testing.

Compare that with some GP Tech Sb2.2's flow is pretty close, but you can see how a 4.125" test bore and a 50 deg seat change the numbers. GP Tech Flow Sheet Those are some nice numbers but it also comes at a price, $5300+ for ported castings no parts and no valves.

A quote on that head:

"The head includes as standard 45 degree valve seats. Flow numbers can be greatly enhanced, in particular the exhaust flow, with a 55 degree exhaust valve seat, combined with a 50 degree intake valve seat. Weld Tech gives the customer the option of either valve job. The amount of actual performance increase on the dyno will vary from one engine combination to another. "

Either way should make for a 750-800hp NA motor and probably well over 1000hp on the jug!

Bret

 

Taner, I know you had issues on that pass. I think you're old setup was probably good for 9.3xs. I'll be making more power than you (I think) but your car is lighter. That plus the issues of getting the car down the track and suspension knowledge that I'm not as good with will be the deciding factors. It's gonna be a toss up but I'll be right in there. I know one thing, it'll have wicked mph. Plus I don't know if I can shift as good as you, your videos scare me. In reality if I can get the car going 9.50's at some big mph like 150+ I'll be happy. After all, it's still a road race car too.

As far as engine management it's going to be either FAST or BigStuff3.

CFM in Indiana did the conversion and made the fuel rails/plumbed the intake.

SStrokerAce, I got them used and they had the 50/55 degree seat package but the low lift numbers were not what I was looking for. I think the .400 number was 240 which by 23 degree standards isn't bad but I knew they had more in them. I had them changed to 45 degrees in hopes of getting the low lift numbers up and it worked. This was done in the interest of making it work with the road race cam. I think these will work out good.

I'm having Burns do a design and a local guy fab up the headers.

I will be running at Maple Grove for testing and the Pro Fastest Street Car event in August.

Thank you all for the input.