Hi all. My son was recently born so I've taken some time away from my project. Now I'm anxious to dig back into it and thought I might share some info and a video about my car. I've got a 2 bolt main sbc 400 punched .040" over to a 408 (closer to a 409 but don't want it confused for a W motor.). Heads are an old smogger set that have 76cc chambers, good porting, 2.02"/1.60" undercut swirl polished stainless steel race valves, 1.6 Howards roller rockers and springs to match my Howards hydraulic roller .560/.560 (.597/.597 with my 1.6 rockers part # CL111815-10.) Pistons are forged aluminum flat tops with deep valve reliefs on 5.565 I beam rods taking me to a pump gas friendly(ish) 10.0:1 compression ratio. Torker II and Holley 600 cfm (I know way too little carb this is just the intake and carb I had around when I was eager for the first fire. The 750 had some gaskets tear while setting float levels.) fuel is supplied by a Holley black pump with the supplied regulator from the summit kit. Torque converter is somewhere in the vicinity of a 3200 stall in my car. I have a Mellings high pressure oil pump. Cooling is handled by a Be Cool direct fit system with dual puller fans. This is all fed through a TH350 and what I think is the stock rear end. I foresee my trans and rear end being replaced soon with this kind of abuse. The trans plan is a TH400 full manual reverse valve body in the future. I'm not sure what gears are in the car. I'm hoping that my Z28 came with the 3.23 posi. I plan to figure that out when I can take the car out for a cruise. Certainly better than the slightly hopped up 305 that came in the car with only 1 side actually having the bolt through the motor mounts. So any of you experienced gentlemen have anticipated power output/ 1/4 mile ets for this car. I don't have good rubber on the car so if you want to estimate ET based on the right rear end and a good set of slicks feel free! I know I've got a ways to go before this car is finished. Recommendations for improvements are very welcome while insults are not. I'm still and forever will be a student in all this. When you stop learning, you stop progressing. Here's a video of myself and Dad during the first fire. Keep in mind that timing hasn't been tuned in and the car was kind of thrown together in a way we could see and moniter everything.

 

Once I figure out how to add video from my iPhone, I'll post it here.

 

Here's the video:

 

Nice build! My current project will be tamer, 350, fuelie heads, th400 trans, stock rear. I plan on making it street friendly, and keep it on pump gas.

3200 stall is fun, but I am mostly looking for low rpm lift off instead of all out war at the traffic light.

 

Get rid of those old 882 smogger heads and swap in some vortecs or any modern aftermarket 64cc head and you will make so much more power. Good set of heads and it should be a beast!

 

Thanks! My father has a set of "fuelie/double hump/camel hump" worked over heads we thought about putting on my motor for an all out race motor. With those 64 cc heads, compression would've been something like 12.7:1 if I remember right. I can't remember what it was exactly, but definitely beyond pump gas. He has those on his 70 cam with dished pistons (406 sbc) so we're pretty similar at around 10.0:1 compression. He's got the weiand high rise intake with dual Holley 450s I bought him a couple years back with deployment money. He's got a hydraulic flat tappet making a little less lift so it'll be curious to see who's got more power. We're running the same torque converters except his is on a TH400. I need to get mine finished so we can play at the track.

 

I posted above about considering some 64cc heads while you posted that. I'll definitely agree that I'd make more power but I don't want to give up running on 93. I've got a set of Vortec heads strapped on my 97 suburban I considered using. I think the port work I had done to my heads will make some serious power compared to a set of stock smogger heads. I just wish I had them flow tested to know for sure. I've thought about some open chamber Dart Iron Eagles but the budget doesn't like them anymore.

 

Any noticeable difference in the feel of the engine with forged pistons?

 

I don't necessarily have a straight up apples to apples comparison with my 408 because these are the only pistons I've ran in this block with this combo. I'm not sure how the feel would compare to aluminum hypereutectic pistons. What I can tell you, is that my father and I pulled the cam and top end parts off his 406 which had dished forged aluminum pistons that are similar to the cast iron pistons in the standard bore 400 they went on in my truck. The cam is a crane fireball II the heads aren't anything special and the intake is an old Torker. Oh both engines had summit plasmoly rings so that helps keep things level as well. The 406 made more seat of the pants power and the revs came up and dropped more quickly. The 406 was through an automatic and the 400 has a standard. I think the weight of the flex plate vs flywheel may have a heavy impact on this as well. Forged pistons will enable you to use nitrous more safely later on if that's desirable and will stand up better to high power applications. I imagine in a mild build, hypereutectic pistons would perform comparably at a lower cost. Anytime you reduce the weight of your rotating assembly as a whole, you can expect to see a snappier engine all other things being equal. The weight of the harmonic damper and flywheel/flex plate will affect this as well. This is based on limited personal experience and a lot of time reading. Your budget and expected power levels should be balanced. If you've got the money, I'd go forged in case you want to make more power reliably later without tearing down the bottom end. That's my 2 cents.

 

You didn't mention exhaust. Hopefully 1-3/4" primary headers and something free-flowing behind them.

It's easy to nit-pick somebody else's combo. But, you asked.

The 600 carb, Torker II intake, smog heads (nothing good you can really do with them), will all hold you back. Get your Holley fixed, first thing.

You didn't say what the duration is on your cam, that info would help. Especially for recommending an intake manifold.

I wouldn't bother with Vortec or double-hump heads, get some decent aftermarket heads (bare, if possible, so you can put your valves & springs in them to save a little money - aluminum would be an improvement as well). I'm guessing these would fit the rest of your combo well without breaking the bank http://www.summitracing.com/parts/rh...make/chevrolet You can do even better if you're willing to spend more.

TH350s aren't bad for a mostly-track car. The gear ratios are better than TH400, and they are more efficient. Just need to be built for it (which isn't hard, or expensive). But, a TH400 is good, too.

In your current configuration, you're under-carb'd, under-geared, most likely under-stalled, your intake & heads aren't very good. Assuming good exhaust and good traction, you'll probably run low-14's, maybe high 13's on a good day.

But, get the carb fixed, put on a real intake, good heads, more stall, 3.73-4.11 gears (in a rear end that can take the power), assuming free-flowing exhaust, and you should be in the mid-low 12's. Maybe even 11's.

 

Ahh thanks for pointing out I forgot to mention exhaust (knew there'd be something lol.) Yes I currently have 1 3/4" primary full length headers. At the track, they'll be uncapped. On the street, they'll have a dual exhaust with X-pipe. I'm definitely already planning on changing the carb and intake when the budget allows. I'm considering a weiand team G and a call to Holley as to what they think I should run (prolly 850 cfm). Until then, I'll likely stick with the Torker and get what I need to put the 750 back into action so I'm not so terribly undercarbed. I'll be sticking with my heads for awhile though while I get everything beyond the power plant sorted out a bit. I seem to think my heads weren't 882s though. I'll post a pic I took before they were ported in case you can id them by anything other than the #. I seem to think they're a 5xx but I've got too many sets to remember right. They're definitely 76cc. As for stall, I'll definitely be in the 3200-3500 range. I'll agree I could prolly drop a couple tenths with a 4000 stall, but I decided to keep it a little lower for the purpose of streetability since the torque of my 408 will help make up for it. As you can tell, there is a little compromise for street use here and there. I know that rear end is going to have to go. I really am just hoping that 10 bolt has the 3.23 posi so I can do a little testing before it has to go. Thanks for all your input. I'm sure that getting the rest of the car right is going to be my bigger issue for now. I'm anxious to get some tires and wheels on it to figure everything else out.

 

Forgot the pic.




This is the dress up I went with.





Without the intake.





Playing around with other parts around for a different visual. This is the intake and dress up on my Dad's 406 with camel humps (not the block and heads pictured.)

 

Almost forgot to post my duration info on the cam. Here's the part # cl 111815-10 for it again if you want to look over all the specs on it. It's a Howards hydraulic roller unit. With 1.5 rockers, it's .560"/.560" lift with 237/245 @.050 (290/298 advertised which I don't look at too closely.) LSA 110 centerline 106. From what I've read on cam theory, I'll see just maybe 1-2 more degrees of duration @.050" lift with 1.6 ratio rockers. Valve lift is easy to calculate just divide by 1.5 to get the lobe lift then multiply by 1.6 for the ratio of my rockers. The ramp rate has an effect on the @ .050" duration. The cam companies tend to keep that info on the downlow since it's what makes 2 cams that look the same on paper perform differently in the motor. Best example I can think of are the Lunati Voodoo cams that advertised a slower closing rate for less valvetrain abuse. Anyway I'm getting off subject again. I think the cabin fever has set in and I'm getting knee deep in tech articles to stay out of the knee deep snow.

 

Finally posted the video above. First fire was a little rough. You'll see wires everywhere, electric Holley black fuel pump in the engine bay, and some other things that were just for the first fire. Some mice decided to build a nest in the exhaust and that's the black fluff you see on the ground behind the car. I'll have to shoot a new video to show progress that was made since the video was shot April 2015. It definitely runs better since the timing has been set right, rocker arms readjusted, fuel pump mounted back at the tank, etc. Just thought I'd share the first fire of my freshly rebuilt motor with you all.

 

Not sure what kind of racing you'll be doing, but I gave up on the capped-to-the-track/uncork-at-the-track/capped-going-back-home thing a long time ago. If the dual exhaust is properly designed, it'll actually run quicker with it than it will with open collectors - you need "torque tubes" after the collectors to make open exhaust quicker than capped. A properly place X-pipe serves the function of the torque tubes. And, it's easier to hear problems with mufflers.

Sounds good.

624s, perhaps? Or 545s? Basically the same as 882s. Hopefully not 513s.

I'm running 4000 stall in my aforementioned driven-to-the-track "race car" ('57 Bel Air), which is now 4L80E overdrive lock-up TC. Prior to that was 4000 stall TH400 (no OD or lock-up), and prior to that was 3200 stall in the TH400. I don't know how far you intend to drive it, but I can say the proper stall on the track more than makes up for the few extra RPMs it takes on the street (nowhere near the stall difference). 60' times will be more consistent with a stall speed that gets into the "real-world" engine powerband - especially with a single-plane intake manifold (which I did try when I had the 3200 stall converter). Single planes just work better if never below 4000 RPMs at WOT.

I'm just talking long-term optimization. I understand in the real world things may need to be taken in steps. The 10-bolt in my Camaro has been abused since 2010 with my current set-up, regularly in the low-13's, made several 12-second passes, and even a few in the high-11's. But with 3.73 gears and everything you can possibly do to it to help it last. A Moser 12-bolt is waiting to go in.

 

Thank you for all the tips five7kid. I've definitely learned with my old Chevy truck that an exhaust helps to hear what's going on with the motor. I'll keep your tips in mind when I can see what the car is actually doing. It all seems like sound advice.