New project, 71 Camaro + 406 w/highly ported Vortec race heads = fast as hell

[bananahammock]

Hey everyone its been a long time since I have been on here! Anywho, thought id share my new project with everyone. I got my hands on a 71 Camaro (rather than building my 78, for smog reasons), and am in the process of building/restoring it. First order was to do the interior and wiring since both were an absolute nightmare. In the meantime, im buying 406 parts like crazy! Bought a $650 set of Manley lightweight H-beam 6" rods last month and today I splurged and bought the 371 casting Vortec race heads and all the port work/matching they can handle! I have to thank Tim at Airflow Performance for taking care of me. Anywho, the rest of the setup goes as follows...


4/7 swap solid flat tappet cam (254/258 duration, .620/.630 lift after 1.6 rocker calculation on 108 LSA)
Forged Steel crank (undecided on brand)
Forged lightweight pistons (undecided on brand)
950 cfm 4150 carb
Victor Jr. intake (since the motor wont see much past 7.5k rpms)
Dual 3" exhaust w/cutouts, x pipe, and 2 Dynomax race mufflers w/2 dynomax bullets (yes I know, thats 4 mufflers) Its necessary if I want to drive the thing on the street.
TH-350 trans with all the good parts, including the big sprag. (already paid for)
TCI super street fighter converter, which on this motor will probably give about 4000 stall (already paid for)
GM 12 bolt rear end w/3.42 gears, built to the hilt obviously. I have the housing, but no parts as of yet.
Still undecided on brand/kind of tire, but I have the draglite wheels for the 28x12.50's going in the back.


Plus im putting the car on a small diet, taking out anything that isnt needed. Not sure if im going to put fiberglass fenders, but definately going with a fiberglass hood w/3" cowl (hope everything fits LoL). Then to top it all off a 150-200 shot of nitrous when it goes to the track. Im not sure what 3.42's with 28" of tire equals out to, but it should make it a lot easier to keep the power down. And with plenty of converter and a light car it should compliment the combination quite nicely, while keeping the cruise RPM's down. Hoping to have it to the track by August, September at the very latest.

Car should weigh about 3000 lbs when its all said and done. That, combined with a motor that should build at least 600 hp (plus whatever amount of nitrous I run) should make for one mean machine. I will keep you all posted, and feel free to comment or suggest anything you feel might help me out. Thanks all


Mike


By the way, I'm well aware that im going to end up breaking the block. Its the weak link of the whole car, but cant afford another $2k for a race block just yet. I will get some pictures up soon for you all to check out.

 

[Dirt Reynolds]

Hey Mike -- looks like an awesome combo you have there. You may want to recalculate your net valve lift, as thats a lot of lift for an FT solid of those cam specs and a 1.6 rocker. Remember to deduct for lash.

As to breaking the block, you might or you might not. If you do a Hard Blok street-fill you should be okay for the 600 HP range and then some. I have a fresh 408" combo based a lot on Doug's (Rustbucket) old solid cam 600 HP 408" combo, and I have a street fill of Hard Blok (up the bottoms of the freeze plugs) in a 509 block.

Once you got it all together and running, you may want to install an 8-point cage for those 10-second runs. Yer gonna love the 400!

 

[lluciano77]

I don't know if you bought the cam yet, but if it is a lot more expensive don't do it. The 4/7 swap is way overrated. I had a Ford 302 that I put a 5.0 cam in. That is the same as the 4/7 Chevy swap difference. There is nothing to be had by the swap. You can put your money somewhere better believe me.

As far as the 3.42s go, I have a TH350 and 3.42s and 26" tires. My highway cruise is about at 3,200 RPMs. I actually didn't see much difference from going 2.73s to 3.42s off the line. But I also have mad grips of torque too.

 

[rustbucket79]

The weak link there is the torque converter, it won't handle the nitrous and will end up taking out the thrust on the crank. (ballooning) Also, the gearing and tire size is all wrong for drag racing, and will hamper any decent 60' time and will also overwork the engine, trans and converter due to insufficient multiplication, also having you cross the finish line at a low RPM. The heads and intake are a good match, but don't expect any power at 7500, try closer to between 6000 and 6500, which is just as well since the 400's strong point is torque over a broad range instead of just peak power.
Your car will be quick regardless, but with some fine tuning of components it will be even quicker. Best of luck to you!

 

[Dirt Reynolds]

lluciano77 has a point -- David Reher says he found no power on the dyno running a 4/7 swap cam in a small block Chevy. The only engine he says he has found any sort of power from that swap is the big block Chevrolet.

I forgot about the converter aspect. As Doug mentions, this is a VERY important piece with the 400. My old 413 had several track passes and some street miles on it when we pulled it out. The thrust bearing was worn to the copper. The converter was way out of its league -- a B&M Torkmaster 2800-3000 stall, which did not have anti-balooning plates. With a 400 in any sort of a performance build, I would highly recommend you get a converter with front and rear anti-ballooning plates. My new converter is a 3600 stall B&M Nitrous Holeshot. It has front and rear A-B plates, roller bearings throughout etc. I dont have nitrous (at least not yet ) but I bought this converter because it has all the features I needed at a good price. I did not want to have a thrust bearing issue with my new 408 caused by a cheap converter.

 

[bananahammock]

Hey Mike -- looks like an awesome combo you have there. You may want to recalculate your net valve lift, as thats a lot of lift for an FT solid of those cam specs and a 1.6 rocker. Remember to deduct for lash.

As to breaking the block, you might or you might not. If you do a Hard Blok street-fill you should be okay for the 600 HP range and then some. I have a fresh 408" combo based a lot on Doug's (Rustbucket) old solid cam 600 HP 408" combo, and I have a street fill of Hard Blok (up the bottoms of the freeze plugs) in a 509 block.

Once you got it all together and running, you may want to install an 8-point cage for those 10-second runs. Yer gonna love the 400!

The cam I will be using is a custom grind, adding about .030" extra lift. Of course, what I said prior was before lash so deduct .019" for that so it nearly equals out in the end. And im not worried about the miniscule gains of the 4-7 swap, its custom grind and im still only paying $175 whether I want it or not. And thanks for the suggestion Dirt on the block fill, if its going to have a chance at saving the block I just might have to do that

Gearing - I know this car needs 3.73's + to be "right, but I really want to do what I can to tame the beast. The way I figure it is that its a light enough car with plenty of converter to compensate. And in all reality its still going to be a "street car", just a really fast one. Who knows maybe I should just throw some 3.73's in it and call it a day, its not going to hook anyway LoL.

Converter - I stress about this one, really I do. Truth is that I bought this converter when my 78 was still going and would like to reuse the near $500 converter that only has about 1000 miles on it. A buddy of mine had the same converter in his 65 Elky on a 406 thats probably nastier than the one im building, plus nitrous and prolly 400 lbs heavier. Whether or not he has great luck with cars not blowing up (which he does, this guy ran I-beams in that 406...) the converter never failed. I can only hope for similar results.



Thanks for all the positive comments and suggestions everyone, keep em coming!

 

[hardline_42]

That sounds like a wicked build! My 406 build is a bit more mild since it's strictly a street motor, so I'm going with regular Vortecs. I'm assuming the 371 Vortecs are the Bowtie Vortecs. There's not a lot of first hand info on these heads so make sure to post up your results on their performance when you get to it. Flow numbers would be great too!

 

[bananahammock]

That sounds like a wicked build! My 406 build is a bit more mild since it's strictly a street motor, so I'm going with regular Vortecs. I'm assuming the 371 Vortecs are the Bowtie Vortecs. There's not a lot of first hand info on these heads so make sure to post up your results on their performance when you get to it. Flow numbers would be great too!

Yes the 371 castings are the big port Bowtie Vortec's (the big daddy's as I like to call em). And I will post all results, especially the flow numbers!

 

[ZS10]

Get a plated converter.