A close friend of our has a 72 chevelle with the zz4 crate motor, th350 (built with shift kit), 3.73 posi rear. We helped him install a set of Hooker Super Comp 1 5/8" headers has dual exhaust with H pipe. The car has 275x60x15 Comp TA radials. Made a couple of passes at HRP (Baytown) the best the car would run was a 15.22 @ 91 mph, of course it was spinning out of the hole (20 psi). He has a Demon 650 dual inlet single carb that is now on the car, he has a set of 1.6 rockers to put on the heads and changing over to 28x10.5 et streets. Don't know the weight of the car he has never weighed it, but has full interior. With the carb swap and 1.6 rockers installed what kind of times should the car run?

The motor did have the Edelbrock AVS 650 carb on it, think the carb was hindering the car up on the topend, and the car was left in drive as he had no tach.

I'd say easy 14s......possible low 14s/high 13s with proper engine/suspension tunning, slicks, and weight reduction. Good Luck!!! graemlins/thumbsup.gif

Thanks, the demon is already on the car, we still have to install the 1.6 rockers and install the et streets. Also next time out will disconnect or loosen the front sway bar.

His car is a fun weekend cruiser but he is trying to get it into the 13's, have recommended the "hot cam" setup to him and he is looking into that now.

Sweeeeeeeet graemlins/thumbsup.gif

ZZ4 heads use self aligning Rockers so make sure they are the right ones. You also better pay attention to coil bind and valve clearance on the exhaust side, as the 1.6 rockers will put exhaust lift at .544" The intake will be at .506 (stock .474I and .510E. If you have a timing light, take a look at where your timing is too. ZZ4's usually don't get the timing all in until 4500-5000 RPM, and have too much on the vacuum advance.

I don't know much about the ZZ4 but controlling the wheels off the line is key to getting out of the hole. Also, if this is automatic, what torque converter are you using? You need to find out what range your power peaks at and get the right torque converter to engage the engine with the tranny right at the sweet spot to get you out of the hole. B&M make some great ones! Sounds like it's right between 4500 and 5000RPM, but like I said I don't know much about this ZZ4. But sounds like you have plenty of power off the line already, just need to control those tires to get rolling first for good times. Also, the 2nd part to this mystery is after getting out of the hole... timing is a main issue like ZZ69 mentioned, but also take a look at the little things holding back your ET. Roller rockers really improve your top end performance and also the type of ignition you have. Electric fans free up a good few ponies and take a look at your cooling for top performace. With high end torque converters, you'll want to put an extra tranny cooler on to keep your temp down becuase those torque converters can heat up your ATF pretty good. Horse Power really has to be earned for good ET. Seems like all these little rice burners claiming they have horse power these days think that everything is glue on. Let everyone know how it goes! Good luck! graemlins/thumbsup.gif

Yes the 1.6's that he bought are the self aligning rockers. The converter is a 2500 stahl 11", the tranny has a shift kit and a tranny cooler is going to be installed as well. The 2 passes made we did not check the timing or nothing he drove it into the track, I jumped in and made 2 passes back to back (left lane & right lane). The car made the 15.22 pass which was the second pass, the first pass was a 15.26 at 91 mph.

We will check the timing and also look at coil bind, thanks for the advice guys. This board is just overwelming on help and advise. Right now the car has the HEI that came with the motor, think he needs to change over to a MSD distributor and coil and play with the springs that come with it.

Oh the tranny did short shift into high gear (way to soon), it was shifting at about 5000 1 2 shift(that is what the tranny guy set it up for, but he has to look at the 2 3 shift now) and shifted at about 3000 on the 2 3 shift so the tranny guy will look at the transmission again.

Thanks guys for the help.

It should run a bunch quicker when you get it sorted out. My 66 Elky driver (350/350, 280 hp, 3.36 gears, open diff, 255/60/15 BFG TA radials, exhaust manifolds, with no prep at all) ran 15.05 @ 95 mph at part throttle (carpet and heavy return spring fooled me, probably would have run 14.9's). The ZZ4 engine should do much better. I recommend putting the 1.6 rockers on the intakes only. Most engines make more power that way.

My trans (in drive) shifts at 5500 for both shifts. I'd get your buddy's setup for 5500-6000 rpm shifts. The early shifts are hurting him.

Recurving the distributor will help a bunch. Get it setup so you can have 14-16º initial and 36-38º total all in by 3000 rpm.

Not knowing the weight I think your about 8-10 mph off what you should be running right now. My dad's 57 has ZZ4, 750 edelbrock carb, shorty 1 3/4" headers, stock stall 700R4 with 3.25 rear. Traps in the 98-100 range on average with a best mph of 102. 91mph is way too low for that engine striaght out of the crate. I would look into tuning what you have before buying parts. Also are those hookers D port shape flange? I believe the zz4 heads have a D port.

Yes the Headers are the D port style. He took the AVS carb off, has the Demon already mounted just rerouting his fuel line now. He has mounted a 4 hole phenolic 1" spacer under the demon carb. Will check the timing before the car goes out. Printed out this thread and gave it to him, some good information here thanks for all the help and advice. Will let you guys know how the car does. He got a killer deal on the Nitto Drag radials so we will play with those and see how they work. Have not heard anything bad about them and seen some cars at our local track hooking hard with them.

Originally posted by NickThaP:
A close friend of our has a 72 chevelle with the zz4 crate motor, Hooker Super Comp 1 5/8" headers Nick,

Sorry for hijack, can you find out the P/N for the headers he's running? AND do you have reasonable access to the plugs? I have exactly the same setup, minus the Hooker headers, and getting to the plugs to tighten them is darn near immpossible. The Super Comps I have found all indicate they won't work with angle plug heads.

Thanks,

ttt

Right now I have Dynomax shorties on my ZZ4, and I also have a pair of Hedman full length headers that work well with the angle plug heads. I wouldn't wory too much about the D ports as an issue. The header tube is larger than the port, and they seal fine.

Tim,
The headers are 1 3/4" tubes so I stand corrected. The owner contacted Hooker about the Super Comp Series they gave him a number and he contacted Jegs and got them through Jegs (he is looking up the number, will post it when he gets it).

As to getting to the plugs, the easiest way to get to them is to remove the front tires and go in through the wheel well. It is pretty much a straight shot. He also put the high temp spark plug boots on cylinders 6,8 & 5,7. These headers fit great and do not hang down at all. Hope this helps sorry for not getting back sooner.

The Demon carb is on it now and he has installed the Nitto Drag radials, will play with the timing and carb and we may try it again this coming weekend.

Nick,

Thanks for the info. I want to stay with the smaller tubes, so I am thinking Hedman. If anyone reading this has a better choice that is NOT a shorty, please chime in here. These old BlackJacks are a total pain.