Hey, I've had an idea for a great combination to make good streetable power. At my disposal is a GMPP ZZ3 350 CI Motor with less than 30,000 miles on it. I was going to swap it into my Z28 which currently has a 305 TPI. I was planning on taking the TPI setup off and putting it onto the ZZ350. (Seeing how 305 and 350 parts are interchangeable) I have talked to multiple reputable performance shops and all of them say it would be a great idea. It would pertain to the originality of the car (which I like) and give me massive amounts of torque, and still keep fuel injection. I'll have to get bigger injectors, was thinking something along the lines of either the 22lb or 28lb and of course it will all have to be tuned. But does anyone see a possibly problem with this swap that I haven't calculated? And do you think its a good idea?

 

I don't know the specs of the cam in the ZZ3 or what heads are on it, but as long as you are shooting for low-midrange power, it sounds like a great idea.

- Justin

 

Dont expect it to be a rev monster. It'll do good until 5500 RPM. It'll make good torque. You will definitely want to get an aftermarket intake and runners though. Then it'll make great torque! You'll give up 60 HP/60 ft.lb or more on the stock intake/runners, and you wont need 28 pound injectors, either, unless you upgrade those components. The biggest throttle body you'll probably ever need is the 52mm.

 

Sounds good to me since your looking for a torque motor.

What kind of heads are on it? If they are Vortec style you'll need a different manifold base.

 

Good thought on the runners and throttle body But yes I am only really looking for a torque monster. The ZZ3 comes stock with Aluminum heads, Im not sure if they are any particular style or not. I will have to look into that more. From what I've asked, and found out, my plenum will fit. I was told by a couple local reputable performance shops in my area that this swap sounds like a great idea for a street/block runner, and that i would be looking at a possible sacrifice of HP by about 15 horses, but a possible gain in Torque by about 50 to 80 ft/lbs due to the Tune Port design, which is what Im looking for

 

Ok, now let me give you some information, as I ran a ZZ4 heads/cam engine a few years ago. The ZZ3/ZZ4 camshaft is 208/221 duration at .050", has .474/.510" lift with 1.5 rockers, and 112 LSA. I was able to use it just fine with the stock program in the chip. The ZZ3/ZZ4 heads are the exact same castings as what came on the 87-91 TPI Corvettes. They have three major problems with them. One, the four middle intake bolt holes have the older style bolt pattern, so you will need an aftermarket TPI intake (Edelbrock is the cheapest, unless you buy used). They are NOT vortec style. You can reuse your '85 stock intake, but why choke it off like that? Upgrade if you can. Second, those heads have no EGR passages, and without EGR you will have a hard time passing the emissions test. What I did was use an aftermarket TPI intake and set up the EGR like the Corvettes did, with a pipe coming from the #8 header to the EGR port on the intake. You'll need headers for this as the f-body manifolds dont have the port, and the Corvette ones wont fit. Dyno Don over at thirdgen.org can make you headers that fit, he is my father and he made mine. I have posted pictures over there, you can search for them. Third, the front of the heads are missing a bolt hole for the serpentine accessory brackets. Since you have an '85 you should be ok with you v-belts. 22lbs injectors will be fine, any larger and you should get a custom tune.

My engine with a T5 trans made a best run of 13.23 @ 107.19, and put down 282 RWHP and 380 RWTQ.

 

Thanks, as of this year for my state, my Camaro will not have to go through Emissions Also, doesn't the aftermarket intakes cost a lot? Like in the 1-2 Grand range? I was hoping to make this a rather cheap biuld using mainly what I already had, but I will have to look into it. Plus I was hoping to fool everyone by making them think it is just a stock 350 TPI when its actually a ZZ motor making a lot more power. (most people wouldn't be able to tell) I was already going to put headers on the 350 once its out of the vehicle its currently in, making it a lot easier. And could you specify what you mean about the casting on the block for the intake setup? Why exactly won't it fit? Thank you.

 

You *can make the intake fit bu tyou need to enlongate the center mounting holes with a die grinder and a file. The reason is that the angle in which the center mounting bolts go into the heads is different to facilitate installation of the bolts. They are angled outwards to rotate the bolt face away from the intake manifold.

...and no, the intake is about $400 to $450. Runners you can get used for decent prices off thirdgen.org or ebay. Probably the same deal on the intake if you are patient.

 

Thanks a bunch. When I get some time I really look into the intakes that are available. Oh, and I did have one more question that I have forgotten to ask though. The ZZ3 motor currently has a carb setup on it. Think I would run into any problems/complications putting my TPI system on it other than what I've been told so far?

 

Sounds like a plan. The only other thing I can think of is simple.

Just make sure you get the runners with the cold start injector holes if you get them used.

 

Don't forget to swap over the sensors that are in the block before you install the motor. Knock, oil pressure, etc are a pita to get too once its installed.

22 or 24 lb injectors will work just fine.

 

Thanks for all the input. I had anticipated all of the sensors already. Oh and by the way. Will I need to get a bigger radiator at all? My cooling system right now is top notch, I have electric fans already on there, and my temp never even goes above 120. But, I ran out of time yesterday to visit some of the other performance shops in my area, but today I will be visiting them, and see if I can address some of the issues that were brought up, and maybe find and exploit some hidden problems. But in all of your opinions, does this little build idea of mine sound like a good idea? Especially for a budget?

 

torque!

 

Ok guys, I went around to a bunch of performance shops around the area. One is located right down the street, and I found him to be most knowledgeable, and had a good reputation, plus personal experience with many TPI and 3rd gen cars. And what i got out of it all is that the build is actually not that great of an idea. The TPI setup is just to restricted to make good power. On top fo that, I found somebody who actually did this with a ZZ4 motor. And has dyno and time slips. While the time slips came out nice, the Dyno only rated his ZZ4 TPI at about 285-310 AVG HP at the wheels. While those numbers are ok, its not the best considering it could have so much more. I think I might scrap this TPI idea, maybe still do this swap, but put on an aftermarket FI system of some type

 

I've heard good thing about the Accel Super Ram

http://www.goingfaster.com/spo/superram.html

I have the Scoggin Dickey intake with SLP runners. Here is an article that explains both: http://www.chevyhiperformance.com/te...ead/index.html