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Chevy ZZ4 350

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duckluv26

Well-known member
i'm swithcing from a 200 lycoming to a car engine. i plan to put the ZZ4 on my 13 X 8 Diamondback with a belt reduction and powershift prop. does anyone know anything about the performance of the ZZ4? any info would be appreciated
 
duckluv26,

My new boat! 1st ZZ4 350 engine blew-up with 11.9 hours on it! (almost sunk the boat as we were in deep water on a plane when it happened. Really, it sounded like a NASCAR engine when they blow! Flames, rods through the oil pan and everything!).

2nd ZZ4 engine ran like a raped ape but just would not push the boat across dry ground even with several prop configurations. The 14 X 8 boat with long belt reduction and the 454 performs as expected now with a much better warranty,(one year on the 454, 30 days on the ZZ4 crate engine).

Good luck with the ZZ4 and I would like to know how well you are satisfied with the longevity of the engine?!

Jeff
 
owww!!! not what i wanted to hear. did you have a belt reduction on it? polymer bottom? what kind of hull was it on? maybe i should just invest a little more and get the 454!!! thanks for the info........anybody else have any feedback?
 
welcome to the forum duck luv pm waterthunder he is in the keys now so it might take a few days for him to get back with you he builds a bad *ss aluminum block 450 & 550 hp small block with a rotator box this combination will be 100s of LBS lighter with more HP and he can tell you which power shift prop will work best . check out the monthly ride thread for next weekend in kissimmie he will be there with the 550 HP I got to hear it run last week on his new boat thats almost done and it sounds very ,very impressive this combination will be lighter, faster and cost less
 
duckluv26,

Yes, long belt drive, (2.3 then 2.0 reduction> 14 X 8 aluminum hull with 1/4" polymer. I really believe that my incident was an isolated experience. The best news is that Diamondback stands behind their product 110%!

I'm partial to Fords anyway so please don't listen to me!!!

Jeff
 
Duc - Those ZZ4 are fairly good motors. Watch the temperature and watch the oil pressure. There are some good threads if you look through older posts about ZZ4s. Keep the radiator clean and make sure she is always running near normal temperature. Most should run around 150 -160, I realize that you truck may be running 180-190, but it doesn't have aluminum heads and probably is not getting turned up nearly has fast.

I know of several 13 & 14 footers with ZZ4 in them, with reduction drive and polymer on the bottom, they run dry fairly well. Mostly depends on the hull.

Whatever you do, don't get that motor up above 190 - 200 or you might be replacing the heads. The walls are thinner than the ZZ3 and she will warp easier than the older ZZ3. Most of this you will find in older posts, and I advise you to look it up to read for yourself.

I wouldn't turn her over 5100, and most I know have the prop pitched to turn about 4900. But that is my opinion.

Good luck and enjoy
 
Dont know alot about how long the zz4 will run but have had mine for about six months and have had no problems I built the motor using a set of gm performance fast burn heads from Jeggs so it is not a crate motor I am running a 2.3 to 1 reduction belt drive with a 80 inch three blade sensenich prop and am turning motor at about 5100 rpms on a 16 ft alumitech boat and seems to run very well Copperhead
 
I would strongly recommend the Iron head Vortec 350 it’s a great motor. Any crate motor from G.M. with aluminum heads is a piece of crap. G.M.’s aluminum head castings are way too thin. Rick the site administrator maybe able to pull up a few of my threads discussing these issues with ZZ-4 motors. My opinion is the ZZ-4 motor is not a good choice for an airboat besides that the Vortec is cheaper and much more reliable. Some people have had like good luck with the ZZ-4 but every Vortec 350 I know that has been put on an airboat is still running. Some with over 1,000 hours, I have yet to see that kind of reliability out of (any) other motor plus their under $4,500 for a bran new one.
 
waterthunder,

should i just buy the crate motor....350 330 hp w/iron vortec heads. if so, what kind of performance should i expect on a 13 X 8 diamondback, 1/4 polymer, belt reduction and power shift? this motor would have better longevity than the ZZ4? thanks.......
 
Duckluve26

I have a 14x7.5 Dimondback with a ZZ4 and a belt drive and polymer and it has about 80 hrs on it and it runs fantastic it is putting out about 425 hp thanks to Waterthunders advice and I have had 0 problems and it will run dry ground all day and I have done it with five people in the boat but I agree with what has been said keep the temp around 170 and the RPM
not over 5200 mine turns 5100 with a two blade power shift prop I also don't run the hell out of the boat either I just use the power when I need it.but what ever you do I would listen to WaterThunders advice because its all ways good, he the man when it come to car motors.
 
I have a 15x8 diamond back with a zz4 polymer powertec I hit 220 hours yesterday and not a probelm that I know of yet. I know early on the boat busted 2 flywheels but now there is a racing flywheel on it and have had no probs.
 
The ZZ-4 is a good motor but once you get them hot it's all down hill from there. They run what I call disposable heads you never want to deck or repair them just get rid of them and put on a set of aftermarket heads. The Vortec with iron heads is as reliable as it gets. If you want a little more power and you can work on car motors install a set of 1.6 ratio Crane roller rockers and install a curve kit in the distributor. Run the weakest springs in the kit and set your total timing to 32 degrees. If you are a little more experienced with motors buy the long block and install a Edelbrock RPM airgap intake if your concerned about fuel economy install a 750CFM vacuum secondary Demon (also install the lower vacuum secondary spring) or if you want the most performance install a 750 mechanical secondary Demon carb. The only thing you have that I don’t like is the belt drive they are heavy, don’t come in the higher ratios and torque roll the boat more but they are very reliable. Have you already purchased your prop? Thanks for the complement Sniper I have heard from several different people that your boat run’s very strong.
 
waterthunder,
i have a bachelor's in biology and you just lost me there!!! my buddy is a mechanic and i'll get him to translate for me. i really would rather spend money on a better motor than have to work on it. with this hull, would a 383 stroker be better? i have not purchased the prop or reduction unit yet. i've heard the stinger gearboxes are not as reliable as belt units but i don't know. i want enough hp so i can put a 3 blade prop on it. i'd like to get your number so i could call you and get more info from you if you don't mind.
 
duckluv26

My advice to you if you have not purchased a motor yet is to buy one of waterthunders all aluminum motors if I had to do it over again thats what I would have done but I did not know about his motors or this web site when I bought my boat ,I have learned a lot in a year so if you have a few extra bucks I would get one you would have a lot of power and a whole lot less weight.
 
Waterthunder is right about the torque from a belt unit. The motor, the belt, the prop, and the belt gears all turn the same way. On some boats you can start stomping on & off the throttle and the boat starts rocking like crazy. Especially with the 7 and 7.5 foot wide hulls. Was in a Panther that was 13 X 7 and we STUPIDLY put the BIG guy (300+) on the torque side on a really windy day. Going down a shallow bayou and hit a bend with a deep spot as the bayou twisted to the left. Wind from the left and big man on the right side and that side just kept dipping lower and lower and water can in and the driver beached it.

The only plus I can say about belt drives is that 95% of the oil field seismic boats are running them and they get abused badly, but hold up.
 
Marshmaster Pat,

Excuse the ignorance..

So if the engine rotation is clockwise, the torque curve is clockwise?

And the "big guy" shou set on the left side of the boat to compensate?

Thanks so much for your never ending expert advise!

Jeff
 
I believe it works like ... for every action there is an equal but opposite re-action so the torque roll is opposite the rotation so in a belt drive all rotation is same direction = lots of torque roll. In a gear box the prop rotates opposite the engine rotation so torque roll is less or at least partially compensated for. it should only take a second just hit the gas once and you know where the big guy should be sittin.
 
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