Problems with the ZZ3 crate engines???

[Steve1968LS2]

A friend of mine recently picked up a used one and is going to go through it. He seems to remember that the ZZ3 crate engines from GM had some sort of inherent problem (valvetrain?)

Anyways, he wants to address it durring the rebuild.

Anyone hear of a problem with those crate engines??

Thanks!

[BobB66SS]

I've got one in the '38 Chevy street rod my dad first built about 10-12 years ago. He even put it on a 1/8 mile track most weekends for about 4-5 years before buying a different car to race. Car ran great then and runs great now, no issues. It did get gone over each winter just to make sure nothing got hurt from racing it, everything was fine each time. Neither he or I were aware of any inherent issues with the ZZ3, anything particular I should keep an eye out for now that I own the car?

[GeoffP]

I remember the issue being with the earlier ZZ series engines. I thought the ZZ3 and ZZ4 had the corrections. I don't remember what the issue was though.

GeoffP

[kwhizz]

The Early ZZZ engines had a lot of Piston Noise......when they were cold they sounded like Diesels......even after warming up these were still on the noisy side.............As I remember they changed the Pin location as the originals were offset, or something like that........

Ken

[tiznodd]

Of the only two I've seen, both had piston slap. One was the original ZZZ and the other was a ZZ3 that I had in my IROC. It was pretty bad with the ZZ3 I had and the noise was still audible even after it was up to temperature.

[zzamjam]

I to have a ZZ3 low milage and there is something very wrong with valve train.
What did you need to do?

[camcojb]

I to have a ZZ3 low milage and there is something very wrong with valve train.
What did you need to do?
Being that this thread is seven years old I'd recommend starting a new one with your question in the engine forum.

[mnm99]

I bought the crate 290 hp and started blowing blue smoke after 200 miles. I brought it back to the dealer where I bought it. That's the main reason I bought it from the dealer instead of Jegs ect.. They fixed it right away. It ended up being the valve seals. 6 of them were crushed because the weren't pressed in enough. It was all good since then. Built in EL MEHECO....