is anyone out there running a supercharger on a TPI/HSR ZZ4 shortblock??? i'm thinkin bout doin this and would like to know how the ZZ4 shortblock handles the boost. also if u would please share the rest of ur set up with me ie cam heads compression ratio and HP/TQ numbers
thanx harold

 

Some have done it BUT detonation will destroy your engine. You need to be on your game when tuning and stay below 450 HP with those parts.

 

why do u say that what's so weak on a zz4?? it has a forged crank and hypereutectic pistons?? do i really need a fully forged engine to suport 400 blown WRHP???

 

hypereutectic pistons are only rated around 450hp. Detonantion will crack one.
it also has PM rods I really don't know there rating but you might want to check

 

no, it has powdermetal rods, hyper pistons and a cast steel crank...

400rwhp is gonna be pushing it to its limits... keep the rpms down!

 

Detonation breaks/burns pistons, RPM breaks rods. Boost actually somewhat lessens the overall load on the rods (especially when you consider that you can make the same power at much lower rpms). If you keep your RPM reasonable (say 6K or less) and are pretty religious about staying out of detonation, then you can run a lot of power/boost through that engine (more like the 700hp or so range) before you start breaking things “just because…”

OTOH, the first time you screw up pushing real power through those parts you’ll know what it’s like to carry your engine home in a bucket.

 

there is a lot of information contained in this forum about blowers and cast pistons.

 

you = crack = bad.

zz4 has a steel forged crank

and like everyone said,it detonates,and your going to be doing a rebuild,very easy to crack,explode one of those pistons under boost. get the tuning dead spot on before you start hammering on it.

 

It would be sooo easy to get some gaskets, some forged pistons, and some rings. Have those forged pistons pressed on and have the rotating stuff balanced. Your bearings likely won't even warrant replacement. It would also give you a chance to put a hotter roller cam in.

 

don't forget your ZZ4 is 10:1 compression


cast pistons + too much compression + too much boost = too bad

play again?

please insert $3,698.23

 

There are several people running ZZ4 motors with an SC on top...

 

keep fuel quality up and boost levels and timing down and it can happen. still not recommended.

 

zz4 and the zz3 had what is refered to as a 1053 steel crank... it is NOT a forged crank, it is just made of a better quality steel than the normal cast cranks...

 

I prefer to call them a "factory steel" crank. The block and rods are what really seems to make this motor. If GM would simply go the extra mile to make a crate shortblock identical to this with TRW or SRP forged pistons they could probably bail out their nearly bankrupt auto sales divisions.

It really makes sense, since they have a business relationship for pistons with both companies. All of the 60-70's 350 LT1 carb motors, High powered 327's, the 302's and the "L" series high performance bigblocks had TRW's from the factory. Some of the 502 and 454 crate motors have JE pistons. It is a "makes dollar and sense" kind of idea which is very past due. People have told me the L2256F piston has a similar compression and is even the same weight as most GM cast pistons. I guess it is a common thing to replace (without even rebalancing!) the pistons in a ZZ4 (and others) shortblocks with the L2256F-STD pistons.

Offering this shortblock in the $1500-1800 range ($150-$400 more than the cast piston engines) "No Warranty" would result in a huge sales success.

If they did this, and added maybe an upgraded rod bolt and better quality control and balancing, you would have a basis for a 9-10 second shortblock which would be replacable for sportsman racers. The rods would become the new weak link in these motors, I have seen these new factory powdered metal rods twist into pretzels without breaking. So its not much of a weak link.

As far as these 1053 cranks go, properly prepped, I have seen them reving to 8500 in 327's, 355's and 377's and making 850 hp in blown alcohol dragsters.

 

never had so much of a peep out of the 1053 in the race 350 circle track motor... 7200rpm motor... spinning between 5 and 7 the whole track....

 

factory steel cranks are very big among those cost conscious in the sportsman circle track world.

 

for sure! thats all we ever ran

 

I always liked seeing the stock 396 and 454 "L"-series in old stock novas and chevelles running 10's on a 150 superpowershot at the track with thier factory forged cranks and factory forged pistons.

 

I just replaced my 305 with a zz4 crate engine and was thinking about installing a super charger at some point. now that I have heard of the dangers of doing this I'm not sure whether or not to take the risk of possibly damaging the engine. there are other ways to make more power, such as porting the heads which isn't all that costly.

 

Can you explain this in a bit more detail?

 

Amen to that, Tom! I've been thinking that for a LONG time. Espeically now that I just blew a few ringlands to pieces on my supercharged 383 that used Keith Black hypereutectics!

Mind you, I got 2 years out of this combo (mild roots blower application with a carb), but even at 8.7:1 compression with aluminum heads it's too "touchy" with detontion. Like tuning on a knife edge- the difference between 26* advance and 28* advance is the difference between a long life and time for the next rebuild.

And yes, it was definitely detonation that caused the damage. Not the slow creeping kind, either. The kind where the motor lets go a fraction of a second after it starts. Blower motors are unforgiving of that sort of stuff. Not anything like tuning a high compression N/A engine.

Side note- a ZZ-4 SHORTBLOCK with 76cc heads on top and a .028" GMPP head gasket would yield MUCH lower compression than with the aluminum 'Vette heads it comes with (58cc). Compression would drop down in the low 8s.

 

I may be wrong, so 83 Crossfire TA will have to correct me here, but I believe it's a combination of more power at lower RPMs mixed with the fact that compressive loads on the rods aren't a big deal typically.

 

Aftermarket heads for $2k or so would probably get you 50-100hp

Plus you can sell your ZZ4 heads afterwards

 

yeah there are lots of buyers for those heads. Those L98/ZZ4 heads go for $400-650 on ebay.

Those new and improved large and small port GM irons based on the L31 vortec head look might nice, and they are going to be cheap.

Swapping the cam to the hot cam and 1.6 rockers is a popular normally asperated power gaining move for ZZ4 owners.

ZZ4 + new large port GM vortec irons + hot cam or better (like comp or lunati) = 500 plus hp?

I know going from aluminums to irons seems like a crazy move but in this case the benefit in cost and power would outweigh the consequence in weight (no pun intended).

 

Just wondering about the switch to cast .... in a blown setup aren't you looking for ANY method to reduce the POSSIBILITY of detonation ? Wouldn't the addition of a cast head in his setup ....increase the chance of detonation ?

 

The iron heads will increase the possibility of detonation, but there are other factors to take into consideration in the overall choice such as chamber design, quench, etc...If he's willing to run lower boost or higher octane rated fuels, etc...it's cool.