Turbocharged Z22S?

[Ratrod720]

So I am think about turbocharging a Z22. Has anyone ever done this before? I don't think using the stock pistons would be a good idea. If i can find some forged ones that would be ideal but DNJ makes good cast pistons that should work okay. Has anyone ever done this and how did it go? Any input is welcome. Thank you!

[datzenmike]

Cast? Cast aluminum like forged, or cast hypereutectic? Stock hypereutectic pistons are fine at 7-8 PSI. Will survive a very quick buss to 10 PSI, but I wouldn't hold it there. If starting from scratch open up the ring end gap, this will give them more room to expand from the extreme heat produced. If they touch they can't expand any farther and will break and or break the ring walls. Going double digit boost is a whole 'nother ball game. Really expensive to do it right if you want the engine to last more than the summer.

 

I imagine this will be a blow through set up? 

[Ratrod720]

16 hours ago, datzenmike said:

Cast? Cast aluminum like forged, or cast hypereutectic? Stock hypereutectic pistons are fine at 7-8 PSI. Will survive a very quick buss to 10 PSI, but I wouldn't hold it there. If starting from scratch open up the ring end gap, this will give them more room to expand from the extreme heat produced. If they touch they can't expand any farther and will break and or break the ring walls. Going double digit boost is a whole 'nother ball game. Really expensive to do it right if you want the engine to last more than the summer.

 

I imagine this will be a blow through set up? 

Yeah I was imaging it would be a blow through. I was hoping to get double digit boost. Money is not a problem and I don't have a problem putting all new internals in it. I dunno. I got plenty of time to think about it. I am also wanting to run twin carburetors. That could get complicated. The 1982 Lotus Esprit Turbo was 2x carb so that is helpful. Thanks for the information!

[Stoffregen Motorsports]

Z22 is not a great motor. The block and crank are great for using to build a hybrid LZ2300, but that's a custom build, using custom pistons and an L head.

 

Turboing any motor sounds awesome at first, but trust me, to get it dialed, it takes time and money.

 

For double digit boost, it would be wise to use forged pistons and a tough ring pack for the boost. Maybe even o-ring the block and/or, use a layered steel head gasket.

[datzenmike]

Side drafts would be nice, gets rid of the 90 degree bend of the down draft and multi carbs would flow more and be less restrictive.

 

HEAT is the enemy of turbo engines. It's what allows diesels to operate without ignition. On a gas engine it's deadly.

1/ As the Z series are cross flow an inter cooler should be considered. Removes heat cools and condenses the air.

2/ An oil cooler. There are any amount of filter adapters that have outlets for a cooler. I bought 10 feet of 200 PSI hydraulic hose and a wrecker Ford F350 transmission cooler. Hose and cooler less than $50. Oil draws away excess heat from pistons and internals where the coolant never reaches.

3/ Larger rad.

4/ Ceramic coatings for the piston tops and combustion chamber. Absorbs less heat to transfer to the cooling system. More heat to expand combustion gasses and push down on pistons doing more work. Increased efficiency. Do the outside of the exhaust turbine also. Reduce under hood temperatures.

5/ Turbo air definitely drawn from in front of the radiator. If you run 15 PSI that's double atmospheric so if it's 80F ambient this will double to 160F. So many times I see the air filter in the engine compartment. Hot air is less dense than cold air. See 1/ above.

6/ Look at a water/alcohol  injection under boost to cool the air through endothermic action. Heat is absorbed to vaporize the alcohol and water turns to steam cooling the combustion chamber.

 

Definitely forged pistons and O ring the block.

 

I would install a high volume oil pump from any KA engine from a D21 Hardbody. Top pressure is the same 55-60 PSI but it builds pressure much sooner at low revs. You will need oil for the turbo anyway.

 

Some kind of ignition timing retard under boost is needed.