I rebuilt my ZZ4 2 years. Did lots of reading and getting new parts lined up for the build. The timing gears and chain are very beefy single gear. I believe a double roller and gears are to wide for the stock cover. The stock cover also has a 1 piece seal for the oil pan. Was reading about alot of people having trouble with oil leaks at the pan using other than the stock covers. I went with a new stock plastic cover and new stock chain and gears. Figured the guys at GM performance know alot more about building that block than I do. Everything fit perfect and havent had a drip of oil in 2500 miles.
HELP Need opinions.....head gasket
- Thread starter 83StreetMachine
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Have those heads resurfaced!
My bet is that's why they are leaking.
Dorman makes a replacement cover https://www.dormanproducts.com/p-8023-635-505.aspx?origin=keyword
My bet is that's why they are leaking.
Dorman makes a replacement cover https://www.dormanproducts.com/p-8023-635-505.aspx?origin=keyword
The ZZ4 was made from 1996 to 2014. Be advised that the stock composite timing cover cannot be used with the "short" water pump because the cover bolts hit the back of the pump. Also, I'm not positive but I don't think the head gasket is the correct one for the engine. I don't ever remember seeing a hole in the gasket that has a stamped hole protruding past the inside edge of the block. Good luck.
So I got curious and looked up a stock zz4 head gasket and there is a hole right where that one is. There also looks to be a water hole right next to the hole you can see. It is highly possible that the seal around that water hole is leaking. I would absolutely pull the motor down enough to check it all out but first, just to see, I would check the torque on the (both) heads to see if it stops the leak.
Thanks for the input guys!
I finally had the time and the weather to get the heads torn down.
I was wasn't disappointed with what I found, TRW flattop Pistons with Felpro 1003 head gaskets. So with the 58cc heads, flattops with 4 valve reliefs and this .041 gasket, definitely has higher CR than I thought.
So this above was the area I was questioning. Still hard to say but I don't think it was the head gasket leaking. Possibly the intake gasket....
Anyway, I'm going to go a little further and pull the cam to hopefully find a grind number on it since it's currently unknown.
I already pulled the pan and timing cover. Melling hv pump with arp shaft. Pickup has been welded to pump.
Single roller GM timing chain and gears look brand new. The plastic timing cover definitely needs to be replaced.
I would like suggestions on replacing it. Another plastic one? Holley makes a cast aluminum version of it. On the zz4 the 10 and 2 o'clock timing bolt holes arent used and are therefore untapped. And there are no 1/4" dowel pins in the block, they are apart of the cover.
Thanks guys
I finally had the time and the weather to get the heads torn down.
I was wasn't disappointed with what I found, TRW flattop Pistons with Felpro 1003 head gaskets. So with the 58cc heads, flattops with 4 valve reliefs and this .041 gasket, definitely has higher CR than I thought.
So this above was the area I was questioning. Still hard to say but I don't think it was the head gasket leaking. Possibly the intake gasket....
Anyway, I'm going to go a little further and pull the cam to hopefully find a grind number on it since it's currently unknown.
I already pulled the pan and timing cover. Melling hv pump with arp shaft. Pickup has been welded to pump.
Single roller GM timing chain and gears look brand new. The plastic timing cover definitely needs to be replaced.
I would like suggestions on replacing it. Another plastic one? Holley makes a cast aluminum version of it. On the zz4 the 10 and 2 o'clock timing bolt holes arent used and are therefore untapped. And there are no 1/4" dowel pins in the block, they are apart of the cover.
Thanks guys
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