I have a zz4 engine I bought from my next door neighbor . He is a drag racer and builds motors all the time . Well , as I was going over my engine , I noticed the arrows on the pistons that are supposed to point to the front of the engine are pointed to the rear of the engine . He says he does that all the time , and that it will work fine . I dont believe him . Sounds like I gotta tear it back down again and fix it ........ What do you guys think ?

Thanks again for all your help ,

Joe

 

yep you need to have the arrows facing forward, no matter if "it'll work" or he's "done it all the time"

 

Yeah, I believe I'd put it together right; unless he's planning on warrantying the motor for you if there's problems.

Make sure the pistons are hung on the rods correctly. If you set all 8 of them on the table with their notch pointing up, as if you were looking at them from the front of the motor, you should have 4 of them with their rods oriented such that the bearing tangs are on the left, which will be the even-number cyl bank assemblies; and 4 with the bearing tangs pointing to the right, which will be the odd-number cyl bank assemblies. The side of the rod opposite the bearing tangs should go in the motor next to the cam (the "inner" side).

 

If he is stupid enough to put the pistons in wrong , it makes me really worry about his motor building skills . If I take it all apart and the only thing wrong is the piston direction , do I need to re-check all the bearing and ring clearances ? I am wondering if he did the same with the rods .....

 

Well before you go kill the guy on some pistons it doesent really matter as long as the rods are correct but if there pointing a certain direction its best to point them in that direction.

 

I dont understand what you are trying to say SSC . Please explain a little more . Yeah I am P.O.'d to say the least . First it was the cam , the guy didnt even put the thrust plate back on ,and the timing chain wouldn't work with the zz4 cam , it would only work with the aftermarket cam that I pulled out of it . It all adds up to me being screwed by my neighbor , which sucks pretty bad . You think you can trust someone who lives two houses down from you . I have more trust now for the guy I bought my tranny from and he lives 12 hours away from me . Oh well live and learn I guess . This will be the first and last motor I will ever buy . The next time I will go buy a core and go get it rebuilt .

Thanks ,

Joe

 

I can't tell you what you "should" do; but I know what I would do if it happened to me.

This is yet another example of why I build my own motors.

I don't know that he's "stupid"; maybe lazy or careless though. Alot of people don't pay much attention to detail. And of course, the difference between a long-lasting, smooth-running, trouble-free, leak-free engine and a smoking, leaking, short-lived POS is nothing but attention to detail. This guy sounds like some of the people on this board that put together motor after motor, and every one of them explodes some way or other within a couple of hundred miles, if they even ever work at all; yet they don't seem to learn from their misfortunes. Kind of makes you wonder how the factory can put them together and 999 out of 1000 start right up and run for the life of the vehicle; some people would be lucky to get one out of 100 of theirs to do that.

It definitely matters which way the pistons go in. Most pistons are made with the pin slightly offset to one side, on account of the motor's rotation. And it absolutely matters which way the rods go; depending on what bearings you have and how the crank is ground, the motor might not even turn at all if a rod is in backwards.

 

Yeah I just got off the phone with Steve Ashworth ( a well known motor guy around these parts ) and he told me the same thing RB . I believe I am going to take the motor to him and let him sort it out this weekend . I only want to put this motor in once . Nothing sucks more than to have to do it twice back to back .

 

Amen brother! Testify!

 

Some NVR flat top pistons can go in either direction. Usually you will have an arrow or an indention indicating direction if so you want them in that direction. I had one kit that came like this, no name brand, called my machine shop up worried about it, ect.... Put it togather and it ran great, infact seen the truck going down the HWY today about 30 over the limit.

People who race arent always choice for building an engine as in your case. We get sevral calls a week from people who's buddy who races built them an engine now it smokes, leaks or just stoped running. Not just any engine a 400hp engine, always seems there "400hp high performance" engines.