What happens when your parts bin math is off?

MNFatz · Post by **MNFatz** » Sun Sep 03, 2006 10:24 pm

This:

http://www.fiero.com/forum/Forum2/HTML/076528.html

I feel really bad for this guy. Alot of money down the tubes. I'm not sure what he did, but I have a feeling he might have upped the rocker ratio. There's not any mention of a new came or heads.

donk_316 · Post by **donk_316** » Sun Sep 03, 2006 10:46 pm

oops! :thumbleft:
For people like me who feel dirty clicking a link to that site:

Well last week will out on a test drive, there was a small noise from the engine area sort of a rotating type sound and then it stopped. Luckily I was not far from home, the engine would not start, seemed to be locked up, anyway I got the car home via a AAA flatbed. This weekend I pulled the engine to see what was going on, taking the engine out a 2nd time is certainly easier, anway the trans seemed fine, rotated with no noises or any apparent issues. So it must be the engine, see the pictures below of the engine and my new Voretc heads !!!!
In the engine pic you may be able to see the head of 1 of the inlet valves, just below the big hole in the piston !!
I had been having a problem with the engine not wanting to rev much past 3000rpm, I noticed that all the pistons had marks from where the inlet valves had been touching them, I had assumed I would have pleanty of clearance, I assumed wrong. At least I now know what the problem was, for anyone else reading this be warned check your piston to valve clearance. As for my engine I am not sure what to do, should I just buy a fully assembled crate engine or try and re-build, my coidence in my abilities is currently low.

The Dark Side of Will · Sun Sep 03, 2006 11:03 pm

Vortec heads... he couldn't have gone with crazy lift without machining the heads... I wonder if he had them shaved or did something silly with the pistons.

Either way, he'd better learn that like the $2000 lesson it is.

MNFatz · Post by **MNFatz** » Mon Sep 04, 2006 12:01 am

Take a look at the far left cylinder in the pic of the piston bores..are those pistons only relieved on one side of the connecting rod?

They might be on upside down...

I took the silver marks on the pistons to be valve relief cuts, but now that I look at them they might be into solid piston. I think the reliefs are on the other 1/2 of the piston...

The Dark Side of Will · Mon Sep 04, 2006 12:04 am

Those are in the right places to be intake valve marks, and there aren't corresponding exhaust valve reliefs... you might be on to something.

I bet you've put together a couple of Chevies in your day...

Weponhead · Post by **Weponhead** » Mon Sep 04, 2006 10:30 am

p8ntman442 · Post by **p8ntman442** » Mon Sep 04, 2006 11:55 am

4 valve reliefs, its clear on the far left piston.

The Dark Side of Will · Mon Sep 04, 2006 12:21 pm

The shiny upper mark on the far left piston is valve damage in the intake valve location. I don't see a matching exhaust valve relief on that piston.

MNFatz · Post by **MNFatz** » Mon Sep 04, 2006 1:03 pm

Crank up the brightness on your monitor. I'm pretty sure that's what happened.

He mentions installing a zz4 cam. I'll bet he was upping the compression with those pistons and installed them backwards.

It's almost painful to look at those pics and read something he posted:

"..the car runs and starts well up to just past 3000rpm where the engine just falls flat on its face, it seesm like there is something holding it back."

http://www.fiero.com/forum/Forum2/HTML/070540-2.html

When the oil pressure got high enough the lifters wouldn't bleed fast enough..boom!

The Dark Side of Will · Mon Sep 04, 2006 1:51 pm

Like I said, I hope he learns that for the $2000 lesson it is.

Weponhead · Post by **Weponhead** » Mon Sep 04, 2006 3:00 pm

now were gonna have to make pistons with "install this side DOWN" or "this side up" on them ... DURRR my valves are teh backwards!

p8ntman442 · Post by **p8ntman442** » Mon Sep 04, 2006 3:42 pm

IN A QUAD 4 THE ARROW POINTS TO THE FRONT OF THE ENGINE. Nothing is mistake proof.

Post by **eHoward** » Mon Sep 04, 2006 5:23 pm

I used to think it was silly when I'd see pics of people marking hte tops of pistons with magic marker. Guess it's better to be silly then have a broken engine.

The Dark Side of Will · Mon Sep 04, 2006 6:14 pm

You can never idiot proof yourself too much.

Polished block? Nice.

whipped · Post by **whipped** » Mon Sep 04, 2006 6:27 pm

dirty in a month :la:

p8ntman442 · Post by **p8ntman442** » Mon Sep 04, 2006 7:04 pm

As far as I can recall, If you try to instal the pistons/rods upside down on a SBC the rods dont line up with the crank journal. I guess you could always instal the pistons on the rods wrong though.

p8ntman442 · Post by **p8ntman442** » Mon Sep 04, 2006 7:06 pm

The Dark Side of Will wrote:
Polished block?

looks more like silver paint, unless he polished part of his engine stand at the same time.

I shined up my al. block and clear powedercoated it. It stays very clean.

Post by **eHoward** » Mon Sep 04, 2006 8:29 pm

I think it's paint too.

p8ntman442 wrote:
The Dark Side of Will wrote:
Polished block?
looks more like silver paint, unless he polished part of his engine stand at the same time.

I shined up my al. block and clear powedercoated it. It stays very clean.

Series8217 · Post by **Series8217** » Mon Sep 04, 2006 8:50 pm

They generally make it pretty clear which way the piston goes.. there's either a notch in the wrist pin area or a notch on top of the piston itself (as in the case of my 3.4 DOHC pistons from Speed Pro). I always figured all pistons had something like that but I guess not..

Kohburn · Post by **Kohburn** » Mon Sep 04, 2006 9:44 pm

i thought the pics made it pretty clear that they are 4 reliefs on the pistons - they are the standard ones used so they can't be installed upside down.