found my problem

[that national]

ive been chasing the problem as to why my car was running poorly and i finall found out why, so heres the story
last summer i let a buddy assemble my short block (i didnt have time because my son was just born), i fugured he had assembled lots of motors and it should be no problem for him and i had already checked clearences and such, so all he had to do was slap it together.
well, the begining of last week i started tearing my car apart to do a head and cam change and install a girdle, and this is what i find.

 

[unobetr]

???

 

[that national]

forgot to post the pic

 

[unobetr]

wow.. are those nicks coming stock now?? heheh/// j/k

 

[berserker6]

2 questions

1. When you say it was running poorly what exactly was the car doing? Detonation?

2. obviously the nick wasn't there when your buddy slapped the motor together. So what happened?

 

[Blazer406]

Has the block been decked?

Is the piston sticking out of the hole?

Have the heads been shaved?

What lift cam?

 

[that national]

it just didnt move like it should, kinda sluggish. the intake valve was opening right before the piston was reaching TDC so the air fuel mixture was being pushed into the intake and then getting sucked into the motor.
the timing chain gear on the crank has multiple key ways and 2 alinement dots, the dots were lined up it was just the wrong ones.

 

[that national]

Has the block been decked?

Is the piston sticking out of the hole?

Have the heads been shaved?

What lift cam?

he just messed up on installing the timing chain.

 

[jasjamz]

I was showing a friends how I put my engines together when i swapped short blocks. He asked why it had to be on that one if the crank gear had three spots. He also didn't know you had to line the marks up. Granted he's not a mechanic but he is eager to try and learn so he can stop paying people to work on his own stuff. I will show him this so he can see what can happen. At least you can fix it now.

 

[Blazer406]

Ah..... makes sense.

How many valves kissed the pistons?

Sorry for the sour luck..... it doesn't look too bad...... buff the nicks out.... replace the valves if they are bent..... and install the cam right and slap that thing back together....

 

[that national]

Ah..... makes sense.

How many valves kissed the pistons?

Sorry for the sour luck..... it doesn't look too bad...... buff the nicks out.... replace the valves if they are bent..... and install the cam right and slap that thing back together....

every piston has the exact same nick in it. i have a set of GN1s sitting on the shelf waiting to be put on.

 

[Turbo-Archie]

But, think about how much better it will run with the cam set up right.

I like finding easy mistakes that explain why it doesn't run the way you think it should.


..

 

[that national]

yeah, i just wish i would have found it before the end of the season.

 

[Boostdeznuts]

Do you have a pics of how to line up the timing chain ?

 

[that national]

i havent reset it yet, i just pulled the heads off last night. i can take some pictures and show you how not to set it up.

 

[GNVenom]

Grind those 'eyebrows" smooth to prevent hot spots. Put it back together with the timing chain installed RIGHT then you're good to go. You need to pull both heads as there will be others like it.