: Do N* heads crack EVER?



BIGGUN
06-07-04, 11:14 PM
Had overheating under load problems.
When engine is running under load it is blowing anti out the overflow even before overheating. No steamy exhaust or coolant were it doesn't belong(except on the ground).

Must be the head gasket right?

So I pulled the heads along with three threads of block on a few bolt holes (that's just frickin great!), but I can't seem to find any noticable bad spots on the gaskets????

What else should I look for?

Do I need to disassemble the heads and have them magnafluxed?

Oh the metal tube running across the block from the overflow box was checked and is clear.


Thanks,
Kevin

BeelzeBob
06-08-04, 12:24 PM
Had overheating under load problems.
When engine is running under load it is blowing anti out the overflow even before overheating. No steamy exhaust or coolant were it doesn't belong(except on the ground).

Must be the head gasket right?

So I pulled the heads along with three threads of block on a few bolt holes (that's just frickin great!), but I can't seem to find any noticable bad spots on the gaskets????

What else should I look for?

Do I need to disassemble the heads and have them magnafluxed?

Oh the metal tube running across the block from the overflow box was checked and is clear.


Thanks,
Kevin

It is probably the head gaskets. It isn't always really obvious where the leak is. The gasket doesn't just fall apart.

Clean the stainless steel fire rings on the old head gaskets (the ring around the combustion chamber) with some scotchbrite and look CAREFULLY for cracks in the firerings. This often happens when the steel substraight of the gasket collapses due to corrosion.

I have never seen a "cracked" head on a Northstar. I wouldn't bother looking for cracks in them.

This is why it is good to do the cylinder pressure test before pulling the engine down so that you know which cylinder(s) were leaking before hand so that it is easier to diagnose the failure mechanism.

my_bro
06-08-04, 08:19 PM
the gasket is most likely leaking where you had the bolts that had the block threads on them. Look at the ring around the cylinder on the gasket for any discolorization. It might not be real noticeable.

file:///c:/gasket.jpg

BIGGUN
06-08-04, 11:04 PM
the pic didn't come out. Can you repost so I can take a look.

The rings on the back gasket look good but the area between the ring and the water jacket has an area about 3/4" long that looks deterierated slightly.

Did a compression test on the motor and #1,3,& 8 all read 190. most others were between 215 and 225.

Kevin

etcCanuck
06-09-04, 12:21 AM
I had a headgasket fail after some over-heating. There was no cracks in the head, though it was warped .003". They machined it true without having to remove the valves. Make sure you get the time-sert kit and repair ALL the threads in the block.

BIGGUN
06-09-04, 03:45 AM
Where is the cheapest place to get the time-sert kits?

Thanks,
Kevin

my_bro
06-09-04, 11:07 AM
I'm having a hard time with the pic. I was leaking at two cylinders.

file:///c:/gasket.jpg

file:///c:/gasket.jpg

etcCanuck
06-12-04, 01:21 PM
Where is the cheapest place to get the time-sert kits?

Thanks,
Kevin
Sometimes they show up on ebay, there are probably a few on these forums. If you cant find a set you may need to get it direct from time-sert.

BIGGUN
06-12-04, 07:59 PM
Got it $350 later OUCH!!

All are installed with no problems.

Heads checked true to <.015

Thanks,
Kevin

etcCanuck
06-13-04, 01:09 PM
Got it $350 later OUCH!!

All are installed with no problems.

Heads checked true to <.015

Thanks,
Kevin
I hope you mean 0.0015:)

BIGGUN
06-13-04, 07:57 PM
oops, I do.
darn zeros. :D


Have fun,
Kevin