Vohaul

argh, my car is now stranded....i just got a new header --> engine gasket, cos something is leaking down there badly....

and to my dismay, i got 3 nuts off....but the 4th...no nut...no threads.....just a hole in the header where the screw threads are supposed to be...

now what..do the header bolts thread into the engine block....help....its my daily driver and im stranded till i figure this out......

thanks,

Paul

piston pounder

Is the stud that goes into the housing missing completely or is half of it broken off in there?. If its just missing you can pick up a new stud at a auto parts store or just put a bolt in there. If its broken off you are gonna need to drill it out and heli-coil new threads in there, its a pain in the *** and you need to be very carefull!. I had one broken off on one of my old engines and it didnt leak with three nuts on it, The flanges on any header for a rotary are pretty beefy and should not warp and leak.

Manntis

sometimes you can use an easy-out instead of drilling and retapping or helicoiling.

Why did you not notice until you had 3 of the nuts already off? Didn't you follow a torque pattern?

Vohaul

the top rear onew is missing...
from the top you cant see it....i did do a tourque patter..but that bolt was last

Manntis

usually with removing you 'break' torque all around, then loosen and remove all around. If you simply remove them via the torque pattern you can distort your parts - then they'll require machining or replacement

Vohaul

ahh..that makes sense......

thnks

Manntis

A bolt or nut torqued down can put tremendous pressure on the (surprisingly) soft metal.

Imagine a flat sheet of metal tightly screwed down at four corners. Each piece of metal surrounding the screw is actually compressed by the torqued screw, bolt, nut, or whatever, causing a spring tension. If you undo one of the screws the metal tends to want to pop up at the now uncompressed portion while the other 3 corners remain under tension.

On a part such as your header, this 'popping up' can permanently warp the metal and it has to be machined level again. Now it will be a flat surface and a warped surface, meaning the gasket will be expected to be extremely tight in areas of close tolerance (tight) and less compressed or even loose in areas of less tolerance (further apart). This means the distorted surface may not seal properly against the block, even with a gasket, as a gasket is meant to evenly compress and fill in micro imperfections that prevent metal from meeting perfectly, not fill in varying distances of up to a few millimeters.

The greater the torque, the greater the potential for warping if you don't follow a torque pattern. If you DO, you must remember to make one pass just barely breaking torque, then a second to loosen. I prefer making 3 rounds of the torque pattern to slowly relieve the compression at each fastener unless the manual specifies otherwise.

This torquing rule is true of any torqued part, be it a cylinder head in a boinger engine or rims at your wheel hubs.

BTW I do hope this comes across as an explanation, not a lecture, as it's intended to help.

Vohaul

nope..not taken as lecture...thanks for the info

Manntis

An easy way to check your header gasket surface for warping is to take a metal straight edge and place it on the (well-cleaned) surface where the gasket goes, corner to corner diagonally. The surface should meet the straight edge at every point with no gaps. Then check the opposing diagonal. If it's okay, just replace the gasket. If not, call a machine shop that does metal planing.