Torque Settings On Head Bolts/head Gasket Issues

[Mike XR6T]

  hiddeous said:

how hot do you think it got when you ran it up to 1/4 on the gauge with no coolant in it?

oh crap I missed that bit

:( engines can overheat with out the gauge even lifting off zero if air around the temp sender!!!

good pic hiddious

[01txr]

I cant beleive you ran the engine without coolant.

Never have heard anyone doing that before.

just out of curosity did you check your head & engine deck for straightness before fitting?

Dont know if you where thinking the head gasket just blew so must just be that so replace it.

Since you said the number 1 and 6 bores where cracked, I would assume it got very hot.

When you have 2 different metals that expand and shrink at different rates in extreme heat situations

your bound to have warped the head.

was the gasket surfaces throughly cleaned

also you did use new head bolts as the head bolts are a use once throw away bolt (Nickname-plastic Bolts).

If you remove the head again you will need to get new bolts again, also when a gasket has been crushed (Torqued down)it may not seal again.

Next time you assemble a engine make sure you fill with water, if concerned about head gasket sealing first, leave the header tank cap off so it doesn't build pressure.

If your number 6 was the only cylinder with crack I would be thinking your water pump could have caused it as if your pump doesn't build enough pressure the rear cylinders suffer being furthest from the pump.

Also never remove a thermastat as you need it to restrict flow from engine so the rear keeps coolant pressurised.

Learnt this with a old crossflow I built, exactly 1 week on the road the brand new thermastat decided it would not open and my car boiled at a set of lights.

I then pulled it out and thought never again will I use one.

That engine ended up losing compresion on number 6 just over 12mths from build.

I would say the fact of the rear cylinder not getting enough cooling pressure ment it was running hot, there for causing the rings to lose tension over time from running hotter than other cylinders.

also thermastat helps keep your engine at its best operating tempeture.

[senna_T]

Aren't the standard bolts torqued to 90Nm?

[XRDRIFT]

The block wasnt re used with the crack in it albeit it was a mere hairline crack at that and could have been sleeved, I got a new short motor and rebuilt that. As for the head bolts, Ford did not say to replace once removed, I know with the Toyota 4AGE and 3SGE engines you do. And the Ford repair manual doesnt specify either.

As for running the car without coolant, it barely got hot, sump/head and engine barely got heat in it.

I spoke with Spiro anyways at Autotech yesterday and even he thinks its very strnge what happened, but he recommended me to get a genuine head gasket and use that. And I went today to Ford and got it, and what do you know, its the correct one!!!! Single layer as well, still different to the original one that was on it but overall its same.

Head is coming off tommorow and hopefully problem sorted. But the dual layer head gasket is a stupid idea as water'may' have creeped in between the layers and found their way into the oil journals, its only a hunch, but its the only thing that could have caused it. Head was torqued down right and couldnt have blown as its new.

Anyways, thnx for all your info and help guys and when its done I'll let you guys know

PS This is the installation technique as per manual which I followed.

Installation

1. Ensure all joint surfaces are clean and free of oil

and grease.

NOTE: A new cylinder head gasket must be used.

2. Lightly lubricate the bolt threads and washer

surfaces with engine oil.

3. Tighten the cylinder head bolts in the sequence

shown.

4. Rundown all bolts to 30 Nm.

5. Retighten in sequence to 90º.

6. Back off all bolts by approx. 1 turn each.

7. Tighten all bolts to 40Nm in sequence.

8. Rotate bolts 90º ± 5º in the sequence shown.

Edited 06/02/09 07:40 AM by XRDRIFT