Head bolt Torqueing

Post your technical queries / problems here!
Message
Author
jonnyhahn
Posts: 7
Joined: Fri Jun 12, 2015 7:55 pm

Head bolt Torqueing

#1 Post by jonnyhahn » Sat Jun 13, 2015 2:18 pm

Firstly would like to just say hi, as I'm new to the forum and I hope you guys can help.
I have just done an engine change in my 1989 Lancia Delta HF Turbo after my last decided to eat itself. However I have tightened the head bolts to torque and one corner is leaking oil. I obviously used new bolts new gasket etc but I cannot get the leak to stop. The bolt instructions said +90 +90 however I have done one set of +90 and any more i feel like the bolt is going to sheer. Will the bolt sheer if I do another +90 or will it take it? I'm also concerned about crushing the gasket and the faces if I over tighten them?
Thanks
Jonathan

User avatar
TerryG
Posts: 6754
Joined: Wed Jan 05, 2011 1:54 pm
Location: East Midlands

Re: Head bolt Torqueing

#2 Post by TerryG » Sat Jun 13, 2015 6:06 pm

Assuming you have used new stretch bolts they should deform slightly as you tighten them and they certainly feel rather tight doing the second round. From experience (or stupidity depending how you look at it) if you skip the second round of tightening you'll be doing the job again in less than 100 miles.
You should never re-use stretch bolts so it gets expensive having to do it twice.
Understeer: when you hit the wall with the front of the car.
Oversteer: when you hit the wall with the back of the car.
Horsepower: how fast you hit the wall.
Torque: how far you take the wall with you.

History
Posts: 365
Joined: Tue May 05, 2015 8:03 pm

Re: Head bolt Torqueing

#3 Post by History » Sun Jun 14, 2015 6:35 pm

You must follow the correct torturing procedure to the letter.

If oil is leaking then I am afraid that the head will have to come off to find out why and repair.

Bob

Whiteshadow
Posts: 2
Joined: Mon Dec 30, 2013 7:12 am

Re: Head bolt Torqueing

#4 Post by Whiteshadow » Sat Jun 20, 2015 7:57 am

Hi,

I don't know if this will be any help...

Pre-war Singers have all sorts of issues with head tightening and constant movement, i was advised the following...

Mark the position of all the nuts (those tipex pens are good), loosen slightly in sequence and the re-torque to the correct value. If the marks do not broadly line up then its still moving!

sierra3dr
Posts: 439
Joined: Fri Feb 11, 2011 10:20 am

Re: Head bolt Torqueing

#5 Post by sierra3dr » Mon Jun 22, 2015 10:23 am

jonnyhahn wrote: I have just done an engine change in my 1989 Lancia Delta HF Turbo...However I have tightened the head bolts to torque and one corner is leaking oil.
Hello Jonathan,am I to understand that you built up the second engine? Is it likely the cylinder head is warped? When working on my Fords,the instruction is to tighten again after 20 mins or so

jonnyhahn
Posts: 7
Joined: Fri Jun 12, 2015 7:55 pm

Re: Head bolt Torqueing

#6 Post by jonnyhahn » Sun Jun 28, 2015 4:16 pm

Hello again guys.
I let the engine run up to temperature and gave them all about another 90 degrees and it sealed the leak completely.
However now I have a bigger problem. One of the Cam housings was leaking oil too so changed the gasket and refitted and its sealed however now the engine just wont start. Im getting good compression, the timing is perfect and im getting air fuel and spark. The car will turn over and start the a fraction of a second then just conk out. I replaced the fuel filter and cleaned the injectors and it started again for about 5 seconds then gave up. Does anyone have any clues at all? I think it is something to do with the fuel or the ratio?
Thanks

User avatar
TerryG
Posts: 6754
Joined: Wed Jan 05, 2011 1:54 pm
Location: East Midlands

Re: Head bolt Torqueing

#7 Post by TerryG » Sun Jun 28, 2015 5:12 pm

If you hadn't said that you had the cam housing off i would say that sounds a lot like the MAF sensor is either not connected / faulty (stuck?) or you have a HUGE vacuum leak so the information the ECU is getting from the MAF is incorrect.
I don't know your engine but as you have had the cam cover off, does it have a cam position sensor? did you disturb it?
It's also possible that the fuel pressure is really low but my money is on the cam position sensor if there is one or MAF if there isn't.
Understeer: when you hit the wall with the front of the car.
Oversteer: when you hit the wall with the back of the car.
Horsepower: how fast you hit the wall.
Torque: how far you take the wall with you.

History
Posts: 365
Joined: Tue May 05, 2015 8:03 pm

Re: Head bolt Torqueing

#8 Post by History » Mon Jun 29, 2015 9:21 pm

Further to TerryG posting.

The engine wiring loom on cars with electronic injection lives in a hostile environment.
Often the loom is OK until someone started taking the engine apart and moving the loom.

So first check is the cam position sensor is it plugged in.
Then the MAF. Then check that engine breathers and any vacuum pipes are connected. Brake servo.

If everything is present and correct.

With battery disconnected if possible. Check the continuity of the wiring from plug / socket to plug/ socket. Only use a digital high impedance multi meter. Mine has a buzzer as well.

I have had looms break wires after working on engines. Its a hazard of disturbing the loom.

I am sure that the fault will be simple once found.

zipgun
Posts: 856
Joined: Thu Apr 07, 2011 10:50 pm
Location: Crowborough

Re: Head bolt Torqueing

#9 Post by zipgun » Mon Jun 29, 2015 11:08 pm

Slightly off topic History, but in another thread you said oil on bolt threads was a good thing . I am aware some headbolts are placed in oil and allowed to drain for a period ... but in other cases the particular pitch of a thread chosen for the amount of friction that is required to keep the bolt tight at a set torque. Surely by lubricating , 1, the bolt would be overtorqued if using a torque wrench ,and 2 could come loose if not ..? However, i also do do it , i copperslip my wheelbolts, but only if it's ME tightening them by hand and not a zipgun.
I was spannering for someone once at Snett , belt and braces guy who left nothing to chance , I fitted "wet tyres wheels" , torqued up precisely the wheelbolts . 3 laps later the car's juddering into the pits ,ALL the front wheelbolts loose.. and i'm red faced ...and i know i didn't drop a bollock?
Further investigation ,NOT my fault really ..The wheels had just been painted, the conical bolt seat hadn't been scraped off , paint had melted between the bolt and wheel , and the wheel and the hub ..with the race temperature brake heat.. = loose wheels

History
Posts: 365
Joined: Tue May 05, 2015 8:03 pm

Re: Head bolt Torqueing

#10 Post by History » Mon Jun 29, 2015 11:24 pm

Torture settings are subject to whether oiled or dry. So check first.

Bob

Post Reply

Who is online

Users browsing this forum: No registered users and 18 guests