Torque Head Bolts & Adjust Valves

[memphis]

Hi All,

My engine was rebuilt approx 1,200 miles ago. When should the head bolts be re-torqued and valves adjusted on a fresh rebuild? Then how often on an on-going basis?

Thanks in advance for your advice.

Bob

 

[Superwrench]

You can check the head nuts, but if he used new studs and nuts you should be fine. They accually hold by the stud stretch. At 1,200 miles the valves can be checked and adjusted if needed and you should be fine there also. How often do you change oil and filter ? That is the most important part ! Quick

 

[shorn]

Kind of like to change that break in oil at 500miles and check the head bolts and adjust valves then too.

 

[memphis]

Thanks Guys!

So what is the torque sequence (which head bolt first, second, etc.), what lb torque?

I assume I need to torque the head when engine is hot? Then let cool overnight and then adjust the valves?

I do have a AH manual, but this is not clear. Thank you for your help with this!!!

Bob

 

[nevets]

Sorry, don't have my manual handy but if it's the same one I have it includes a head bolt torque sequence diagram, as well as specifications for all critical torque values, including head bolts.

FWIW, I never re-torqued the head on my engine, which now has several thousand miles since rebuild.
Couldn't bring myself to bugger up all that pretty green paint.

 

[Keoke]

FWIW, I never re-torqued the head on my engine, which now has several thousand miles since rebuild.

The rebuilder should have taken care of that.----Keoke

nce (which head bolt first, second, etc.),
Check the manual again
what lb torque?----75 LB FT

You need to adjust the valves when the engine is hot hot?

I do have a AH manual, but this is not clear. Give it another go there is aicture sequence in there.

Bob

 

[memphis]

Thanks Everyone!

My experience has been with a Mercedes (w113) 280SL engine. It had an aluminum head which requires a retorque every several thousand miles and also several hundred miles after a rebuild.

I appreciate the replies.
Thanks again,
Bob

 

[shorn]

If you number the head bolts on the drivers side of the engine from the front to the back as numbers 1 through 8, and the right (passenger)side of the engine from front to back as numbers 9 through 16, (left hand drive car), Then:
The first bolt you tighten is the number 12 bolt (4th back right side), the second bolt is 4 (4th back left side), then numbers 13, 5, 11, 6, 14, 3, 10, 7, 15, 2, 9, 8, 1, and finally 16 (back bolt right side). FIT ALL BOLTS FINGER TIGHT, AND TIGHTEN EACH IN THE ABOVE ORDER ONE TURN AT A TIME TO 75 FT/LBS. Esentially the pattern is from the engine center outward.
When I retorque, I loosen the each bolt and retighten to specs. You can't get a proper torque without loosening first.

 

[memphis]

Thanks shorn!

Torque with engine hot, correct?

Bob

 

[Keoke]

Thanks shorn!

Torque with engine hot, correct?-------

Bob

 

[shorn]

Torque bolts with engine cold.
Adjust valves with engine hot.

 

[BoyRacer]

If you have a cast iron head, re-torque the nuts with the engine hot. If you have an aluminum head, re-torque the nuts after a cool down.
In every case, back off the nut one-half turn and then then slowly and steadily pull on your torque wrench until you reach the desired setting.
The stock torque recommendation is 75 ft lbs. If you have a higher compression engine and are using ARP studs and nuts, torque to 85 ft lbs.
Measurements that I have taken over the years show that generally, new head gaskets are .050" think, used head gaskets are .040 thick. This means that the gasket will compress about .010".
A stock Healey engine may not need to be re-torqued and I have been so advised -- but, I have always done so, even before I began building serious race motors.
And, I have a serious race engine with an iron head and one with an alloy head.

 

[memphis]

Thanks Richard,

Seems that we have a varied opinion on torquing the head bolts with engine hot or cold?

Also with valve adjustment, hot vs cold?

I did find the torque sequence in the manual, just had to put my reading glasses on ... However, dont see any mention of any adjustments based on engine temp?

Thanks again,
Bob

 

[BoyRacer]

Valve adjustment is always done when hot.