Torque Settings on Head cylinder!!!

[aaronsinclair]

I am almost done doing a ring job on my 98 protege, as discussed earlier. I was torquing my head cylinder down and the middle bolt broke. I was torquing it to 69 foot lbs as per the haynes manual for the car. I am pretty sure this is too tight and was wondering if anybody has a real mazda manual with the correct specs in it. If anyone can offer this info it would be greatly appreciated.

Thanks again-

[Intruder]

Are you talking about the cylinder head bolts?

According to my '97 FSM the torque specs are as follows:

For Z5:
17.2 - 22.0 N-m
12.7 - 16.2 ft-lbs

For BP:
76 - 81 N-m
56 - 60 ft-lbs

[pigeon]

I am almost done doing a ring job on my 98 protege, as discussed earlier. I was torquing my head cylinder down and the middle bolt broke. I was torquing it to 69 foot lbs as per the haynes manual for the car. I am pretty sure this is too tight and was wondering if anybody has a real mazda manual with the correct specs in it. If anyone can offer this info it would be greatly appreciated.

Thanks again-

You made an error. They haynes manual says the 'end plate bolts' are 69 ft/lb

The Z5 head bolts according to the haynes manual says 12 - 16 ft/lb around the whole torque sequence. Then start from the beginning of the sequence and turn another 85-95 degrees. Then start from the beginning of the sequence and once more turn another 85-95 degrees.

If you did all that and it still broke, your bolts were already stretched. Hence why you ALWAYS check them before reusing them.

[Project Protoge]

You can also look at the sticker on the hood. For some reason these cars have the head bolt specs on the hood sticker.

[kansei]

If you broke a head bolt there is a good chance there was oil or coolant spilled in the bolt hole make sure to blow them out with compressed air to ensure no debris is down there .

[Project Protoge]

Thats a good idea. I have seen guys torque head bolts on aluminum blocks when their was oil in their and the hydrolic pressure blew a chunk off of the block around the bolt hole.