Atill93

I am replacing my head gasket for the first time and I was wondering if it is absolutely necessary to have the head and/or front timing cover machined. I already have the motor out of the car and the head removed. I am planning on using ARP head bolts and new gaskets.

Why do the head bolts that come off of my motor look like this?



and all of the ARP bolts look like this?



do they torque down with the nut versus the head of the bolt? I just want to make sure I order and install the correct bolts

Is there anything else I should do besides gaskets and bolts? I want my KA to be strong and reliable

anti tyler

There are plenty of online tutorials on head bolts and such, if you have the motor out you may as well have it machined for accuracy and such. Never hurts to be safe and have a well built engine.

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e1_griego

Because you have stock head bolts and ARP stuff are head studs.

Dboyizmlg

^ what he said

jza80king

As you already have been explained by the previous guys, OEM are head bolts which are torque to yield design and ARP are head studs. The ARP studs you will install on the block BEFORE you put the head on where OEM design you line up the head on the block with the dowels and then AFTER you have the head on you will put the OEM style head bolts in. All that being said remember you got an iron block and Aluminum head. The chances of the block being fine is very likely since it's iron. The chances of the aluminum head which is much softer metal being slightly cracked/warped however is much more likely so I would strongly suggest to have the head checked out. Imagine if you put everything together now and then 1000 miles later you have to take the motor apart again because you didn't have the head checked out and machined and you now have coolant/oil leaks and are overheating?

Just re-read your post, you wanna have the head looked at then.

angel mkiv

Basically the studs hold better then the factory bolt design..and just change all gaskets and any maintenance parts now since it's easier to do while the reassembly

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Atill93

awesome thanks for the feedback everyone

so the arp studs and nuts replace the factory bolts

so basically:
1. screw the studs into the block
2. fit the head over the studs
3. torque the head to the block by tightening the arp nuts to the studs on top of the head

jza80king

yes basically. All ARP hardware will come with the instructions and lubrication if necessary for install. Also, you will want to clean out the head stud holes with a thread chaser. I really hope you have the head checked out, countless people cheap out on the rebuild and then end up tearing the motor apart again and again. At the VERY least, go to harbor freight, buy a straight-edge and feeler gauges and then download the FSM from 240sx.org or another online site. There is a step by step on how to check the head for straightness with feeler gauges.