teach79

02' z with a 407 n/a motor . i have arp head studs currently on the car and have a leaking pass side head gasket , how would all of you who have done the job before do it ? i am a master cert. mechanic that runs his own shop with all the tools . was wondering if i am able to take heads off without removing wiper cowl or not ? anything i should know before starting ? thanks

Bill Curlee

Well,,, If it were ME,,,,,,,, I would RETORQUE the head bolts and see if you still have a leak!

If it doesnt correct the leak issue,, NO,, you will NOT have any issues taking off the heads with studs. The heads clear everything! STUDS are GREAT!

When you remove the INTAKE MANIFOLD, you will not be able to fully remove/ extract the two manifold bolts under the cowl. Cut two 3/4" long pieces of 3/16" vacuum line and slip them in under the heads of the two intake manifold bolts. That will allow the bolts to be moved UP so they clear the holes in the cylinder heads and you can easily remove the manifold.

Hope the retorque resolves the leak!!! It does most of the time.








BC

LoneStarFRC

One thing's for sure, getting the heads off a C5 is not nearly the PITA it is on an F-Body.

teach79

thanks alot for the info !!!! i have fel pro 1041 head gaskets installed on the car , can i re torque those type head gaskets ? they are not mls style gaskets . they are what i would call old style head gasket's . so u know that was the specific gasket tony mamo of afr used ??? i am a huge fan of mls gaskets over the old school stuff but i figure he used these gaskets because of the machined surfaces on the block and heads also because he proably wanted a specific thickness to the gasket ( 41 thou ) . please remember i work on stock application type cars and i get a little lost when it comes to race car stuff . if you have an idea of what you would do instead of putting another set of fel pro 1041 gaskets in i would love to hear it . also would like to know if you think tony used those gaskets because that was the best at the time but now XWZ is the best to use . the engine was built in 08/09 winter by him . i am very familiar with re torquing gaskets i just figure its a waste of time due to the type of gaskets they are . also just in case you were wondering the pass side head leaks externally in the center of the head , the car runs and operates great no other issues and once the engine heats up does not leak . ????? THANKS IN ADVANCE

Bill Curlee

Well,,,,,,,,,,, If it were me,,,,,,,,,,,,,,,,,,,,,,,,,,, I would retorque... What will it hurt? Especially since it isnt a compression to coolant leak!

If its only a minor external leak, I would consider a block sealer if the retorque doesnt work. Some of the advanced sealers are a multi step product and dont cause any coolant system damage. I would do all that I can the easy way vise tear it apart!

Having ARP Head studs makes it EASY to check the torque!

NOTE! I would be very careful when you check the head studs in the area where the leak is happening. If you find one stud with very low torques, you could have a stripped head stud hole.
It happens a lot when using the OEM head bolts and usually happens on the two short end head bolts. I have not seen it happen to a block that uses head studs. Just trying to figure out what would cause it to leak after all these years.

Call Tony Mamo and see what he recommends for the gasket replacement if you end up removing the head and why he used what he used and maybe he can also explain why it leaked. If you have to replace ONE head gasket, I would match what is on the other side for sure!

He has a LOT more expierence with the ins and out of engine assembly for performance than I do!

feeder82

fyi the cometic mls gaskets come in .41 thickness also.

vettenuts

I think a retorque may not be possible depending on how much the motor has been run. If the ARP lube is washed out, then the loosening and re-tightening to the torque value might actually end up with less preload than the current situation if the lube is gone.

However, if it were me, I would remove the nuts/washers one at a time in sequence and then torque to final value. You essentially have nothing to lose since it is already leaking.

I did a retorque on mine after two heat cycles to ensure I didn't have an issue with the Cometics. I also sprayed them with a light coat of Hylomar prior to installation.

leadfoot4

I have a head on my 4th gen Z-28 that has a stripped thread. I hate to admit it, but I tried to shoot a heli-coil in the bad hole, and didn't get the hole at the right angle. Now, instead of a thread that was sort of bad, I have a good heli-coil, but off angle, with the bolt not going in more than 2-3 turns.

I'm going to have to pull at least one of the heads, and I'm NOT looking forward to it!!

2GOFAST

I changed from fel pro to cometic MLS with .041" thickness because the fel pro were prone to leaking externally. No problem with the cometics. Don't worry about matching both sides just do the leaking one now and when the other one leaks but a cometic on there. Same thickness so no worries. Also, passenger head is much easier than the driver's head.

zeevette

GM mls gaskets are .052, IIRC. Less than a 10th of a compression point difference. Cheap, and sturdy, but I still used copper spray when I installed them. I wish I had gone with head studs, because I ended up pulling them 3 times so far. I love the ARP header studs.