Topic: Reassembling a 6X head

[Andy78TA]

Okay everyone,
   The heads will be back from the machine shop tomorrow afternoon. In a perfect world that also means I will be starting reassembly tomorrow also. I got the full gasket set from Fel-Pro in today and with recommendations from others I am starting a new thread for the reassembly.

To start off, is there anything I need to do to the actual block aside from using the green scrubing pads to make sure the surface is clean? Is there any specific sealant I will need to use with the new gaskets? I know the heads will be prepped because I am sure the machine shop will get it ready for me.

Lastly, what is the torque specs for the head bolts? 95 ft lbs? Is it the same for the lower header bolts and the ones under the valve covers?
Thanks!!

[Mongo]

95 should be correct per the workshop manual torque specs. All the head bolts are the same torque. Did they work on the block too?  If they didnt just clean any left over gasket material from the deck and cylinder walls and you should be good to go. If they bored or honed the block, wash/scrub the cylinder walls down with trans fluid and paper towel. Change the paper towels often until they come out pink and have no black crap on them. This will get the honing grit out of the bores. wipe them down with mineral spirits or laquer thinner and then wash the entire block with soap and water and then blow dry with shop air. Hit the bores again with a light coat of trans fluid to stop them from rusting.

[Mr. P-Body]

   I highly recomnmend a wire "wheel" over the ScotchBrite to clean the deck of the block. Care must be taken to keep debris from going unwanted places (with either cleaner).  The wire wheel won't remove material, where the plastic pads will "round" the edges. If you buff a piece of iron and see ANY sparks, you ARE removing material.

   Head gaskets are installed clean and DRY. DO NOT use a sealant.  Torque IS 95, as another has already said. Start in the upper middle, go to the lower middle, and "spiral" your way out to the ends. A drop of motor oil on the threads and under the "head" of the bolts will yield the most accurate torque value.  Just  a DROP. Too much oil on the threads can make the bolt "hydraulic" in the hole, and give a false "tight" reading. Also, use the torque wrench and socket only. Adding an extension will also give a "false" torque value. A "deep" socket is called for.

   Silicone sealer (a very thin bead) can be used to hold the valley pan gasket to the pan. One side ONLY. Too much silicone is also a hazard, as the "droplets" shed when tightening can find their way into the oil pump (bad).  If a little's enough, a little's enough!

   The intake should also be installed clean and dry. If there are significant pits around the water ports in the front, a slight amount of a "brush-on" sealer (we use Permatex "Aviation") oin the "head side" will take care of potential leaks. Tighten the "draw bolt" (in the front) after installing but not tightening the intake "flange" bolts. Then, torque the intake bolts to 28 lbs., again, starting in "the middle" and spiraling your way to the ends.

   With the Felpro head gaskets, "retorque" is not necessary.

   Be careful and have fun!

Jim

[Andy78TA]

Jim, Very informative. Thank you very much for all that information. I unfortunately am working an overnight tonight so I won't be able to do any work until Sunday but I will keep everyone posted. I will also upload some pics of the new clean and painted heads haha. Thank you again!

[Andy78TA]

Ok everyone, I got my head backs yesterday but had to work an overnight so I will be starting the reassembly tomorrow with my dad. I however, have some pictures of the heads so here they are.






Also the price was $580 to do the following: 3 angle valve job, replace all guides with bronze, extract 5 bolts, helicoil one bolt hole, grind 12/1000 off (which the machinest said it really needed) clean everything completely, and paint GM Corporate Blue which is I guess the correct engine color from 1977-1982, even though I have never seen this more teal-ish color before?

I will have pics of the intake manifold Monday when I pick it up. Its getting sandblasted or glass beaded because I couldn't get it clean and the guy who did the heads said he would do it for free


Edit: this is what they looked like before

[jphillips3333]

What year is the car?  That's really the determing factor as to what color to go with.  Here's a comparable blue color ... looks real close.  It doesn't matter, over time the paint will burn off at the exhaust ports anyway 


You might want to run a bolt into the manifold bolt holes to ensure there's no issues (paint, debris, burrs) when you go to bolt up the headers.  It's easier now than once they're on the car.

   That said, run 'em.  They look good.

[Andy78TA]

78. Im not too worried. The color doesn't make any difference to me as long as they are running and gaining me hp ha.

Also with the spiraling of the bolts as indicated above: I understand torque the upper center bolt first, than the lower center, but than should I do lets say the upper 2nd bolt in, than lower 2nd bolt in, than upper 4th bolt in, etc.?

Side note: Can anyone give me the torque specs for the rocker arm nuts? In a perfect world I will have the heads on and the rocker arms put back in the heads by tomorrow night.

[72blackbird]

Andy,
Tighten the head bolts in a counterclockwise direction, starting from the center and working your way out.

The rocker arm nut torque is 20 ft-lbs., but you should ditch the bottleneck studs, convert to 7/ 16" straight studs and use poly locks, setting the valve lash like you would a SBC. If you're running a replacement cam  with lift greater than .400" and with your heads milled .012, if you just torque down your rocker arms you could end up with some bent pushrods.

Geno

[Andy78TA]

Does that mean I should do all of the upper head bolts first and than all of the lower ones? or go u3, u4, u2, l2, l3, l4, u5, u1, l1, l5 with u being upper, l being lower, and 1 being the front of the engine 5 being near the firewall?

also, and possibly more importantly, I truly have no idea how to set backlash at all. I really didn't think about the rocker arms at all until now. I now see it is  not as simple as just torquing the bolts tight. As for the cam, that is still the stock cam.

[72blackbird]

Pick a center bolt (I usually start with the center one under the valve cover) and work your way outwards.

If you're absolutely sure the cam is stock you can just tighten the rocker nuts down- if your cam as more than .400" lift, you'll need to convert your valvetrain to an adjustable one.

Geno

[Andy78TA]

Geno,
  Thank you for your cooperation with my idiocy haha. And I am 99% positive the cam is the original stock one as when I pulled the heads it still had the original metal gaskets and everything else on the car seems to be original except the intake and carb. Thanks again!!

[jphillips3333]

How's this ...

[Andy78TA]

John... that is the best thing I have seen today haha. Thank you!!

[SoonerTA]

Look at John coming through with the pictures.  Great job.  

Looks like your project is coming along great.  Keep up the good work.  

Geno...Can you use stock pushrod guides with the bigger 7/16 studs? 

[Andy78TA]

Ok so the drivers said is in and torqued all around to 95 lbs. Now I just realized I am going to need to take out the motor mount bolts to get the headers in because there is no way they are getting there otherwise haha.