In-truck Head Removal - need advice

[highperf4x4]

Since this is your first round with this, I'll add some important info for ya. When you put the heads back on it's important that you torque the bolts properly. A gen1 engine with iron heads will torgue to 60 lbs but you have to do it properly. You can't just torque it all at once and you need to do them in order. You need to do it in 15lb incrememts. 15, 30, 45, and then 60. Start with the center/middle bolt on the head and work your way out in a circular pattern. Since you're not going to "deck" the block, don't use a "shim" style head gasket. Get a composite gasket that's at least .028" thick.

I know this will sound stupid but I've seen it happen. The head bolts inside the vavle covers aren't the only head bolts to take out. There's a row of short bolts beneath your exhaust manifolds that have to come out too. I've actually seen a head that was pried off without removing these bolts and the head busted across the bottom. I'm sure you're already aware of this though!

[highperf4x4]

I am a little suspicious of your motor now though. Sitting for 5 years wouldn't cause your problem and if it was recently rebuilt before it was parked then you shouldn't have a cylinder with only 20psi of compression. I'd look things over very closely.

[Rippin-J]

For those keeping up with the thread, here is a brief history of the motor: bought the truck 2 years ago, has never ran well at all. the truck had sat for 5 years in a garage prior to me and the motor 'was completely rebuilt before that.' No way of knowing what all was done to it or if it was broken in correctly, etc. I do know one thing, the motor and engine compartment are super clean so it's not a rusty/dirty old beater motor (at least on the outside).

I need to spend money like I need a new hole in my head, but I can't help it I love these trucks and I am dying to get mine running well!! These Carolina spring days have me aching to get out onto some country roads.

Based on everyone's input, I think I am going to push forward in getting the heads taken care of in hopes of that being the answer to my prayers. From there I can evaluate whether it'll be necessary to rebuild the entire motor ...that's something I have always wanted to do, but not until there is an absolute need for it.

If I read everyone right the major things to recall are:
- take lots of notes
- take lots of pictures
- drain the oil
- drain the coolant (rad and block)
- soak up fluid in valley
- clean (and paint) everything being removed

Weather permitting, I may tear into it this Sunday and will try to post an update as soon as I can.

Thanks a ton for eveyone's help thus far! Headed over to Amazon.com right now to see what David Vizzard is all about.

Berencam - thanks for the heads up on your thread.

[wwhijr]

Good luck with it. I didnt make it to the meet this time, but I am just down the road a bit in Gastonia. If you get hung up on the heads give me a yell. 704 418 0602. I might be able to come up and get greasy.

[gcburdic]

Hey J,

I'm up the road from you too....I could come over and at least hand you tools, cheerlead, and read instructions from the manuals if you need it..LOL...I have a haynes manual I can bring as well!!!....Let me know if I can help....I'll bring the Mistress too...

[highperf4x4]

Jam a spark plug back into your #6 and #4 combustion chambers flip that head over and fill those chambers with gas. See how fast it runs out.

If they both lose the fuel at the same rate then try the same test with the cylinders in the block. (Drain your oil afterwards).


Oil up the combustion chambers and cylinders after you get through so they don't start to rust.

[Rippin-J]

just to clarify, put fuel on the valve-side of the #6 and #4 cylinders on the head?

[highperf4x4]

Yes. Turn the head upside down with the spark plugs in and fill the #6 and #4 chambers up with gas to the surface of the head and see if #6 disappears alot faster than #4.

[Rippin-J]

sure enough. the fuel in the #6 pretty much drained out as fast as it went in. the #4 is just pooled up on there. I bet it will still be there in an hour. VERY COOL TRICK.

on the #6, is looked like it was leaking out the exhaust valve. SO ...where do I go from here? just need to have a valve job done on the head?

I will do the trick again later and post pics up on here. seems like it would be a useful test for everyone to see.

[Ackattack]

Congrats on finding the problem and it not being the worst case scenerio.

I would pretty much have the heads rebuilt at this point. New valves, springs, oil seals, valve job, etc. That way you don't have issues with them later and have to go back in and work on them again.

[Rippin-J]

Returned 3 hrs later to find the fuel still pooled up nicely in #4! No problems there.

Decided to test out the other cylinders and found a slight leak in #2 as well. Not nearly as bad as #6 though. #8 checked out well.

Posted this video of the test on youtube. WARNING, crappy quality but you get the idea. my battery was running low and it tends not to focus well on low battery.

YouTube - Broadcast Yourself.

[gcburdic]

Sweet Jordan!!!....Looks like four UN-trained eyes are pretty good looking at things!!!LOL....

Glad the problem is found!!!

Question for all....Is it okay for him just to rebuild one head, or should both heads be rebuilt (sorry J if I'm stirring up a question that has already been answered!!!)

By the way J....it tells me that the video isn't available?!?!?!

[C20-67_N_MO]

Originally Posted by gcburdic

Question for all....Is it okay for him just to rebuild one head, or should both heads be rebuilt (sorry J if I'm stirring up a question that has already been answered!!!)

I would think you might as well get BOTH heads redone while they are off the engine. Just makes sense to have them done at the same time and not worry about the other one going bad in the future.

[ERASER5]

Before spending money on the old heads, get prices! If you need valve guides, valve seals, valves etc, often you can find new/ better heads for very little more than the cost of rebuilding the old ones. Also the old heads may have soft valve seats. You need hardened valve seats for unleaded gas.

[highperf4x4]

Glad I could help rippin. Don't give away all my secrets though!

Eraser is right. Your heads won't have hardened valve seats unless someone had them installed before you. However, your heads aren't cheap like small block heads would be so you need to investigate prices a little bit. One thing you don't want to do though is swap yours for heads with larger combustion chambers. You'll lose alot of power. Make sure they're giving you the same heads if you're gonna trade yours in.


As for doing both heads, it's a matter of opinion really. If the engine is high mileage anyway then it really doesn't matter much. However, if you think the bottom end is in good shape and will go another 50,000 with no problems then I'd do them both since you're this far into it. The engine will run the same though whether you do both heads or just one as long as the other head isn't in bad shape and provided you only mill the one head enough to make it flat again. If you mill one head .030 and not the other one then you'll have a big difference in compression from one side to the other.

[Rippin-J]

ha, great, leave it to me to decide what I should do! i need more financial decisions like a i need a hole in the head. I have considered purchasing some reman'd heads, but wasn't really able to locate a great source. any suggestions?

and I did notice that the big block heads were more expensive than the small block ones ...so maybe it's cheaper in the end just to have mine rebuilt for $300-$400?

i would like to believe that the bottom end is in good shape based on what I have found in disassembly (clean, good gaskets, no metal/copper shavings, etc). as for the shotty valves ...I don't know what would have caused that. ideas?

are there any 'bottom end' tests I can run get an idea of what condition it's in? might not need total confirmation, but some hints on what things might look like would be good enough for me. my thought is that is seems like a waste to spend more money on the heads if I am not confident the bottom end isn't just going to blow up 5,000 down the road and turn the motor into scrap metal. BUT at the same time is makes sense to get them both done and be confident that at least there won't be any issues with either of them anytime soon. (this is basically me trying to get you all to tell me what I should do!)

hipo4x4 - don't worry, your secrets are between you, me, and the world wide web.
GC - you probably tried to view just after I posted and the dorks at youtube hadn't posted the video yet.

[gcburdic]

Originally Posted by highperf4x4

Eraser is right. Your heads won't have hardened valve seats unless someone had them installed before you. However, your heads aren't cheap like small block heads would be so you need to investigate prices a little bit. One thing you don't want to do though is swap yours for heads with larger combustion chambers. You'll lose alot of power. Make sure they're giving you the same heads if you're gonna trade yours in.

After reading this post, I am convinced (but you don't have to convince me...it's not my $$$$....) if one side didn't have hardened valve seats, why would the other??....It's the old "might as well" factor that I learned on my build.....So RippinJ....looks like a rebuild is in your future....and all the might as well's too......should be fun, and don't hesitate to ask me to come down and help....I'm learning right here with ya man and look forward to helping you where ya need it!!!!

[highperf4x4]

I would invest the money in a valve job if it was me. They really only need to replace the valves that are too bad to be turned and using a reputable machine shop will give you more piece of mind. Sometimes the reman head shops go through them too fast to do a good job and you really don't know if they did a 3 angle grind or a 2 angle on the valves and seats.

I would also recommend doing both. If you find that you have to rebuild the engine sooner than expected you won't have to do anything with the heads but pull them off and put them back provided that you didn't overheat the engine or throw a rod.

As for the bottom end, if your oil pressure is ok, it wasn't smoking at higher rpms, you don't have any rods making noise, there isn't any copper in the lifter galley and all the lifters appear to be rising to the same height then you're probably ok.

So, I would do the valve job, clean everything up and slap it back together. Since you have it torn down this far, I'd probalby go ahead and replace the timing chain and front seal too.

[mrein3]

I would definately do a valve job on both sides. Hardened seats, bronze-wall guides, etc.

I don't remember exactly but I think the last time I did a pair it was $125/side.

Now is a really good time to replace the timing chain.

Paint the heads right away when you get them back. While they are at the machine shop you can change out the timing chain. With the timing chain cover off you can clean it up and paint it to match the heads. Since the valve covers are laying there you can clean and paint them too. Same with the intake.

With most of the engine sheet metal all fresh looking and fresh paint on the rebuilt heads you'll have to snap some pictures for us to drool over. Not only will your engine run good it will also look good too.

rebuilt heads $250
New timing chain $40
Gasket set $125
2 cans Chevy orange paint $15

Sweet looking, good running Chevy: Priceless.

[gcburdic]

Originally Posted by mrein3

While they are at the machine shop you can change out the timing chain. With the timing chain cover off you can clean it up and paint it to match the heads.

J....you're probably getting tired of me posting in here, but I saw this thread about replacing the timing chain....thought it might help too....http://67-72chevytrucks.com/vboard/s...d.php?t=334774

Okay....I'll quit posting....

[Rippin-J]

post away!

i found that same thread earlier ...def useful. thanks for sharing, GC.

I will probably start another thread asking for help in diagnosing the wiring problem so I don't just go pulling/replacing things and so I can keep this thread strictly about the issue at-hand - in-truck head removal

[highperf4x4]

Originally Posted by Rippin-J

post away!

i found that same thread earlier ...def useful. thanks for sharing, GC.

Do not ever, under any circumstance, hit your crankshaft with anything. I'd skip that thread.

If you have trouble getting your new crankshaft gear on, go stick it in the oven at about 400 degrees for a couple hours. Put on some welding gloves, pull it out, and go slide it on the crank as fast as you can. Keep both gloves over it until you're ready to slide it onto the crank. Air will shrink it quick.

If for some reason you can't make this work, then get the installer that screws into the end of your crankshaft.

Do not ever, under any circumstance, hit your crankshaft with anything.

[gcburdic]

Hey J,

post a WTB ad over in the parts section and see if anyone has one that is in pretty good shape....I say replace it now if you can....why wait for the truck to burn up and say if I only replaced that when I was there?!?!?....Just my $0.02!!

[gcburdic]

Sorry for the double post.....

by the way J, i think I saw a harness for the headlight section in my garage last night....if you need it??

[Rippin-J]

actually the wiring for the lights and everything is clean and functional. it's everything the leads to the motor that is half-assed.

Here is the thread I posted for WTB - http://67-72chevytrucks.com/vboard/s...31#post3339131

going to try to get head #2 out tomorrow evening and will update thereafter.

as usual, thanks to everyone for the input ....very, very helpful.