In-truck Head Removal - need advice

[Rippin-J]

Originally Posted by highperf4x4

Since you're pulling all the accessories off the front of the motor anyway you can take the 4 bolts out of the water pump and take it off to drain the coolant. That will get your coolant below the head line. That's how I do it when I'm pulling them in the vehicle.

As mentioned before, pull the intake first and spin the motor (take the spark plugs out and it will turn easy). If the lifters for that cylinder aren't moving as far as the others then it's the cam and you need to pull the motor and start from scratch.

If you're going to do one head, then you should do them both. If the engine is old enough that it doesn't have hardened valve seats for unleaded gas then you'll want to have them installed. If the engine is high mileage then you can expect it to smoke after you do the valve job as you've increased cylinder pressure thereby increasing "blowby"

Definitely put some clean rags in the cylinders before you start cleaning off the old head gaskets but I wouldnt' drain the oil until after you've cleaned the gasket surfaces. Whatever falls in the motor will drain out better with the oil. I'd also flush the lifter valley with deisel fuel while you have the drain plug out. Run your finger around in the valley while you're at it to see if you find any copper. Copper is in the "core" of your bearings. If you find any then your bearings are in bad shape and you should pull the engine and rebuild it.

Another thing to check while you have the heads off is the "ring ridge". Your piston rings stop about 1/4" from the top of the cylinders. If you find a pronounced "ridge" there then your cylinders are extremely worn and you should pull the motor and rebuild it.

adding all of the above to my 'things to look for' notes. thanks.

[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.

[berencam]

Get a couple boxes, poke some holes in it in the same bolt pattern as on your heads and use it to keep your bolts straight. Some people dont care, but i always put every bolt back in the same hole, same thing with the pushrods if your reusing them. Also dont forget to thoroughly clean the bolts before installation. There is a specific bolt pattern, USE IT. When reinstalling the intake you can cut off the heads of two old bolts, and screw them in on one side to hold the gasket in place, then on the other side use just a tiny spec of high temp sealant to hold the gasket in(depending on what gasket you use you dont use silicone on it, some require silicone in key spots). So when you go to install the intake you go in at an angle to the side with the studs, then rotate it down to the other side. Hope that all helps.

[Rippin-J]

the box idea is perfect, thanks.

highperf4x4 - if it is indeed a valve issue, what could the possibly cause have been? that's why I used the "" when talking about the motor being "rebuilt" cause it's all say-so ...I have no evidence other than a super clean motor and it would check out with the condition of the rest of the truck having been taken care of and in good shape. if you want, I can pm you the long version of the story of the motor since I have had it, I just didn't want to distract on this thread from what my initial purpose was... thanks.

[BluTrukker]

I bought a 91 chevy a while back that was basically the same scenario. Owner rebuilt the motor, then he died and the truck sat for 5 years. I had one cylinder going bad, and a lot of blow by. Pulled the heads and found one cylinder that was all rusted and pitted near the bottom. It took out the rings in that hole. Ended up replacing the engine all together. Not to scare you, but it can happen.

[WorkinLonghorn]

I had a cylinder drop down to 20lbs or so on my last '69 and it was a burnt valve. Pretty easy to take a head off. I didn't bother with the other side since it was good (and I never had a problem with it later).

One thing,maybe mentioned already- I didn't read every post. You will be scraping old gasket material off of the block and you should stuff a rag into each cylinder to keep stuff out. I also like to vacuum out all the little pieces before I start re-assembly.
Buy a gasket scraper, or just use a narrow (1-2") putty knife,(put the bevelled side down when working or you can nick up the gasket surfaces,plus it's a pain).

[Rippin-J]

WorkingLonghorn - Thanks for vote of confidence and reinforcing the rag-in-cylinder pointers.

Should have some pics and more questions tomorrow for everyone after I dig in.

[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.

[Rippin-J]

hey all,

ended up getting busy doing domestic work this past weekend (!!!), and since I am working outside I am at the mercy of the rain until it subsides.

It might be a couple of weeks (mother's day weekend, vacation, etc) before I am able to give this enough time to work on, but will post some updates as soon as they come!

[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]

Originally Posted by Rippin-J

the box idea is perfect, thanks.

highperf4x4 - if it is indeed a valve issue, what could the possibly cause have been? that's why I used the "" when talking about the motor being "rebuilt" cause it's all say-so ...I have no evidence other than a super clean motor and it would check out with the condition of the rest of the truck having been taken care of and in good shape. if you want, I can pm you the long version of the story of the motor since I have had it, I just didn't want to distract on this thread from what my initial purpose was... thanks.

Hey, sorry I missed this question!! If it's a valve issue and not a piston/ring then it could be either a burnt valve or a burnt seat. If it has the original heads on it then it won't have hardened vavle seats for unleaded gas. It could also be a flat cam lobe that isn't opening the valve far enough. You can check that after you get the intake off by spinning the motor and watching the lifters. If that intake lifter doesn't move very far then the cam is shot.

[Rippin-J]

UPDATE...

Finally got into it yesterday with the help of my friend gcburdic from up the road.

nothing surprising (to an untrained eye) and everything came off smoothly.
- no copper in the valley
- everything was clean (compared to pics/videos I have seen in trying to learn about this)
- lobes on cam seem to be in good working order (though I am going to include a pic of the lobes for the cylinder in question ... #6)
- no signs of disaster on the rods or lifters
- gaskets were all in decent shape (though there is one oil drip in question around the #6 cylinder I will include in the pics to follow)

so, my amateur assessment is that there is nothing upon inspection that points to any major problems - emphasis on amateur - so my thought is that there is something only a pro or a shop can diagnose now.

pictures to follow...

[Rippin-J]

first pic - open valley
second pic - pic of the head gasket, note the oil on the left side of the third cylinder opening (#6 cylinder) ...is this a problem?
third pic - bottom of head for #6 cylinder (bad cylinder)
fourth pic - bottom of head for #4 cylinder (a good cylinder)
fifth pic - note where the screw driver is touching the lobe. each of the lobes had this little grove (I assume) caused by running against the opposite side lifter. ALL of the lobes has this little notch, but we figured we'd snap a shot of the lobe for the cylinder in question in case anything caught your eyes!!

NOTE - should have drained the coolant from the bottom of the block first (see coolant in pic #2)! dammit. AND notice the shotty wiring in the back of pic #1. that's the next project ...I hate electrical. ALSO, thanks to gcburdic for coming through with a camera as mine never made it back from colorado over memorial day weekend!

[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.