Dauntless Head Removal

Got a couple bad cylinders on the driver side bank. Both reading about half the compression of the other 4 cylinders, and terribly low readings when doing a leakdown test on #1. Not sure if it's the head gasket or bad valves on both #1 and #3, but the leak seems to primarily come out of the carburetor from #1, and I got lots of backfiring trying to run it.

This truck is really just my learning experience, had it for several years and only gotten this far with it. So I was wondering, is it possibly on a stock Dauntless setup to pull the driver's side head without removing the timing cover, etc, and just pulling the carburetor and manifold? Used a borescope and the piston looks fine but couldn't get the mirror that came with it to work well enough to see the valves. Just wondering if I can pull the manifold and the head to see where the problem might really lie, and get just enough parts to put it back together and get it running again. A more complete head rebuild might come down the line if I can get it as far as staying running under its own power. The manuals mostly cover pulling off a lot more from the engine than looks necessary to get at the head bolts, so just wondering if it might be as easy as I hoped.

This will be the first time I've town the heads off of any engine, FYI. Like I said, learning experience.

Edit 10/18: The teardown began, post gets pretty image heavy middle of page 2.

 

Welcome to the party.

yes you can take the head off without pulling the rest. Lots of good info around on checking your dauntless out, Tarry99 has a great 'blue-print build' article on the dauntless in the tech section and is a soup-to-nuts reference for all to review.

There's a few dauntless related posts currently.

A factory service manual (not a chiltons, etc.) will be your friend. They can be found on ebay. There are electronic (PDF) versions. I have one of these, it's pretty decent, but some of the images get blotted out (too much toner in the image problem).

Your digital camera, your phone camera, etc. will also be your friend. A hosting service like photobuck or flickr will be useful for posting pictures here, and keeping a 'backup' of your hard work. (google drive, drop box, etc. are also good places to keep backups of your photos, and are free)...

 

Usually ... when you have one cylinder bad, it's a burnt exhaust valve. You have two bad cylinders, which makes me suspect the head gasket more. Pulling the head is pretty easy, especially when the heads are small like on a 225. Not sure why a head gasket on a 225 would fail though... the head is short, which makes warping unlikely. Leave the exhaust manifold attached, and take it loose at the pipe. Leave the carburetor on the intake and lift off the whole assembly. At a minimum you'll need a head gasket, manifold gasket, and exhaust pipe gasket. And a torque wrench.

 

It's been a lot of years since I've had one of these apart, so someone please correct me if I have memories mixed up.

Remove the rocker assembly first, and make sure the push rods don't "stick" to the rockers. If you pull that out too fast, or pull the head off without removing the rocker assembly first without care, the push rods can stick to the rockers AND to the lifters down inside the engine, and you'll make the job bigger than you planned by tearing it down to put the lifters back in their homes. Everything sorta sticks together from oil adhesion in the cupped mating surfaces of the push rod ends. After the head is off, you should be able to see down in there to make sure you are pulling the rods out without bringing the lifters with them. Or just leave them sticking out.

 

with intake off you'll be looking at lifters and push rods . valve covers and intake first . then rockers shafts

 

We're talking about doing it without removing the intake. It's not necessary for just pulling a head.

 

Really? I can understand leaving the timing cover on, but I would think reassembly without removing the intake would be difficult. And you'd still need an intake manifold gasket set, so there's no real savings in not lifting the intake off. You'd have to position the intake gasket and the head gasket at the same time ... if even possible, it would be particularly difficult for a just-learning mechanic.

 

My bad. I thought that's what we were talking about.

He's trying to get it going with minimal effort, and not pulling the intake is easier than it would seem. BTDT. On reassembly, just tighten the intake bolts as you tighten the head bolts, and everything draws in nicely.

 

The intake is attached to the heads though right? So wouldn't not pulling it separately, basically mean I'm pulling the heads and the intake all as one unit? Ok I guess it hadn't occurred to me that might even possible or easier, but I had already planning on removing the intake separately since I was planning on only messing with the problem head for now to see where the actual problem lies. Planned on a FelPro or VR upper rebuild gasket kit. Already have the blue book manual reprint and a PDF copy, and the 40-something to 86 Haynes PDF.

I definitely suspected head gasket because of the adjacent cylinders, but while I had the leakdown tester hooked up to #1, I took out the plug on #3 and did not seem to feel any blowby through the plug hole. Additionally, with the valve cover off, I don't recall that the #3 intake valve was open when the #1 was at TDC on compression stroke. Based on just all that, it would seem the only good explanation left for the majority of the leak going out the carburetor would be the intake valve right?

Wish the stupid borescope mirror I got was worth a darn, but the entire Android borescope kit only cost me $15 so I can't be too surprised. Camera itself worked well enough to see that the piston tops were in ok shape if a little carbon coated.

And yeah, I always document the complicated disassemblies with my phone camera as I go, it's definitely helped with every carburetor I've rebuilt so far. I even have this trick now of not only documenting what the carburetor screws were set to for a rough estimate, but I photograph the exact screw position so that with both the written note and the photo I can put the screw back exactly as it was, and fine-tune from there.

I'll take a look at that blueprint thread. I'd already read a photo-heavy thread of a complete Dauntless rebuild on 4wdmechanix, but that one hadn't come up on Google yet. I'll admit, I've been a member here since I got this thing years ago, but the site reorganizations have really made it hard to find a lot of the info I used to peruse here. Looks like that tech forum might be where some of it has ended up.

I kind of get a wild hair each year about this time because the weather's nice enough for me to mess around with it in my garage. This year though, I might just move the motorcycle and some other stuff more out of the way so I can work on it with the garage door shut and some space heaters running, assuming I can figure out how to get this current problem fixed.

For anyone curious, I'll include some history on my time with this CJ5. It's become kind of depressing really. When I first got it, I figured, the engine wasn't seized, shouldn't be too hard to get it running, then I'd rebuild the blown T-86 and the Dana 20 and be off to the races. But first the distributor hadn't been timed correctly (bracket was loose so I couldn't trust it), then I unstabbed it without thinking and really set myself back some time while I got around to figuring out how to time it. Once I got that locked down, decided the carburetor needed a rebuild as it just still wasn't running right and thought an accelerator pump was stuck or something. Fresh carb rebuild and this thing would just run like horse manure for about 5 seconds and die. That's when I decided I needed to get some experience with a compression and then leakdown tester. Partway through the compression tests, the starter crapped out on me. So I got a reman Delco one for $15 after core rebate from Amazon because they had something messed up with their pricing (supposed to be $40 after core rebate, but they kept listing it for either $40 or $65 depending on the time of day), and then had to wait until I got the girlfriend's stuff moved out of the garage enough I could get to the starter area easily, and as I don't do anything quickly except type, that took me a while. Once that was done, finally finished the compression test, and also realized that taking the shround and fan off would make using a long ratcheting breaker bar the easiest way to put the engine where I want for a leakdown test. So I've spent a lot of time enhancing my tool collection specifically for this Jeep but haven't gotten much closer to having a running engine yet, and I figured I'd have had it running sometime in 2012 when I first got it. At this rate I'll probably end up moving again and having to either sell it or flat tow it to another house to sit in another garage (it's been towed to at least 3 garages and another driveway since I owned it).

 

Have you leaked the rest of the motor?.............2,4,& 6? Most times a leak that you can hear through the Carburetor is an Intake leak but you can further verify that by taking a brass or soft tipped plastic hammer and while the leak test is in progress do a sharp tap of the tip of the rocker above the valve spring and listen for a change in noise or tone , of course don't damage your parts!

I would also do a TDC ( Top Dead Center) check on #1 Piston.........meaning getting that Piston up to TDC on the compression stroke. Once at TDC or as close as possible.........look at your front cover timing marks versus the single mark on the vibration Dampner and see how they both line up.....Then pull the Distributor cap and see if the Rotor aligns with #1 spark plug in the cap............backfiring and low compression can be valve related , timing related , piston rings and perhaps even a head gasket.........but normally with a head gasket blown between 2 cylinders there may be air bubbles in the radiator when running or during the leak testing and water that is oily and contaminated and the escaping air could be heard out the spark plug cavity...........In either case check all of the above before you take it apart.............much easier to confirm things with more points of information.

 

The head fits into the corner formed by the intake and the block. The manifold sits like a plug in the valley formed by the heads and the block. The head bolts go down into the block, under the valve cover. The bolts into the head from the intake are visible up on top. I have no doubt that you can remove the head without removing the manifold - it will still be bolted to the opposite head. However, I kinda thought it would be difficult to position the gasket between the head and the manifold while keeping the head gasket in position. Seems not. What you usually do is install the two heads on the block, torque down the head bolts, then plop the manifold down into the valley.

 

The heads are on the block at 60 degree opposing angles and are also located by dowel pins in each head...............next to impossible to remove these 3 components as one.

 

Yes, but can you R&R a head without removing the manifold?

 

Yeah that's what I figured, I'll go my original plan of removing the manifold, rocker assembly, then the head. tarry99, so you're basically asking me to confirm that the timing marks' TDC is actually the piston's TDC? I have already confirmed that the rotor was correct as I spent way too much time making sure of that. The carb backfire is actually what was throwing me off. I thought for sure it must be 180 out, so I'd rotate the cap 180 and see if it changed and it ran as bad or worse. My leakdown tests were annoying on #1 as well. And no, I haven't leaked the rest of the motor yet because using the timing marks to line up TDC is only easy for #1 and I guess #4? Not sure with the Oddfire if there's another cylinder that shares a 360 out TDC with #1. I'll probably use the borescope or a dowel or something tonight to try to find the top of the other cylinders and leaktest them as well. I have a problem of making things I haven't done before into a bigger deal than they probably seem like they should be. I've had a habit of rushing into things without thinking first before and end up breaking something expensive, so now I overcorrect and read and research the problem to death before I take any real action. Here were the results for my #1 cylinder, one is at TDC on compression and the other 360 around. I can't tell the difference can you?

 

The manifold would have to be loose on both sides to allow for enough clearance to raise the head beyond the dowel pins.............once the manifold is loose it may as well come off so that it can be resealed.

 

By the way, lots of awesome info so far in that blueprint thread. Maybe some day I'll tackle my own first garage rebuild of the whole block. Just want to hear it purr for a minute or two first at least so I know there's something worth rebuilding.

 

Chief, Take all the plugs out........put your thumb in the plug hole on any cylinder and slowly turn it over until you feel the compression start to push your thumb off......stop there and look inside the hole and bring it up the rest of the way to TDC via a breaker bar off the front crankshaft bolt............do your leak down test.

And what was the result of the timing cover marks versus the vibration dampner?

 

You are talking about the gauge on the cover that you use with the balancer mark right? That seems to line up with the piston's placement and distributor cap, everything looks to agree with everything else. Is there another mark set I'm missing? I already had the valve cover off and confirmed that the rockers were in the disengaged position while the piston was confirmed with the scope to be about as high as it could get. Not that it should matter for a leak test other than keeping the engine from rotating from air pressure right? With the leak it has I don't see it rotating any time soon. I actually planned to rotate the good cylinders throughout the leak test with the breaker bar, perhaps on a lower pressure, just to see what happens. I could pull the rockers to avoid a chance of them being opened. Read that it might be good to check other positions to see if the wall has a bad taper.

 

You have to pull the intake manifold to pull the heads on a 225.