Dauntless Head Removal

Just the pic probably. It hasn't ran right since I bought it, wasn't seized, hoped it just needed carb work or something. Had this intake backfiring problem since day 1. Had been sitting for at least a year when I got it six years ago. I'd hoped to at least be able to identify the problem with these cylinders before committing to a complete rebuild. I could try rebuilding the 1 and 3 lifters and valves, and a new headgasket, as perhaps that should run cheap, put it together and see if there's a compression improvement? If it gets better, then I decide, OK we have the major problem figured out and it still has life left. I can start rebuilding the drivetrain.

 

I would go ahead and send heads to machine shop . now the block . I would also rebuild it . your choice . timing chain / cam and lifters would be my concern . any marking on pistons . as to size .

 

I hate to say spend more than you expect / really wanted to, but you're already this far down the rabbit hole. The time and effort to put it together, pull it back apart, let alone the cost of the gaskets ($75 or so, IIRC), would have me on a rebuild path. Do it once, do it right, be done and not second guessing it... everyone's personal mileage may vary tho.

Tarry99 and Twin2 offer the same advice.

I went through an econo-build on my short block and head job (done by a buddy's shop), I added a new HV oil pump from TAPerformance, new rods/lifters from TAPerformance, NOS timing components from a member here and some other bits of new odds and ends I scratched about... mounted in the frame and attached to the transmission, not fired up yet.

Tarry99's build thread he shared with you sets the bar for doing it in detail with paths to follow for the home / shade-tree rebuilder, and paths for the guy with all the cool tools that knows how to use 'em. It is a great read if you have not read it.

 

I understand the points, but my thing is, time is something I have enough of as this is primarily a learning experience for me. If I just rebuild it now, I likely won't have learned what the original problem was, and that will annoy me something fierce, it's just in my nature to need to understand things like that. If I have to change one thing and put it back together 5 times, I could live with that as long as the cost of each change isn't exorbitant, because I'm learning as I go. Paying for an education essentially lol. I do feel more and more like I could tackle the complete rebuild at some point, but before I get there I just need to develop a deeper understanding of the engine by this diagnosis process. That's why I figured get a head gasket or two and a valve spring compressor, reattach the top end, perform a leakdown, if it's still bad, pull it again, rebuild the valve seats or whatever, and try again.

Luckily I only have to get the head on to perform a valid leakdown test right? Manifolds can sit on the sidelines for now? That doesn't seem like a lot of work to keep testing one thing at a time until I find what restores my compression (or doesn't, in which case maybe it is rings).

 

I'm still with you on the just fix what's wrong.
I'd at least pop the valves out of the suspect cylinders on the head and have a quick look.

 

The heads can be vacuum tested before removing the valves to identify the leaking valves. I've heard of pouring diesel fuel into the ports as an alternative to the vacuum test.

 

I could go either way as far as full rebuild or fix a couple things. Personally, I would probably do a cheap refresh on the whole thing. The only thing you really need to have done is block boiled, cylinders bored and maybe the head/ block trued. If you wannna spend money having new valve guides or ones in there knurled or machined for real seals is good. I would have a machine shop install the cam bearings too. Its kind of a PITA.
I need some engine advice

Lapping the valves is easy and close to free. The rest of the stuff is pretty easy to do. Just get a book or cobble together some torque specs and do it.

 

Looking at the shots of your lifters, the most critical area is the flat that rides on the cam. You can check for flatness by holding that bottom against the side of another lifter. The surface that rides on the cam should actually be crowned (convexed) and should rock slightly. Your lifters look like they are done for. That means the cam could be in the same shape as they wear together. The pushrods, so far, look to be in good shape and will likely clean up fine.
All those dead-end passages you see on your heads will make more sense when you compare to the other head; they are the same (not handed right and left). The intake has a large water passage from the thermostat area to the front of each head. There is no similar passage at the back of the manifold, though the heads have a passage that is blocked by the intake.
-Donny

 

On thing I learned from Tarry99 was that you can use water to clean engine parts. I have been using oven cleaner and a small wire brush on smaller parts to get them clean, then rinsing with water, repeating as required, dry with compressed air and shoot it with WD40 to displace the rest of the moisture. I just finished doing that process on a motorcycle transmission/assembly where I split cases and it worked excellently. I even cleaned the roller bearings in this fashion and it worked perfectly.

I would take that head apart, clean it real well, check the valves and mating head surface for straightness. If the valves are good, lap them well and assemble. Take the rocker assembly apart too and look at the bottom of the rockers to check how badly they are worn into an egg shape. If your push rods are straight and the ends are round, reuse them. One of the oil passages that is full of junk in the block is not used to oil the head.

Every 225 V6 i have taken apart has had round cam lobes and bad lifters. I expect yours is similar.

 

Looks kinda like the oil was drained and then the engine run with no oil. Lifter valley too clean and the top of the heads too clean. Shows some push-rods galled to the lifters.

 

If you have an extra dishwasher laying around, it can work great for a small parts washer.....

 

I so want to do that.

 

No extra dishwasher here, just the one I spent $300 getting fixed so I'd like it to stay functioning for a while.

In lieu of doing a vacuum test, I read that a fluid test can also be performed to test valve seal. Well, all three intakes failed. I'm not even sure the #5 (which had good compression and decent leakdown performance) was much slower to leak than the other two. I used carb cleaner shot in copious amounts into the intake port and tiled and watched for it to seep down from the valve. It was basically more than just a seeping. More like a running out. So, clearly in need of at least a lapping, if not a full rebuild with new hardened seats installed by the machine shop. As far as diagnosis goes, is it even worth attempting a lapping to see if I can get a decent enough seal with that kind of leaking? I actually would like to do a vacuum test first just to get some concrete numbers for comparison.

Thinking about building something like this here DIY - Vacuum Tester to Test Valve Job for Less than $20 - NASIOC
Could be nice to have a tester like that on hand in my collection, and some spare material to build additional plates as needed.
That pump isn't available anywhere I can find now, but https://www.amazon.com/gp/product/B000SKYV20/ looks like it would be equivalent.

I'd be willing to spend a little more to not have to make a homebrew tester, but these seem to be something only high end machine shops make and charge $500-$1000 for. I can settle for a homemade kit for that kind of savings.

 

Unless the valves & seats were recently ground , lapping is a waste of time.......and as far as vacuum testing the seats and ports. This is not a high performance engine and even after having a competent mechanic grind the valves , seats and clean up the guides and install seals............putting <-10> inches of vacuum on them they will still probably leak some. Just not that big of deal when the pressure within the cylinder is not that high.

I would take them to a good machine shop and have them tune them up..............grind the valves and seats, install hardened seats in the exhaust side and have them install a good press on stem seal..........they should also check the flatness on the head surface............I would also talk with these folks about looking over the short block as I feel it also needs attention.

 

I would not be surprised if the valve seats are damaged. Your heads require hardened valve seats to run on unleaded fuel if you're going to do regular driving. I'd for sure take the opportunity to upgrade the heads while they are off.

 

I've read a lot of discussion on the hardened seats for unleaded fuel thing, but it sounds like if they're already off and getting the work done, better off installing them now than worry about pulling them again, as long as it's in the budget.

I'm still going to take the time and get the numbers for posterity's sake, as I want to have something concrete to say, #1 and #3 were X percent worse than #5/#2/#4/#6, and this explains the significant difference in compression and leakdown results for #1 and #3. Again, this is a learning experience for me mostly, and also, diagnosis is really one of the things about working on old vehicles that I like the most. Perhaps if I understand specifically what went wrong, I'll know where to spend a little more money to prevent it from happening again.

That being the case, I probably want to get as much info from the head and valve system specifically as I can before I take them to the shop. That would mean at least disassembling the suspect intake valves myself, to inspect the seats, valves, guides, etc for any abnormal wear or damage. Unless this is something I would expect the shop to do before performing any work and letting me know what kind of oddities they saw.

Ultimately though, it looks like I will be getting the heads rebuilt, as well as cleaning up the intake manifold, and rebuilding the lifters. I'm skeptical about replacing the parts like lifters or pushrods just because, as I have no guarantee the replacement parts were built as well as the originals. I can provide more photos of the rods and lifters, etc, if it would help tell whether they are worn beyond re-use or not. I can't really find much info on testing hydraulic lifters for proper behavior online. The FSM has a guide to rebuilding them, which is why I planned to follow that as it seemed reasonable to do that vs replace them, if they can be salvaged. Also not sure about what's involved in adjusting the valves once it goes back together with rebuilt lifters.

 

I should have mentioned I was where you were a year ago. I had multiple issues with my Dauntless and the most significant was a blown head gasket on #5 to a water jacket due to corrosion in the cooling system. However the seats in my heads were in various states of degradation causing smaller compression variances in other cylinders. My point is that if I had just put headgaskets on I would have continued to have engine issues.

In addition to a valve job with the heads also resurfaced I ended up replacing the cam, lifters, pushrods, three rocker arms, timing chain, tensioners and gears, oil pump, water pump, fuel pump and about 10 broken bolts. Mine runs great now. Good luck on your endeavor.

 

Mostly I think I'd just like to get a couple years out of it until I can move to a place with a bigger garage. That's definitely in my life plans. If I can get that much out of it, a full rebuild is probably in its future. Plus, this is such an easy engine to work on and get to things, compared to most, if I have to take the top end apart a few times I'll just keep getting better and faster at it.

The FSM mentions "valve lifter pliers W-324 or equivalent" for checking lifter leakdown; anyone know where to get a tool like that? I haven't had any luck with Google so far. If not I could probably rig something up that would do the same thing.

 

So assuming I do decide to disassemble the valves myself for inspection, I need a compressor. Found a few that look like they could do the trick on Amazon. OTC is a brand I've liked for a while but they do cost quite a bit more. I did just see that it dropped $6 while in my cart though, so I should probably grab it before it goes up if that's the call to make here.

TruBuilt (Chinese junk? Several copies floating around in this price range) https://www.amazon.com/gp/product/B010CMK4B0
Copies like this one https://www.amazon.com/Unknown-50602-Valve-Spring-Compressor/dp/B002GQEZH0
OTC https://www.amazon.com/gp/product/B000F5ECUY
J&R (several sellers with basically this style floating around) https://www.amazon.com/Quality-Tools-Spring-Compressor-Service/dp/B00XO6BW40

I'm leaning towards the OTC one but if one of the others would be just as good it'd be nice to save the money. There are what look like a lot of other clones of both styles, I'm guessing most of them are similar build quality, about what I would get at Harbor Freight. Wondering if there's a reason to go for or avoid the lever-style ones, etc. There are other styles but only in the way more expensive price range, not sure I'd need anything more than the OTC one so that's where I figured I'd put my ceiling on this.

 

Beauty of buying good tools is they will last your lifetime and many more.