My 71 Duster work in progress

[b-body-bob]

It definitely has/had an exhaust leak. All 3 bolts on the passenger side collector were loose. I was so happy to see that I forgot to check the driver's side, but the noise is all on the passenger side.

It doesn't sound like a Cummins now, but the exhaust on this car sounds like butt even disregarding the leaks. I watched the temps to a little above 190 while setting the timing/idle speed (15* at 900 RPM w/ the vac advance discoed) so the gauge situation is fixed.

 

[Dr.Jass]

The mark at the top must have been me coming back in. I'm pretty sure I heard the sure-grip ratcheting too, so there's that.

Put another bottle of limited-slip lube additive in it. If you've got a Powr-Lok (clutch) diff, the "aggressive" clutches may just be a fact of life. If you didn't install new clutches, though, I think another bottle of additive will clear that somewhat, if not completely.

The transmission isn't happy. It's not noisy AFAICT but it didn't like my weak attempt to bang 2nd or when I tried to downshift into 1st while rolling. All I got was 1st and 2nd. I'll give it some time, wait on the clutch to break in some more.

With a brand-new clutch, it's very likely the pedal has to go completely to the floor to shift properly. Although I don't think it's an issue just yet, if you have the rubber fork bushing instead of the steel ball used on trucks, it's worth checking your adjustment again now that everything's been through a drive cycle. You can also adjust the clutch to your preference; if the release bearing's not touching the fingers at rest it can be closer than OE spec. That would release the clutch sooner in the pedal travel.

It seems pretty danged strong but I've almost forgotten what it's like to have a a muscle car kicking me in the ass.

There are two schools of thought for where you are after an engine build.

The first says to drive it mildly with some part-throttle acceleration to higher RPM but don't hammer on it for 500-1,000 or so miles.

The other says beat it like a stolen rental.

I did the former on my RA-III, and other than its appetite for RH head gaskets and tossing belts that engine was virtually trouble-free. Obviously, the belt issue was my dodgy (at best) accessory drives. The 440 got the latter, and while that engine did lunch on a cam lobe I know that was due to the break-in foibles. Both engines lived rough lives, the 440 arguably rougher which might explain its much shorter life (28K). The Poncho lived through two further owners and a move to CO, where it was eventually sold and replaced with a built 455 that never ran as well.

At 54, I'm much more likely to go with option 1 without issue, but age 20 those 500 miles were agonizing. I was 25 when I put the 440 in my Charger. That car got option 2 due to some sub-legal activity on my part (driving it unregistered/uninsured). With maybe 30 miles on it, I found myself pursued. Trying to outrun the law is one thing; several minutes of loading a brand-new engine over 6,000RPM while doing so makes it downright harrowing. It held and I got away, which is possibly why I was so confident about beating the living crap out of that engine.

The clutch is something. I've gotta avoid stopping on hills until I get used to it or it's going to be wait on the car in front to pull away then 3 grand and dump the clutch.

I have Biondo line locks stacked like cordwood in my basement, not because I plan on doing a lot of drag racing but because they're fine "hill holders" on manual-transmission cars. I used to have hill starts pretty-well nailed. I wasn't fond of slipping the clutch that much, but it didn't seem to have any negative effects (I never smelled clutch). However, having sold my last daily-driven manual transmission more than three decades ago, I'm obviously a bit out of practice.

The problem of locating the switch for the line lock is the issue. I've got it worked out nicely for Agnes, on which the horn ring will be dual-function. I can use the Rim Blow switch the same way on the '74. The '71? I'm not sure. That car will have a Tuff wheel, and the center horn button isn't as conveniently located.

 

[Dr.Jass]

It definitely has/had an exhaust leak. All 3 bolts on the passenger side collector were loose. I was so happy to see that I forgot to check the driver's side, but the noise is all on the passenger side.

It doesn't sound like a Cummins now, but the exhaust on this car sounds like butt even disregarding the leaks. I watched the temps to a little above 190 while setting the timing/idle speed (15* at 900 RPM w/ the vac advance discoed) so the gauge situation is fixed.

Does this mean that horrible noise is gone? It was hard to tell because of the limited audio bandwidth, but on the laptop it sounded like a rod and on the desktop (run through a home stereo) it was either exhaust or valvetrain but still hard to discern.

Check the driver's side anyhow, and it never hurts to give the bolts at the head another check after that first drive.

As far as sounding like butt, do you know what mufflers are on it? It's a very subjective thing, of course, but there are some mufflers that to my ear just cannot sound good--anything straight through, for example.

 

[b-body-bob]

Put another bottle of limited-slip lube additive in it. If you've got a Powr-Lok (clutch) diff, the "aggressive" clutches may just be a fact of life. If you didn't install new clutches, though, I think another bottle of additive will clear that somewhat, if not completely.

This has one of those hypoid diffs in it IIRC. It was brand new so not likely to be a clutch type as I would describe one.

if you have the rubber fork bushing instead of the steel ball used on trucks

I've got a steel ball here but I used what came from Brewers so it's got a rubber grommet on the fork backed with a steel washer.

The first says to drive it mildly with some part-throttle acceleration to higher RPM but don't hammer on it for 500-1,000 or so miles.

I didn't make it out of the subdivision so there was no hammering on it yesterday. I would just goose it every now and again. I will just drive it like normal so not like granny but not like Ronnie Sox either. I've got some ridiculous number of clutch cycles to go through for break in too.

used to have hill starts pretty-well nailed. I wasn't fond of slipping the clutch that much, but it didn't seem to have any negative effects (I never smelled clutch).

Same here. I don't remember any problems with the last 4-speed I drove (blue gTx) but that also had a Centerforce DF in it so I think it was a gentler unit in general. This is WV so we've got a hill or two. Right now it seems like it's either engaged or not but it should become more reasonable after it's worn in some. I've got a Hurst line lock from the A12 if the body shop didn't remove and toss it. I don't really want to go through the plumbing and all that through.

Does this mean that horrible noise is gone

Yes, most of it. There is still either a valvetrain noise and/or more header leaks. I have not broken out the stethoscope (or broomstick) yet. Again, the valvetrain seems OK. For now I am going to avoid doing any lifter adjustment because I am unlikely to improve things at this point.

Check the driver's side anyhow, and it never hurts to give the bolts at the head another check after that first drive.

I've hit those twice now.

 

[b-body-bob]

Here you go





I've got the hood about as good as I care for it to be. In other words, it's unacceptable if I paid to have it done but it was free so it's just fine.

 

[b-body-bob]

Something's definitely going on in the valve train.

When I first started it, clack-clack-clack. I shut it off, found I had a vac gauge laying on the engine, restarted, noise gone. But I knew it wasn't the gauge. left it running long enough to get some heat in it, then shut it down. Started it again after a couple of hours, clack-clack-clack, so I said screw it and left it running and eventually it stopped (or at least got better).

It doesn't sound like it's in the bottom end of the motor. FWIW the engine starts up almost immediately.

Could that be caused by too much or too little lifter pre-load? Too short pushrods (def. not too long)? I don't know.

 

[Dr.Jass]

It sounds pretty good out the tailpipes, in my opinion. It spins up pretty well, too.

Something's definitely going on in the valve train.

When I first started it, clack-clack-clack. I shut it off, found I had a vac gauge laying on the engine, restarted, noise gone. But I knew it wasn't the gauge. left it running long enough to get some heat in it, then shut it down. Started it again after a couple of hours, clack-clack-clack, so I said screw it and left it running and eventually it stopped (or at least got better).

It doesn't sound like it's in the bottom end of the motor. FWIW the engine starts up almost immediately.

Could that be caused by too much or too little lifter pre-load? Too short pushrods (def. not too long)? I don't know.

It's possible that it's a pushrod length issue, but I doubt it. If you were able to get the preload set without the hexes hitting the rockers, you should be good on length. I also doubt that the cup ends of the pushrods are hitting the rockers, but that's one of those "check during assembly" things that's tough to go after now. It's also not likely.

While you had the valve covers off, did you check the torque on the rocker-shaft bolts? It's entirely possible they've loosened after a heat cycle in aluminum heads. I'm not speaking from experience here, just spitballing regarding the different expansion rates of two different metals. It also might be worthwhile to double-check head-bolt torque while I'm on the subject, but I don't expect that would affect the valvetrain.

While it's common practice is to subtract .006" from the valve lash--not preload--on an aluminum head/iron block engine, I'm not sure if one should increase preload by the same amount. Do I think it would hurt anything? No, because the factory preload is all over the place. 3/4 turn past snug would be .031" preload, which is still less than OE. With .006" of growth, you'd still be at .025", which is well within acceptable specs. It's worth considering.

 

[b-body-bob]

It sounds pretty good out the tailpipes, in my opinion. It spins up pretty well, too.

Yeah it seems to run great. That helps with my worries but not a lot.

If you were able to get the preload set without the hexes hitting the rockers

IIRC the hexes won't hit the rockers because there's is dead space above the threads. There are 3 or 5 of them that were at the extreme end of adjustment - 3/4" turn of pre-load is all I could get. But that was all I wanted. Part of me thinks those were all on the passenger side but I might be misremembering.

The rockers all had plenty of threads below the body so there shouldn't be any problem there

While you had the valve covers off, did you check the torque on the rocker-shaft bolts?

I did not. Will do the next time the valve covers are off.

It's worth considering.

I have been wondering if the growth is related to the noise being mostly at startup. If so I think that would mean I have too much pre-load and the growth gives it more room.

Either that or the lifters are bleeding off. I don't know why they would, at least not excessively.

Another part of me questions the used rockers, but I'm not sure what could be wrong there unless I ground them too thin and they're slowly failing.

I think there's no avoiding the need to go through the valves again. I don't wanna.

I'm not going to start it unless I've figured out something to change. There's no reason to keep starting it up just to check if it's still noisy.

 

[Dr.Jass]

I have been wondering if the growth is related to the noise being mostly at startup. If so I think that would mean I have too much pre-load and the growth gives it more room.

Based on my experiences, a collapsed lifter in a SBM sounds like a rod knock. It's loud and it's not a tick--it's a knock. I thought my engine was coming apart but it was just low on oil. Long story, but don't let your pal borrow your car based on a free full tank of fuel. Things snowball after he accidentally fills it with diesel.

Anyhow, I don't think "too much preload" is a concern. The factory stamped rockers can put .060" or more preload on the lifters, and you're nowhere near that. I had .030" shims under the rocker shafts in my 440 and still had quite a bit of preload. Although I didn't measure it, I'm pretty certain it was still .020"-.030" depending on the lifter (production variances). I eventually took them out--I got tired of losing track of them--and other than a slight loss in willingness to rev, nothing else changed.

Either that or the lifters are bleeding off. I don't know why they would, at least not excessively.

Possible, but not likely. It is possible you got a bad one that's bleeding down, but short of pulling the intake I don't know any way to confirm such a thing. Plus, you said the rockers were all moving normally when you had the covers off. If one was bleeding down I'd expect you'd see less movement on that one.

It's also possible, though not likely, that you've got a bent pushrod that's requiring the lifter to pump up to quiet it. Pushrods can get bent during the installation process if the ball's not fully in the lifter cup or the top gets wedged under the rocker (not on the adjuster) when the shafts get torqued. I nearly had that happen on the W2 heads, because they don't have nifty cast-in rocker-shaft stands across which one can lay a coat hanger to align the pushrods. The stands go on with the shafts on W-series heads.

Another part of me questions the used rockers, but I'm not sure what could be wrong there unless I ground them too thin and they're slowly failing.

You'd have to grind them awfully thin, especially with ductile iron. You'd also probably have to grind the rib across the top. I've got some aluminum arms that are absolutely hogged for mega valve springs that show no ill effects in the engine. As far as the rockers being damaged, methinks it's a non-issue. If the tip hits the arm and the adjuster's in the cup, it shouldn't make a difference. Yeah, if one was bent or misshapen you'd probably lose (or gain) some ratio, but I can't see where it'd create an audible problem.

Were it a burned/misshapen adjuster ball, I would expect the noise to be constant. As you may recall, I had several on the W2 engine. It sounded like a typewriter on tin with the valve covers off. A lot of blame for that falls on the defective Sealed Power rocker shafts that were leaking oil--a lot of oil--past the end plugs rather than spray-oiling through the rockers.

I think there's no avoiding the need to go through the valves again. I don't wanna.

I don't blame you. It's tedious. Also, if I don't touch it there's no possibility I can make a mistake.

Unless I made it previously.

And then I'll probably make it again.

 

[b-body-bob]

I don't blame you. It's tedious. Also, if I don't touch it there's no possibility I can make a mistake.

Unless I made it previously.

And then I'll probably make it again.

Yeah that sums it up.

I've got the valve covers off, the rocker shafts are torqued, nothing is loose but that doesn't mean anything until I've looked at each one while the lifter's on the base circle. I thought it was kind of odd that in the photos it looks like only one side hasn't bled completely off, but again, that doesn't mean anything but a snapshot in time.


I read of some Fram parts not having Anti Drain Back Valve (ADBV), which can lead to lifter bleed, but according to the Fram site, they all have an ADBV. If an ADBV is what I think it is, a rubber looking seal behind the end cap, it's definitely got one in it.

 

[b-body-bob]

In a close up of the rocker adjusters you can see some are sunk, others are not. I didn't pay enough attention to that when first noticed because by then I was just sick of it and I had the pre-load that I needed. It was at the limits on some of them though to where I didn't think I was going to make it.

Maybe that loosened up just enough after starting the engine to where some of them are rattling. Or, maybe the cause of those sunk adjusters is wear (but where?) that in turn causes noise?

But I mos def had 3/4 turn after zero lash.

Driver side


Passenger side


I see at least 3 in there that could use a longer pushrod.

I think the next step is to loosen all adjusters one turn, and check/set the pre-load again. I think I will have to use the TDC method to be sure I'm not missing lifter action all the way at the top. IOW I don't trust that one or more lifters isn't bled off to where the valve spring has closed.

 

[Dr.Jass]

I see at least 3 in there that could use a longer pushrod.

Pushrods aren't really an exact science. I measured at several points in my engine, averaged 'em. My adjusters weren't consistently at the same depth, despite being solids. I didn't sweat it because the lash was good across all 16 lifters.

 

[b-body-bob]

Yeah I dealt with measuring for the pushrods as an inexact science too, but it kind of has to be unless you've got a fully kitted out machine shop. I remember measuring and remeasuring over way too long a time period because I was never sure I got it right.

I will probably continue studying it to look for something, anything, but as far as I can see my next move will be rolling it over to the next 90* mark and re-running the valves from there. It's just past #6 TDC so the next mark is going to be #5. Maybe something will show up during that. I sure hope I can get to the crank without taking the fan off.

Would it be smarter to go ahead and remove the rockers again, just to look before running the valves?

I'm skeptical that there's anything wrong because it runs so good, but that noise, man o man.



I noticed there are some gaps beside the rocker arms - I presume these are self-centering and don't need shims. You can see that in the photos from above that show the whole head side to side.

 

[Dr.Jass]

Would it be smarter to go ahead and remove the rockers again, just to look before running the valves?

I'm not sure that would accomplish anything, really. There's not much you can see with 'em off that you can with 'em on, unless you think you've got a bum adjuster/pushrod tip or a beat valve--neither of which I think is a possibility unless you assembled it that way. I wouldn't think it has enough run time on it to have sufficiently failed anything yet.

I'm skeptical that there's anything wrong because it runs so good, but that noise, man o man.

I get it--I hear noise, I'm worried about it and want to find the source.

I noticed there are some gaps beside the rocker arms - I presume these are self-centering and don't need shims. You can see that in the photos from above that show the whole head side to side.

They can be shimmed, but how you've got them is how they left the factory, even on the wild-solid-cammed '66 D/Stock factory Dart. I don't think there's anything to be gained there whatsoever.

 

[b-body-bob]

I made it as far last night as to pull the plugs, drop the fanbelt, and turn it over by hand to the next mark.

The first valve to check there is #6 I, and guess what that is the one that is the most maxed out. I tried to break it loose with 1/4" tools but ha ha sure I will. By then it was time to put the feed bag on and I didn't go back out. I'll use larger tools next time.

A tip, FWIW, a piece of tape around the extension with the two ends stuck together like a pointer keeps you from losing track of how many turns you've taken when you absent-mindedly spin the ratchet backward.

 

[b-body-bob]

I ran the valves, didn't notice any big discrepancies. I've got 5 that won't go past 3/4 of preload, the rest I took a full turn on.

I see instructions telling me that I should spin the pushrod and feel for resistance. I really don't get that, so I loosened them up until I could move the rocker by grabbing it by the "nose", then tightened until I couldn't feel any motion in it. Then went 3/4 or 1 turn further.

I dunno what's next, maybe drop the exhaust on that side to see if I can seal that up better. That would just be an attempt to eliminate extraneous noises because I'm 99% resigned to it not being that. I think it's the lifters bleeding off, for whatever reason. I'm gonna swap out that oil filter just because too.

 

[Dr.Jass]

When I set lash/preload, I start at a point where the pushrod rotates freely but has no up/down movement. In my mind, if there's resistance, there's already preload.

Don't discount the exhaust out of hand. Many a valvetrain problem has been solved with exhaust work.

 

[b-body-bob]

When I set lash/preload, I start at a point where the pushrod rotates freely but has no up/down movement. In my mind, if there's resistance, there's already preload.

That's my mindset too. I remember going back through them and looking at the lifters to make sure the plungers were all about a sparkplug gap off the retaining clip. So I wasn't expecting going through them again to improve anything. Now some of them have a little more preload than before.

I just remembered noticing one pushrod cup had a tiny ding on the top edge. I need to go through them again looking for that.

Don't discount the exhaust out of hand. Many a valvetrain problem has been solved with exhaust work.

Maybe it's part of it, but it's not it because it gets better once it's run for a little while. Next startup I'll video the whole thing. I've got a habit of turning the key off as soon as I notice it, then when I restart it there's little to none of the noise. Like I said, the only explanation I have is the lifters are bleeding off.

 

[b-body-bob]

There you are dammit. I put the full size photos out so you can zoom in to see what I finally noticed...



It looks like some rocker arms are hitting the valve retainer. If that's what is making that perfectly straight line on the retainer, this would be called dodging a bullet.

 

[b-body-bob]

Well I've never been so disappointed to have not found a problem.

Those lines are just grease or something on the retainer. It wiped right off. It's weird that the other side does not have them. So there is something different there.