1984 Bronco build thread

Gary,
Thanks for the warning about wet pavement - I hadnt heard that yet. Ill be sure to take it easy until I know what its going to do. I have considered a 2nd battery but hadn't thought about it as a solution for my stall out issue. its certainly something I would consider. the odd part is that the engine doesnt necessarily die while the winch is rolling and drawing current, it can sputter out and die any time even if its been several minutes since I used the winch. A 2nd battery and an isolator may be coming down the line eventually for camping/winching etc. I have heard a lot of talk of POR15, Ill do some reading. Thanks!

Randy - Good luck! I will end up needing a new choke housing (mine is cracked), a choke cap, and I think Ill wrap copper tubing around my exhaust manifold for hot air. I have seen some other 300-6 users on this site do this and get good results. I do think its a better solution than the manual cable, its just going to take more doing to get right than I can dedicate right now! I'm currently push mowing about an acre of grass once a week because my snappers engine locked up, so I need to put some time into fixing that, then the other more glaring issues with the Bronco. I do hope to circle back to the choke soon.

Not sure what is causing your stalling, and it doesn't sound like the winch is really doing it.  With a 1G alternator, which would be stock, you wouldn't have much power being generated at idle.  So you could pull the battery down during winching and if you had much else running it might die minutes later as the load finally takes the battery below whatever is required for ignition.  But with the 3G you shouldn't have that problem as it should easily keep up with any load, other than the winch, when idling.

Anyway, I don't like the idea of being "out there" where I might need a winch and possibly killing the battery and the engine while doing that.  So that's why I have the aux battery and the Cole Hersee 48530 Smart Battery Isolator 200A.  That way I can pull the aux battery down and still have the starting battery for running the truck.

I should also point out that POR15 gets so hard when it sets up that getting any paint to stick to it isn't easy.  The instructions say to scuff it with some sandpaper.  But that you can top coat it while it is still tacky.

I used to use POR15's base coat and then their top coat, but I found that to be less than desirable as I couldn't get a complete coverage with one coat of the top coat, and by the time you brush on two coats on the brush strokes are showing pretty significantly.

So now I've started using a spray top coat that is UV stable.  Get it on while the POR15 base coat is still tacky, and that's pretty easy, and it sticks.  You can put several coats on of the top coat within the specified time limits of that paint, and it should stick fine.

Hey Guys! Its been an eventful couple of weeks..
I replaced all of my front door and window seals about 10 days ago (write-up/photos coming at some point) and its been much quieter in the cab which is awesome. I would highly recommend this repair for a lot of reasons, but perhaps the most important is that you may hear some new sounds. In my case, I heard some pinging at part throttle around 2500 rpm any time I was on a positive grade. I assume its been there since I did the DS2/2150 swap a few months ago but I could never hear it over the roar of highways speed air coming through the windows and doors.

I played with it a good bit and after some research, I unplugged the vacuum advance canister (it was hooked to a ported source). With the vacuum advance canister unhooked the engine wouldn’t ping under any conditions. I attempted to adjust it, but my original ones adjustment screw doesn’t seem to do anything. Applying vacuum does move the arm, and moving the arm does change the timing. By moving the arm with a screw driver I picked up 22 degrees. Then I used a hand pump to apply vacuum to the vac canister and found that it begins to pull in at 2psi vacuum and is fully pulled in at 4psi. I wish I had applied vacuum with the hand pump and measured timing but I didn’t think about it at the time.. anyhow, I was reasonably confident that 2-4psi was not the intended range of pressures that it should operate at (I imagine it should operate from 4-7psi or so?) so I ordered a new vacuum advance. Its in the mail.

In the mean time, since I had the distributor out and apart, I decided to do the mr gasket 925d recurve that all of the ford 6 guys seem to do. I recognize that this will generally give me MORE mechanical advance than the factory “curve” and my pinging problem is the result of having too much timing under certain conditions. Im counting on the idea that the new vacuum can will work more correctly and that I can have more mechanical timing without pinging if my vacuum can isn’t staying “pulled in” until the throttle is nearly wide open.

Anyhow, the new springs went in and I started taking a series of test drives. I was driving it pretty hard up hills, pushing it to 3000+ rpm, things of that nature and listening for pinging then going back and making spring adjustments (all with the vacuum hoe disconnected ofcourse).

And then disaster struck! I cranked it after one of those spring adjustments and had a very loud ticking coming from the front half of the engine.  Shut it off, checked oil level, looked for anything unplugged, nothing seemed off. I re-cranked it and observed that my oil pressure did come up as the engine started, but perhaps not as high as normal? It didn’t make it to the “n” in “normal” which is where it normally rides when the engine is hot at highway speeds. Im not positive it the oil pressure was lower than normal at that time or not. Next I checked my timing thinking that I may have done something extreme to the distributor but I still had the same 12 degrees of base time that I always do.  Next I started pulling plug wires. Pulling #1, 3,4,5 and 6 wires made a large difference in how the engine idled. Pulling #2 plug wire made no noticeable difference. I pulled #2 plug and it was not wet with gas. So, at this point I assumed that #2 intake wasn’t opening and that my problem was some kind of major mechanical issue with #2 lifter, cam lobe, rockers, or something like that.

I left it to cool over night and cranked it the next day. It ticked for 3-5 seconds, then the ticking went away and it was quiet as can be just like normal. The oil pressure needle was at the “m” in “normal” which is typical for cold start. Nothing I did would make it tick. Pulling #2 plug wire still has no effect on idle. With my friend Luke helping out, we pulled the valve cover. There were two little pieces of black plastic under the cover but I don’t think they have anything to do with it. Otherwise, we were both pretty shocked at how clean the it was under there. There is almost no sludge buildup. Anyhow, we found that we could run the engine with the valve cover off without making a mess. This is what we found –

https://youtube.com/shorts/23Nfbmkuw9A?feature=share


everything is quiet even with the valve cover off. Its clear that all of the valves are moving. Intake #2 rocker arm isn’t getting nearly as much oil as the others, though it does move approximately the same amount.

After these observations, I found this great thread which some of you have actually contributed to!

https://www.ford-trucks.com/forums/1544119-low-oil-flow-to-rockers.html

Im very open to suggestion and observations. Id love to hear what any of you think about it. At this point, Id consider the “symptoms” to be a come and go tapping in the valve train, probably on #2 intake, and low oiling on that rocker. I think I’m going to try to “ignore” the issue where pulling #2 plug wire at idle doesn’t do anything. I do have a new plug in the mail. My guess (or what Im telling myself to feel better) is that #2 may just not be contributing enough at idle speeds for it to be noticed when you unplug it, perhaps because of a fuel distribution oddity, lower compression, whatever it may be. While Im very open to additional suggestions, my plan is to roughly follow the advice given in the tread above.

1) Mechanical oil pressure gage
2) Remove and inspect rocker arm and pushrod for #2, possibly try to clean out oil passages in both
2b)   snake oil? Are any of them worth fooling with?
3) Possible lifter, pushrod, or rocker arm replacement on 1 or all valves, depending on severity and what I find

As always, thanks for reading and for any suggestions!
P.S.  – change out your window and door seals! And I have a “free to a good home” rear window seal for a 1980-1986 f series truck without sliding glass. I bought an f150 kit, it was cheaper that way.

That's quite the story.  Or, should I say "quite the quiet story"?  

Yes, door and window seals make a huge difference, and they are to be highly recommended.

On the noise, I'm going to guess that something cause a lifter on #2 to not pump up properly on that start, but that in reality all is well.  However, since you can remove the valve cover I would check out the rocker and pushrod.

As for #2 not changing the idle when you pull the plug wire, I've seen that before and have always assumed exactly what you did - that mixture distribution is such that at idle it isn't adding much to the rotation of the engine.  Mind you, I don't know that we are right, but at least we are together.  

On the timing, I think you are on the right track.  Get your mechanical/centrifugal advance nailed down and then move on to vacuum.  And that vacuum unit you have is awful!  No wonder you had pinging!  Hopefully the new one will be adjustable.  Anyway, you might like to read Crane's instructions on ignition timing: Documentation/Electrical/Ignition and then the Instructions tab followed by the Crane Cams Instructions tab.

Gary,
Thanks for the reply. Frankly, your cool seemingly not panicked take on the situation is soothing to my shot nerves. Between this and a new job that I started Monday Im a bit overloaded.

Were you able to see the youtube video? It pretty clearly shows #2 intakes oiling behaving differently.

Id love to put the cover back on and just let it ride, and honestly I think that would probably be just fine so long as the noise doesnt come back. It does worry me that #2 intake valve is receiving less oil than the others.

Im planning to build my other long block for the bronco in the next 12 months or so, but I still want this one to "be right". There is a fair chance that this engine will be destined for another truck in a few years so I do want it to be in serviceable shape.

Thanks!

Yes, I was able to watch the video, but in order to make sure others can I'll embed it here. (I can do that by getting the Share/Embed code from Youtube, ticking the "Message is in HTML Format" box above, and pasting it in.)

You are right that there is less oil flow on that valve. But oil flow to valves is a binary thing - there is either enough or not. More than "enough" doesn't help. In fact, all the oil that goes to the valves is taken away from that going to the bearings, so you don't really want a whole lot of flow.

But it doesn't take much to block a lifter's orifice and stop the flow. So that raises the question of what the inside of the engine looks like. In other words, is it really clean and there's not likely to be pieces of gunk in the oil flow? What you found under the valve cover would suggest it is clean, so I think I'd put the cover on and drive it. And if you find that the noise comes back frequently then I'd figure out what the issue is. The valve and side covers aren't that hard to take off on that engine if you need to do so.

I would pull that rocker & push rod to make sure the rod is clear.
Might also pull the lifter cover just so you know what it looks like in there but if find the rod was clear then maybe pull the lifter and take it apart for cleaning and reinstall and see if that dose anything.  

I have had the valve, lifter covers off and the oil pan off mine to replace the gaskets when I first got my truck. It looked clean under the valve & lifter areas, pan had a little sludge but I cleaned everything before I put them back on.

Now after I got the truck running and on the road the oil would get a little dirtier than I liked between changes so I add a QT of ATF to the oil just before I change it.
Dump it in, start the motor and let idle bring up to normal temp and drain.
So far it seams to be running cleaner with the 2 changes I have done.

I am also running Shell Rotella T4 oil in this last change that should have more cleaners in it than other oils but not so much that if the motor was really dirty would cause issues when bypassing the filter and hurting bearings like a motor flush can do.

Dave ----

Update - I pulled #2 intake rocker and push rod. I couldnt see light through the pushrod, so I blew the pushrod and rocker out with 100 psi air. Both were clear after that. I reinstalled them, cranked it up with the valve covers off and watched for about 5 minutes. I never had a drop of oil make it to #2 intake rocker.

At this point Im assuming Im looking at lifter replacement. Seeing as the block is within its last 20k miles without a total rebuild, I dont think Ill replace the cam. I do think Ill follow the cam replacement lubrication and break in guidlines for the new lifters (sealed power th-900 were what I could put my hands on today, 12 for about $50).

At current all of the push rods are out and the side cover is off. I plan to preemptively coat the lifters in penatraring oil and call it quits until tuesday afternoon. Ill be gone all weekend and Im helping my dad with the "displacement on demand delete" for his 2007 suburban 5.3 on monday. Unless I can find the lifter puller tool mentioned in the post linked above, I guess Im doing it the "old fashioned way".

I dont really want to spend $75 for the cheapest lifter bleed down tool on ebay, but absolutely will if need be. Is there a better way to bleed down my new lifters, or will they not require bleed down to check my rocker clearance (plan to soak them overnight) ? The engines at work get a valve lash adjustment with set screws that Ive performed atleast a few hundred times, go figure this one doesnt work that way :/ unless someone knows better I plan to follow the factory service manuals instructions for valve train adjustment.

Gary,
I dont mean to be dismissive of your advice. I really appreciate it and did seriously consider your recommendation. Thank you for your help as always. I couldnt leave that rocker alone. Knowing what I know now, I assume that there isnt much of a choice.

Dave,
I hadnt really been thinking of the lifter as a servicable part, but Ill pull it out first and have a look. Im not sure how Ill know its in "serviceable" condition,  but I plan to look. And Ill do some research on your atf trick! I hadnt heard of that before.

All,
Please dont think Im beyond the point of taking recommendations and thank you for reading.

Here's a video link of a guy disassembling the lifters on his 300 CI Ford engine. https://www.youtube.com/watch?v=gV9NOtr-CVU

Not getting oil is bad, obviously, so I'm glad you didn't take my advice.  You were right to check it out, and your findings prove you have a problem.

But I can't answer your question on the valve lash adjustment other than to say I'd follow the factory service manual's guidance.

Frank - I was wondering if cleaning the lifters might work.  The guy on Youtube said he had a tapping sound under load, which seems to be similar.

I don't think it could hurt and likely would at least make it better. On the other hand though a new set of twelve lifters for that engine and a bottle of assembly lube is not that expensive. One thing to remember is flat tappets aren't truly flat and are slightly concave which can wear down to being convex over time and no amount of cleaning will correct that. Replacement solves that and the issue of no oiling of the rocker arm as well.

Frank Wyatt wrote

I don't think it could hurt and likely would at least make it better. On the other hand though a new set of twelve lifters for that engine and a bottle of assembly lube is not that expensive. One thing to remember is flat tappets aren't truly flat and are slightly concave which can wear down to being convex over time and no amount of cleaning will correct that. Replacement solves that and the issue of no oiling of the rocker arm as well.

Thats what I was thinking, "cant hurt" to pull the lifter, take it apart and if it still will not let oil pass then you have the new ones to throw in the motor.

As for pulling the lifter(s) if you are careful not to mar them if going to reuse you can use vise grips and carb cleaner. Vice grip to twist and lift it up and carb cleaner to wash off the stuff that will not let it lift out.
Spray and little CC around the lifter and let it work down a little then try and twist & lift. Push it back down and spray and ......
Keep doing it till out. If lucky it was not marked and you can take it apart, clean with CC, little oil going back together and ready to go back in motor.

I thought the  rockers get tq to spec and that is it, non-adjustable right?
You have not changed anything like mill the head or deck the block to change what was there from the factory so no need to change push rods to get them back in spec.
Dave ----

Frank,
Thanks for the advice! Ill be sure to take that lifter apart and see it there is a smoking gun to be found.

All,
I already have the new lifters so I suppose Ill be putting them in. on valve "adjustment" - these rockers are non-adjustable. all you can do is torque the nut to spec. However, my shop manual does describe a procedure for checking the amount of space between the rocker arm and the top of the valve with the lifter bled down fully. As I understand it you compress the lifter with the lifter sitting on the base circle of the cam then check to see if you have between 0.100" and 0.200" worth of clearance. If you dont you are supposed to get new pushrods to make up the gap. assuming that my new lifters have the same dimensions as the old ones, Im sure it doesnt matter here.

when it comes to lubricant for break in - I know I need a break in grease to apply to the bottoms of the lifters during break in, and Im also fairly sure that the castrol non synthetic 10w30 that Im using in the engine is not appropriate for break in. would it be correct to say that I need zinc additives for the engine oil to be used for flat tappet break in? Is there a special product I should be looking at? oil for a diesel? I need to do some reading on this.

hopefully Ill be able to work on getting the old lifters out after work today. I picked up one of the lifter remover slide hammer type tools on amazon for about $17.

Thanks Guys! I hope you all had a great 4rth!

You need either a break-in oil with high ZDDP or an additive for break-in with gobs of ZDDP. Scotty The Mad Porter, who built my engine, said that I had to use a break-in oil to keep my warranty. So I went with Brad Penn’s break-in oil.

All,
Ive made good progress and I hope everything is in order.

The old lifters came out easy, it probably took me 15 minutes to get all 12 out. The first 8 came out by me opening a pair of needle nose pliers inside of them then pulling the lifter up. The last 4 came out with the assistance of a CPU magnet. Im not sure how much the carb cleaner helped but I m grateful that it wasn't too difficult. My old lifter cover gasket was toast, so I replaced it. I was able to do it all without pulling out the distributor or taking apart the induction/fuel system which is nice because I should be able to fire the engine up quickly and easily without too much cranking.

I purchased 12 quarts of 30wt Lucas break in oil and an 8 oz tube of lucas assembly lube. I used the majority of the tube of assembly lube on the rods and lifters, but Im sure it was excessive. I did check my rods for straightness by cleaning them off and rolling them against each other.

Anyways, the engine is fully assembled and filled with the Lucas break in oil. I got it all put together last night and decided it would be wise to wait for a new day to crank it and break everything in. As for break in procedure, I am looking for any advice/input but my rough plan is to start the engine, get it up to about 1500 rpm, then slowly vary engine speed from about 1500 to about 3000 rpm in about a 1 minute cycle for a total of about 30 minutes. After that Ill change the oil and filter to a fresh fill of the Lucas break in oil and let it cool down. After 500 miles Ill change the oil and go on about my life I guess. Does anyone have any advice on flat tapped lifter break in?

Thanks! Ill let you guys know how it goes. - John

That is good progress.  And I think your break-in plans are good.  I've always heard that 20 minutes is critical, so I aim for 30 just like you are.  I think you'll be fine.

Welp guys, disaster has struck. Or perhaps thats a bit overdramatic.

Upon starting the engine up yesterday I had a lot of valve noise for about the first 5-10 seconds, then the majority of it went away but there was still at least one valve worth of severe rattling even after nearly 3 minutes at or above 2000 rpm so I shut it down. In hindsight, I shouldn’t have run it even that long but it hardly matters now. I pulled off the valve cover and every rocker except for #2 intake was full of oil. #2 intake was dry. At this point, I assume #2 intake lobe is gone, and was gone when I started this job a week ago. We ran a compression check on #1 and #2, #1 was making about 130-135 psi while #2 made about 100 psi indicating to me that valve lift on #2 intake is significantly low. I really wanted to measure the valves stroke with a dial indicator but that didn’t work out.

My buddy and I disconnected everything but the power steering pump, exhaust bolts, flywheel housing bolts and the engine mounts yesterday evening. We hope to fly the engine out this afternoon. Should I take the hood off for that?

At this point Im trying to decide between two basic plans –
1) Put a new cam (need to select cam and make sure to end up with a steel gear if I don’t have one already), and a new oil pump in the engine, reseal some stuff, engine mounts, maybe a clutch, and put it back together relatively quickly and inexpensively.
2) Move my plans for a 2022 engine build up to now. The cash is sitting in an envelope, my lack of knowledge is really the most important reason I was waiting for next year. I have a lot to learn. My basic build plan is as follows, but remember, Im a self-proclaimed “know nothing”.
- Rebore cylinders, no more than needed for clean up
- “fix up” and balance rotating assembly
- Flat tappet performance cam
- All new bearings everywhere
- Oil pump
- Possibly roller rockers (maybe not needed for my low rpm application??)
- Use a combination of head/block decking and piston selection to achieve the highest compression I can have while safely running 87 octane gasoline
- Port and polish work in the head
- Oversized valves and valve job
- Clutch

My goals for such an engine build would be to produce an engine that makes gobs of torque between idle and 3000 rpm reliably and with at least decent fuel economy in 87 octane. I don’t really care much about power and I don’t care what happens after 3500 rpm at all. With the way I drive it there’s nothing useful to me much past 3000 rpm anyhow. I suspect most of that comes down to head work, cam selection and getting the compression ratio right (and of course the new bearings, oil pump etc).

if I build the engine, it will go back together for the time being with my efi manifolds, the offy C, my 2150 carb and the durraspark 2. Building the engine will pretty much suck my “bronco budget” dry for the next year or so. There is a good chance Ill eventually either go to a larger venturi version of the 2100/2150, a 4 barrel carb such as a holley 390, or even throttle body injection. But for the next year it will be either my carb or one I don’t have to put much cash into.  

Perhaps I should rebuild my transfer case if my engine is about to be producing more torque? Im pretty sure a 12V cummins wouldnt hurt my np435, but that np208 very well may be at 280,000 miles. opinions?

I was planning to spend the next year soaking up information about building a long block but it looks like I may need to accelerate that a bit. Ill rely heavily on my engine builder for technical expertise which is a practice that generally makes me nervous. Can anyone recommend a crash course? Maybe a book I should read, etc? that would be greatly appreciated. Im going to speak to the builder today on the way home from work and should make my choice about how to proceed some time today. No matter which way I go I need to figure out the cam. I already looked over the comp cams site and the 252H seems like their best offering for what I want to do but I haven had a chance to look for reviews and write ups on that cam or to research the many other options. Any advice, specific or general, about cams or otherwise, would be greatly appreciated as always. Thanks! -John

I'm sorry that it didn't work out.  That is a bummer!  But I think you are right, the cam must be flat.  However, I would check before I tore it down or even pulled the cam out.

Getting the engine out is easier with the hood off, but people have done it w/o pulling it.  However, the boom on the engine hoist will have to be really close to the engine or it'll hit the hood before the engine clears the crossmember.

As for what to do, I think it is probably time for a new engine.  However, I've come to the conclusion that it is better to buy at least a short block, if not a long block from someone that does this routinely.  Having said that, I don't know of someone that builds the 300 "routinely".  But, when I asked Scotty The Mad Porter about it a couple of years ago he said he does build them.

On the head, I'm not sure that oversized valves are what you want for a low-RPM engine.  Certainly you want good valves and seals, but larger valves are usually needed for engines are going to spin pretty high.

And on the compression ratio, there is another variable - quench or squish.  If you get the piston-to-head clearance down to less than .040" then that results in the air/fuel mix being swirled in the combustion chamber, which is supposed to reduce the tendency to detonate.  So you need someone that knows what he is doing when you pick your engine builder.