1984 Bronco build thread

Gary in particular and everyone in a general sense-
The engine is out, and a thank you mexican dinner has been bought for everyone that helped. We removed to hood and the radiator to do it. Neither would necessarily be required, but both made our lives easier.

My engine builder of choice is backed up 14 weeks, and Im not ready for the bronco to be down until 2022. Does anyone know a reputable engine builder in georgia, or even the south east? I sold myself on building a fresh block, but now Im back to a cam, oil pump, and anything else that I find and doing it in my garage. If I do that, Ill leave the head, the crank and the rods/pisons alone if I can. Ill take them apart if I have to.

More details and some pictures tomorrow when I know more and have slept some. Thanks!

Glad you got it out.

Before deciding on what to do, and before pulling it apart, I would do a leak-down test.  Harbor Freight has a tester that looks pretty good, but there are others as well.  To me, a key thing for them to have is an on-board regulator and two gauges.

A leak-down tester allows you to inject air into the cylinder via the spark plug hole when the cylinder is at TDC, meaning the valves are closed.  The air comes in via a tiny orifice and if there is leakage you'll see that as lower pressure due to the drop across the orifice.

It will determine if you have valve leaks, head gasket leaks, or a cracked block, and how tight the rings are.  If your engine passes on all of those things then just pull the cam and lifters and replace them.

A leak down test is a good start but I would look into why no oil to that rocker?

I would pull that rocker & rod and distributor so I could spin the oil pump and see if oil comes out the lifter.
If not pull the lifter and see if oil comes out the block.

If you don't get oil out of the block the garage rebuild will be for nothing.
Maybe that should have been done before pulling the motor?
Good luck
Dave. ----

My understanding is that oil to the rockers comes up the push rods as the lifter is pushed up by the cam.  So my assumption has been that with a wiped cam lobe there won't be much pushing up of the lifter, hence little if any oil to the rockers.

And speaking of wiped cam lobes, I've been reading lately of problems with Comp's cams having that problem.  I don't know if this is because they sell a lot of cams so there's more chance that people don't break them in correctly, or if they are having problems.  But I'd research whatever manufacturer I was considering before buying.

This was the exh. Valve IIRC so if not opening the exh would back up into the intake and cause a pop from cam over lap was there a pop more so under load?

Still easy  to measure pop the side cover and check the lifter movement  to the others.
Dave  ----

Ok folks - here's the update for today. We drained the block and ran the leak down test. We used 80 psi for the air feed. All cylinders were between 30 and 40 psi oyher than #3 which was at about 66. So not great, I presume :( several valves had a fair deal of blow by but we never heard any air moving in the water jacket so I think the head gasket is fine.

Next we got the pan off and had a look around. Just looking at #2 intake lobe, I wouldnt have assumed it was "flat", but then again we knew it was moving the valve some. There is still crosshatching in the cylinders. No gunk on the pickup screen. Ultimatly, other than the eing blow by that we already new about the bottom end looked really healthy to me all things considered. We didnt pull a main or a rod cap, but I may. I do have a steel timing gear.

After much discusion with my friend, I think Im going to take my second block to the engine shop to be built with the expectation that I probably wont get it back until January 2022. Ill be taking it over sometime this week. In the mean time Im going to make this block servicable and put it back in. My preference is to leave the head, crank and rods in place. I plan to address the cam and the valve train, the oil pump, maybe a water pump because its easy, and other little things I find. I plan to seek out a stock cam. The goal for this block is to get through the 10,000 or 20,000 miles between now and January.

I know ignoring the ring blow by and the valve blow by long term is not acceptable, but Id rather not have the vehicle down for 6 months and this is the best idea I have been able to come up with.

Thanks for reading! Opinions and recommendations are more than welcome as always.

That is quite a bit of leakage, but that's roughly what Big Blue's engine had when I pulled it out and it was running quite well.  So I think if you get the cam problem sorted you'll be fine for 20k miles.

But on the valve or cam problem, I'd do as Dave suggested - pull the side cover and measure the lift.  I sure wouldn't want to pull the cam only to find out it isn't bad.

Otherwise I think your plan is solid.

Dave and Gary,
Thanks! Thats a straightforward way to check lift and it should be a quick and easy check with the block on the stand. It may be a day or two before I get a chance to try but Ill post results here asap.

Im still sorta hoping to identify a shop that could turn the block around by September or so. Id prabably just swallow the down time at that.

as I said in my other post when you can measure the lobe(s) from the side cover area so you know if the cam is good or bad.

I think if I had it down this far I would pull 1 or 2 main & rod bearings so I know what they are like.
To throw a set of bearings in it would not be hard at this point.

I would also measure the holes to see if they are factory or been bored over size and maybe throw a set of rings in it after running a hone to break the glaze this way the rings will seal good.

On the head and you saying the valve had leakage I would check on either a replacement head from one of the local parts stores or maybe pull yours apart and lap the valves so you know what you have.
Maybe check to see what the turn around is on a valve job on it.

Yes it is a quick rebuild without the machine work and other than the head would last longer then the 20k you might put on the motor and even if you do get the other built you have this as a spare.

BTW I did a quick rebuild on a AMC 360 motor I had never heard run when I got it.
All bearing were showing copper but the crank measured factory so a set of bearings fixed that part.
I forgot to check the cam bearings but did not have a way to change them anyway.
All the rings were stuck in the pistons and i had to break them to get them out. I used the broken parts to clean the grooves. I picked up a new set of rings but the gaps were large, I was in a time crunch and went with them anyway.

I had a set of heads that were good to bolt on, same on the oil pump as it is partof the timing cover.
I went with the largest lift cam kit I could with out machine work, did I say I was building this for my drag car?
I cleaned the block for hours as it was really bad.
Ran a hone in the holes before the pistons went back in and did all the measuring just like you would when rebuilding a motor, even coil bind for the cam.
I got to say the motor ran strong, great oil PSI even hot idle, did not smoke at all I was kind of shocked because of the ring gap.

Other than the money for the parts and time I think in my case was all well spent.
Dave ----

Dave,
You're rebuild on the 360 sounds awesome. Id very much like to do that some time. What became of it? Thanks for all of the sound mechanical advice you’ve given me over the last few days.

All,
Im a notoriously slow decision maker and its not unusual for me to labor over a choice for days or weeks before making a decision that was ultimately pretty straightforward from the start. With that being said – Im changing my plan one more time. Im just going to take my block to an engine shop to be built. Sure, that means the vehicle probably wont run again until December at the earliest, maybe March at the latest, and I hate that.

This will give me a chance to rebuild the transmission and transfer case myself, possibly paint the tub, and do the headlight upgrade. By the time the engine comes back ang goes in I will have rebuilt the entire drivetrain other than the front axle and the vehicle should be road worthy enough to take me anywhere without worrying too much about mechanical problems. If the goal is a rebuilt driveline, this is the fastest, cheapest, and lowest effort route to that goal. It just means 6 months or so of downtime.

I can also take advantage of that time to fix other things that Ive been failing to find the time for Like my living room trim, or my snapper engine. Maybe a bit of life balance for a few months is a good thing!

I have canning to do tonight (we froze 14 quarts of cream corn and about 50 ears whole yesterday), but I should be able to sneak into the garage for a few minutes to finish stripping my engine for the trip to the machine shop. Hopefully Ill have it dropped off sometime this week. Im sure there will me more to come in the next few days! Tentatively, Id like to work out the transfer case and transmission rebuilds in August and September.

As always, thanks for reading!

I think that is a wise move.  I used to think I could do everything, but I've learned that some things just go better if I get a pro to do it.  And having a pro build the engine gives me peace of mind.

And, as you said, this will let you rebuild other things in parallel as well as do other things besides trucks.

Thanks Gary. I think I could handle a ring and bearing type job, However, I know I dont know what a professional engine builder knows. Additionally, for me to really do that job right, I think Ill be in for about half of what Id pay a shop for time and materials. The difference is that if the shop does it they can nail down all of the details like getting compression ratio right, bore and balance everything, head work, etc. I think I could spend half the money and put together a long block that would be ready for another 100,000 miles of service in roughly factory state. These guys can build a performance oriented engine that may yield over 200,000 miles if I take care of it not to mention performance improvements. I'm excited. Dont get me wrong the expense is going to be a kick in the guts, but if it was just the money Id pay it today and be extremely pleased. The time is what bothers me. maybe Ill finally learn some patience.

I think Im going to start an Engine build thread over at FordSix and link it here. Ill continue to document work on the vehicle here including transmission and transfer case work. Thanks Guys!

That AMC 360 was still running when I laud the car up, you know you have time to race and no money or the other way around.

I could not get the car to start to load on the trailer for the move south and has since rusted up and won't turn by hand.
I am sure if I put oil in the plug holes and let it work in it will free up but have other projects to work on.

Other than doing really good measuring like a machine shop would only because of the tools I have everything was done like one even making sure the block was as clean as I could get it with hot water and soap many times.
Dave. ----

Hey Guys!
here is the FordSix build thread for my engine.

https://fordsix.com/threads/300-build-for-a-1984-bronco.82577/

I wont bog this thread down too much with redundant information from the FordSix thread - but here is the high level view. The Frenchtown Flyer and PMuller9 are helping me out and have recommended a direction for my build based on my desire for a low revving torque engine that doesnt have to make power or spin faster than 3500. Their suggestion is to use a factory profile cam, higher ratio chevy pedestal rockers, oversized valves and a bit of porting in the bowl area of the head, and to pick up just a bit of compression with some hypereutectic pistons. all in all, it should be a relatively simple build. I found a shop that I like a lot about 20 minutes from home, they have my block and it will probably be torn down and cleaned this week if I had to guess. when I told the guys that I was ok with it being November or December at the earliest before the engine was done they looked at me funny and suggested that it may be a little quicker than that. Who knows!

in the mean time - my tailgate and rear glass seals came in finally. I hate to complain, but Ill never do business with LMC truck again. I wont drag you all through the mud.. but there is the warning. Never again LMC truck. On the bright side my "powered by ford yard ornament" should be a little less wet inside soon.

Im "full steam ahead" on plans to rebuild the transfer case and transmission. Ill identify and order rebuild kits in the near future. Id like to start with the transmission because it is easier than ever right now, while the transfer case is pretty easy to get to any time.

before the new engine starts up I plan to install an AFR gauge and mechanical oil pressure gauge. Ill preserve the function of the original oil pressure gauge. The AFR is for tuning purposes and to give me a "warm and fuzzy feeling" about taking good care of my new block.

upon removing the pigtail from my 3g alternator I found that the heat coming off of my efi exhaust manifold had caused considerable damage. I know I am probably not the only one with this pairing. I plan to come up with some kind of heat shield for it.

thats all I have for now! the next few weeks until mid August will probably be a lot of parts ordering and a little less working on the vehicle because of some family trips that are planned between now and the 9th of August.

Ill keep you guys posted!

Hey Guys!
The Novak np435 kit arrives in the mail today.

I have been having a bit of trouble identifying a np208 rebuild kit that specifies that its for ford np208s. Will "all purpose" chevy/dodge/jeep type kits work for bearings and seals? I suspect the chain is different at least. Id like to purchase the chain+ master rebuild kit from Jeffs Bronco Graveyard but the kit is out of stock. their tech said the chain is a new process chain and the kit is from new process. all together without shipping the chain and kit would be $170 which seems really cost competitive by comparison to other offerings. Seeing as the transfer case will be the last part to go back into the truck and that is probably going to be November anyhow Im tempted to wait for the kit on JBG to come back into stock.

all of the parts for my mechanical oil pressure gauge and AFR gauge should be at the house by the end of the day. my current plan is to make a panel for those two gauges by bending it on my uncles miniature metal brake. Im currently planning to mount it under the dash near the forward position for the transfer case shifter. there is a metal bracket there in front of the computer bracket that originally mounted the heated rear glass control switch. seeing as I no longer have heated rear glass (and I live in a place where it wont be missed) Im planning to use that bracket to mount my new gauge cluster. does anyone have any photos of trucks that have something like this as food for thought? Or ideas in general?

sometime this week I plan to get the transmission, transfer case and both driveshafts out and roll the bronco up into the garage to get it out of the relentless Ga summer rain. That may be all until after 8/9.

Thanks for reading!

Interested to see how it goes with the tranny and transfer case.

Gauge idea sounds as good as any, long as you don’t hit it with your knuckles shifting the transfer case.

I've purchased my transmission and t-case rebuild components from Midwest Transmission.  They know their stuff and have had good pricing.  I like buying from people who are in "that business".

I'll give you an example of why.  When I was rebuilding my BW1345 t-case I discovered that there are two different seals that have the same ID and OD.  A quick call to Midwest and they told me which went where.  Can the people at JBG do that?

Grumpin,
I hope there is nothing "interesting" about the transfer case or transmission rebuilds. I dont think there will be any trouble with the Tcase shifter since Im putting all of this in the stock location for the heated rear glass. Ill be sure to keep you guys posted.

Gary,
Probably not! but what I do Like about JBG is that their prices are reasonable, shipping is fast, customer service has been good so far, and it seems like all of their "kits" are complete and have high quality components in them.

For example, my truetrac kit for my 8.8 came with all timken USA bearings, an American made Eaton ring and pinion set, Grizzly misc hardware, plentiful amounts of all of the little things you need but dont think about (thread locker, gear paint, a brush, crush sleeves, shims, etc). A good kit full of good parts at a price lower than what I could have bought the same stuff for on my own, and I didnt have to think too hard because they genuinely put everything I needed in the box. I doubt the guy at the phone at JBG knows as much about the np208 as the folks at midwest but I do suspect that someone that knew what they were doing spec'd out the kit at least. at the end of the day, probably both are great suppliers assuming they have what you need. Ill shoot midwest a call or check their site out. buying from or working with the People that make their daily living in what youre working on is surely a good practice. Thanks!

Hi Guys!
Its been a while but things are still moving along on the bronco. My engine is torn down and the machine work on the block should be getting done any day now. I recently finished my port and polish work on the head. I wont say too much here, but dont be afraid to do a port and polish job. It wasnt as bad as I though. Im taking the head and a big pile of parts over to the machine shop today.


representative photo of head work, minus the 320 grit polishing in the chambers completed after this photo

Yesterday was a big day, my buddy and I managed to get the NP435 and the NP 208 out. The date tag on the transmission is 1 month earlier than the bronco, so I assume its original. The T-case is dated a few years earlier, so it may or may not be the original case. Other than a little bit of trouble getting the transfer case off of the adapter it all went smoothly. It appears that the transfer case was mounted using an entire tube or rtv.





The gear box seems to be in pretty good shape all things considered, I havent seen a single chipped gear tooth or anything like that. I wont have any more time to work on it until next week so I left it assembled, less parts to lose that way. Hopefully the engine, transmission and transfer case jobs will all be done in the next 30-45 days. Im feeling good about having her all put together by mid fall, certainly by new years.

Gary - I never heard back from JBG on the Tcase kit, so I had to eat humble pie and call up midwest.. They seem to be a great outfit as well. Thanks!

I hope everyone is doing well and staying safe!
-John

Hey guys! Work is coming along on the transmission. Its fully disassembled, the case and the shift mechanism have been cleaned. The press fit items on this trans are as follows, along with how we got the old one off and the new one on.

Input shaft tapered roller bearing - pressed off with bearing separator and hydraulic press. New bearing pressed on with a long (6-8") pipe nipple equal in diameter to the race of the new bearing.

Input shaft tapered roller bearing cup located in input bearing retainer/snout - old bearing pressed out by opening a blind hole bearing puller (reverse collet type tool) between the cup and the housing with the stem pointed away from the snout. Lowered press ram through the snout until resting on the flat face of the blind hole bearing puller, and pressed it out. I know that sounds bad, but novak tells you to just buy a new input retainer, that removing the old one is too hard. We were proud to have MacGyvered a way to do it. The new bearing cup was tapped in to start with an old bearing race of slightly smaller diameter (you could use a dremel or die grinder to reduce the old bearings od a little) and a finishing hammer. After that, the whole assembly went to the hydraulic press.

Countershaft rear bearing, retained in the aluminum housing on the rear of the transmission - pulled out with a blind hole bearing puller and a slide hammer. New bearing started in with a jumbo cast iron pipe nipple of matching diameter and a finishing hammer. Afterwords, the whole assembly went to the hydraulic press.

I think coming up with a way to remove and install these press fits is probably the hardest part of the rebuild. Im sorry, I didnt think to take photos of all of this. Ill keep you all posted! I hope to have the transmission back together this week. -John