1978 Royale Update and Restoration

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Matt Colie

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Oct 25, 2019
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Mike_H,

Be very cautious with that double roller set. It has crank locations for +&- 4°.

The problem with the timing chain was both the loads it saw in TZE service and the age it might get to. That was because the nylon cam gear face wore, aged more than in other service.

The block off plate that circled i believe was for the EGR valve that was not installed on the coach engines. There is probably one on the other side that has two holes in it and that was for the choke heater. They often leaked and were replaced by another block off plate. That left electric choke as the only alternative.

Matt
 

Mike_H

Member
Oct 3, 2019
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Mike_H,

Be very cautious with that double roller set. It has crank locations for +&- 4°.

The problem with the timing chain was both the loads it saw in TZE service and the age it might get to. That was because the nylon cam gear face wore, aged more than in other service.

The block off plate that circled i believe was for the EGR valve that was not installed on the coach engines. There is probably one on the other side that has two holes in it and that was for the choke heater. They often leaked and were replaced by another block off plate. That left electric choke as the only alternative.

Matt
Hi Matt. I got it on Zero ;).

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Thanks for the info on the EGR. I ordered a set of Block off manifold gaskets from Applied today. I'll have to return the factory style Pan I already bought from Summit.
 
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Matt Colie

Member
Oct 25, 2019
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Mike,

When you lift the intake, inspect the area of the coolant ports. That is a very common leak area and it leaks into the lubrication oil.

Matt
 

Mike_H

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I got my heads and intake off today. Kinda got a kick in the nuts on my intake too. It appears to be cracked beyond repair. The center section between the two large bores is cracked like probably everyone's is.

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However, mine is also cracked to the outside on one of the outer walls.

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So...Anyone out there have a spare intake for a 403 they want to part with?
 

Mike_H

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Been a little while since I've updated. In the meantime, I've been pretty busy getting things ready for re-assembly. Also had to fit some whitetail hunting in there too! Anyway, I've been putting things back on the engine in the last couple days.

To re-cap, I pulled the engine down to the short block because of a coolant leak somewhere. I figured that since my intake was going to be coming off anyway, I might as well pull the heads and have the valves done.

One of my employees is a "boat guy." Used to race offshore, has three boats (including two go-fasts). His engine builder is also his best friend. So, he offered his guy up to do my heads. I told him there was at least on broken bolt, I wanted the valves done, and to "clean them up". In my mind, that meant look them over and fix what was wrong. I guess I should have been more specific. He Degreased them, ground the valves and replaced the seals and one guide. Didn't do anything with the exhaust manifold mounting surface...or fix the 4 other bolt holes that were screwed up (he did fix the one I told him to). Not sure why he didn't mention it before he gave them back to me. Seems like he should have. A couple days later, my employee said the builder noticed the surface was garbage and the other holes were wonky, and was going to fix it, but then thought since it was assembled before he got it, he didn't want to "fix" it and make it not go back together. I guess that makes sense...but it left me with heads that I didn't feel right about putting back on the engine.

I have access to a full machine shop at work and the guys that work in there are a little lacking in work right now, so I had one of them take a couple hours and mill the manifold surface and install thread inserts into the screwed-up holes. Being the boss has a couple advantages! :)

Anyway, some pictures...

Here are the heads as they came off the coach and after they were returned to me from the engine builder...

Majorly screwed up mounting holes. I figure someone has been trying to fix exhaust leaks on my girl for a while. Removing the manifolds broke some bolts and they played amateur hour fixing it. The drilled and tapped holes were off center and crooked.
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This has been leaking exhaust for a while! I've never seen such an eroded surface.

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This is how my heads look now. Took about 15 thousandths to clean up one head, the other (pictured above) took considerably more...like 45 thousandths! The picture on the right is the head from above. That dark spot is the only place it didn't clean up. I got some high heat JB weld and filled it, then filed it back flat. I also shot a quick coat of Dupicolor Engine Paint, Corporate Blue on them. I don't really expect it to last, but we'll see. Looks nice for now.

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Why go through all this? I ALSO bought new manifolds from Cinnabar. I didn't want to have $500 dollars worth of new manifolds on the coach and still be fighting manifold leaks. For reference, here are said manifolds. They are VERY nice and look nearly identical to the originals. Only difference I could see is in the markings. It makes sense that they are the same. Cinnabar said they use the original patterns to cast their reproductions. They did a nice job of finishing too. Machining marks are nice and uniform, they removed most of the casting flash, and there isn't anything left internally to interfere with the flow.

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So, with my freshly machined mounting surfaces, brand new manifolds and Lenzi's Copper Gaskets, I should have a tight, leak free exhaust.

That covers exhaust...My last post was about the intake being cracked. I ended up buying a brand new Edelbrock intake manifold, Number 2711. One of differences between the 455 and the 403 is the deck height. The 403 is considerably shorter, which means the intake doesn't have to be "concave" as Jim Bounds puts it. The standard performer intake from Edelbrock is only about 0.25" taller than my factory manifold, and only in the back. It was kind of expensive though. Not sure why...as you can buy a SBC intake for about 150 bucks. The Olds one is $400'ish. Still WAY cheaper than the super-special, custom aluminum one that the 455 requires.

Shiny Aluminum Goodness

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With all my parts now in hand, I started putting the top end back together this weekend. Got the heads on yesterday after finishing my Honey-Do list. Had more time today, since I did all the honey-do stuff yesterday. Took my time during assembly to make sure everything was clean and in good shape. The rockers are showing some wear at the pivots, so I may look into replacing those. I installed Dick Paterson's exhaust crossover block off plates and intake manifold gasket, and got the intake installed and the first step torque done. I'll torque to the full 45 ft-lbs after the RTV cures so I don't squish it all out. I also need to get another 1/4" pipe plug for the manifold.

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With a good push this Thanksgiving weekend, I hope to have her fully assembled and running again. I know my dad would appreciate it, as its taking the room in his barn where he would normally park his truck to keep the frost and snow off it!
 
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Mike_H

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Oct 3, 2019
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It no longer Thanksgiving, but I am happy to report that my GMC is a runner again! I'm still working though flushing the coolant and heat cycling the manifolds, and I have to set the timing, but she runs really well.

Here is a short vid from the tailpipe. Phones do no justice to the beautiful music that an American V8 makes.


Here is a slightly longer video from inside the coach.


She runs SOOO smooth. I haven't touched the carb and haven't adjusted the timing, other than advance it enough to keep it running.

What a difference from when I bought her. I thought it ran good then...I can't wait to take her out for a spin.
 

pvfjr

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Oct 4, 2019
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Here is a short vid from the tailpipe. Phones do no justice to the beautiful music that an American V8 makes.
You're right, it sounds like it's off about 90 degrees! ;)

Sounds pretty smooth though. This makes me want to get cracking on mine. The PO screwed everything up, and has had 3 different carbs on it, all with the wrong fuel pressure. It's going to take some doing.
 

Mike_H

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Oct 3, 2019
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I've been lax in updating this thread, but I have been working on this ol girl. After getting it running again, I had a bit of trouble with the cooling system. It appears that my Stant SuperStat was sticky out of the box. Surprised me, as I've had good luck with them in the past. Any way, I replaced it with a high flow Robert Shaw and things are good.
What a difference. She fires up almost immediately now. Haven't driven her down the road yet, but I have high expectations. I've got her tucked away until the weather breaks here. Hung a tarp up too, after I took the pictures.

Next project is my generator. Update soon.

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Mike_H

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She's looking good Mike!
I'm jealous of your aluminum intake. I need to pull mine out just to clean it up and powder coat it.
Thanks! The aluminum intake is a nice addition. I was SUPER excited the first time I dropped the engine cover down after all the work and didn't have any interference from the new manifold. You read that it works on the internet, but until it actually does, I always have some apprehension.
 

Mike_H

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Oct 3, 2019
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Generator Update. I just spent 515 dollars on parts! I might still have to spend some more. The field winding core (the big square metal piece that forms the outside of the electrical plant) on my generator is loosing its varnish. I have a call into an electric motor repair shop to see what to do about it. Everything else checks out good, with the exception of the bridge rectifier. I was getting funny, inconsistent readings when I tested it, so I ordered a new one. The Onan part is 40 dollars...I bought a 400V, 25W part for 5 bucks from Amazon.

The engine part of the generator is getting the bulk of the spend. Its getting all new bearings and seals. I started just wanting to give it a quick clean and check compression, spark, and maybe rebuild the carb. Well, the deeper I got, the more I realized that I wasn't going to be happy putting that leaky chunk of aluminum back in my nice clean coach. It seemed that every gasket was perished, the oil/grease mixture was at least a 1/2" thick. It was gross...I think I went through a box of nitrile gloves just to take it apart.

Good news is that it all measures to spec. Crank journals are in spec, Cylinder bores are in spec, Cam is in spec, so new rings and bearings will be all that is needed. I do need to have the valves done, so I'll arrange that with a local garden tractor guy here in town.

Some pictures...

Shes a HEAVY SOB

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Some of the Goo to clean off...

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More nastiness...Rat nest! Public Service Announcement...Keep your air cooled engines clean. I'm sure this nest caused this engine to run hot and gall the rear main bearing (the only damage I found). These Generators actually pull air through the engine from the Rear power head to the flywheel. This nest would have blocked ALL air flow to that side of the engine.

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The engine has been running real rich too. I think this is the most carbon build up I've ever seen. The rust on an aluminum block tells me the head gaskets probably had gone too.

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Pre-cleaned but nearly all taken apart. The crank came out shortly after the picture was taken..had to make a puller for the timing gear at work.

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Next few days will be cleaning and painting, hauling pieces around that need professional attention, and organizing my shop for re-assembly.
 

Matt Colie

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Oct 25, 2019
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Mike,
Jim Miller in Hamilton Ohio knows all about rewinding the fields of Onans, you should talk to him.
Matt
 

Mike_H

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Oct 3, 2019
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Been a while since an update, but not for a lack of work. I think I figured out what was going on with my Generator, and why the previous owners hadn't figured it out. It was told to me that they went through about three boards before giving up. All trouble shooting was focused on the starting circuit I believe. However, when I was cleaning parts, I discovered a dead short in the Choke. The choke is energized when you push the start button. On mine, the insulator to isolate the 12V signal that activates the solenoid from ground was broken, so I was getting short to ground. Its protected by a 5A fuse. So, if the fuses kept blowing that would make sense. I'm hopeful anyway, as everything else looked OK.

Also working through painting everything...

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This weekend I hope to make some progress on reassembly.
 

JodyPackerfan

Member
Feb 2, 2020
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Racine, Wisconsin
It no longer Thanksgiving, but I am happy to report that my GMC is a runner again! I'm still working though flushing the coolant and heat cycling the manifolds, and I have to set the timing, but she runs really well.

Here is a short vid from the tailpipe. Phones do no justice to the beautiful music that an American V8 makes.


Here is a slightly longer video from inside the coach.


She runs SOOO smooth. I haven't touched the carb and haven't adjusted the timing, other than advance it enough to keep it running.

What a difference from when I bought her. I thought it ran good then...I can't wait to take her out for a spin.
WOW nice job