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73-87 Chevy _ GMC Trucks => Members Rides => Topic started by: LRobinson on April 06, 2021, 08:19:21 PM
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Ok, so a bit of a story about this truck and my trouble with it. It's a bit of a long post but I feel it will help with people understanding my problem. It started when I came back from my time in the Air Force. I was attending college and found myself in need of a truck. My family and I have a history of limited resources so I was limited on budget. Eventually I found a 81 c10. Its the usual farm truck story. Got used hard and the son was getting rid of it. To the trucks credit it did run (somehow). With it being about the only thing in my budget and knowing it would be a big project I became the new owner for about $200 under asking price. The main reason I went for it was that my stepdad is very knowledgeable and was willing to guide me through it. It was a bonding chance, his last big rebuild project and my first. I wanted to take him for it's first ride and see time roll back for a moment. Hindsight sucks at times. It took 40 bucks of gas to drive it less than 100 miles to my place. I'm a total noob when it comes to using a manual so my friend drove it while I followed behind in my car. Had an issue midway where the battery was garbage. Luckily Walmart was nearby. We were less than 3 miles from the house, it was the middle of the night, and it was foggy out. My friend in my new truck ended up striking a loose black cow that was in the road. Wasn't a direct hit but the impact spun it into the rear quarter panel and dented it. Sadly it killed the cow but the truck was just dented. We managed to get it off the road and finish the trip that ended up taking too dang long. It was an omen of things to come.
Over the following months we began the process of fixing it. Here's some specs about it. It's an 81 c10 short bed fleet side. It has the 250 straight six with the integrated head, and a 3 speed trans with a floor shift mod. We decided to keep this setup as it is uncommon and cheapest option. Would have been easier to just do a swap and be done with it. While i was in college my stepdad did the teardown. Unfortunately he didn't really document or keep track of much info about the engine. He did find bits that were just safety wired on. Sent the block to a machine shop where it became the worse engine they have ever had in about 40 years. The max they could bore it out was 60. There was a cylinder that was 53 over that. So they had to sleeve it to do a stock to 40 bore. The cylinder head had more cracks than a dropped egg. Thinking it was the cheapest and easiest option I managed to source a new integrated head for about 300 bucks. Under my stepdads guidance things were progressing well. I bought a carb rebuild kit but to my utter frustration couldn't figure out how to get it apart. It's a Rochester varajet 2. Ended up admitting defeat and sent it to get rebuilt. The shop that rebuilt it confirmed that that carb is a real pain in the (southern hemisphere). Eventually we got the engine mostly together and back in the truck. This is where the project stalled.
The smog emission system was/is beyond me and my stepdad. To this day I have been unable to find any information on how to set it up. I took it to a garage where they claimed they could do it but it just ended up sitting in their lot. For more than a year. Granted the shop was going through a tough spell and a project like that was probably out of their capability. Eventually the truck came back to the house and i lost the financial capability to continue the work. I also lost my guide. After years of fighting as an Army Ranger in Vietnam. Years in the California desert racing dirt bikes. A career as a aeronautical engineer. Having survived cologne cancer. Broken his neck enough times that his neck was fused. He was about the toughest and smartest SOB you could ever meet. Pneumonia ended up being the final straw. Even worse was it happened shortly before Christmas when due to lack of employment and financial desperation I had enlisted in the Army and was away on training. That was 2019 going into 2020.
Now to the present (sorry for the long story). I finally after years of struggle find myself in steady employment with financial resources. I am determined to finish what we started and get this truck back on the road. I am going to make that straight six run again. But..... I don't know how. I don't know what parts are required or what can be bypassed. This is just outside my realm of knowledge. I continue to be unable to find any information to help me. Every shop I have called either wont do it or will but at a price I can't afford. So I have come here to this site hoping to find someone who is willing to help me do this. That engine is the only engine I will ever be able to claim that I have worked on with my stepdad. So somehow, some way I will hear that engine roar again. I just need help to do it. I'm looking for good pictures, diagrams, or anything that can tell me what I need and where it goes. I can provide pictures of what I have and will answer what questions I can. Any help is appreciated, thank you for your time.
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What was your stepdad's name? Sorry for your loss, sounds like a man I would have gotten along with...
I'm here for you. Start with smog; do you still live in Cali? If not, does your state require inspection?
So the engine has never been started since the rebuild?
How much of it do you have reassembled?
Pics of engine compartment will be of great value.
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Welcome from AL! Your story was interesting and as JP said, condolences on your father. There are many on this forum with a wealth of knowledge.
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I'm here in North Carolina. The truck is old enough that it's exempt from having to pass emissions.
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Cool, wish that were the case in Cali
get pics posted and we can guide you on emisions.
What about the other questions?
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Been buisy but I plan to post some pictures tomorrow, and have a list of the random parts I have by Monday.
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There is a wealth of information in the Technical Forum (Read Only) (http://forum.73-87chevytrucks.com/smforum/index.php?action=forum#c8). To help get you started, peruse the 1981 Service Manual (http://www.73-87chevytrucks.com/techinfo/7387CKMans//Service/ST_330_81_1981_Chevrolet_Light_Duty_Truck_10_to_30_Service_Manual.pdf); it takes a few moments to download depending on your Internet speed. Wiring diagrams are toward the back of the manual.
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here is what it looks like right now
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Quite a story, sorry about your loss.
As the owner of a Six cylinder 250 in a vintage camaro, that it took me two years to figure was rebuilt with the wrong pistons, I've come to really know and appreciate that engine.
I've found the inliners.org forum super helpful. I know quite a bit (now), but targeted to my engine if you have specific questions.
Mark
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Quite a story, sorry about your loss.
As the owner of a Six cylinder 250 in a vintage camaro, that it took me two years to figure was rebuilt with the wrong pistons, I've come to really know and appreciate that engine.
I've found the inliners.org forum super helpful. I know quite a bit (now), but targeted to my engine if you have specific questions.
Mark
Not to highjack Mr. Robinson's thread, but what effect did having 'wrong pistons' cause? Or, in what way were they 'wrong' is pry the better question?
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Quite a story, sorry about your loss.
As the owner of a Six cylinder 250 in a vintage camaro, that it took me two years to figure was rebuilt with the wrong pistons, I've come to really know and appreciate that engine.
I've found the inliners.org forum super helpful. I know quite a bit (now), but targeted to my engine if you have specific questions.
Mark
Not to highjack Mr. Robinson's thread, but what effect did having 'wrong pistons' cause? Or, in what way were they 'wrong' is pry the better question?
250 pistons on a 230 crank. Compression was low, 105 vs 135. No power, backfiring. If it were today, would have pulled the engine first thing, but there's a learning curve and confidence necessary. It's got a 250 crank and fresh pistons now. Runs great! Look for "my 230/250 build". On inliners for details.
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This might be a double post but here goes. The thermostat housing has an attachment with four lines coming off it. Where do they go? Can I ditch it for a new housing without it? Also the coal canister might be damaged. It has three rubber hoses coming off it that attach to nothing. What do you think I should do with it?
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If you're not required to have smog equipment you can ditch anything related to vacuum hoses except the vacuum advance on the distributor, and the PVC hose to the valve cover, and brake booster if you have one.
I don't have an opinion on the canister, perhaps someone else can offer one.
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so all that stuff on the termostat housing is for smog?
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Yes, everything except the necessary things listed are for smog. Remove any mental block from these items.
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I dont know what the necessary things are though. I'm new to this, automotive is just outside of my experience...
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The downward movement of the pistons create vacuum in the intake manifold, where the carb sits.
This force is used for work in some of your devices.
You need manifold vacuum for the following:
1. Vacuum advance to your distributor
2. Positive Crankcase Ventilation
3. Brake Booster Diaphragm
4. If you choose to keep it, the charcoal canister.
If you post some pics as some here have suggested, we can be of more assistance.
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Issue i'm having with pictures is every time I try to post one, it wont let me because the file is too big.
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Look for a app called Pixresizer
store your big pics in a folder, then create another folder as a destination for the shrunken pics.
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I'm curious, does anyone know what those lines are for off the thermostat housing? It looks like there are two sensors involve.
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LR! After you download your pictures to your computer go into preview. Select the picture you want from your photos and pull it up with preview. Then export (and give it a name) it to your desktop in JPEG format. Afterwards, open that picture on your desktop, click on tools and adjust size (width and resolution) until you get it to 500 KB or less.
If you can find an easier way to do what I mentioned above that is good. If not, what I said will work! I use a MacBook Pro, other devices may be a little different.
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Mike! Great advice!
Look LR, we want to help, but asking Questions over and over is not constructive without enough data to intelligently respond.
If you want proper guidance, it seems you need to go the distance. Your brief mention of your mentor/stepfather leaves me with no doubt that he would recommend the same.
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Ok here is one photo.
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and another
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Well done LR!
Looks like thermostat housing is not in the pic but we see the square hole in the front of the head where it goes. Ditch the sensors and plug them, or keep them and ignore them completely.
First thing I would do is give that girl a bath. Cover the carb and any openings that face upward, and gently wash down the surfaces after spraying some degreaser or even household cleaner.
Easier to discuss the house condition without dirty dishes all over the table.
Next pics we need are any other parts you have, like air cleaner, hoses, fittings, ignition parts.
It's a puzzle right now, but hang in there. We'll get to the correct picture.
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Here's the thermostat housing. I bought some vacuum caps for the lines. I plan to clean it up, replace the thermostat and throw some paint on it.
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Great, clean it up and paint it. New T-stat is a good idea at this point. ;)
You can just cap off the vac ports to make it look clean, but you won't have any line going to or from.
What about the air cleaner and any tubing associated?
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Ok so i mailed the carb out of state to a rebuild shop, hoping to get it back like new. Thermostat housing got cleaned, painted and capped. It hasn't been mounted yet but plan to today. I had to get new bolts to attach to engine. I guess next step is to clean some more and work on coal canister as I wait for the carb.
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Looking good!
How old is the thermostat?
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Brand new with standard temp rating.
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Ok i was off on a camping trip. While I was away the carb got sent off, rebuilt, and returned. I'm going to be talking about it shortly. However todays questions involves something different. I have two parts that I'm unsure about. I have no idea what they are for but I think one bolts onto the manifold as something is suppose to go there. Any information is appreciated.
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Here is a photo of the two parts
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That's an EGR valve (exhaust gas recirculation). You will need to install it unless you can find a way to seal and cap off the openings on the manifold.
Vacuum items are not needed for your build.
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Ok, I will clean it out and re install it. What is the purpose of the valve? It doesn't look like anything hooks up to it.
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One of the ports it covers is to your exhaust manifold, the other is to your intake manifold.
Under certain condition, vacuum opens the valve, and allows exhaust to be recirculated into your intake, mixing with the air/fuel.
It was designed to reduce emissions.
Be aware, if and when they fail, they will induce unwanted exhaust gas and your engine will run like poop.
I would look for a way to seal it off and never look back.
Maybe someone here knows of such a product. Can't cost much-it's so simple. I would probably make one if they don't exist.
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Been trying to find a replacement to no avail. I'm going to try and make a cover plate with a piece of steel and some gasket maker.
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I finally managed to order a replacement and should have a new EGR Mid week. Does it run from a line off the carb?
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In a roundabout way, but since you have no smog requirements, leave it disabled.
You gain nothing from having it active.
Good to see you making progress ;D
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OK on the intake manifold above the EGR valve and right below the carb is a large diameter threaded hole. I have no idea what screws in here. I don't have a whole lot of parts left. I also have a lever on the exhaust manifold. Again I don't have a clue as to what bolts on to this Worse case just put a large bolt in the intake hold and wire the lever in a set position. But I don't know which position it needs to be in.
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Here is the large hole above the EGR valve. Yes i see the loose crap on it. I'm going to vacuum the heck out of the intake and try to clean it up as much as I can.
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Hard to say what that hole was used for-Threaded right?
Can you take a couple of pics from back a few feet?
The lever may be used to direct exhaust gas to the area under your carb, is there anything on the other side of it?
Again, pics from as many angle as you can will help a lot!
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I was able to find out that the big hole above the EGR is plugged. I was able to look at the old cracked head and that hole has a bolt with a square head on it. At least from what I can tell. For the lever best guess is something that isn't super crucial. more pictures to follow.
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Doing some more digging and it looks like the lever could be the EFE or thermal vacuum switch or something like that. Something to help in cold weather. Issue with that is if I wire it in the wrong position it wont be a happy engine. If I'm right that is...
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Something actuated it so it would be good to find out.
My V8 has a similar valve that causes the exhaust port to close till it warms up.
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Agree with Johnny! I had one on my exhaust manifold (passenger side of engine) that I removed long ago. I would imagine the it is not critical. However, I don't know much about diesels.
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It took longer to post but here it is. The part that moves that lever is called a EFE or TVS. There are none around and it's an optional component. I have found a photo of one on the same engine i have on a similar truck. The big issue is the 5/8 threaded hole above the EGR valve. From looking at my old cylinder head it looks like it was plugged. But by looking at the same photo i have found it looks like a line comes off it. So right now I'm not sure which route to take. Do I just plug it? Does the lever need to be secured in the up or down position? Currently I'm stumped.
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That picture is extremely helpful!! Good job!!
So under cold conditions, vacuum is active at the rear of that canister, pulling a diaphragm and the rod inside, against a spring, thus pulling the lever.
That affects the exhaust flow so the engine heats up quicker.
When temp is correct, vacuum is stopped, and the spring in the canister pushed the diaphragm and rod back out.
This allows for a free flow of exhaust, something you want.
Since you have no smog equipment, you won't need the diaphragm.
So looking at the valve lever, move it to the right, or away from the front of the engine and tie it off with a wire.
Done and done!!
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Happy to have that figured out! Now I just need to figure out what to do about the threaded hole above the EGR valve. Do I plug it with whatever I can find or do I need to figure out if it had a more important purpose. I'm unsure what to do here.
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Okay, while it's kind of hidden in the picture, the EGR is near the center of the carb landing, We're looking at the back, kind of brassy finish, right?
If yes, then the pics you sent earlier were 90 degrees to the left which make perfect sense because it leads us to what that port might be.
First shine a flashlight into the opening and see if you see lite in the area that the carb will cover. That is the intake plenum.
If yes, then looking at the picture of the engine, and where the tubing is going, it looks like a vacuum line going to a power assist brake unit.
Do you have power brakes? They require positive vacuum to work, and get it from the the intake manifold.