Build The Clustertruck Rides Again - Refurbishing a 1975 Chevota

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SuperBuickGuy said:
I completely get the save money aspect, unfortunately, (and fortunately) externally, the gen 1 sbc is the same from 1955 to 2002. Unfortunately because everyone swaps to 350s, it costs far less to rebuild a 350 than a 283 - I know of 2 people who did 283s, and the cost to even re-ring was mindblowing. Fortunately, all your brackets and such will bolt straight on. Your intake manifold is different from the Vortec, but when the heads first came out, many, many people simply redrilled their existing manifolds to the Vortec spec. The only other issue you'd find, is that some blocks do not have the hole drilled for the mechanical fuel pump. There are lots of advantages to the later 350, most notably (beside the heads) is the roller cam and the one-piece rear main seal. No leaks, no flat cams, 200,000 mile reliability (and a lot more if you take care of it).

Don't be afraid of efi, be afraid of aftermarket efi systems. the GM system is so well sorted, that, once you make the switch, you'll never be sorry... in many ways, it's easier to set up because you're not deviating from GM validated on their production trucks.
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I think you might be misunderstanding the "rebuild 283" part - I'm not going to be re-ringing it, boring, replacing pistons, etc. I'm going to be slapping in some new oil seals, valve covers/gaskets, and probably fuel, water, and oil pumps - if I even go that far. Just enough to keep it from leaking itself to death.

Someday, a long time from now, I will absolutely go to a 350. But if I can spend $600 now and get another 5-10 years of life out of the 283, it will allow me to drive the truck while I continue refurbishing it. Once the truck is sound, the body work is done, etc. it will just be a "simple matter" of pulling out the (now properly mounted) 283 and replacing it with whatever flavor of 350 I can come up with.

It's not so much the EFI I'm worried about - it's a FAR superior system to a carburetor, especially off road/off camber. It's all of the damn sensors and emissions controls and everything that you need on the later engines. Just a lot of adapting/wiring headaches I don't really want to mess with at the moment.

I'll definitely check out your build - sounds about in line with what I hope to do down the road.
 
then you're pricing to reseal the motor is wayyyyyyy high.... a complete gasket set can be had for $60.00. when you have it apart, pull a rod cap to check the bearing - but, for more importantly, to check to see if you have a large journal 283. If you do, your new motor will cost substantially less. The large journal 283 crank fits nicely in a 327... which makes a 302, one of the best mashup of gm sbc parts - point is, it's valuable ($400-$600), don't throw it away.... block, it's really not worth much if anything, but the crank can be.

too bad you're not closer, we could make a deal ;)

just a note about leaking, though, if it's leaking oil because you have too much blow-by; you'll need to get new rings as well... and then we're back to the prior discussion. I got thoroughly educated on that little characteristic on my first, blower equipped motor... ugh, it was so bad, it'd pop the dipstick out under boost.

I've always heard that experts are ones who have made the mistakes.... then I have a Phd in this stuff ;) wonder where I get my degree?
 
and don't be afraid of an efi set up, if you calculate all the parts for a carb'd set up (parts required to run); an efi set up has 50% of the parts (take the carb apart to its component level) of a carb.

I've always meant to do this, so I'll do it right here:
How EFI works, simplified.
A carb meters a set amount of fuel for air flow mechanically, it adjusts for air temp, air pressure (elevation), humidity, and the specific weight of the gasoline being burned.
An efi simply moves those actions from one point to another. It adjusts the air/fuel ratio by increasing or reducing the time the injector is open. Most older motors have 2 injectors - thus, like having dual carbs, you have redundancy- An injector opens and closes with a magnet - simply put, when the magnet is charged, the valve opens and lets fuel by the needle valve.
A carb uses 3 basic circuits to regulate air/fuel - and that's based upon starting, steady state, and acceleration. EFI uses a throttle position sensor to do all three of these jobs plus one other circuit.
that other circuit is the air temp and motor temperature. Those both are, normally, just one, small device. A block temp sensor like you have for your gauge, and an airflow sensor.
air flow sensors are, quite simple as well. the more dense the air, the colder the air will be as it rushes across a fixed space. Thus, as you have a coolant sensor, the air sensor is simply that sensor more refined.
O2 sensor... in reality, you don't have to have this for the motor to run - and most motors run closed loop only checking the o2 sensor to verify what their program has already told them is true (thus, the GM validation I talked about before). What it does it checks the amount of oxygen in the exhaust stream, the hotter the exhaust (being very simple here), the less oxygen. To cool the exhaust, they add more fuel, to heat the exhaust, less fuel... in all cases, you're deal with 3 different types of temperature sensors - all of which test exactly the same way

Why is it simpler? because you will never have to do the base tune (though even that's easy because its so linear). Modern motors also control the spark, but efi doesn't NEED to control that... it does add a layer of complexity; but as long as you isolate each system, it becomes pretty easy to figure out what is wrong with the system - which is opposite of a carb. With a carb, you must adjust for altitude - but which circuit? all of them? maybe, with efi, it does it automatically and if it doesn't - you simply do a test of the air flow sensor. The sensor should read between 1 and 5 volts - and it's easy to test, take your air compressor blow gun, blow across the wire, and check the reading.... not so with a carb - is it plugged? does it have sufficient fuel pressure? did you get more alcohol in your gasoline? do you have the right jets to upsize?

last but not least, the most common failure is the crank position sensor - which controls the spark, not the efi... but it does get people saying how terrible the efi system is because it won't start - which is ironic since it's not the efi causing the problem.
 
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SuperBuickGuy said:
then you're pricing to reseal the motor is wayyyyyyy high.... a complete gasket set can be had for $60.00. when you have it apart, pull a rod cap to check the bearing - but, for more importantly, to check to see if you have a large journal 283. If you do, your new motor will cost substantially less. The large journal 283 crank fits nicely in a 327... which makes a 302, one of the best mashup of gm sbc parts - point is, it's valuable ($400-$600), don't throw it away.... block, it's really not worth much if anything, but the crank can be.

too bad you're not closer, we could make a deal ;)

just a note about leaking, though, if it's leaking oil because you have too much blow-by; you'll need to get new rings as well... and then we're back to the prior discussion. I got thoroughly educated on that little characteristic on my first, blower equipped motor... ugh, it was so bad, it'd pop the dipstick out under boost.

I've always heard that experts are ones who have made the mistakes.... then I have a Phd in this stuff ;) wonder where I get my degree?
Click to expand...

All good info - definitely stuff to consider down the road.

I remember looking up the block numbers - it's a 65-67 era block from a truck. Not sure if it is large or small journal. Would be interesting to know.

As for the cost of the reseal, as I mentioned, it's more than just gaskets and seals. I just won't be doing any machine work to it. If machining is necessary, I'm buying a 350. I'll probably be replacing fuel pump, oil pump, water pump, alternator bracket, rams horns, etc. which is where the majority of that cost comes from.

The oil leaks don't strike me as a blow-by issue. I've got a (very slow) rear main seal leak, which seems pretty common. I have a leaking oil galley plug over the oil filter. Up front, I recently developed a bad leak at the timing cover/oil pan union. It also leaks oil from the intake bolts. Probably a good thread chasing/cleaning is all they need.

As for coolant: the thermostat housing leaks, but only if it sits for a while and the gasket dries out. The thermostat is stuck open, I think - so that will get replaced too.

Exhaust - driver's side ram's horn leaks at the head. The pipes are heavily rusted and ready to be replaced.

Don't worry about me throwing out the engine. I have had guys in my father-in-law's car club basically beg me to sell them the engine. A lot of them are running 50's and 60's Chevys and would LOVE the period correct motor. It will go to a good home when I'm done with it.
 
sounds like a solid plan, if you like the current power level, I'd certainly stay with cast-iron exhaust manifolds - headers get you more power, but don't last as long.

recently I tried one-piece, retrofit pan gaskets (they work really well on the newer gen motors); but they don't work.... so in case you're tempted, just say no - old school plus silicone in the corners works very well.

I like the o-ring sealed water necks, but they require a very clean, smooth mounting surface - otherwise they don't seal... that and, there is a huge quality difference out there, so buy one you can actually look at prior to purchase... I'm sure Summit hates me because the last several I got from them got a return trip without even mounting because they were such junk.
 
I'm fine with the power level. I'm in no way interested in building a drag car, and the 40/283 keep up with traffic just fine (certainly better than the 2F does). It's got plenty of guts to do what I do with it (aimlessly tool around and use it as an expensive mountain bike rack).

Interesting about the 1-piece gaskets. I've read you have to be very careful to buy the proper thickness, as there are two different oil pan/timing cover set-ups and thicknesses on the 283. I have a one piece on my "wish list" at Summit, as I'd heard good things elsewhere. Might have to re-evaluate.

Yeah, Summit makes me a little nervous. They seem to be HEAVILY skewed "cheap Chinese parts." A water neck - whatever I'll return it and make do...but an oil pump or something - that could be catastrophic!
 
Well, the Clustertruck survived another 40 mile drive to its new (and finally, permanent) address.

Even though the brake master cylinder was leaking, it wasn't nearly as harrowing an event as last time.

I started getting a bad squeal around 2500 RPM while I was on the way. At first I thought it was a belt, but I'm beginning to think my long-suffering throw-out bearing may finally be giving up the ghost.

I'll have to investigate more when I (once again) replace my master cylinder and bleed the brakes.

A couple shots of the new place, complete with the finace, and the cruiser - gang is all here!

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A lot of work to come, converting the garage into a shop, but for now, here's a final shot of the 40 in the new house, with its new bunkmate :D

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Now that the truck is right out my back door, I decided to take advantage by replacing the FJ60 brake master cylinder that had failed and started leaking literally hours after installing. NAPA was kind enough to replace it for free. Got the new one bench bled, and bolted in. Now I just need to bleed the brakes again. Hopefully this one will hold up better than the last one.

Up next, I plan to do as full an evaluation of the 283 as I can. Hopefully a wet/dry compression check, a look at the spark plugs, and maybe pulling the valve covers will be enough to determine whether there's enough life left in it. This thread may go dormant for a while after that, while I scrape together the cash for the necessary repairs to the existing engine, or a replacement. I have most of the conversion parts already lined up, but I'll most likely need to shop out the welding/exhaust/driveshaft work that goes with it, which means big repair bills.

I was hoping to actually drive it this summer, but the leaks are getting out of hand, and as I mentioned in the last post, the throw-out bearing is on its last legs.
 
Not a whole lot to report. I've been up to my eyeballs in house projects, and haven't had a lot of time or money to dedicate to the clustertruck. That said, I'm slowly plotting out the final (mechanical) hurdle, and figuring out where I want to go when the engine gets pulled and remounted properly.

Given the condition of the trucks mechanicals I've been preparing for the worst - probably replacing the engine. I've been tossing around the idea of a diesel, and looking at crate 350's. today, I ran a compression check, and I think I can safely put both those concepts to rest.

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I was blown away by how good the compression is in this leaky old 283. There's some oil fouling on the plugs, but 1. I have no idea how long they've been in there and 2. The engine doesn't smoke at all. I assume I need valve seals.

In short, it looks like the 283 is going to get yanked, resealed, and thrown right back in.

:bounce:

Probably the best news I've gotten in 3 years of ownership.

The truck got 8 new spark plugs, warmed up, driven around thre block, and put right back in the garage. Back to yard work.

I did notice that the engine tends to "surge" at idle lately, especially cold. When I clamped off the fuel supply today to drain the carb bowl, it smoothed out immediately. I've had a sneaking suspicion the fuel pump is bad - and pumping gas into my oil. I think this might be further evidence that I'm correct.
 
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With the knowledge that my engine isn't on the verge of complete failure, I decided to finally really address the some of the issues I had been ignoring from day one.

1. I seem to still have a fuel-in-oil issue. I originally thought it was the carburetor, but after plugging the welch plugs in the quadrajet an epoxying them, I'm still running into the same issue. I decided to change out the fuel pump to ensure its not leaking into the crank case. Simple, except that the new pump outlet didn't match the old one, so the hard line didn't fit. No matter, since it is completely shot, and linked, anyway.

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So, fuel pump will have to wait until tomorrow when I can find and flare a replacement.

So I moved on to the thermostat. As long as I've owned the truck, it takes a solid half hour to come up to temperature. I always assumed that the thermostat was stuck open. So I ordered a replacement thermostat and opened up the water neck. Turns out, the old one works:

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Figured I would drop the new one in anyway. Then I looked at the water neck. It turns out, it is completely disintegrating.

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So, thermostat replacement is also on hold until I track down a new water neck too.

The Clustertruck strikes yet again! Turning a one hour job into a 3 hour one!:doh:
 
Better to find that kind of problem now instead of an hour, or more, of walking out for help.

Don
 
And we are back in business!

The truck still takes a half hour to warm up. I'm guessing it's probably the belt driven fan 1/4in from the radiator. When I move the engine, I'll probably swap over to a clutch fan.

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For what it's worth - I am not a fan of chrome. It just so happens that the aftermarket for Chevy small blocks is flooded with cheap chrome parts. Makes it pretty obvious what I have/have not touched yet!

New fuel pump is in too -

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That was way harder than it should have been! Used a wooden tongue depressor to hold the pushrod up, then wedged in the pump arm, and slid out the depressor. Then I needed to overcome the spring resistance from the pump arm in order to start the bolts, all while keeping the gasket in place...a job that really needed 4 hands, in a section of the engine bay that only has room for 1!
 
RWBeringer4x4 said:
That was way harder than it should have been! Used a wooden tongue depressor to hold the pushrod up, then wedged in the pump arm, and slid out the depressor. Then I needed to overcome the spring resistance from the pump arm in order to start the bolts, all while keeping the gasket in place...a job that really needed 4 hands, in a section of the engine bay that only has room for 1!
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Sounds like the fuel pump cam was at its high point. If you world have rotated the engine a little, the fuel pump would have been easier to install.
 
Unfortunately, I tried that. The rod was at least close to fully retracted. The real issue is that I didn't "grease glue" the rod up against the cam, because I didn't remove the pump backing plate. This means every time I would lost the gasket or a bolt and have to pull the pump, the rod would fall, and wedge itself against the backing plate. Moving an oily pushrod back up is harder than it sounds.
 
Drove it into town this morning to pick up some coffee and confirm everything was working. It's about 70 degrees - the engine held temperature nicely. Took the full 15 minute drive into town to get there, so nothing has really changed, haha.

No fuel delivery issues. The fuel line still back-drains when the truck is shut down so it's still a little hard to start. However, there is less of a "surge" at idle. Hopefully there won't be any more fuel ending up in the oil. I'm going to change put the oil one of these days and start with a fresh baseline. A new quadrajet is also in the future. The current one has never worked quite right, probably because it is warped and leaking vacuum from the baseplate.

In either case - beautiful day to have the clustertruck out terrorizing small town America!

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I'm not sure about your particular motor, but in the late 60's the SBC had a bolt on the front side of the block that was perfectly in line to the fuel pump push rod. By removing this bolt you could use a stick, or whatever, and push sideways against the rod to hold it up. You could then install the fuel pump easier. I don't remember what motor it was I found this on. It could have been my 69 Camaro with 307, or the 67 Chev pickup with 327.

Don
 
handcannon said:
I'm not sure about your particular motor, but in the late 60's the SBC had a bolt on the front side of the block that was perfectly in line to the fuel pump push rod. By removing this bolt you could use a stick, or whatever, and push sideways against the rod to hold it up. You could then install the fuel pump easier. I don't remember what motor it was I found this on. It could have been my 69 Camaro with 307, or the 67 Chev pickup with 327.

Don
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Yeah I looked for that - granted not very hard, but that might have been just after this engine - mine is a 65-ish and I didn't see it. I probably should have just removed the backing plate and greased the rod. That is exactly what I'll do in the future.
 
Weber Sarge said:
Most of the older engines we removed that short front bolt and temporarily replace it with a longer one . Holding the rod in the retracted position you can snug the long bolt to hold it there , then install your pump . Remove long bolt , re-install short one and it's done .
Sarge
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Thanks, Sarge. See post above. I didn't see a bolt. That doesn't mean it wasn't there - I may not have looked hard enough, but there was a huge freeze plug in the vicinity. It may have been slightly later small blocks with that bolt. That, or I just didn't see it. I tend to get tunnel vision when it comes to stuff like this! :meh:
 
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