1983 Chevrolet C10 - Need help

[cLaWz]

Where to begin...

My fiance purchased a truck from her stepfather for $1,000. Used it at their ranch and around the small town she is from for a long awhile. Apparently at some point in time there was a fire under the hood with the original 350 so he tossed a 454 in it along with a replacement wiring harness.

To be honest, this truck is more trouble then it's worth in my opinion but my fiance has an attachment to it.

All started back with the distrubutor flaking out. Then I had a bad leak form at the transmission cooler connection into the radiator. On top of that it is leaking oil from the rear main seal I believe. A lot of other stuff going on but the symptoms below are our biggest problem.

Got hotter then normal the other day while we were moving to our new place (by maybe 20 to 25 degrees) and found the radiator was low. Topped it off and took it for another drive... started getting hot again as I pulled back into our driveway and it puked out over 2 gallons of coolant onto the driveway through the overflow container.

Only thing I have done so far is a quick visual inspection due to time constraints. Current plan is to pull the thermostat and test it, then move on to a pressure test on the radiator. Doing some research here on the forums I can let the system sit pressurized for 2 hours or so and at the completion of that pull the plugs then turn the motor over and watch for any coolant coming out. Should tell me if I have a head gasket problem. Guess the easiest check for the water pump would be to run it for a few minutes then check for circulation but I am not sure if it is wise with the way it is acting. Any suggestions on that front?

I'm a "weekend" mechanic per say. My ideal would be to find a used complete 350 from somewhere and do a swap since we *really* do not need the 454 and the 8 MPG that goes with it. Never done a full swap but I'm sure I could handle it with some time.

Anyone have any advise?

Thanks

[old Rusty C10]

usually if its a head gasket you will either find water shooting out the exhaust or you will find water in the oil.. you can try your methods too but im wondering if you have an air pocket or a blockage in your cooling system

[kelsfine69]

If it got hot once the stat is junk now put a new one in and go from there.

[sperz1]

Sounds like you're on the right track. As mentioned above, I don't think it's the head gasket based on the symptoms you've described.

Let the truck heat up and feel the top and bottom hoses on the radiator. If they are the same temp then the thermostat is opening. If the top is cold and the bottom is hot, then the thermostat needs replacing.

Good luck!

[babyJay]

There are a lot of members down there in Texas that would probably trade you a decent 350 for the 454. They'd be silly not to, IMO. Sounds like you're on the right troubleshooting track.

[gchemist]

Welcome to the board.
Swapping an engine is easy!

All you need is tools and a replacement engine.

Replace the thermostat with a lower temp. I would use a 180 or lower. It's hot in Austin!

[babyJay]

Originally Posted by gchemist

Welcome to the board.
Swapping an engine is easy!

All you need is tools and a replacement engine.

Replace the thermostat with a lower temp. I would use a 180 or lower. It's hot in Austin!

Way up north, we always say 180 or higher, so we can have heat in the winter.

[cLaWz]

Thanks for the advice. Sound like my research paid on in putting me on the right track!

Hell if someone wanted to do a straight swap of a 350 for this 454 I would do it in a heartbeat. Fiance drives it most of the time (mainly due to gas consumption and my commute is 25 miles compared to her 5). As I mentioned... no need whatsoever for it and I'm not looking for a hot rod. Just want to get around town and do some light hauling here and there.

[cLaWz]

New info. Pressure tested the radiator and found a bunch of issues with it. Took it to a radiator shop and it was going to cost more to repair then to replace it so I put in a new one along with a new thermostat, water pump, and coolant recovery system.

Bled all the air out of the system and took it for a short test drive, no issues. Great! I'm in the clear I thought... yeah right. Fiance took it to work this morning (without asking... I wanted to road test some more) and had a sudden and sharp temperature spike which then dropped and returned to normal. She turned around and brought it home. Was blowing white smoke and I could see coolant coming out of the exhaust manifold to exhaust connection.

Radiator is very low so it went through a good chunk of the coolant I just put it so I think it's a safe bet that the head gasket let loose. I'm guessing this is due to the fact that the cooling system was now able to pressurize better due to no leaks out of the radiator (high in the system so they were dumping steam constantly). Higher pressure caused the gasket to finally let loose after what I am guessing it being weak already.

Going to pull the plugs and do a compression test just to verify but is there anything else I should be looking at? Intake gasket maybe?

<sighs>

[old Rusty C10]

could be many things but again im betting head gasket now.. ive seen a head on a six crack and cause that same kind of issue when you pull it apart it will be obvious

[sperz1]

I've seen a crack in the block do that on a 350 at the old shop I worked at. How did your compression check come out?

[cLaWz]

Been awhile since I posted up this thread but I finally had some time from work and the heat (105* avg temp during the day sucks) to work on the truck. Pulled the plugs after a pressure test on the new radiator I had installed and lo and behold I had about a cup or two of coolant drain out. That sealed the deal and I began the tear down. After 4 hours yesterday the image below shows where I am at. Right side is the one with the issue and I found coolant residue on the rocker arms as well as it's generally "burnt" appearance. Turns out whoever did the intake gasket last put it on wrong which is why I had an oil leak down the back side of the motor as well. Black rubber seal has slipped out of place and the RTV they used to try and fix their mistake didn't hold very well it seems.

I ordered up a complete engine gasket kit from Felpro which includes valve stem steals and all the gaskets I need to complete the repair. On to the fun of pulling the heads!

Do have one question... my Haynes manual I am using as reference says it is fine to reuse the head bolts. Any way to verify they are not TTY's?

Thanks

[60ratrod]

well you can re-use the old bolts, but you gotta clean the bolts and then re-apply some thread sealant. i was going to do this on my 305, but then my patience ran short and i went a head and bought brand new head bolts(fel-pro) for about 33.00 dollars after tax, before my $20 autozone discount and military discount. so in my opinion its better to get some new head bolts and have the piece of mind knowing that they have a less probability of breaking than used head bolts, especially with the amount of time that the engine has spent above the normal operating range.

[cLaWz]

Yeah, I have no idea what kind of problems it may have had before we got it. Such is life just sucks it was supposed to be a "good" truck coming from a family member.

It's been sitting in the driveway since my last post.. and we never let it truely overheat per say. Got a new radiator, water pump, hoses and all that good stuff to put on when I put it all back together too. Hope it fix's all the issues and it can be back to being the backup vehicle for short trips.

May just order the replacement head bolts. Seems Autozone and Advance do not stock them on a normal basis

[87Bob]

For someone who is not a mechanic I think your doing a fine job. As far as changing motor sizes you will not gain a great deal in MPH. These trucks are geared low for pulling power. If you truly want a MPH gain you need a over drive trans. I think once you get the bugs out of it you'll be a much happier camper. Keep up the good work!

[cLaWz]

Worked on it some more and got the heads off. Good god I wasn't expecting them to be that heavy! This is where I am at, can see which cylinder the head gasket let go at since it's the only one that has been cleaned of most of the carbon deposits.



Have 2 valve assemblies that look different then the rest. Not sure whats up with that.



I am completely stumped as to what in the world is going on with these exhaust headers. They have connections into each port by way of metal tube that lead out to the larger tubing then is pinched off. One of them has broken away from the connection point and I have no clue what to do about it. Any ideas?



And last but not least, can anyone help with some info on this Holley carb? I have found mention of it being a 600 CFM model but cannot find specifics on their website. From the front of the air horn:



Thanks

[87Bob]

Originally Posted by cLaWz

Worked on it some more and got the heads off. Good god I wasn't expecting them to be that heavy! This is where I am at, can see which cylinder the head gasket let go at since it's the only one that has been cleaned of most of the carbon deposits.



Have 2 valve assemblies that look different then the rest. Not sure whats up with that.



I am completely stumped as to what in the world is going on with these exhaust headers. They have connections into each port by way of metal tube that lead out to the larger tubing then is pinched off. One of them has broken away from the connection point and I have no clue what to do about it. Any ideas?



And last but not least, can anyone help with some info on this Holley carb? I have found mention of it being a 600 CFM model but cannot find specifics on their website. From the front of the air horn:



Thanks

Those header tubes were for part of the pollution control system and were hooked up to an air pump to direct air in the exhaust system to finish burning any unburnt fuel in the exhaust gas. You can just plug them off if you want unless your in a emission tested area. Give me some time and I'll find more info on your carb. Update: The carb is an obsolete 4160 series model. The rebiuld kit is a PN 3719.

[cLaWz]

Thanks Bob. I am in an emission tested area BUT the truck is over 25 years old which is supposed to make it exempt.

As for the carb, that helps a ton. Can find some diagrams now and see what all (if anything, crossing my fingers) is missing. I think they were either extremely high or extremely drunk when they rebuilt this truck

Least the wife appreciates me trying to get it running for her again

[N2TRUX]

Since emission testing isn't a concern pull the air tubes and plug the holes with brass plugs. I would soak them with your favorite penetrating oil overnight at least.

It looks like whoever put the heads together used what ever was available.

[cLaWz]

I think that they did that for more then just the heads. I had many moments where I just shook my head in disbelief while I was doing the teardown.

Not going to just toss it back together with new gaskets as a quick fix. Going to clean everythiing up and do a detailed inspection and do whatever work I can while the heads are off. Biggest area of concern is the carb. Got vacuum lines that lead to nothing, some just plugged with screws and it looks like it may not even be fully built correctly.

Guess it makes a good project truck to learn on. Always wanted to do this kind of stuff growing up and never got the chance.

[60ratrod]

i would use some liquid wrench on those egr tubes on the exhaust manifolds. and if you are questioning/worried about those heads then you can always take the heads to a machine shop in your area and have them cleaned, inspected(for cracks and straightness), and assembled with new seats if needed, valves, springs, and seals. things i would check for while you have the heads and intake off is to see if there's any carbon/sludge build up, any loose and free floating hardware(i've found nuts bolts and spring chunks in the lifter valley oil pan and oil pump pick up screen), cylinder walls for deep pits and gouges, and how bad the ridge is at the top of the cylinders.

[87Bob]

Depending how far you want to go with the Holley they have a shop that will rebuild it for you. They look for things you may overlook and it will look like and run like new when you get it back. You can find all you need through the Holley web site or their tech line. Their very helpful!

[project_77]

Might I also add,


When I did the head swap on my sbc....I prepped the new Fel-Pro "blue" gaskets with copper spray....seen it done on HotRod TV I think and I used new Fel-Pro head bolts.

No issues as of yet.

[shockermotorsports1]

if you were a lil clser I would trade you straight up

[cLaWz]

Ok, another update. Started cleaning up everything and worked on the gasket surfaces and such. Under a bunch of grime on the front left side of the block I found what I believe to be the casting date but I cannot decipher it fully with info from www.mortec.com Only thing that *looks* obvious is the year 1967 but I'm not even sure if that is right.



Piston head has 030 stamped into it. Does this mean it is .030 overbored?



I am finding more evidence that this motor was recently rebuilt. Between my suspicion of it being overbored (above) the cylinder walls are smooth with a very very fine ridge at the top. (Yes I know I need to clean them up ) I have learned though that just because it is rebuilt doesn't mean it was done correctly. I am thinking the gaskets and such were not installed correctly which caused the issues.



Didn't work on the heads today due to not having the tool to remove the valves and springs. Dunno if the seals and such would hold up to carb/brake cleaner or degreaser so I didn't want to risk it. Good news is that I have not seen any cracks in the block so far so with what I have cleaned.