The Stovebolt Site Forums The Shop Area Engine Shop 235 Smoke

I have a Chevy 235 that is not original to a '53 GMC 100. While trying to source a differential, I got bored and decided to try to start it. I cleaned out the carb (Zenith) and got a battery, a jerry can as a provisional tank, and water in the radiator. After a few cranks it started up, but I have two issues:
1. There's quite a bit of smoke once it warms up.
2. The oil seems to have gotten water in it.

I had checked the oil prior to the initial start up and it seemed fine, although I suppose it is possible that there was some water in there because I have no idea how long the engine had sat. I changed the oil to see if the water showed up again and there seems to be considerably less water in it after running it for a few minutes to let it warm up. However, the smoke is still there.
The plan is to pull the head and check it out to rule out any damage to it. I'd like to know if anyone could give a basic breakdown of the procedure (since it's an OHV, can I just pull the head as is, without any disassembly?) and if it is safe to reuse the head bolts? I'd also appreciate any other related advice.

Too many wrong moves to count- - - - -

Starting an engine out of long term storage without doing things like changing the oil, adjusting valves, oiling the cylinders, etc. is an invitation to disaster. Better late than never, so go ahead and change the oil (and filter, if equipped), adjust the valves, soak the cylinders with Marvel Mystery Oil or some similar kind of penetrating oil, and fill the cooling system with fresh water. No antifreeze for now- - - -if there's a head gasket leak, you don't want it in the combustion chambers.

Check the points for proper gap, inspect and/or change the spark plugs, and do a static timing procedure to get the ignition timing in the ballpark. Then crank up and do a short run-in to check for expensive noises, smoke, etc. Sometimes a smoker can be rehabbed by overfilling the crankcase with 2-3 quarts of kerosene or Diesel fuel, and letting the splash from the crankshaft bathe the inside of the engine with solvent. Don't drive the truck of put any load on the engine with solvent in the oil. Drain the oil/solvent mix while hot, and mo9st of the gunk will drain out with it.
Jerry

I will add some kerosene or diesel to the oil and run it for a bit. The ignition has been gone through (new cap, rotor, wires, plugs) but I did not have a spec for the points or valves (it's also my understanding the valve clearances should be checked with the engine warm). They seem to be working since the car fires.
I'd like to pull the head and get a look at the pistons, cylinders, combustion chambers, and visually inspect the head. Can I reuse the bolts?

I was thinking these were valve-in-head (not sure if that's the term used), but you can re-use the cylinder head bolts after removal. Before you get to the task of removing the cylinder head, just follow Jerry's advice & see if any of the engine's ailments work themselves out.

There's also a few tech tips on these procedures, but here's the shop manual links:
Point gap in the manual.
Valve clearance procedure . Yes, the valves need to be adjusted while warm, but you need a baseline starting point since the engine has set idle for a while.
Valve timing.

What color smoke is it?

Brad

Thanks for the pointers! The smoke seems to be whitish/blue. It doesnt seem to smell like burnt oil, but the coolant level (even though it only ran for a few minutes) seems to be staying put. It increases as the engine temp increases and is considerably more when revved. I should also note that the plate that blocks off the exhaust (not sure of the name) that has some sort of preload spring running behind the manifold and half-moon (counter weight??) toward the front of the vehicle is stuck in position (not sure if open, closed, or somewhere in between).

right column - last paragraph manifold heat riser & heat control valve (1954 - same for most 216/235/261 years/engines)

If the valve swivel is rusted open. The intake manifold might get too hot? Others will post better explanations.

It's the heat riser valve that you have stuck; read about it & its function here. See if you can free it up- here's a recent thread about one being stuck.

I got lucky & a few light taps with a ball peen hammer dislodged mine. Being stuck 'open' or 'closed' is not ideal and will cause poor engine performance. I don't know if it could cause the smoking, however.

Keep mentioning symptoms & what you see (like this heat riser valve being stuck) and folks will jump in & help out. I wouldn't bust out the head-pulling gear just yet.

Brad

Thanks!!

Hmmm.... "It increases as the engine temp increases" How much smoke are we talking about here? Little? Lot? Smoke out of the exhaust pipe, correct?

(I will probably advise the following for the rest of my life...) BUT: I would check to make sure the rocker arms are getting oil. It's as easy as removing the valve cover & looking at them. Dry cylinders would not be good.

Again, read & follow Jerry's advice (squirt oil in the cylinders).

Brad

It's a considerable amount, but it doesn't form an impenetrable cloud.
Since we're talking rocker arms: there is some sort of "fix" in a copper pipe leading from the center of the valve cover. It goes to a T-fitting on the driver side of the block from which something goes into the firewall. I tried pulling the valve cover but that "fix" does not allow the valve cover to come off. It can only be rotated off. Inside the valve cover, it is attacehd to the center of the rocker arm assembly with what looks like jb weld.
Would lack of lubrication to the rocker arms lead to smoking? What could that "fix" be?

"What could that "fix" be?"

I'm guessing the 'normal' passage for the oil to reach the rocker arm was/is plugged (Hotrod L's reference to 'slug' would apply here) and someone redirected oil from the easiest available source.

Does the copper tube go through the valve cover, or over it to a tapped hole in the cylinder head? There's a drilled/tapped hole at the center of the head that intersects the oil passages to the rocker arms. It's common to find a shade tree fix involving running a tube from the oil pressure port on the driver's side rear of the block to the threaded hole in the head. If somebody has drilled a hole in the valve cover and glued the tube in, you're dealing with Mr. Bad Wrench for sure! That fix needs to go away! It could starve the bearings for oil by bleeding too much away from the normal routing.
Jerry

The home in the valve cover looks like it should be there. The tube is definitely a shade tree fix. It does seem to come from the oil pressure port into the head. Should oil be flowing up that tube to the rockers?

*hole

If the valve cover attaches with 4 screws around the perimeter (not 2 studs through the top) there shouldn't be any other holes in it. A very few had four narrow slots in the top for ventilation, but I think the last year for that was 1954.

The original oil routing was from a passage drilled to the rear cam bearing area, and through a tube hidden by the pushrod cover which attached to the rocker shaft connector in the center of the 2-piece rocker shaft. Later model 235's eliminated the tube altogether and used drilled oil passages in the block and head.
Jerry

It has the two bolt cover with a hole in the center through which this "fix" runs. Should I be concerned? Is there a suggested way to fix this issue?

I would suggest removing the tube, weld up the hole in the valve cover, and run a bypass line around the back of the cylinder head to the plugged hole in the middle of the head on the passenger's side. A piece of 3/16" steel brake line makes a good bypass line, and provides just enough restriction to avoid over-oiling the rocker shaft. Some modification to the rocker shaft oil connector might be required, depending on how the oil reaches it now.
Jerry

I read a bit on the fix you suggested and I'm seeing some conflicting info. I took a peek under the hood and noticed that there is a random bolt on the center of the head (passenger side) that seems to be leaking a bit of oil (it's wet). The bolt does not seem to belong there and may be being used as a makeshift plug.
I also read several threads about that top line being pinched off to build more oil pressure on the rockers since it is an overflow of sorts that redirects oil back to the crankcase. Can anyone confirm this?
I think I am going to pull the side cover and see if there is any more pertinent information to share and try to sort out. I truly appreciate all the help.

gusco, are you talking about this plug?

Brad

I believe so, if those other two bolts are the ones that hold the hoop for the coil. There's a bolt in there that seems to be too big sans have the wrong thread pitch. Is that where I want to connect the line coming over from the fitting that goes to the pressure gauge?

gusco, there's no way to confirm everything you read in those threads can be verified for your engine. There are some facts we can find out if we back up, though...

What year 235 are we talking about here? There's a number by the distributor you can post here, or use the search function to figure it out (number is right behind the oil dipstick in one of my pictures, something like "F255X"). It's not my intention to derail your smoke investigation, but it may help you out to do a quick reset; find out which year the engine is, and start from there. The way this thread reads back (to me), I'm not sure if I helped you or not asking you to mention all the other details.

Yes, those other two bolts pictured hold the coil, and yes, the plug location is where Jerry is talking about running the bypass line.

Do you have a photo-sharing account you could link pictures with?

Brad

Block: 3837004, Head:3835913. I don't mind answering questions as long as I get help from knowledgeable people. I'm coming over from fixing mostly modern motorcycles. So, I can use all the help I can get.

3837004 = 1955-57 235 block
3835913 = 1954-55 235 head

Tim's a knowledgeable one, and if you look at his website, there is a diagram of how the oil lubrication system on your engine works. That helped me understand what people were talking about when I was in about the exact same situation on my engine. My only problem was I didn't know what to ask or what anything was called.

Here.

I'm just trying to help- I was running an engine that was not oiling properly (I'm not saying that is your case), so my expertise is in knowing what not to do to the exact engine you have; a lot more experience there than the ability to explain why you don't need to do it. Good luck!

Brad

I appreciate the help. I'm trying to make this as reliable as possible since the idea is to take a little trip with my wife for our 10th anniversary next summer (2016). However, I'm don't have a ton of money to throw at it, and I like to work on projects myself.
By what I see here (http://www.1954advance-design.com/W...1948-57-rocker-arm-lubrication.html#1954), the tube coming from the rocker shafts should stay inside the valve cover. I'm thinking I should pull the cover, pull the rocker shafts, and check the lines to make sure they are not clogged. Then see what exactly is going on with that tube going from the rockers over to the oil pressure tap on the driver's side. How does that sound? Does anyone sell that center section of the rocker arms (the oiling tube)?

Does it look like the rocker arms were getting oil at their base? The rocker arm shaft (if you remove it) needs to be kept in the exact configuration it is in. In order and left & right the same. It won't hurt to clean it & every other tube you see on there. I've heard of folks using a wire in a drill for the tubes, but I never tried it.

Where are you at in South TX? Somebody might be close enough to give you a hand checking this thing out.

Brad

About as far South as you can go before hitting Mexico; just outside McAllen, TX.
It sounds like you suggest it best to fire it up with the cover off (at least as far off as I can get it since that tube keeps it from coming all the way off, and checking if the rockers are getting oil.

That would work since it's already been running. If you stick your finger under the valve cover and it's dry, as in- no oil has ever been there, do not run the engine until some more diagnosis is done. (Ideally, before all this & before cranking, I would remove the distributor and turn the oil pump gear with a long flathead bit in a drill to prime the engine).

Brad

Edit- you will do no damage by diagnosing this engine without starting/cranking/running it.

Is there somewhere I could hook up a oil pressure gauge (my gauges are shot)?

You definitely need to get an oil pressure gauge hooked up before running the engine again. There's a 't' fitting (supposed to be one) at the bottom half of the driver's side of the engine you can connect it to. I'll look for a picture.

You can also remove the 1/8" plug in the middle of the cylinder head to see if it's getting oil to that point. I remember (post engine disassembly) cleaning a LOT of gunk out of that orifice. This is completely independent of getting an oil pressure gauge, though.

Brad

I believe that is the one I mentioned has an inadequate bolt plugging it. Will the oil shoot out of there at high pressure? Or is it safe to remove it with the engine running?

Oil should come out of the plugged hole when the engine is running- if the plug is removed. How good it come out depends on how much pressure, any clogged passages, etc.

Brad

That hole has a 1/8" pipe thread. It would be easy to run a tap into the hole and clean up the threads. Just put a little grease on the tap flutes to trap any shavings you create while chasing the thread.

There are several designs of oil connectors between the rocker arm shafts, and they're on Ebay pretty regularly. Depending on the oil passages in the cylinder head, use a connector that can be supplied from an auxiliary supply tube, if possible.
Jerry

Thanks for showing back up, Jerry!

Brad

Been on a 2-day inspection tour- - -Clarksville to Memphis to Huntsville in a big loop!
Jerry

Update: Put 2 qt of diesel in the oil. Ran it until warm. The smoke still got more pronounced as the engine got warmer. There was no oil pressure in the right (passenger) side plug. There did seem to be pressure and oil at the rockers because plenty of oil came out from underneath the valve covers. Upon noticing that leak, I shut it down and cleaned up. Aside from checking the internal passage from the back passenger side area to underneath the head (the line under the side cover) what can I do? Should I prepare for a complete rebuild? Or get some compression numbers first? What could be causing this?

gusco- here's where I bow out of helping because I just don't know enough to help you past this point. Wish I could, but I'm learning too.

There's plenty to do before a complete rebuild, but like I said- I'd rather someone else jump in to help you.

It is good there was oil to the rocker arms. You needed to NOT have the plug 'plugged' with something (to visually see if oil was there), but if there was oil at the rocker arms that answered that question.

Good luck

Brad

It won't hurt to run a little more, after dealing with the oil leaks. If the rings are completely worn out, or stuck so tight into the grooves they can't seal against the cylinder walls, the smoke won't get any better. If they're just stuck and the solvent can loosen them up the smoke might dissipate after some more running. Either way, all you're out of pocket so far is a little oil and diesel fuel and some time.

Fix the valve cover leak, warm it up one more time with the solvent onboard, drain it hot, and refill with 30 or 40 weight straight weight oil. If there's an oil filter, also change the element and suction the leftover 1/2 quart of oil out of the canister. It will either improve enough to do a little driving, or at least you've done a pretty good sludge cleanup with the solvent prior to a teardeown and rebuild.
Jerry

I appreciate all the help and the honesty, Brad.
Jerry, I've taken a while to cool off and think a bit. I agree there's still a few thinks to check before pulling the engine out. From your advice, it sounds like your money is on there being a problem with the rings. I will put some Marvel Mystery Oil in there tomorrow and let it sit for a while. How much should I put in each cylinder? A capful?
Any tips for getting the valve cover to seal better?

You have to be a bit of a tin smith to get these valve covers to seal properly. I don't know which style of valve cover you have. For either style, you need to set the cover on the head without any gasket. This will give you an idea of where the trouble spots are.
The four screw style covers are often over-tightened and need to be hammered back flush at the screw holes.
The 2 acorn nut covers often bow out on the sides, and the area around the holes in the top get mashed in from over-tightening.
Use the head as your guide and anvil and straighten the flange area out.
I glue the gasket to the cover with 3M weatherstrip adhesive. No adhesive on the head.
Carl