oil burn

[HACK]

I was wondering if anyone could help me out with some ideas what to do. My 84 k10 has a somewhat tired 400 small block. My problem is when i start it i get alot of smoking that seems to taper off after i warm it up. also the last couple of months it has been sputtering on hard acceleration. I did a tune up. Cap, rotor, wires, fuel filter, and when i pulled the plugs atleast three of them were terribly gunked up with burnt oil. so anyway put it back together and ran great again. my question is do you think rings or valve seals. im leaning toward valve seals.


That being said im also trying to determine where to go from here. i always had plans on rebuilding the engine at some point into something a little more durable. i wasnt looking for a race truck just something that has an increase in power but more importantly a dependable hard to kill engine. not having the money to rebuild it right now im hoping for just valve seals and redoing the heads. now how much can i do with the heads for a reasonable price? i would like roller rockers is that something i could do with the stock heads? should i just get a new set of heads already set up? can or should i get into anything deeper like roller lifters? just would like some info and thoughts on this. thanks

 

[RetroC10Sport]

I would lean towards valve seals as well.

 

[Chaz]

An inexpensive test you can do is hook up a vacum gage to the intake,,,,based on the readings u can diagnose engine problems like bad valve seals or rings,,,,you just have to research how to read the gage

 

[austinado16]

You don't want to rebuild heads on a tired engine. Making the valves seal perfectly tight against the valve seats will create increase cylinder pressures which the tired rings in the worn bores won't be able to withstand, and it'll burn oil like crazy.

Smoke on start-up is typically valve stem seals, along with worn out valve guides and valve stems. Best you can do is install a high quality viton seal with the heads left on, and continue to enjoy that engine.

 

[HotRodPC]

If the smoke goes away after warm up, normally that is seals. But, if it's bad enough it's smokes alot and it's fouling and gunking up the plugs, I'd lean also towards valve guides being worn. Replacing the valve seals can help, but it's also alot of work for a heads on the block job. I'd use those umbrella type valve seals instead of the simple O ring type in that case, but all it is is a band aid.

If the motor is very well worn, sometimes a heavier grade of oil can help a little bit. If you can find SAE 40, give that a try for the summer months and SAE 30 in the winter months.

 

[HACK]

Thanks guys for the input. Sounds like my best bet is to take care of the valve stem seals, and let it be until that money comes rollin in. ha! Now i could use some info on the project. how do i determine what size seals to get or who could i ask? and what do i need to do? I am guessing i need to remove the rockers and valve springs and retainers. is there anything to look out for like dropping a valve into a cylinder? Are there any Valve adjustments i need to make? only valve work i have done in the past was on motorcycles or small engines. Any info would be appreciated thanks.

 

[Irishman999]

Thanks guys for the input. Sounds like my best bet is to take care of the valve stem seals, and let it be until that money comes rollin in. ha! Now i could use some info on the project. how do i determine what size seals to get or who could i ask? and what do i need to do? I am guessing i need to remove the rockers and valve springs and retainers. is there anything to look out for like dropping a valve into a cylinder? Are there any Valve adjustments i need to make? only valve work i have done in the past was on motorcycles or small engines. Any info would be appreciated thanks.

Changing only the valve seals would be a good move considering the situation, dropping a valve into the cylinder is a bad thing. Two options for keeping that from happening: There is a tool that threads into the spark plug holes you can connect an air hose to, charge the cylinder with air pressure and it will hold the valves up while you take all the stuff apart. Option two is a hill billy trick I always wanted to try, you thread rope into the cylinder through the spark plug hole and it wont let the valves drop in.

As far as an upper engine rebuild it depends on the condition of everything below the heads. I just had a pair of heads rebuilt for my big block and it was only 250 bucks, start adding all the gaskets and nonsense needed for an upper engine rebuild and you might as well freshen up the bottom end while your at it. I am currently learning that engine assembly is just a snowball effect. If everything is in good shape you could do a re ring job with minimal machine work and maybe some good pistons for about a grand.

My dad assembled the engine in his truck in the early 90's, he has put a shitload of miles on it since then. Some time around early 2000 it got a burnt a valve, 2003 we pulled the heads and got them rebuilt. Now ten years later it runs strong and does not smoke. We are talking about 25 years of service out of a small block, I would not be afraid to go for a upper engine rebuild considering it does not knock and the smoke stops after warm up.

 

[austinado16]

I've done the rope down the cylinder trick often. Feed the rope in to the cylinder, and then rotate the crankshaft so the piston crushes the rope against the valves. Works great. I've used the air method as well, but there are a couple problems with it: 1) you have to have a continuous supply of high pressure air, so that means a real air compressor, that's running often. 2) You have to have a way to hold the crankshaft from rotating, otherwise the air pressure shoves the piston down, and that rotation of the crank and cam takes you off TDC, the valves open, and you dump all your air. 3) When removing the valve stem keepers, you can apply enough force to open the valve and dump air pressure.

Regarding the seals, you want a viton seal with a spring arouind the sealing lip where it seals against the guide. Any machine shop will have these, and they can get more by dimension, from the supplier located in MI and TX. There are a number of on-the-head valve spring compressors and you'll find them at your local auto parts stores, as well as ebay, harbor freight, etc. You just have to find the version that works well with how your heads are built/shaped. There's a version that is like a gear puller, w/ a couple of arms that come down along the sides of the valve springs, and then a center section that you screw down until the valve spring seat is loose and you can pick the 2 keepers out with a pencil magnet. Reinstallation of the keepers is a reverse, but you put a dab of grease onto a long screwdriver blade tip to glue the keeper to the tip, and then insert the keepers one at a time. It can be tedious to say the least.

Regarding putting fresh heads on an old engine, think about it this way. As the engine wears, it typically wears pretty uniformly. The rings leak a little pressure, the valve seats leak a little pressure, but it still runs great, and there's a sort of equilibrium that takes place. If you tighten up the heads......by that I mean grind the valves and valve seats....so that there's no more "slight leaking" you suddenly increase the pressure that the rings have to withstand. Maybe you get lucky and the rings are fine and you wind up with a solide engine again. But more than likely, and if you talk to machine shops and guys who build a lot of engines, you'll find that it'll start burning oil. Sometimes, it'll burn a lot of oil.

 

[MrMarty51]

On the rope down the spark plug hole to hold the valves shut when the crank shaft is rotated to keep the valves closed, by compressing the rope against the valves face.
The "VERY FIRST STEP!!!!!!" "DISCONNECT THE BATTERIES NEG CABLE" the rope trick works better than the air method, for holding the valves shut, but, if the rope is in the cylinder and someone bumps the starter, it will bust the piston and shove the rod right through the engine block, disconnect that neg cable before doing anything else.
If were Mine vehicle, I would just do an in frame overhaul, pull the heads, drop the pan, ream the ridges off the tops of the cylinders, pull rod caps, shove pistons out the top, either clean up the old pistons, being sure to get ALL OF THE CARBON out of the ring grooves, if the bores of the cylinders do not have any major scars, do not hone them, just install the pistons/rings and new rod bearings, a .001 over size bearing can be had to close up tolerances if stock bearings are out of specifications, a .002 can also be bought. The main bearings can be rolled out and new ones installed, again there are .001 and .002 oversized bearings for these too, check tolerances using "Plasti gauge" and fit bearings accordingly. make sure there are no roughness to the crankshafts journal that will scar the bearings, if so, dress them down with about a 240 or 250 grit emory cloth, after polishing the journals, take the emory cloth and drag it across the sharp edge of a piece of steel, that will smooth the emory cloths roughness, then use that piece of emory to finish polish the crank shafts journals. if it has a two piece rear main seal, that too can be replaced while the main bearings caps are loose, before tourquing them down. have the heads rebuilt, pull the timing cover and install a new timing chain and front crankshaft seal and You have an inframe rebuilt engine.
I say, do not hone the cylinders if they are in good condition, a very controversial subject to say the least, I have done a lot of study on this subject and decided to try not honing the cylinders on My 318 Dodge, it did not smoke one bit after I got the initial assembly lube burned out of the cylinders and it has not used one drop of oil in about 500 miles, by honing the cylinders, the rough hone pattern wears the heck out of the rings and by the time enough of the roughness has diminished, it has taken a lot of miles out of the rings. try doing an "ASE" search for the no hone rering method, they did some very extensive studies on this matter and concluded that an engine that has not been honed will use less oil and run longer than an engine that has had the cylinders honed, they run those engines a LOT of miles too, but, the cylinders have to be in very decent condition, without any major scarring or deep scratches in the cylinder walls.
Be sure to check the end gap on the rings, both in the tops of the bores and at the lower portion, where the rings stop, be sure the end gap is not too small, other wise the ends of the rings will contact each other and not flex which will cause the engine to smoke because the rings are not flexing to the cylinders, use a file to remove some off the ends of the rings. OH YEAH, one other note, use cast iron rings, I have had two engine rebuild projects use oil because I had used them chrome rings, had to do a tear down, installed cast iron rings and cleared up the problem. Another controversial subject too.

Try looking in "Northern Auto Parts" for an engine kit, I think the complete rering with timing chain and oil pump kits can be had for around $250.00.
Might also check with your local supplier, they will have closer access to the under size main/rod bearings which will make doing an exchange for different size bearings a lot easier too.

 

[Irishman999]

On the rope down the spark plug hole to hold the valves shut when the crank shaft is rotated to keep the valves closed, by compressing the rope against the valves face.
The "VERY FIRST STEP!!!!!!" "DISCONNECT THE BATTERIES NEG CABLE" the rope trick works better than the air method, for holding the valves shut, but, if the rope is in the cylinder and someone bumps the starter, it will bust the piston and shove the rod right through the engine block, disconnect that neg cable before doing anything else.
If were Mine vehicle, I would just do an in frame overhaul, pull the heads, drop the pan, ream the ridges off the tops of the cylinders, pull rod caps, shove pistons out the top, either clean up the old pistons, being sure to get ALL OF THE CARBON out of the ring grooves, if the bores of the cylinders do not have any major scars, do not hone them, just install the pistons/rings and new rod bearings, a .001 over size bearing can be had to close up tolerances if stock bearings are out of specifications, a .002 can also be bought. The main bearings can be rolled out and new ones installed, again there are .001 and .002 oversized bearings for these too, check tolerances using "Plasti gauge" and fit bearings accordingly. make sure there are no roughness to the crankshafts journal that will scar the bearings, if so, dress them down with about a 240 or 250 grit emory cloth, after polishing the journals, take the emory cloth and drag it across the sharp edge of a piece of steel, that will smooth the emory cloths roughness, then use that piece of emory to finish polish the crank shafts journals. if it has a two piece rear main seal, that too can be replaced while the main bearings caps are loose, before tourquing them down. have the heads rebuilt, pull the timing cover and install a new timing chain and front crankshaft seal and You have an inframe rebuilt engine.
I say, do not hone the cylinders if they are in good condition, a very controversial subject to say the least, I have done a lot of study on this subject and decided to try not honing the cylinders on My 318 Dodge, it did not smoke one bit after I got the initial assembly lube burned out of the cylinders and it has not used one drop of oil in about 500 miles, by honing the cylinders, the rough hone pattern wears the heck out of the rings and by the time enough of the roughness has diminished, it has taken a lot of miles out of the rings. try doing an "ASE" search for the no hone rering method, they did some very extensive studies on this matter and concluded that an engine that has not been honed will use less oil and run longer than an engine that has had the cylinders honed, they run those engines a LOT of miles too, but, the cylinders have to be in very decent condition, without any major scarring or deep scratches in the cylinder walls.
Be sure to check the end gap on the rings, both in the tops of the bores and at the lower portion, where the rings stop, be sure the end gap is not too small, other wise the ends of the rings will contact each other and not flex which will cause the engine to smoke because the rings are not flexing to the cylinders, use a file to remove some off the ends of the rings. OH YEAH, one other note, use cast iron rings, I have had two engine rebuild projects use oil because I had used them chrome rings, had to do a tear down, installed cast iron rings and cleared up the problem. Another controversial subject too.

Try looking in "Northern Auto Parts" for an engine kit, I think the complete rering with timing chain and oil pump kits can be had for around $250.00.
Might also check with your local supplier, they will have closer access to the under size main/rod bearings which will make doing an exchange for different size bearings a lot easier too.

This in frame rebuild is something I have only herd of on 18 wheelers. How could you torque main caps and rod caps with a big ass cross member in the way?

As far as finishing a crankshaft at home, dont waste money. I tried this the first time with emery cloth the first time when I was about 18. I got a chevy sprint that was a jewel of a car for 100 bucks, I did the emery cloth trick on it and even ran a penny over the journals to see if it left metal (another folklore thing) and when I started that mother ****** it immediatly trashed the bearings. My Dad bought it from me, got the crank turned and got new bearings, put it together and the car ran great.

I had a turned crank that I slightly screwed up and tried a home polishing job on, I used a tube sock and polishing compound. The journals looked beautiful but the crank still trashed brand new bearings. Point is, any crank work you want to be done should be taken to a machine shop. I trashed 70 bucks worth of bearings the first time, getting the crank micro polished cost me 40 so I would have been 30 bucks ahead of the game in the first place and saved alot of time by just dropping the crank off at my machine shop.

How do you get a crank out of ANY truck with the block still in the truck?

 

[MrMarty51]

This in frame rebuild is something I have only herd of on 18 wheelers. How could you torque main caps and rod caps with a big ass cross member in the way?

As far as finishing a crankshaft at home, dont waste money. I tried this the first time with emery cloth the first time when I was about 18. I got a chevy sprint that was a jewel of a car for 100 bucks, I did the emery cloth trick on it and even ran a penny over the journals to see if it left metal (another folklore thing) and when I started that mother ****** it immediatly trashed the bearings. My Dad bought it from me, got the crank turned and got new bearings, put it together and the car ran great.

I had a turned crank that I slightly screwed up and tried a home polishing job on, I used a tube sock and polishing compound. The journals looked beautiful but the crank still trashed brand new bearings. Point is, any crank work you want to be done should be taken to a machine shop. I trashed 70 bucks worth of bearings the first time, getting the crank micro polished cost me 40 so I would have been 30 bucks ahead of the game in the first place and saved alot of time by just dropping the crank off at my machine shop.

How do you get a crank out of ANY truck with the block still in the truck?

Can not get crank out with engine installed, at least I have never tried.
I have polished many cranking shafts and never had one fail, I`ve been turning wrenches since I was ten, now 61, so I have had a lot of experience behind Me.
If a person in frame polishes a crank, it must be absolutely clean before reassembly.
The engines mounts through bolts removed and the engine jacked to the top, blocks between the two mount halves and there should be enough room to slide the pan out, I think. I have never tried it on a two wheel drive Chevy pickup though. somebody in here may have.

 

[MrMarty51]

Can not get crank out with engine installed, at least I have never tried.
I have polished many cranking shafts and never had one fail, I`ve been turning wrenches since I was ten, now 61, so I have had a lot of experience behind Me.
If a person in frame polishes a crank, it must be absolutely clean before reassembly.
The engines mounts through bolts removed and the engine jacked to the top, blocks between the two mount halves and there should be enough room to slide the pan out, I think. I have never tried it on a two wheel drive Chevy pickup though. somebody in here may have.

My book says just what I suspected, do the afore mentioned, but first unbolt the shroud, shove it back against the front of the engine, remove bell housing pan, if there are strut rods, remove them, turn crankshaft to the timing mark is pointing down, unbolt pan, tilt back downwards and pull it out.
I will add, it might be a good idea to remove distributor cap, to keep it from getting busted if it should contact the firewall.

 

[HotRodPC]

The other issue of using the Air tool to hold the valves up, sounds like this is a very tired motor. I have a feeling the rings won't hold the air anyway. So if you're going to do this, I'd plan on using the rope method.

 

[MrMarty51]

The other issue of using the Air tool to hold the valves up, sounds like this is a very tired motor. I have a feeling the rings won't hold the air anyway. So if you're going to do this, I'd plan on using the rope method.

Very good suggestion H.R.

 

[chengny]

Someone should find out why he goes by "HACK".

Is it because he does really bad work? Maybe he smokes too much? Or is it because he is a top-notch computer hacker?

If he's an ace computer hacker - recruit him. We desperately need a hacker on this forum!