I have an '87 camaro with LG4. Heads need replacing due to oil coming out the exhaust pipes. I'm going to order stock rebuilt heads with 194 int and 160 exh. I just want to know what other upgrades i should do while i'm at it so i can get the most performance with out dong stuff twice. Also, this is my first time changing heads and any advice would be appreciated.
Nate

 

If oil is coming out of the exhaust, then the valve guide seals are probably worn-out and need replaced. This isn't a big deal and doesn't warrant purchasing new heads (unless you want to).

If you plan to order the new heads, I would get stiffer springs. These will allow you to run a higher-lift cam in the future. Also, screw-in studs are normally preferred to pressed ones (when using a high-lift cam).

As far as advice... take your time and make sure you torque everything in sequence & to spec. It sounds simple, but a mistake can mean having to do everything all over again (I found this out the hard way)! A Haynes manual definately comes in handy too.

If you plan on reusing your factory valve-train, make sure you look it over before reinstalling it all... with the heads off and everything apart - there is no better time

If you have any further questions, myself and the other TGO board members are here to help!

Best of luck.

 

Thanks, I figured it was the valve guides. I've been saying it's the heads because i had to convince my wife to let me get new heads. I wanted to get these heads out to do a port polish and valve enlargement on them. I have a haynes manual and torque wrench. I'm not really sure what you mean when you say "valve train" though.

The guy rebuilding the heads for me said he's going to put in Z/28 springs that are good up to .450 lift. He's putting in the .194 dia intake and .160 dia exhaust valve for me too. I'm pretty sure he's going to do the screw in studs too. I'll ask again.

I was looking for things like thread sealer on the head bolts (i found that in a thread today) and other details like that. I'm not sure if that is mentioned in the haynes manual.

also, since i'm not brave enough to do the cam yet, do you think 1.6 ratio roker arms would be a good idea now?

 

By "valve train", I just meant you should look over the factory pushrods, lifters, rockers, etc for wear/damage if you plan on reusing them.

I used GM thread sealant on my head bolts. I would recommend it or a similar product.


It may sound obvious but make sure you note where the rotor is pointing when you take out the distributor. Also make sure, when you put everything together, that the wires aren't too close to the exhaust. They melt easily - I found that out too

I don't see why it would hurt anything to go ahead and do the rockers now.

Why are you hesitant about doing the cam? It is a few steps farther but, once you have the heads off, its not much more of a leap.

 

might check price of S/R torquer heads, they aren't too expensive..might be a wash for new heads considering cost of valves and machine work.

 

Link?
I've heard of these heads before bu i thought that they went for about $400 assembled. I'm getting rebuilt heads for about $175 assembled. I would like to have the performance but money is tight. I'll look for them tough.

 

Are you sure it's oil coming out of the exhaust? That typically doesn't happen due to valve guides.

Oil comes down the guides after an engine is run and shut off, and if started again shortly thereafter, you'll get blue exhaust. But, I wouldn't call that "oil coming out of the exhaust".

Oil can also be sucked down the guides by the intake valves, but then it becomes part of the combustion mixture and is burnt, again producing blue smoke.

In both the cases above, it's the valve stem seals getting hard and cracking that leads to the oil going down the guides. You don't need to replace the heads to fix that.

If the guides are so bad that oil is coming down the exhaust valves and into the exhaust stream (not very likely, since the exhaust pressure will tend to put the oil back up into the rocker area), then it would still be at least partially burnt by the hot exhaust gases. And, if it could come down the valve guides due to excessive wear, the engine probably won't run very well.

So, I'm questioning your premise, because what you're describing doesn't sound like something that would be fixed with new heads.

If you would, describe exactly what is happening that makes you think you have oil coming out the exhaust.

 

Alright...I was getting ready to do a tune up the other weekend. I started the car and was scraping snow off the windows ( and jumping back into the car to rev the engine to keep it from stalling when it started running really rough) when i noticed black spots in the snow under my tail pipes. I put my hand under the tail pipe and it was srinkled with oil. I figured it was the heads because i can't think of anywhere else where oil would get into the exhaust. If you have a better answer to the problem that i can test for i would appreciate it.
Thanks
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Oh yeah, it smokes pretty bad when i first start it up. I don't know about blue smoke but it's whitish brownish smoke.

 

The stuff dripping out of the tailpipe was soot and water, not oil.

Is the start-up smoke you're talking about only when the weather is cold?

 

no, it's a year round thing

 

if you mistake soot/water for oil, maybe you interprate condensation being burned off as smoke?

Do u have cats?

 

I assume you mean catalytic converter's. Yes, i have a single cat due to the fact that i have a y-pipe therefore only i exhaust pipe most of the way back. I assume what i see is smoke because it will fill the parking lot at my apartment complex (kinda embarassing when people go out of their way to go around my cloud). I didn't think of the soot water idea when i was diagnosing the problem, and i'm still not 100% sold on the idea. I hope five7 is right. It is hard to believe that oil went all the way through my cat though. I don't know.

 

My compression tested way high too. 185-195 psi on all cylinders except 8 which was 175 psi. I'm thinking that i need to take the heads off anyway to clean out some carbon build up. seems odd that the compression was so consistent if it's carbon build up.
Ideas?

 

Think you could take pix? Dont worry about the black soot, a brand new engine will do that, even with cats. But i the smoke is filling the parking lot, maybe it is bad.

Does it smeel either "sweet" of "burning"? If its either then its bad, but otherwise if its just a regular burning fuel smell, ure ok. Especially if it goes away.

 

yeah the smoke goes away as the engine warms up. Smells like old car exhaust.

 

Do you think the compression is high because of carbon buildup or because the previous owner did something with the heads. If carbon, why did i get the buildup, how can i stop it?

 

It's more likely the gage was inaccurate than your compression was that high.

 

http://www.worldcastings.com/

jegs sells them

 

85-up LG4s actually belt out a fair bit of cranking compression. They share the higher 9.5:1 compression ratio with the L69 HO motor in those years and they have a really tiny cam that shuts the intake valve quickly after BDC. All that adds up to a fairly stout cranking compression.

Yes, carbon and other accumulated schmutz will add something to that number, but it's not like you're 50 PSI high.

Anywho.... if you're in there for heads maybe you could see fit to go a bit further and stab in a better cam. Pretty much ANY mild performance cam would be better than the stock LG4 stick. They refere to it affectionately as the "peanut cam" around here for good reason.

 

i put 2.02 vortec heads with crane 1.6 self-aligning rockers and an edlebrock hi flow tpi vortec intake.

 

Actually haynes says that the pressure should be 100-150 psi w/ no more than 50 psi difference from lowest to highest. I'm pretty sure that i have the stock cam but i'm really nervous about changing the cam. If I do i want to put the xe256 in. Would i need to change the springs and lifters or any thing if i did that?
Update on the smoke....I changed the oil pressure sending unit tonight and popped the distributer off just to check it. (i didn't change it when i did the tune up because the wife wouldn't let me spend anymore money that night.) The cap had some nasty carbon scoring going on. The rotor had a fuzzy carbon ball looking thing on it so i changed that stuff out. I'm pretty sure this will help with the smoke. I already noticed that it doesn't stumble as much when it's idling. The oil pressure gauge works again too, so i'm stoked.
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Have the carb on this car.

 

I think youre worrying too much about this smoke. If it smells like old car, maybe its time for a new cat, but short of that, dont worry about it.

If you have the q-jet on there, the carb will want to rev up to 2000 rpm there abouts, and will hold it till the car warms up. Fix your electric choke if its not working. (quick way to check this, is if you turn the key to ign on, NOT ACTUALLY RUNNING< just on, and wait, about 2 mins later, the choke will be fully open. You could also get a hot air choke, i prefer those.).

Now if you start your car in the Michigan cold, at 2000 rpm, the condensation will prolly fill a good part of the air. To prevent it from idling so high, start it up, let it idle for a couple of seconds, and then blip the throttle rapidly, to about 3/4. When you back off after the blip, it should go down to reg idle speed.

I like to buff the contact points on my distributor cap, at the end of winter, and summer, they like to oxidize slightly, and it makes a huge difference in the car's performance.

Also, carbon build up will not make that much of a problem. The worse thing that can happen with carbon build up is dieseling. The carbon will glow red hot, and when u shut off the car, it will stumble and keep running at about 80rpm, cuz the carbon is igniting the fuel.

A good way to get rid of carbon if youre worried about it, is steam clean the inside. Warm the car up to full operating temperature, get some water in a spary bottle, bring the engine up to a fast idle, about 2000rpm, and spray a bit of water over the carb every 30 seconds or so.

The few drops of water will turn to steam and break down the carbon, and shoot it out the tail pipe. But your car MUST be up to temp.

However, if youre set on replacing your heads, go ahead.

 

The car doesn't idle at 2000 rpm while it is warming up. The choke plate or whatever shuts but the engine stumbles over itself and dies after a 30-60 sec. After that i have to take the air cleaner assembly of, flip the choke open, blow in the opening, turn the engine till it tries to start and push the gas at the right moment. After this the engine will start and run at 2000 or so rpm for a bit and go down to 500 to idle. The smoke is a nice black color against the snow. I'll try to get a picture of it this weekend. maybe a video to show you guys how it idles.
The distributer cap and rotor made a big difference in the idle quality when warmed up. I'll try the spraying water over the carb this weekend.
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I also wanted to say that i decided not to replace the heads...for now. Five7 was right about the carbon and water. I'll probably do new heads when i have enough money saved up to do those and a cam at the same time.

 

Sounds like the choke pull-off ("vacuum break" according to GM) isn't opening the choke butterfly like it should when the engine is first started. Either it isn't adjusted right, isn't getting the vacuum it needs, or has a leaking diaphragm. The choke butterfly should open a slight bit as soon as the engine starts.

See the sticky on the E4ME in the top section of the Carburetor forum.

 

Depending on often this happens, its just a vicious cycle. Choked engine = too rich = fouled plugs = carbon build up of unburned gas = stumbling like you described, and smoke.

 

I looked at the sticky, but i don't have the specialized tools to reset the carb. Should i just do trial and error for a while?

 

I marked the choke pull off and turned on the car. The choke pull off doesn't work. I checked the vacuum lines going to the pull off and no leaks so I ordered a new pull off. Almost got my problems fixd i think.
Thanks for the advice
Nate