71supreme

Hey all,

I am in process of replacing the head gaskets on my 350. Upon removal of the intake & gasket, I have found an abundance of carbon. My question is this:

How do I get rid of it safely? I'm not necessarily talking environmentally friendly, I men in a way that does not endanger, or inhibit the operation of the cam, lifters, push rods etc. There is all kinds of advice out there on how to do this with the motor together, but not much on cleaning it up once the engine is apart. Any thoughts?

71supreme

Oh, it's a 1971. Here are some pics:

michael hilsabeck

you can use gas but you have to remove the oil pan so you have to pull the motor put i dont know about the oil jounals this motor has alot of miles on it you might open up alot of problems

don71

I've seen worse....I would suggest using a putty knife or small scraper, like a screw driver in conjunction with the all mighty shop vac.

Try really hard not to let that stuff fall into the engine where it could clog the oil pump pick up.

Rickman48

That's pretty typical w/206k!
Are you still taking it apart??
Show pictures of the combustion chambers and the bores, and we'll go from there!
3X the above posts - use some balled-up paper towels to fill the oil returns, though.
I found some wire wheels at Ace Hardware - 6 or 8 in variable sizes and shapes, for a drill - cheap, that would help a bunch with that mess!
I'd wait to see when it's all apart though!
Bet after 206k the cam and lifters have seen better days, too!
Don't mix-up the lifters, either - they must go back on the same lobes, if re-used!

michael hilsabeck

if it that thick on top is it thick on bottom

71supreme

Thanks guys, this is just the type of help I was looking for! I am going to devote a few hours to cleaning this mess up tomorrow. I hope to have the heads off by weeks end, but I don't want to get anything into the cyl's, so I am going to get this as clean as possible before I get to the next phase of tear down.

I am learning a bit about cyl head and valve procedure here. It seems each cyl has its own fingerprint from the valves, springs, pivots, pushrods, and bolts.

So what I am hearing, and will do is:

1. plug any holes/openings
2. scrape sides good with putty knife/screwdriver
3. vacuum w/ wet/dry vac

now, should this be enough, or should I rinse with gasoline, or some type of solvent?

I know the engine has high mileage, but I am not yet in a financial spot to rebuild the whole thing. I haven't actually driven it on anything like a regular basis in years, so If I can replace the head gaskets & get another 3 to 5,000 miles out of it it'll probably last me a couple more years while I get the funds together for a rebuild.

don71

I probably wouldn't rinse any thing over it. You don't want to wash the crud into the oil pan. Maybe just wipe it down when your'e done, after you get all the big stuff out. If the engine was out of the car this would be a different story.

I wouldn't try to remove the lifters, they're probably stuck anyways. That will be another can of worms.

OLD SKL 69

x2

You can also use kerosene.

michael hilsabeck

are you afraid to take it apart that stuff is in your oil pan to this is why you change your oil if you save money my not changing your oil this is what happens 12 more bolts and your there pulling motors it not hard and putting it back it the inter parts that makes it hard i have pulled motors just to clean them and paint

71supreme

Thanks for the advice on cleaning Don Darrell & Coldwar!

Michael,

Not afraid, just not equipped. Some friendly advice - If you keep judgments/accusations about my abilities, or maintenance standards etc. (or anyone elses) out of your posts, and add a little punctuation in, your words will increase in value a hundredfold.
Thank you.

Rickman48

IMHO - I'd try to find another running motor w/lower miles!
Easier and probably cheaper than going through this one, even half-way!
This way, you could learn on the original motor at your leisure, or as the money flows.
i was always modifying my 'daily driver', and HAD to get it done to go out, work, school, etc. - lots of 'planning ahead"!

michael hilsabeck

justing to be nice and give you info!

J-(Chicago)

I'd blame the exhaust crossover gasses for the carbon. That turkey tray seal probably gave up the ghost a while ago.

SPEEDROCKET

I know this is kind of left field, but... what kind of oil do you use in that engine? Just somethign I'm wondering.

Thanks.

71supreme

No worries Michael. I appreciate the feedback, but the lack of at least a period at the end of a sentence makes your thoughts and intent difficult to understand.

J, that is a great observation. it correlates with the advice on thread I was just looking at in the big block forum on rocker adjustments. This is exactly where the highest concentration of carbon was. When you say blame these gases, what do you mean?

Speedrocket, I bought the car in 1989 with 137,000 miles on it from the son of the original owner. I drove it daily until 1997 (using 10w30 oil changed regularly at 3000 miles) when I started a business that would no longer allow me to drive it regularly, so I parked it in a garage with moves and so forth it's been in & out of garages (not on it's own power) for about equal time. I changed the oil when I pulled it from the garage in 2003 and gave it a tune up in preparation for it's move to Maine from MA (on a flatbed tow truck) I did nothing but start and run it occasionally for an hour or so at a time.

This past spring I did another tune up and oil change where I put 4 quarts of 10w30 along with a quart of transmission fluid in. I have run it like that since, but again, never for more than an hour or so. Once this mess is cleaned up, the heads are cleaned up, and the gaskets replaced, I will change the oil again and probably use 10w30.

Olds64

Good luck cleaning the engine. Once you scrape most of the carbon away you could use some diesel fuel and lint free shop rags to clean the lifter valley.

71supreme

Rickman, I know where your coming from! That's what I did with this one while I was in college. the toughest part was the timing chain/waterpump at 157,000 mi. I was a full time student working preload at UPS and doing the books for a local bar/nightclub.

If this were any kind of regular transport I would be doing just that, and even so it's crossed my mind at least a dozen times. I just don't have the space for another motor. (even less so when the gf moves in, she's got a bike)

Oldsguy

The intake gasket/turkey tray burns out where the exhaust crossover is between the center cylinders. Part of those gasses get into the area in your pictures. Being so hot and heavily filled with carbon and other crap it causes the oil to dry up and cake like you see in the photos.

After you get it cleaned up and buttoned back together don't forget to change the oil/filter after a few hundred miles because a lot of that stuff will probably end up in the pan.

71supreme

Thanks Oldsguy!

So, are you saying this is normal for the intake gasket to fail/burn out at that spot? Is there some type of regular maintenance thing, or additive that can help reduce this?

Oldsguy

Not saying it is normal, saying that is what he meant. Remember that the engine has mucho miles on it, so I guess with caveat I guess yes it could be normal.

SPEEDROCKET

Oh ok, I was wondering along the lines of what brand, I kind of keep track of when that kind of carbon builds up in an engine. I trying to see if it relates to oil brands known for low thermal break down temps and additives, like since I've started keeping track(for about 7 years now, about 10 engines) it seems pennsoil was used 8 of those times, quakerstate the other 2. Thanks again

Oldsguy

Good point Coldwar about the heat riser valve sticking, very common.

J-(Chicago)

Oldsguy and Coldwar are correct. The exhaust gasses run out of that center port instead of it all going out the exhaust pipes. If the gasket fails, you are pumping exhaust into your lifter valley and baking a carbon cake.

The best permanent solution is to have the port filled with molten metal and the valve bowls re ground. However, it will pose a choke problem in the winters because the warm air will be unavailable upon start up.

6 of one, 1/2 a dozen of the other. Either reseal your intake every few years,and clean up carbon, or run cold for the first 10 minutes for the rest of your life.

Oldsguy

Or use an electric choke.

71supreme

No worries speedrocket, I would love to know the findings. I am afraid I can't be of too much help there, as I generally used whatever ADAP had on sale at the time, until I began using an oil change service, then it was valvoline, and this last change was with Sunoco. Unfortunately I don't remember what the previous owner used for the first 2/3 of its life. I guess you could say the car has dined on a smorgasbord of oils over the years.

This is starting to get exciting. I am learning a lot from what seamed like a simple question.

lol, yes, I meant to qualify my statement with "for a car with 200,000 miles on it".

The car had a single exhaust on it for a good 150,000 miles or so. I'm trying to remember when I put the headers & duals on. It was before the timing chain change, probably around 150,000 or so.

If I block that port on either side, where does the exhaust go? Does it create a backpressure situation of some kind?

I may find the answer when I pull the heads, but that won't be for another day or 2.

That manifold was heavy enough as it is. I can't imagine how heavy it would be with more metal in it! Thanks guys!

Oldsguy

The exhaust gases simply go out the two header pipes of the two center cylinders on either side. Since Oldsmobile heads have siamesed center exhaust ports it makes this possible. If you look at the picture in J's post #26 with the read circle you can see the two intake ports for the center cylinders then you see two blank spots that are solid metal and then the crossover port. On the opposite side of the head from where those blank solid metal areas are there would be the two exhaust ports for the center cylinders. If you were to be able to cut an Oldsmobile head in half horizontally you would see the two exhaust ports and the crossover port and they would look similar to a 'Y' . Did that make sense?

greenslade

Just wondering,Why are you replacing the head gaskets?

71supreme

Yes it makes sense, thanks Dan!

So If I am understanding correctly, if the y passage in the head is filled, the exhaust will flow smoothly out their intended ports with no flow issues, or perhaps even better exhaust flow characteristics than before, correct?

It does seem like an awful lot of work/engineering just to warm up the air in that lil tube to operate the choke. Was that really the only function?

71supreme

Greenslede, the more I get into this, the more I am asking myself the same question. I just got the car running again after about 13 years in storage. I found that I have leaks in both head gaskets, and I don't have a ton of money, so I figure If I can spend a little to get it running well for another 3-5,000 miles (more if possible), I can buy some time until I am able to rebuild the whole thing. In the mean time I can pick up the pieces I really want, so when it comes time to rebuild, I will have the money to do it right.

Another part of why is the learning experience. I have never done anything like this before, so I am hoping to learn a few things about how this engine works. On that front it has already been a screaming success thanks to the folks here on CO.

71supreme

OK, drivers side head is off, pics are here: https://classicoldsmobile.com/forums...e-project.html

I'd love to know your thoughts, (including if I am doing this right crossing between posts & all) Thanks guys!

71supreme

OK, I've got both heads off, and it seems they both had blocked passages in the coolant holes of the head gasket on the cyls that corresponded with the leakage evident on the spark plugs. Does this make sense? what causes the kind of corrosion that plugs these holes? Are there any other spots within the cooling system I should be leary of?

I am glad I waited until I got both heads off to post results here. I was nervous about the corrosion I noticed around the top of the cyl.'s. I coated it with a little transmission fluid and let it set over night. Today I wiped them off, and they are smooth.

The cylinders look nice and smooth. No signs of scoring or anything like that. Is there a way to check them without sending them to a machine shop?

Thanks!

Oldsguy

I haven't filled the crossover passage in the heads before but people have done it. They melt an alloy like aluminum and pour it in the crossover port. some drains out through the exhaust ports which then has to be cleaned up. Another way of blocking the crossover is to put plugs in the intake manifold. We have threads on both of these methods in our forums, an exhaustive search may reveal them.

To answer your last question, apparently that and to atomize the air/fuel mixture in the carburetor better by heating the baseplate.

Warhead

Basically, correct.
PLUS, the engine will scavenge the cylinders much better. 18436572...once number 4 fires, that crossover is pressurized, and you lose any scavenging effect from tuned exhaust, headers, etc.

Even a short fill (not entirely up to the valve seat) will do the same thing as a complete fill to the seat. Doing this is a job, and you must be carefull, everything must be DRY. I use old pistons, melt them in a cast iron pot with a propane "weed burner". The pistons are cheap (FREE), and they have a higher melting point than the Zinc sold by Mondello. Some have complained that the Zinc in their heads had melted a bit, by the seats.
You need to run an electric choke with blocked cross overs.

The sludge on your engine is typical, I have seen some (older Penzoil engines) that had 10X that amount. The manifold was literally welded to the block with sludge. ALL it takes is the extreme heat to burn oil here-gasket or no gasket issue. This heat will lay waste to older oils, not so much on the newer oils. The oil will cook inside of parts, or on surfaces nearby the cross over. MAKE SURE that you clean out all of your pushrods of this crap, some carb cleaner, and a blow gun on an air compressor will go a long way here.

Things could be worse.
It's looking pretty good so far.
Jim

71supreme

Thanks Jim!

I had heard the same thing about penzoil recently (I think from speedrocket), incredible!

I just may give this filling thing a try. I really appreciate the tips & tutorial!

71supreme

Yikes! The shop just called, Heads have cracks bet. exh ports. can this be fixed reasonably, or should I be looking for new parts? The shop seemed to indicate they were not worth hanging on to.

71supreme

ok, update time. New heads thanks to Speedrocket I had em checked out, and a couple adjustments later they are ready to go. (Speedrocket was great, would recommend him to anyone)

I now have everything home, and am almost finished cleaning the head mating surface of the block. I took a look at the new fel-pro blue gaskets I bought, and now I have a couple questions.

1, does it matter which side faces up? (the side where the metal rings connect, or are separate?
2, RTV, yes or no? If so, where/how much?

I know some of you are laughing at me, but I've never attempted anything like this, and don't want to screw it up.

Thanks!

67 Cutlass Freak

Well I'm glad to here you are making progress. To answer your questions-
1) Yes, it does matter. I believe the Felpro gaskets are stamped on the top with numbers or letters. If I remember correctly the separated metal rings face up.
2) Absolutely no RTV on the head gasket. Some people use a copper head gasket sealing spray but I don't think you need it at all with the Felpro gaskets. If you were trying to re-use the Cometics, then yes.

I'm not laughing at you, actually I comend you for attempting to do this yourself. About twenty years ago a friend of mine was going thru a divorce. His car was repoed so I lent him my '72 Cutlass, $100 beater car, with a 350. I got it back six months later with a leaky radiator and a blown head gasket. When I went to reinstall the heads, on the final torque step, one of the bolts snapped off flush with the deck surface. It's no fun drilling a head bolt out in the middle of the winter with no heat.
Some things you might want to consider:
1) Chase all the head bolt holes and blow them out with compressed air.
2) Purchase new ARP head bolts or studs.
3) Follow manufactures torque specs using appropriate lube on the threads. The torque value changes depending on what lube you use.
4) I highly recomend you pull the block, disassemble, take everything to a trusted machine shop so you can have everything measured, to be sure you aren't going to have any problems with the bottom end.
5) A lot of times when the top half of an engine is freshened up it puts too much pressure on the bottom end and something always fails.
6) From my experience, it's always better to do the full job right.
7) Do not use the turkey tray for the intake gasket. Aftermarket fiber types are superior.
8) It's not too late to fill the heat risers in the heads or block off this passage to the intake.

I've included links to a couple of threads about the process. Please keep us posted on your progress and good luck.

http://www.robertpowersmotorsports.com/Tech1.html

http://www.realoldspower.com/phpBB2/...miller+filling

http://72.22.90.30/phpBB2/viewtopic....+riser&start=0

MHENDERSON

Do not use the turkey tray intake gasket I had to do mine over the next day because of it!!I would get new head bolts it is a pain if they snap been there.Good luck Mark.

coltsneckbob

So can you share the full results of your survey??