travlnman

I had considered this as a possibility. I have read the primer you speak of. I have no reason to think the gauge is in any way incorrect. Most vehicles , even if they have a gauge, it's not a true pressure reading, just a high and low . It seems accurate in terms of higher reading when cold , with a drop as it warms. Steady lower reading at operating temp, higher at apeed. Sending unit is new. I believe I'll not try to overthink it and just enjoy the results. Thanks for the input, was just curious if anyone else had experienced similar results.

Just to hit the highlights. Stock '78 acquired last year. Been running HDEO Rotella 15w40 in conjunction with small doses of Marvel Mystery Oil ( I know , keep your opinions for now). It has been working wonders in cleaning out a slightly grungy engine. Been changing oil from 1500-2000 miles, because it has been getting really nasty , really fast. Idle oil pressure (aftermarket gauge) has been about 12-14 PSI, at speed , about 45-50 PSI. Made a change today, and went to Rotella 5w40 synthetic. Started it up, let it come to temp (180 deg ) Idle pressure is suddenly about 24 PSI, and pressure at speed is between 70-75 PSI. An oil change has never made this kind of difference before. I have not used a 5w anything in this engine before. Curious if the 5w is responsible for the sudden jump in oil pressure, or have the HDEO and MMO simply finally flushed out enough crud to account for this. Don't get me wrong, I'm glad for the additional pressure but it seems too good to be true to get such a large increase with such a simple change. Anyone else experienced similar results ? Search function brought up mostly idle oil pressure questions and gauge questions. Welcoming all opinions.

Was planning on removing the head on my '78 Z (stock) . Suspected blown head gasket, due to need to fill overflow after every drive, with no visible leaks. Evidence of burning something due to residue on all plugs. Puff of smoke from tailpipe when I added stop leak to radiator after thermostat opened. No water in oil, but maybe some slight evidence of moisture in the baffle of the rocker cover. After removing rocker cover, plugs and all associated hoses and wires, I removed the throttle body. The throttle body was completely soaked on the backside of the butterfly, and I was able to pout water from the orifices leading to the now removed BCDD. The only source of coolant in this area is what I believe is called the TVV. A temperature controlled valve for the EGR system, that is threaded into a housing with coolant circulating through it. Has anyone ever known this valve to fail internally, and let coolant bypass and be sucked into the vacuum line for the EGR ? The entire intake tract was wet, and if the problem was the head gasket, I cannot see how coolant would get into the intake tract . The car has no overheating, and runs hard with no issues otherwise. Anybody ever seen anything like this ? Thanks for the help.

Thanks guys. Like I said , it's not my primary means, so down time is not a big deal, just love driving the thing. I originally bought it to have to fix up with my son (15) and if he's really lucky, maybe let him drive it one day.

I have already fixed the cause. The previous owner was trying his best to turn it into a "ricer" clone. Gauges screwed onto the A-pillar, that lit up, but were attached to nothing ?? Cut the original exhaust off, and ran a straight through 2 1/4 " pipe all the way out the back , big coffee can tip, no muffler. It was so loud it hurt to drive it. I'm all for to each his own, but wow. The timing was cranked way up, and it would detonate on 93 octane, he just could not hear it over the exhaust.

Tony D and Braap, I know a head gasket is in my future. My car drinks coolant with no external leak. It will pressurize the overflow tank and blow the top off of it. After adding stop leak the other day, immediately upon the thermostat opening, I almost immediately got a light blue smoke out of the tail pipe, and the car does not burn or use oil otherwise. Also, I doubt anyone here would pull a head to replace a gasket on a car with 92k/192k (take your pick) and not have it surfaced , at least I would not. Did not check compression , as the above reasons are enough for me, I'm not a pro like some here, but not a novice either. I could easily pull down my engine or a salvage unit and build it from the top down , and I plan on just that, just not this soon. The budget is a little tight as lots of folks are. The long range plan is to take it off the road and overhaul the entire drivetrain. I also have a small leak on my rear main, so all of the above may well just answer my question. One responded that his rings had failed, on had not. As of now I have a 50/50 shot with the responses so far. That coupled with the rear main and such will probably justify at least a bearings , rings, and gaskets. All that being said, WHEN I pull the head and have it surfaced, since it's an open chamber head, how much can I shave without needing to shim cam towers and such ? May even throw in a small cam while I'm at it, and along with the "krylon rebuild" just call that my engine overhaul for a while. As to the posting rules, sorry, did not violate on purpose, more out of ignorance. I frequent many forums for Z's and other vehicles, as many do, I don't read the "rules and regs" as well as I should, just "agree to" and keep going. I don't even try to keep them all separate , not that much room left in the old hard drive.... you fellas go easy on the coffee now

I have seen the ring issue on chevy's and ford's , but have never heard of it on an L6. Otherwise, this engine runs great, just eats coolant. No external leaks, and yesterday added some stop leak to radiator, on the off chance it was a small high pressure leak I missed. As soon as the thermostat opened, and started to circulate the stop leak, I began to see a light blue puff of smoke out of the tail pipe when i would blip the throttle. The car uses no oil otherwise.

I have a '78 Z , all stock with supposedly 93k original miles. Looks like I have a head gasket change in my near future. My current setup is N42 block (stock) and N47 head (stock). My main fear is, that in pulling the head and having it resurfaced and sealed with a new gasket, I may open another can of worms. I know that sometimes when a fresh new seal is applied to a 30+ yr old cylinder , the rings may be the next to go. I could pull off a gasket change in a day, no problem, but has anyone ever had a problem with piston rings failing on a newly sealed head ? I have read every thread having to do with heads, detonation, etc, but no mention of ring failure. My local salvage yard has a complete '78 , from which I could acquire the whole engine , tear it down and give it a complete freshening up . It's just my project car/toy, so no big deal on being down for a while. Not looking for a big HP gain, just want a reliable weekend driver. If no one has had ring issues, my just pop for the gasket swap, otherwise, I'm off to the salvage yard. Thanks in advance.

No argument from me. It's why I use an oil that already has it. No additive necessary. But I disagree over the angry part. Oil, in any part , even additives, is a very touchy subject. People have their fav's and they will not be swayed, and they must convince you to think the same. Some forums are full of it. Fortunately, this forum has been delightfully void of any such nonsense......so far. I hope and pray it stays that way.

If either of you fellas are planning on winning the debate, give up now. Just read the info, make up you mind, and choose accordingly. I have never seen anyone suddenly change their mind once it's made up. You'll just get frustrated and angry otherwise. Remember, share info, and make your decision. You want it, use it. If not don't . We should not make it personal. Remember, help each other, it's what we do .

Good read. Thanks for that.

http://www.bobistheoilguy.com/index.php?option=com_content&view=article&id=62:article-of-the-month&catid=40:past-articles-of-the-month&Itemid=78 This article from BITOG has good basic information on contents of oils. It even speaks to the reduction of ZDDP, and it's replacements to control wear. Enjoy...

I think someone already said it, but here goes. On a stock engine , you may not see any benefits. Worse case, maybe a reduced life span (maybe) and that will be hard to prove without a side by side comparison. The more radical you get with the cam, compression, RPM etc, the more benefit you will see. Personally I'm stock, I just run the Rotella for the reasons I've stated above, ease of purchase, increased protection (assumed) , and it makes me feel warm and fuzzy inside. There are pics of cams in this forum, as well as others (classic Z car club) that folks have installed that were non stock, and they did not last long. They have posted pics of flattened cam lobes after a short time running newer conventional oils. Maybe they did not install it correctly, maybe it was not broken in properly, maybe the oil was to blame, there is no smoking gun. After many hours of reading here and other Z forums, as well as BITOG, I have made the decision to use an oil with higher ZDDP , based on VOA, and UOA, to give me piece of mind, which is what I believe the original poster is looking for. I too would be interested in any hard data that is out there to prove one way or the other. However, unless someone has done a side by side comparison under strict laboratory controls, there will always be some variable that folks will say contributed to failure. All I can say is lurk around some other sites like me, compile any data you get, and make your own decision based on that. I can't have all the fun....you guys be safe out there

No ego here guys. This forum is for us to help each other, not impress each other. We need the ZDDP in our cars for them to work the best. Not having it can range from minor, to disaster. To the Original Poster, there are lots of ways to accomplish the higher amounts, just pick whichever makes you feel warm and fuzzy and use that, my feelings won't get hurt.

Long story short,bryand2 I'm not throwing stones at anybody. But you have heard two totally conflicting opinions here. My point is , go to the source and get facts, not rumor , or conjecture. I do not intend to start an oil war, which is waaayy to easy . People are crazy about oil, trust me. Don't believe me, or anyone else in this thread. Go to BITOG, read, read, read. Ask questions, they will answer them. Some of the people there are chemists, and have worked , or are working in the oil industry now. I thought I knew oil, then I found BITOG, turns out, I barely even knew how to change my oil compared to these guys. Check it out, make your own decision that's all