I GIVE UP even as I'm typing a response another bit of bad information comes through, yes go ahead and run unleaded fuel. regular motor oil, don't worry about valve seat recession, or zinc additives, I'm sure these guys were the guy's beating me at the drag strip way back in the 70's as I was learning how to keep a 340 Mopar together at 7000+RPM with a solid lifter cam (answer, sell it and buy a 302 Z/28, THAT motor will easily live past 7K with good connectiong rods in it) Read the posts digest the information try to see what is good and what is hearsay, good luck with your Vette, LT-1's are my favorite C3 Vette, I like them so much, that I own 2, one to win shows and another to win races with and both get lead additive and high ZDDP oil packages

 

You don't need the leaded gasoline.

 

Back in the late 80's and early 90's I worked in a machine shop where I did all the head work. I saw maybe half a dozen heads come in with sunken valves. Every one of them were from trucks which were lugging the motors down pulling heavy loads. Never saw this happen on any kind of performance engine. Never.

 

Just as I thought- somebody with no practical experience playing the part of an internet guru.

Thanks for the link to the Chevron site- that makes my point perfectly:

"The problem can only occur in older engines when operating under sustained high speeds and loads."

The keys are sustained speed and loads. A Corvette does one or the other, but not both on a sustained basis. A quick trip up through the gears does involve high (engine) speed but it is not sustained. A Corvette cruising at high revs does not constitute a high load.


Please go back into your cave until you can learn to stop spouting personal insults. Thanks.
[/B]

 

Well, I don't really want to get into this fray due to the tone of some posts, but there is a valid point buried in some of the less-politic stuff above. That being, if you have a pre-71 engine, and plan on spending a lot of time on the road course at the local racetrack, it would be BETTER for your engine to EITHER install hardened seats in your heads OR use a lead additive in your gasoline.

I have a milder hydraulic lifter engine (LS5) that I mostly use just to tool around town and let her pull hard when the opportunity presents itself, and I sleep just fine at night without spending any money on lead additives. I do spend money on high quality synthetic oil, but that is more about wanting the oil to last in the crankcase for a full year without breaking down than it is about fretting over zinc and phosphorous content.

Besides, I have good use for the money I save by not buying lead additive, it looks like this:

 

Sorry PK, but that just lends credibility to a myth and exposes owners to another possibility. Some heads have been ruined through modification for hardened valve seats by accidental machining into the coolant passages. Others have had the valve seat fall out during operation, particularly at high rpm. Obviously this would damage much more than just the head and valve.

Like many owners I panicked when unleaded gas first appeared and refused to use it in any of my toys (most of which I still own). As years went by and more real-world experience appeared, it became obvious that the sky was not falling. The only actual case I know of is with a buddy who owns a pair of TR6s, one a '71 and the other a '74. Both appear to have suffered accelerated valve seat erosion after finally switching to unleaded gas but there again British cars of that vintage were not exactly models of high reliability and long durability.

 

Hmmm, you seem to be working both sides of the issue here a little. Maybe I wasn't clear enough also. Of course you are right that machining heads carries its own risks, and a poorly done job will result in a ruined head. You will get no argument from me there, and probably not anyone else here. The point I tried to make is that for most of us, I am thinking weekend cruisers who like to work on, maintain, restore, and street drive our cars, there is no demonstrated need for lead additives or modifications to the heads, so you can consider me in agreement with you there. I think there is an application for specific engines, namely, older extensively road raced high compression solid-lifter engines, where it would make sense to either add lead to the fuel to reduce wear or otherwise modify the head. Where I may have been less then clear, is that although I believe there is an application where it makes sense to think about such things, the overwhelming majority of us will never be in that position.

Similarly, I have never read anything to support the idea that the milder hydraulic lifter engines need exotic oil additives to prevent damage to the cam lobes. Clearly, using a high quality oil with appropiate additives can be shown to increase engine life when compared to the blue light special oil at K-mart, but I am unconvinced that someone who has, say, a 1976 L-48 needs to run around worried about the ppm of zinc in his oil to prevent premature cam wear. If you have information to the contrary at your fingertips, I would be very interested to read it.

I think a lot of what I am getting at here is that when one sets out to design a truly performance engine, and leaves behind things like hydraulic lifters and lower compression, moving on to higher compression and solid lifters brings along with it higher maintenance (like adjusting valves) and potential problems (like the higher probability of wiping a cam lobe). But somehow, it seems that some of the cautionary tales that are appropriately applied to these engines get caught up in the "Corvette lore" if you will, and get applied to engines when they shouldn't. L-48/LS-5, these are street engines designed for reliability and relatively low maintenance. That doesn't mean I can't wipe a cam lobe tonight on my way to the local cruise-in, as I certainly can, but I can also wipe a lobe on my Exploder driving to Home Depot for a box of nails.

 

I re-read you post further up and see now that you did indeed say "a lot of time on the road course at the local racetrack". I missed this first time through, my apologies. You are correct regarding the potential need for action in this circumstance.

 

Hey HOSER! do you know what a VGS20 is? I use one at least 8-10 times a year courtesy of one of my best friends, and have keys to his shop for 24/7 access. Know what a ARO is? I'll bet I have been to the Opthomolgist MANY more times than you in my life due tp using one of these, can you guess why. With modern parts, and increased income it has been over 10 years since my last Opthomologist visit. Come on down to the SF Bay area sometime so I can give you a good lesson in A** WHOOPING at the Drags, Autocross, or even now a days, the car show circuit (your pick.) You have no idea who you are calling out on these boards, I've probably been driving longer than you have been alive. You probably even believe numbers from a SF901 from the looks of your posts.

 

Some bad information on here regarding Motor oil. If you have any flat tappet cam you need a minimum 1200 PPM of zink and phosphorous in your oil period.

 

Well, again, not wanting to get dragged into an argument where I definitely don't claim to be an expert, I will commnet further. I have read lots of anecdotal evidence that newer oils with lower ZDDP contents are "causing" premature camshaft failures. The problem is, I was trained as a statistics guy, and "causality" is something I care a great deal about. Based on what I have read, even in high quality oils, ZDDP levels have declined from 1000-1200 ppm in the mid 1990s to 700-800 ppm today, so consider me agreed that today's oils do have lower levels of important additives. However, most of what I have read from engine builders discusses the need to use "an appropriate oil", usually diesel grade, during camshaft break-in. Although they don't go on to say that specially formulated oils are not necessary after break-in.

The bottom line is, there are millions of flat-tappet vehicles out there. If the 800 ppm ZDDP level was going to round out the lobes of the cams of these cars and trucks inside of 300 miles or 900 miles, or whatever number of miles the scare-tactic article you last read stated, the public uproar over the change to the oil would be deafening. In reality, even a guy who likes cars like me has to pretty much go looking for information on this, so IMO, the hullaballoo is clearly overblown.

Again, I am a believer in high quality synthetic oils for a variety of reasons, I just don't lose sleep over the ppm of zinc in my oil.

BTW: IMO, STP is a crock. Just as bad as the "octane booster" in a little plastic bottle. Just snake oil to take your money.

Oh, and in case anyone was wondering: a "VGS20" is a Sunnen Valve Guide and Seal machine. I didn't know what any of the other stuff in Solid LT1's posts was, but a quick Google search led me to believe that a "SF901" is a dynomometer. I'm not sure how the mention of that stuff was supposed to impress anyone. Just let it be known that you guys don't have any idea who you are messing with either, because in real life, I am 6' 10" tall, weigh 340 pounds and can bench press a Chevelle 8 or 10 times, depending on how I am feeling that day. Just keep that in mind if it was me that was referred to as a "hoser".

 

First off I apologize to anyone who has had their feeling hurt by this thread. It was obviously not my intention, now besides the fact we all have our own opinions and that I am also 6'5" 280lbs and beat up Chuck Norris and Mike Tyson twice, I appreciate everyone's opinion.


I am the first to admit I know little to nothing about these and most of the other topics I started, which is why I started them.

I owned a 2004 C5 and wanted something different, I knew the 70 LT-1 would require some more maintenance but I was obviously unprepared to the degree of maintenance.

I put Castro GTX High Mileage 10w-30 into my car. Now I here it does not have the proper ZDDP ratings, what am I to do? Is 10w-30 even correct for my car? I live in San Diego.

California only has 91, does this matter? How can I tell if the car is pinging or knocking?

Finally the lead issue, at the very least the 6 dollar bottle of CD2 lead additive is cheap, and lasts for 160 gallons, I figure if it does not hurt I will do it.

By the way, Tyson hit harder the Norris, but Norris had more heart.

 

The lead additive won't hurt anything. If you want to use it. 10W-40 is what is recomended for your temperatures in your owners manual. The Amsoil I refered to is the only 10W-40 that I know of that is designed for Gasoine engines, is the proper weight and has proper ZDDP and detergent additive levels for your application. There may be others but this is all I know about. Racing oils haven't got the detergent and most are the wrong weight. Modern oils don't have the ZDDP levels required to properly protect the lobe, lifter interface.. Solid flat tappet and the increased spring pressures warrant using proper oil even if it is $8.60 a quart, especially in an unrebuilt 1970 LT1. Don't want to argue or fight with anybody Just trying to inform. I am also pretty sure Mike Tyson or Chuck Norris can kick my ***.

 

As far as I am concerned, you are fine. Someone else here is posting ad hominem crap, but especially from an unknown person on the internet, this doesn't hurt my feelings.

I agree with the above that 40 weight is appropriate for San Diego. I use 40 weight in NJ because I don't drive it in the winter. Even if I did, 40 weight would be on the borderline. The regular Castrol GTX is supposed to have 800 PPM of ZDDP. The "high mileage" blend is supposed to have a "higher" content, but I have never seen a specification of how much higher. This is what I was talking about before, your Kmart blue light special oil will probably have more like 200 ppm, so any of your GTX blends are going to be far superior to the bargain basement stuff. People have become married to the 1200 ppm number for reasons that I am not sure I understand. The old API standard, that our engines were designed under, was a minimum of 1000 ppm IIRC, although most of the high quality oils of the day advertised a 1000-1200 ppm content. Don't get me wrong, 1200 ppm is just great, but I bet there were millions of flat tappet engines driving around in 1985 with well under 1000 ppm and we didn't have folks going all about camshaft wear.

Once again, maybe I am not being clear enough. I am talking about street engines here, AND hydraulic lifters. I have read the scare articles about 200,000 psi pressures between the lifter and the lobe, and the engineering side of my brain says "huh? How could that even happen with hydraulic lifters and my oil at 60 psi?" Maybe I have an insufficient understanding of the problem, but it all smells like to me.

However, for the removal of doubt, if I had an original mechanical lifter engine in my car, I would buy the best oil available for it.

You can hear the pre-ignition. It sounds like "knocking" in the engine under acceleration or going up a steep hill. If you were driving in the '70s, or even remember riding around with your parents, a majority of cars then knocked under at least some conditions. If you are not hearing the knocking, you are not getting pre-ignition, and you don't need to worry about octane for your present application. If you aren't sure if you are hearing knocking or not, go to a local cruise and find someone 50 years of age or older who has been working on cars since the 70s, take him/her for a ride (or let them drive, I would think that would be a good sell point for an LT-1 Corvette), they will tell you. But again, if you are not getting knocking while street pleasure driving your car, and later decide you want to road race it, you may need to re-think many of these decisions.

I have never read anything about lead additives hurting anything when used in cars designed for leaded gas. I used an additive for a while in my old car, with no ill effects as well. My recommendation on that is: It's your $6, do with it whatever you want. I'd rather spend mine but to each his own.

 

No need to apologize at all. You posted looking for info, which is what the forum is all about. Some folks have a problem when others don't agree with them and they escalate it into some kind of an aggressive confrontation...what a shame.

For what it's worth I use the Amsoil oil that Mako mentioned- right, wrong, or indifferent!

I'm not as big as you guys, so excuse me while I go kick the dog.

 

I called Castrol and asked them about their ZDDP ratings for all GTX and GTX High Mileage, the lady stated that the engineers to not release that data for those products and the only product she could reccomend was Castrol Syntec which has not had a reduction in ZDDP, and she suggested 20w50.

Now Syntec is a full synthetic, how would I go about switching from Dino to Synthetic?


Also as far as the pinging/knocking, unfortunately/fortunately I am only 25 (26 tomorrow), so I have never been in an old car besides my own (which I got a couple weeks ago) and my friends 65 Chevelle which is in really good condition.

 

the castrol syntech has to say for "classic cars and not be compatible with catalytic converters" its not the regular castrol syntec you find in auto parts stores......there is no swapping issues just change to at an oil change you dont flush it or have to worry about incompatability.....i use the valovine racing oils they have all the correct detergents and zinc and are locally available....you can go to valvolines website for more info.


http://www.valvoline.com/faqs/motor-oil/racing-oil/76

this is what i use
http://www.valvoline.com/pdf/VR-1_Racing_Motor_Oil.pdf

 

Guide and seal machine? I think it is more like a vlave seat and guide machine. You say you are a Statistician, I guess your the same type that MacNamara used in the 60's to fight the Vietnam War (a guy who dosen't have the SLIGHTEST CLUE about what is going on.) My remarks were directed to a cetain Canadian calling me unexpirienced and being a TROLL. I have wreched on cars and motorcylces since I was a teenager and have quite a bit of expirience along with a GOOD TRACK RECORD to back up my reccomendations. Hopefully some of my input will be taken into consideration, how many others here in this thread actually OWN a 70 LT-1 Vette like the poster is refeering to? I DO! I live in the same state, deal with the same crappy gasoline, live at the same altitiude and have made my 70 run OK on the information I have given him. I'm done posting in this thread, anyone who wants to prove their ability to me can come out next year and take a shot at me at the WSCC autocross races or Vette Magic, hope to see some of you there, the competition is WELCOMED. When the green flag drops, the BS STOPS! Just like statistics, liars figure and figures can be made to LIE!

 

I've heard that the engines in Chuck Norris' cars don't need cam shafts. The valves just open and close on their own out of respect for his awesomeness.

Being called a 'hoser' would make any Canadian laugh. The term comes from a skit performed by the McKenzie brothers on SCTV in the early 80s.

The humour within the humour is that most of the jokes were made up just to mock the stereotypes bestowed upon us by our neighbours to the south. I've never once heard a Canadian actually say 'hoser' or 'take off, eh', so the joke worked quite well in this case.

 

when we lived in the Cleveland area the elementary schools taught the kids to sing the Canadian national anthem in respect to out neigbors in the North. i thought that was kind of cool.