Lead Fuel Additive

dba4life · Outlaw Joined: 20 Feb 2003 Posts: 129

Howdy,

My 90 Supra Comp PCM 351 engine calls for leaded fuel. When I bought the boat last year the previous owner gave me his bottle of CD2 lead additive. It treats 320 gallons and has a nice plastic bottle that allows you to measure the correct amount of additive. Plus it was small - about 32oz.

I am almost out of the stuff. And I am trying to find it and am having no luck. The local auto stores sell a single application bottle (treats 20 gallons). What kind of lead additive are you (who need it) using?

Or has almost everyone just gone to higer octane fuel and skipping the lead part?

Thanks
Kevin

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

I just use whatever I can find, usually the kind that only treats 20 gallons. That other setup sounds cool though, because I only have a 15 gallon tank, so I always have to guess how much 3/4 bottle is, then I have a couple almost empty bottles around for a while.

MrBlean · Posted: May 22, 2003 9:09 am Post subject:

Get the correct brand and manufacturers name for the additive and search the web for it! If you don't have this info, ask the guy who sold you the boat. Surely he must know?

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

A higher octane should be fine, as long as your engine isn't knocking, your money.

Nick
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FORD MODEL Y HISTORY

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

CD2 is probably the brand. I know there is an engine oil additive called CD2 that we used on a friends noisy S-10. They probably make lead additive as well. maybe someone like Jegs or J.C. Whitney would have the concentrate you mentioned. If I get time later today I'll check the catalog, or you might want to check their websites I think its just www.jegs.com and www.jcwhitney.com

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

If the engine calls for lead, you need lead, regardless of octane. My boat for instance requires both lead and 92 octane. The lead serves as a cushion and seal between the valve and valve seat. Older motors use hardened valve seats, as opposed to newer non-hardened valve seats. Octane on the other hand affects the combustion properties of the air/fuel mix. Octane allows for higher compression and results in a delayed combustion. Higher octane isn't always good though, it depends on how the timing and tuning is done. My truck runs best on 87 because the 92 detonates later than 87, and at a less optimum point in the stroke of the piston. If your motor is knocking, then yes use a higher octane, but you should also use lead if the manufacturer calls for it.

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

Maybe I need to post a little more, do not use lead additives, they are bad. Leaded gasoline causes many problems, it corrodes exhaust valves, exhaust pipes, spark plugs, and many other bad things that lead to more maintainance on your part. Also, it is bad for the enviroment and if your around the exhaust it will get into your blood. The only "issue" you will hear about is people take about soft valve seating. This is not an issue with most engines made after 1970 since nearly all of them have hardened valve seats (stang has this backwards), and even then there are other additives to address that. Many many studies have proved that using unleaded gasoline in a leaded engine is fine, I have not even heard of a single study claiming otherwise. The only real issue is that you may need a higher octane to prevent engine knock. Gas today is also better, so you may even be able to use 87 octane.

If I were in your situation I'd fill the tank 1/4 full with 87 and see how it runs. If it knocks fill it up the rest of the way with 91. Next tank fill the tank 1/4 full with 89 and do the same thing. Use the min octane that doesn't knock, but I'd bet you a 6 pack that it won't knock with 87.

Here's some information specific on marine engines:

"Marine Engines:

There is concern about older four-stroke cycle engines in marine service, which were designed prior to the introduction of unleaded gasoline (pre-1974). Under severe duty, these older engines could have valve recession problems. If these engines are in severe duty service, owners should consider installing hard seat inserts or using lead substitute additives to minimize valve recession. Products like this have been found effective in minimizing valve recession."

Nick

links to back me up:

http://www.chevron.com/prodserv/fuels/bulletin/unld-gas/

http://www.globalleadnet.org/pdf/myths.pdf

http://www.princeton.edu/~vmthomas/pbgas.html

you can search and find like a million more
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MrBlean · Posted: May 22, 2003 9:52 am Post subject:

There's a lot of misconceptions about lead in fuel and the impact of not having it. Whilst a faster flame speed thro' the higher octane rating derived from the lead additive is beneficial, the main benefit is the protection it offers to valves and valve seats by minimising the impact of the micro-welding that takes place every time a valve closes and opens. However, the impact of micro-welding is MUCH more severe at higher revs (above 4000) and most slow revving motors work fine on unleaded fuel provided the ignition timing is adjusted to take account of the slower burn speed of the fuel thus preventing knock.

I'm not sure if the additives available on the market simply affect the octane rating or whether they offer any "lubrication" to the valves and guides in the way that lead does. Will be worth asking any manufacturer/supplier this question.

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

I amazed sometimes at how misinformed people are, added lead does indeed increase the octane, but a higher octane doesn't cause "a faster flame speed thro' the higher octane rating derived..."

I addressed the valve issue in my first post, hardened valves don't need lead. If your crazy paranoid you can get an additive for this that does not contain lead.

Octane is a measure of gas's resistance to predetonation. In other words, how hard it is to burn. It is not how fast it burns, how much energy it has, etc...

If the octane is too low the gas will ignite before the spark, which is obviously bad. Once you reach the octane where this does not occur, increasing the octane above this does nothing. Also, the more likely reason stang's truck has problems with a higher octane is his ignition system. It is harder to get higher octane gas to start combusting.

Also, modern cars are fairly advanced and contain knock sensors. They also have a lot of control over the spark advance of the engine. If the knock sensors indicate knock the engine's computer will retard the timing until it doesn't occur. Since advancing the timing leads to better performance, in some cases you can get better performance with a higher octance, but only if your engine's computer is retarding the timing with your current gas.

Nick
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HOTELS IN MEXICO CITY

MrBlean · Posted: May 22, 2003 10:07 am Post subject:

Nick

Agree with you re pollution etc and the fact that most post '70 engines have hard valve seats that are relatively immune to recession but what's this stuff about lead causing corrosion of engine parts? A build-up of deposits, yes, but corrosion? That's normally caused by the acids and water vapour that build-up thro' shutting down a motor before it's warmed up properly. Will be interested to read any links you have on the subject of corrosion......

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

Oops. my mistake, I always mix up the valve seats. I could have sworn newer motors had hardened, but last time I double checked with someone they told me the other way around. Guess they were wrong.

Those articles were interesting to read, I was unaware of some of that info. I think I'll still use the lead additive in my boat, but once I look into it a bit more I may quit using it. My main concern is the fact that my boat motor is a 1969, and spends a good amount of time above 4000 rpm because of its low power.

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

And another one...

"Should I be using Lead additive in my fuel?

Answer:
Nope. Actually, I think you mean lead substitute - I'm not aware of a lead additive. Tetraethyl lead (the former gasoline additive) is a violent poison and cannot be sold in concentrate form. When it was in gasoline it was blended in as part of the refining process.

Lead or lead substitute is helpful only in engines which have cast iron (or possibly soft steel) valve seats. Without lead or equivalent, the iron microscopically welds to the valve face under conditions of sufficient heat and pressure. Then when the valve opens it yanks away a few molecules of the seat. That results in valve recession; the valve sinks slowly into the disappearing seat.

Cast iron valve seats are found mainly in older liquid-cooled engines which have cast iron heads, as many do."

http://www.356registry.org/Tech/leadadd.html
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Nevada dispensaries

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

Yeah, 1969 is pretty old, if it has soft valve seats I'd keep using a lead additive that doesn't contain actual lead, but I don't think any of the additives do.

MrBlean,

The corrosion is listed on the global lead link. They don't go into details either, maybe I look more into it because it made me curious too. The lead probably reacts with something or maybe something else that is involved with putting the lead in the gas, but I think a buildup of lead is obvious. Also, lead can't really be used with catalytic convertors, which isn't a issue for us boat people, not yet anyway!

Nick
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HOW TO MAKE A VAPORIZER

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

Just a note on my truck. It still runs fine, just a little sluggish, like you said. My mustang also didn't perform as well on high octane, but again, it still ran fine.

dba4life · Outlaw Joined: 20 Feb 2003 Posts: 129

Sparked a debate!

So it sounds like I can skip the lead substitiute? I have also emailed PCM and asked them. Hopefully they will respond.

Kevin

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

Actually, the valve seats are currently mixed. The last owner must not have used lead because the #4 exhaust valve needed to be replaced. So I have 3 soft and 1 hard. I have an extra head sitting around that I plan to port and polish, then put in all hardened valve seats so I can quit messing with the lead additive. I dont' know if I actually use lead, or a lead substitute or anything, I just buy the "additive for engines requiring leaded fuel"

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

That sounds like a fun project. My new vehicles now never have any problems, though that is probably a good thing since I work full time.

Where do you board in detroit?

Nick
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Ferrari p

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

Oh its been a blast, I guess. haha Two very long years of fixing almost everything, but its finally ready to go for this season. I don't actually board...yet. I'm going to learn this summer, now that I've finished fixing my boat. Tried it once in NC and it was great, so I want to get better. I originally came here just to get opinions on whats good and whats bad in wakeboards before I buy one, but ended up hanging around to learn all I can.

Anyways, In the past I've broke down on Orchard Lake and Ford Lake in metro area, and Lake Fenton up near Flint. I'm going to start going to Cass Lake and maybe try Lake St Clair, but due to the size of my boat I'll be staying close to shore. You know of any good size lakes that have public launches but also a public beach? I can only fit 4 on the boat and theres almost always more of us than that, so we need somewhere with a beach. Cass lake is all I could find online thats nearby and inland.

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

Cass lake is big and hard to find smooth water on, also its launch fills up quickly on the weekend, orchard lake is probably the best for what you what. It has a beach area and the water is ok, but the police are out in full force on that lake and it has some weird rules. I think any drinks have to be in cups, not just alcohol. So you can't drink coke from the can or bottle, also, don't go on the island in the middle. You can see them harrassing someone pretty much constantly, they will check for life jackets, horn, fire exten., etc... St. Clair is also too big and rough for wakeboarding, but I've done it a couple of times. We usually go in Waterford but I really like orchard lake. Check out this webpage, it has all the lakes in MI.

http://www.michigan.gov/dnr/0,1607,7-153-10365_10884-43832--,00.html

You probably want oakland county, that's where orchard and cass are.

Nick
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Lolol

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

Yeah DNR got me at Orchard Lake. Funny story really. It was May last year, right before the Cup finals. Took me a good 30 minutes on the ramp to just get it running. Finally get it goin and we motor out, I thought slow enough for no wake. Get going, break down. Drift to shore because it wasn't busy and so we didn't see anyone to tow us. I get out and start walking back pulling the boat in about knee deep water. We get to the docks just north of the launch and start working on getting around them since the water is over my head there. Thats when DNR shows up and finally tows me in. They checked everything and harassed me because my horn was disconnected and lights had tape over them (I was preparing to paint) Then they took my liscense (actually a NC liscense) and registration. After yelling at me for making a wake and ignoring them whistling at me (BS, i was looking around as I was leaving) they said "Ok one more question and this will determine if you get a ticket or not.... Who you pullin for in the cup??" Needless to say, that was an easy answer, and so I didn't get a ticket.

I never did see a beach there though, but I haven't made it more than 200 yards from the ramp either. And yes, no bottles of any sort on the boat.

Where would you recommend going to wakeboard?

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

Yeah, the first time they yelled at me they whistled too. Then, they asked me what I thought they meant by whistling and I said, "I don't know, adult swim?"

I was towing in some jet skiier that broke down. At first he wanted to ride on the swim platform and I told him to get in the boat since the DNR people don't like that (plus it is bad anyway). Well, when we got close he must have thought he was going to swim it in and got on the platform and that's what the DNR guys wanted to yell at me about.

Check out this picture of orchard, you can see the shallow areas of death to avoid. The beach is on the

Nick
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YAMAHA XS360

Stang6835 · Newbie Joined: 07 May 2003 Posts: 32 City: Detroit, MI

Wow, nice pic. Where did you get that? Yeah I remember looking down as I was drifiting and it sure looked like it was getting shallow for how far from shore we were.

Hopefully DNR let you off easy since you didn't know the guy, were doin him a favor, AND told him not to do it.

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

I've never gotten a ticket there, despite my smart ass comments. I don't think I've ever gone there without getting yelled at either, I think they know me there.

I got the picture from www.mapquest.com. You can click on aerial photo. I usually check it out when I go to a new lake, it is easy to see depths.

Nick
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mykwillis · Outlaw Joined: 05 May 2003 Posts: 105 City: garland, tx.

MrBlean · Posted: May 23, 2003 5:16 am Post subject:

OttoNP

Apologies for the error on the effect of Octane but I do thing higher octane fuels burn faster even if the are harder to ignite in the first instance. If not, where does the extra power come from? You're clearly pretty genned up on this stuff. so maybe you've heard of this issue too: some of the additives are tin based and some are potassium based. Fine on their own but you shouldn't mix 'em and should elect for one brand and stay with it. I read somewhere (at least a couple of years ago) that they neutralise one another and hence are ineffective if mixed.

However, this may all just be marketing bull**** which you have to take with a large pinch of salt. As for ths stuff about corrosion, my experience of some of the info circulated by pressure groups is that it's both exaggerated and presented very selectively. I regret to say, this is even true of Friends of the Earth. Whilst I support most of their motives in general, sometimes they are a bit OTT.

Thankfully we're not forced to use cats on boats yet but I wonder for how long? Here in Europe, on some waterways outboard owners are forced to use biodegradable oil (again a good thing) but it's about 8 times the price of the regular stuff. And with cats, there's the issue that they're not at all effective until they are hot, they use up precious rare elements and are difficult to dispose of.

P.S. The Transport Research Lab in the UK got eight car engines with soft valve seats and set up the valve clearances exactly. They then ran one engine at low revs for ages, another a constant modest revs (around 3000, I think) for the same time and treated the others to varying cycles of hard revving etc over a long period (thousands of hours). Only those engines that were revved hard for long periods and under significant load showed any sign of valve seat recession. So, as the articles and many have suggested here, there IS a problem with older style engines but even then, only under relatively harsh conditions.

It seems that in an engine that isn't equipped with full knock sensing engine management, if you can find a brand of fuel with an octane rating that runs sweet, there's unlikely to be a valve problem.

Maybe we should all stay at home and eat muesli?

MrBlean · Posted: May 23, 2003 5:32 am Post subject:

Oh, and by the way, here's another dimension to this discussion...

Because of the price of gas here in the UK (nearly 5 dllrs a gallon) many people (particularly schools and club owners) convert their boats to LPG 'cos it's less than half the price of gas. As far as I know, this doesn't contain ANY additives (I could be wrong here) and most users claim their boats run fine. I've even heard some people say they run better but I guess this is 'cos the have to have the timing adjusted and the engine then becomes better set-up because it wasn't set up well originally to run on regular gas. Even though you use more, LPG definitely produces less power than regular gas because of it's lower calorific value. 10-15% less power seems to be the figure bandied around but with typically 300 horses available that shouldn't really be an issue.

As for using LPG, having a slightly older (or less sophisticated) engine is better 'cos the costs of converting a carburettored or single point injected engine are modest (about 1800 dllrs) whereas for a multi-point injection system the cost is more like 5250 dllrs. At that rate you have to use a lotta gas to even reach break even!

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

I don't know about the potassium and tin based addtivies, but here's you explanation of higher octance giving better performance...

The first case is easy and based on engine design. With a higher octane you can have a higher compression ratio. High compression engines will knock if the octane is too low. Obviously you can get more power with a higher compression ratio.

The second case is the one that the average driver can benefit by. I'm going to assume we know some basics about how an engine works. With the piston is right at the top in the cylinder after the downward intake stroke, this is called top dead center, TDC, (has other names too). Now, in this position the crank is said to be at 0 degrees. Timing is designated in degrees, meaning the degrees before this that the spark plug fires. Since it takes time for the fuel to ignite, the plug fires before 0 degress, 1-5 degrees or so at idle. As the engine speeds up, it is good to advance the timing farther, up to around 20 degrees or so at full throttle. So the spark plug fires when the crank is 20 degrees from top dead center. If you advance the timing to far, engine knock will occur. The highest horsepower that you can get occurs if you set the timing right before engine knock occurs, in other words you advance the timing as far as you can. Since higher octane fuel is more difficult to ignite, you can advance the timing farther. This made me think that it burned slower, but when I asked a professor they said sort of, the two are interrelated, since it is harder to ignite it starts slower but once the fuel ignites and feeds the other fuel it goes just as quickly. This is why you sometimes need a different octance when you put a performance chip in. Performance chips change the spark advance to give you better performance, without a higher octane gas knock may occur or you engines computer could retard the spark advance.

One of my senor projects at Georgia Tech was seeing if split fires really gave you more HP. We found that a split fire with 10 degree spark advance had more horsepower than a normal plug with 10 degrees spark advance. But, at 20 degrees spark advance the horse power was the same. Changing the spark advance had a much greater effect on the normal spark plug. This means that a split fire does ignite the fuel faster, but in real life use shouldn't be that different.

Nick
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MrBlean · Posted: May 23, 2003 6:03 am Post subject:

Nick

By split fires, I assume you referring to multi-electrode plugs rather than two sparks delayed in time by a small amount? BTW, I have a degree in Electrical & Electronic Eng and a reasonable appreciation of things mechanical so don't worry about explaining the basics!

Jeff

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

yes, multi-electrode plugs
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MEDICAL MARIJUANA

dba4life · Outlaw Joined: 20 Feb 2003 Posts: 129

This is the answer I got from PCM:

Hello Kevin,
Your engine does not require the lead additive or 93 octane. This engine is safe to run with regular 87 pump grade gas. If you need further assistance, please let me know.

Mark Schneider
PCM Technical

MrBlean · Posted: May 23, 2003 9:31 am Post subject:

Great news all round!

core-rider · Addict Joined: 12 Jan 2003 Posts: 531 City: Huntsville, AL

dba4life, It looks as if this thread has gotten a little off topic. The answer you are looking for is Autozone, Walmart, maybe even Target. Autozone and Walmart I know carry lead additive in a 32 oz. bottle, I used to by it from them all the time up until last year. Target may also carry the same thing.

Now, I see you have already gotten the answer your looking for from PCM, but I will just back up their answer. You should not need leaded gas for ANY engine made after about 1986. Leaded gas was no longer available so they didn't make engines to run on it. Your engine should have no problems with unleaded fuel.

Now about octane... use as low an octane as you can without causing detonation. (Pinging, a slight rattle sond) I'm not sure exactly what PCM engine you have, but if it's not an EFI engine then you should be able to go with 89 or lower without problems. If it is a EFI engine then you might need to go with 89 of higher octane. Either way it looks as if you got the answer from the source so it doesn't really matter...

TSchultz · Criminal Joined: 02 Feb 2003 Posts: 96 City: S. Minnesota

Just for everybody's information unleaded gas does have lead in it.

lebaron · Soul Rider Joined: 20 May 2003 Posts: 490 City: Langley