Safe RPM range

[Mr Goodwrench]

lead or no lead and when?????? one could debate this isssue till the end of time.
Now hears a fact, when the lead was removed from ALL gasoline it had a definate and profound effect on valve seat wear, I know this first hand beacause I worked in a machine shop and saw these mysterious sunken valves on 283/327 chevys 289 fords "and some of the best high performance machines this country had to offer" engines that had been operating perfect for years. I guess that I am one of the guys that wasted time and money installing these hard seats. wish I would have kept count it's in the hundreds. Unleaded gas in 1966????? ok I believe you but I would be willing to bet the percentage of it sold verses leaded gas was very low. Hell I got a better theory maybe aliens came to us from another planet and caused all this mayhem I guess somethings you just have to see to believe.

 

[Ronnie Russell]

Cool down Mr Goodwrench, We are all buddies here. Aint it funny that so many intelligent, experienced men can go through the same time period of the 60s thru 80s and have opposite views? You are right, we could debate this issue till the end of time, but most of us older guys have formed an opinion over a long period of time and face it " we aint gonna change our minds". That means you, me, and many, many more. Try to find the humor in the posts . I know in your mind you are "thinking" , man , how can they believe that? At the same time, the other side is thinking the same thing. I have enjoyed each and every post and welcome peoples opinions and their experiences. 7-14-2005 10:49 pm --CarlK60 asked " Hey guys, got a quick question, " I think Carl is out on the highway somewhere, and missed most of his answers.

 

[mpris]

A little more info about the use of leaded fuels. For those that keep insisting that lead was not needed in fuel when the old soft heads were in use, show me a test or study which confirms this. The reason most people don't have a problem today even with the old heads is they do not normally drive the cars on an everyday basis and under a heavy load. Attached is a paper talking about the reduction of lead in fuel.

Poocho

 

[CHEV601234]

It does make sense that when the lead was federally mandated out of fuel, the manufacturers were caught with a time table that did not allow them to blend new compounds into their fuel that would do the job lead did.
The same thing happened when strict emissions standards were imposed on the car manufacturers. They either didn't have the time or ambition to re-engineer more efficient engines - they just threw emissions control equipment on them, and as a result, most of them barely ran.
But somehow (maybe aliens) Amoco was able to formulate a lead free fuel way back then which caused no problems to those old engines.

 

[Geary Trussell]

lead in gas

Why did the OEM's start putting hardened valve seats in their heads? Because
they wanted to lose money on each car for the extra cost? I think not. Maybe
it was because lead offered some lubricity for the valves/seat.

 

[bobs409]

Anyone that would like to see the DVD I bought can pick one up on this website: http://xerog.com/dvd/ They sell this to help pay for their website costs.

Here is a list of what's on it. #20 is the Amoco commercial. Not sure why they made unleaded gas in 1966 but they did. (I'm still using MMO to be safe) It's a really neato DVD for $9.95 and is about 76 minutes long.

Playlist
1. Introduction
2. Goodyear Lifeguard tires commercial
3. 1960 Fords film
4. Volkswagen commercial
5. Corvair introduction
6. 1960 Corvair film
7. Goodyear snow tires
8. Motorama introduction
9. 1961 Motorama film
10. 1963 Chevrolet commercial
11. 1963 Oldsmobile 98 commercial
12. Mustang design introduction
13. Mustang design film
14. SuperShell gas commercial
15. Hertz Rent-A-Car commercial
16. 1966 Chevy introduction
17. Impact 66, Part 1
18. Newport cigarettes commercial
19. Impact 66, Part 2
20. Amoco unleaded gas commercial
21. 1967 AMC wagons commercial
22. Closing remarks
23. Credits

 

[Mr Goodwrench]

sorry for sounding p$$ssed guys I'm... not but unless you have worked with cyl heads on a large scale I guess it is hard to believe. we even got a 283 in one time that had a ex valve sunk so low it cut a hole the size of the valve stem through the rocker arm where it contacts the tip. one other thing to ponder...if youve ever cleaned up a set of valves in preporation for a valve job on some old heads that been on the shelf since before unleaded and noticed all that white carbon like material on the head of the ex valve and under it? thats not there on todays engines. whatever you want to call it I think it's the very stuff we've been talking about.

 

[CHEV601234]

I may be wrong, but that 283 sounds like it had more problems that can be attributed to a lack of lead. I've seen that white fluffy stuff before. Too lean, and maybe a bad head gasket. I doubt a lack of lead would result in the valve stem pushing itself through the rocker. Poor (or lack of) adjustments, no oil changes, overheating, over revving maybe, but no lead in the gas?????? My, my...the mystical powers of lead....... Or maybe it was due to pre-ignition due to hot lead deposits in the combustion chamber?

As other good people have stated, this "debate" will go on forever.....unresolved. Like religous beliefs or your view of abortion, there is no chance of changing how "you" feel or what people want to believe. There are no open minds on this subject. Let's just do what we feel is best for our cars, and hope they have a long life. They aren't making any more of them.

I wish it was still the '60s, when I had my choice of Sunoco 260 or Amoco unleaded premium, neither of which caused me (or anyone else) any problems..........

 

[bobs409]

Amen. And I'll take some of that .25 cent gas too!

I wonder what it's like to fill your tank for $5 bucks?

 

[Mr Goodwrench]

the reason the valve stem pushed through the tip of th rocker is because something caused the seat to erode away which made the valve sink, adjustment goes away bottoms out lifter, something has to give rocker was what gave up. Man I wish I would have taken pictures, I get the feeling some people have never seen this condition, when I say the valve sinks I'ts not just a little bit it digs a hole the size of the valve strait down untill all valve spring tension is lost! seen them many times so deep the keepers were almost ready to fall off. Fill your tank for 5 bucks???????????

 

[gearhead409]

MR Goodwrench

it's unbelievable how much damage a sunken valve will do to an engine and not repaired soon after the problem has started. it will ruin the head, valve, spring retainer,rocker arm, rocker arm stud, push rod, lifter and camshaft. i have seen valves sunk so far up in the head that after taking the head apart, the seat looked like it was already machined for a hard seat insert.

 

[Ronnie Russell]

Have seen sunken seats also, but it was 90 Chev P.U. 350--Engine started running rough at 80,000 mi. Pulled heads, seats were so bad, the heads could not be saved. This has nothing to do with "leaded or not-leaded gas" but dosent this problem happen to a certain percentage of engines, no matter what type?

 

[Mr Goodwrench]

hey I just remembered I can still fill my tank for 5 bucks........on my lawnmower!!!

 

[RPO587]

Interesting discussion. I remember reading a report about valve-recession back in the late 1970s. Chevrolet was specifically mentioned because the SBC was subject to this problem. The conclusion was that Chevy's castings were somewhat "soft" because of low nickel content in the iron alloy, and thus this was the primary reason for the valve seat problems. Cylinder-bore wear was also an issue. Additionally, the 305 engine seemed unusually prone to camshaft wear. Don't know why just this particular engine, but I remember replacing a cam in one which had some lobes which were almost perfectly round. The case-hardening was poorly done and the lobes quickly wore through to the softer metal underneath. This was during those dark days when the big three were looking at many ways to cut costs (remember the Vega engine?).
It seems to me the reason so many cars had this problem back then was because of a "cheapening" of the affected engine parts in an effort to cut costs. I'm sure this is also subject to debate. :stooges

 

[models916]

added confusion

http://www.mindfully.org/Pesticide/Lead-History.htm#cars

 

[Ronnie Russell]

models, You accomplished one thing today for sure. You caused me to read more printed matter than I ve read in years. Man , that was a lot to digest!! A brief synopsis is ----lead did indeed help with valve seat lubrication, but at the cost of valve corrosion, extra ring and cyl. wear , dirtier oil, rusting of exhaust system and more. So the way I see it is " Everybody is right--Nobody is wrong. Those of you who use lead additive will protect your valve seats but maybe at some cost. Those who do not use lead additive will have less engine and exhaust system wear, but maybe with bad valve seats over a long period of time. Everybody wins and nobody loses.. A happy ending at last

 

[BC409]

thought I'd add a twist to the conversation. i have seen valve recession on several small blocks,but by far the worst were the two fleet pickups i saw that had been converted to run on propane! an honest 1/8 inch down the hole on the exhaust side and starting to go on the intakes. dont know if propane was tuned wrong or trucks got ran too hard or what.but i wont be running propane anytime soon.

 

[Mr Goodwrench]

hard seats ars a MUST for propane, and have been for 50 plus years. Propane burns very dry is what I've always been told, though I'm sure someone will dispute that theory. :stooges

 

[jester]

Amen. And I'll take some of that .25 cent gas too!

I wonder what it's like to fill your tank for $5 bucks?

Hey Bob , you can't buy 20 gallons of bottles WATER for $5.00 today.

 

[MRHP]

propane

Propane is a dirty fuel. When propane is used it is recommended that valve rotators be removed or excellerated valve wear is the result. Now not all heads have rotators but you get the point.