Greetings . . .

There was a posting earlier that received lots of replies and included some rather interesting side discussions and tangents. I kinda like that sort of posting - makes for interesting reading and lively discussion . . . though I digress . . .

Some felt all the banter was off topic and that separate postings were in order.

So I am offering the board both . . . a separate posting that cuts right to original question:

PRESSED IN HARDENED VALVE SEATS FOR YOUR VINTAGE ENGINE - Yes or No?

I am building a 216 based on specs from Bill Fisher and Roger Huntington. I have a NOS cylinder head from war time production. Should I hand it over to some machine shop for them to machine and press in hardened exhaust seats?

Some will say that hardened seats are "the best insurance I can buy." But how do I go about choosing the right seat?

If my machinist or I choose wrong there can be problems:
Morris Club Owners
If one chooses the wrong material or they aren't installed correctly then one can end up with heat transfer problems that will lead to failure alot sooner then errosion from unleaded gas:
Valve Seat Installation
How do I know what materials are compatible with a World War II era head? Does anyone know?

When GM originally cast the head "back in the day" they certainly didn't intend for it to be machined in this way. They expected it be used with leaded gas.

Many mistakenly believe that the 'lead' in gasoline somehow acts as a lubricant - when in fact the lead causes a chemical reaction that locally hardens the seats as the engine is run:
SBI International
and that one doesn't even need a steady diet of leaded gas. Once the seats are hardened one can switch over to unleaded gas with no ill effects.

So what should I do with my 216:

1)Take a risk with a machinist and an aftermarket hardened seat
-or-
2)Run lead additives or lead substitutes until local hardening takes place during break in?
Redline Oil
STP

For me choice two seems less risky. Especially since we're talking about a car that will be driven less then 1000 miles per year; won't be used for towing; won't cruise for hours and hours and hours on the freeway . . .

regards,
stock49

P.S. Some interesting reading on gasoline:
Gasoline FAQs

After reading several times the previous long posts you refer to,I tend to agree with you and John Meridith in skipping the inserts. My 235, done several years ago, has them and it's fine,no problems, but when I consider the very low mileage I've put on that motor since the rebuild it was probably a waste of money.When, if ever, I rebuild my 216, I'll forego the hardened seats.

with the intended normal use of your motor, i can see no reason to change to hardened seats. to me it is more of an issue with heat and long term high speed operation. for instance 292 were used in ag equipment such as combines. this was a heavy sustained load and at a reasonably high rpm 2000-2400. this would be a case for hardened seats on the exhausts. atleast to me. tom

I will preface with the fact that I have never installed inserts and do not intend to, but I have heard the chemical reaction hardening by the lead is not permanant , and that if you just run some lead every 4 or 5 tanks you will be fine no matter how you drive it.

Diesel, I have been running my 68 Camaro 250 since 1980 when I bought it on unleaded Calif of course gas and have never had any head work done. I was told if the head had been run with lead since new tha there would be no problems. I typicaly drive 5-6 thousand miles a year. I tend to think that the no insert guys are right. Just my experence. Herb

Gentlemen;

Heat or peolonged heat, is the issue. A stock 216 has neither so there not needed.

The stock 250 that guy had with 70,000 miles on it was a 'test engine' basicaly and this is why I didn't think they were worth the money there.

If he builds a 'turbo engine' then okay, as it will be a 'high rev' situation, probably with heavy valve springs.

Good luck to all.

Yes in a stock configuration I see no need to. In my case yes its on a "test engine" but if I drop the $ into this head (since it needed it with multiple sunk valves) I can reuse it with the turbocharged engine instead of doing work on 2 separate heads.

But like others have said on a high RPM, High load engine its may be worth your time and $.

Good to see this topic still going. The more I read about it the more I get confused.lol
The heat transfer problem with inserts is interesting.

So does an 8-12 hour drive on the hiway with a "cat" mean I should have seats put in?
What about towing a 1500# trailer through the mountains?

g10, in the case you mentioned with the trailer, yes. with the other it is a debate. tom

Any vehicle runing one or more 'Cat's' should have them (if the factory didn't).

As the Cat ages from 'normal' driving it becomes more restrictive (exhaust flow) and creates more heat as a result. Often they become pluged or so restrictive the engine will barely run.

This is why many simply remove them to save their engine and a lot of fuel bills.

The choice is yours.

Well it looks like inserts are the way to go in my case.

The exhaust system is new from a new manifold all the way to the chrome tip.
I'd have to cut the "cat" out and weld up some flanges to but it back for the smog test.
Don't really want to get into all that.
When the smog test comes around I just want to take the van down and smog it, no extra work.

When I took my 302 head in for a valve job and inserts, the machinist tested the existing seats and said they were induction hardened from the factory and didn't need any seats. I don't know if this was since 302's are newer or for big trucks only.

Ed

G10-250,

Your engine was designed for unleaded if it has a catalytic converter, you don't have to do anything.

The induction hardening is only so deep.

One or two valve jobs and you are most likely gone through the surface hardning.

Which will reguire hardened seats installed on the exhaust valves.

MBHD

Best and easiest way around this is to use a tin catalyst...

You can even make this yourself if you want. But I have proved they work in Peugeot engines that work hard, they can easily transfer from car to car and they last almost forever.

If anyone wants to question my judgement on this, be prepared for a long and bitter fight. I covered 1800kms without one a few years ago after dressing up the valves in a head, that trip cost 0.015" from each exhaust valve seat.

The valves were adjusted at that time, the tin catalyst installed and no further erosion took place in the next 80,000kms!

I then started to suffer erosion again and contacted the maker. They advised that there was fuel being sold with fungus in it, that I should clean the tin pellets inside the canister with bleach or sandpaper them. I did both. Another 80,000kms without erosion.

There were no other changes made to the engine initially, though there was some minor maintenance (plugs etc) along the way during the 160,000kms over the next two years.

Heavy use, often hauling a loaded trailer, virtually all highway miles at constant speeds.

I trust them implicitly.

The motor came from the junkyard and obviously been re-ringed and bearinged.
The head looked to be rebuilt at least once before.
Is there a test to check if the hardening has been ground through?

Seats are really not that much money to have installed.
You only need them for the exhaust. (6 total.)

MBHD

WHEN in dout REPLACE.

Thanks Larry that makes sense to me.

Don't know why I didn't think of it.

vince

They are cheap to have done there?

Last time I had a set done, and it was only four, it cost me more than a tin catalyst was worth.

$16-$20 each, parts & labor installed on average.
That's not that much ,,,is it???

What is a tin catalyst worth??

Some info on tin pellet catalyst found here

http://www.oft.gov.uk/News/Press+releases/2000/PN+42-00.htm


Misleading fuel claims stopped

PN 42/00 24 October 2000

The supplier of a fuel additive for cars has agreed, after OFT action, not to make misleading claims about its effectiveness.

Clockwork Orange Limited, based in London, has given written assurances to the Director General of Fair Trading, John Vickers, that it will stop producing misleading adverts for a product called Fuel Cat.

Fuel Cat, a catalyst of tin alloy pellets designed to be placed in either the fuel tank or fuel line of any vehicle, was said to save fuel, reduce exhaust pollution, improve performance and lower maintenance costs.

Adverts also claimed that it would enable unleaded fuel to be used in cars designed for leaded fuel and that there were many thousands of satisfied users.

Clockwork Orange was unable to prove the claims and tests [see amendment] by the Royal Automobile Club (RAC) showed that the pellets did not do what the company claimed.

Assurances were sought after Clockwork Orange was referred to the OFT by the Advertising Standards Authority (ASA). The ASA had already upheld complaints against the company after adverts were placed in specialist car magazines, in leaflets distributed at classic car exhibitions and on the company's Internet site.

Mr Vickers said:

'False claims made for products deceive and harm consumers. The OFT will continue to work hard with the ASA and trading standards departments to stamp out misleading adverts.'

Amendment made on 4 May 2001
It should be noted that the RAC was commissioned by the ASA to produce a report commenting on the claims made by Clockwork Orange Limited in relation to Fuel Cat. The RAC did not, as far as we are aware, carry out any tests on Fuel Cat. However, the RAC report did conclude: 'None of the claims made by Clockwork Orange Limited in respect of Fuel Cat have been substantiated. Furthermore, there are good theoretical considerations and existing knowledge which lead to the conclusion that tin alloy pellets in the fuel tank of a vehicle or fitted in the fuel line, with or without a magnet, will not have any effect on combustion and therefore cannot affect fuel consumption, exhaust emissions, gasoline octane number, exhaust valve seat recession or exhaust catalyst life.'

NOTES

1. The RAC's tests [see amendment] concluded that for Fuel Cat to have any effect at all the pellets would have to be dissolved or mixed with the fuel. In practice this does not happen which means that Fuel Cat cannot meet the claims made for it.

2. The ASA forwarded the case to the OFT after trying on a number of occasions to get Clockwork Orange to justify its claims. The company was unable to do this so ASA upheld complaints against them in July 1998 and then issued an ad alert against Clockwork Orange and Fuel Cat on 6 June 2000.

3. Assurances were made under the Control of Misleading Advertisements Regulations 1988. They came into force on 20 June 1988, implementing an EC Directive on misleading advertising. The role of the Director General of Fair Trading under the Regulations is to support and reinforce existing controls, not to replace them. The Regulations give him the power to step in if the public interest requires that advertisements complained of should be stopped by means of a court injunction. Alternatively the Director General can seek assurances or undertakings.

4. The Director General can act only when a complaint has been received. To come within his scope an advertisement must be misleading (ie must deceive or be likely to deceive and affect economic behaviour), and be published in connection with a trade, business craft or profession to promote the supply or transfer of goods and services.

5. Full details of the assurances signed by Clockwork Orange follow. Similar assurances were signed by Clockwork Orange's Company Secretary and by its Director.

The Company shall not (whether by its officers, employees or agents or otherwise) from the date hereof publish, disseminate or cause or otherwise be concerned in the publication or dissemination of any of the following advertisements, namely:

(a) the advertisements.

(b) any other advertisement likely to convey a false impression that "Fuel Cat:

(i) permits engines which were designed to run on leaded fuel to safely run on unleaded fuel;

(ii) replaces lead in petrol so offering protection against exhaust valve seat recession and increasing the octane number of gasoline;

(iii) increases the life of exhaust catalysts by reducing the exhaust emissions;

(iv) increases miles per gallon;

(v) cleans the combustion chambers of an engine;

(vi) prevents carbon build up in a engine;

(vii) keeps crankcase oil cleaner and

(viii)protects the upper cylinder area including pistons, rings, valves and injectors.

Cost me about $200 each for the two Peugeot heads I had done. The catalysts sell from about $110 each.

Jason, I said that "If anyone wants to question my judgement on this, be prepared for a long and bitter fight."

I ask that you accept that my word is true and that your quote is the product of misinformation.

I am not a liar, and posting that, I'm afraid, is tantamount to calling me a liar.

I have been involved in these discussions before. What I always find is that people who have had experience with them found them useful, and that everyone who was critical of them had never had anything to do with them!

What I have posted about my own experience is absolute fact. There are no mitigating circumstances, no changes to the car that could have made any difference. And please, nobody suggest that someone is adjusting my valves without me knowing, as has been suggested in the past.

I make no claims about these things other than with regard to valve seat erosion. But with that, they definitely work.

I would just install the seats $110-120 US dollars & be done w/it.
And yes ,BTW, that is what it will cost you to have six seats installed.
Hardened seats definately work also.
With hardened seats, the valves will get beat up/erroded before the seats will.

MBHD

Ray, what I posted was the result of a cursory google search. I don't doubt your sincerity. However, its pretty tough to conclusively prove anything without a control group and a controlled environment. If (what appears to be)the UK's version of our Federal Trade Commission says that a company can't make these claims, well...

Jason, I am always leery of a gov't group (like the FTC) that "approves" or "disapproves" something as they are known to disqualify good things on a technicality (like not having i's dotted and t's crossed). You cite an article that is over 6 years old. Lots can happen in 6 years. I wonder when Ray's experience with this happened - after the Oct 2000 statements you cited or before? I also find Ray's challenge to be interesting: everyone that is cricical of them has never had anything to do with them. hmmmmm

6inarow, I wasn't trying to prove or disprove anything. Just did a cursory search and found the cited article. There are a lot of "additive" type of things marketed with dubious merit (tornado, magnetic fuel aligners, etc). If it really does what is claimed, then count me as a convert. We should be able to discuss ideas without anyone taking it personal.

Now, I am not a chemist but it can't be that hard to get out a chemistry book and determine if tin can act as a catalyst, or do a literature search for peer review papers; you don't have to spend your hard earned money to determine everything experimentally. Time and money are too short for that.

Wouldn't matter, 6inarow... but it was after...

These things have been around, essentially unchanged, since the 1920s. There are millions of them out there... somewhere.

Just take one of the statements from the RAC 'test':

I could certainly see wear in the pellets, that they were being consumed. Fact is, they are only required to break away at a minute rate to work.

The pellets are held in place in a steel spring, and the canister is attached to the engine so it gets fed vibrations. This means that there is friction between the tin and the steel, the tin is slowly broken away and joins the fuel stream.

Then there is a catalytic reaction during the combustion process, as I understand it.

And yes, nobody I've ever struck who's used them has found they've failed them. And nobody I've ever struck who was categorically against them has ever used them or had anything to do with them.

Mine saved me a head replacement job, that was what I needed. Until then I was using all kinds of stuff that was supposed to help... zinc-rich oils mixed in the fuel, fuel additives etc, but I lost that 15 thou in 1800kms all the same.

And I lost nothing for the next 80,000kms. I still wasn't ready to change heads, though, so I followed the instructions and cleaned it up, reassembled it and got the next 80,000kms out of it before the same thing happened.

When it stopped working, by the way, it stopped working altogether. The valve seats started to go all at once, rapidly eating away. I was lazy, just adjusted them a couple of times and hoped for the best. But then I found out I could clean it up and so I got it stopped again.

Second time round I put on one of the heads I'd had the seats replaced in. But I'd got two years heavy running out of it, I was able to choose when I wanted to change the head rather than do it when I had to, and it's still there to go in another car when it's needed.

Jason... as far as a control group and controlled environments go, yes, I would agree. To a point. But I was my own controls, I am in total charge of my cars, driving them, fuelling them and maintaining them.

And by the way, what is the point of having the tin in there?

To replace the lead, right? Isn't it logical that it might work?

If it works, then the chemistry will back it up. We have a couple of chemical engineers at work who may have some insight. One of them did his thesis on a diesel engine fueled with a slurry of coal dust. I bet he has a good understanding of HC reactions.

Jason, I didnt mean anything personal.

Is this website related for the gasoline tin catalyst?:

http://www.fuelsaving.com.au/index.html

6inarow, I was hoping that Ray wasn't taking my first post personal. How is your '56 coming along?

A good reason for installing valve seats is to restore the valve height to original specs.A few valve jobs,seat wear and the valve heads get sunken in,the stems are all unequal height.

J;

Ray is 'down under' where the air polution systems are different than here and I think he was refering to a diesel engine too.

There was a problem with fungus here as well (diesel fuel) some years back.

This appears to be an 'aftermarket' device which would be ileagal here as It's a "modification" to what the government says we need etc.

If our commercial vehicles were to prove it worked, tax money would be lost.

Jason, - 56 is coming slow. Stainless restoration is the next hurdle - I had to get some help on it. Then start on interior and hopefully drive it this summer. I thought I'd wait until gas hits $4 until I had it done....

Air pollution systems aren't relevant on cars from the seventies... and I suspect this thread is about cars from the sixties, right?

And I wasn't talking diesel at all. Petrol injected Peugeot 504.

The fungus was affecting what we lovingly knew here as 'Lead Replacement Petrol'... I think it had a lot of potassium or something to supposedly help with VSR... whatever it had it didn't work. Anyway, the fungus was something that you didn't strike often, but it was a known problem.

Dear Ray;

It's hard to say anymore.

Orginaly it was a 1970 (non Cat.) used engine a guy bought to "test out" his Camero.

It's moved "all over" since then.

Happy 07.

Is it really illegal?

It's not an engine modification, it merely slips into the fuel line. Just like a filter.

Dear Ray;

On the later 'smog' engines any modification can be used to fail the test in California.

In the USA (in general) I guess It's up to whoever is testing, what state (is testing) and their regulations at the time.

A few years back a large Co. that did Propane conversions was suied out of business by the State, for just that. It didn't matter that the engines producd less emmissions after the conversion as; they used the (modification) law to "flex their muscles".

It's just "nuts"!!

Most states don't get that 'crazy' about it though.

Vehicles from model years 1974 and before are exempt from testing. So; Our (Hot Rods) are mostly left alone (finally) these days.

Surely, John, they would look at something that's just like an inline fuel filter and let it pass?

Anyway, most cars needing it would be exempt...

R;

They can't afford to.

Here in Calfornia we have a State agency called the Bureau of Automotive Repair (BAR). It was created in 1974 to 'police' auto repair shops, Garages, New car Dealer Service(s), Transmisssion and Auto Body Shops.

To do automotive repair work here you MUST be registered with them. Once this occurs; They tell YOU what your 'rights' are and how to run your business.

When this all began; we (those in the biz) felt it would get rid of the "crooks/dummys" therein and help everyone.

However; like any other bureaucracy it has 'run amock'...

Today; The BAR spends 85% of It's budget checking Smog Stations for 'rules' violations and you can't operate (public only) your vehicle without the State registration (license plate) which you MUST pass the test to get.

It no longer matters what comes out the tail pipe. What matters is what THEY say matters and they want all that crap on (or off) there.

Yeah that makes no sense, if it blows the right #'s then who care what is on or off the car. Thank god were finally getting rid of emission testing for pre OBD-II cars here in St. Louis, MO.

In other words, John, what matters is that they are justified in having a job...

So if there's a way they can put up numbers of 'violations' that they've found, they're in the clear.

I talked to one of the chemists at work. If an additive were to improve the combustion process, it would aid in the conversion of C to CO2; CO is incomplete combustion. Decreasing valve seat erosion would involve tying up the corrosives such as sulfur. He couldn't concieve how elemental tin in solid form could perform these tasks.

R-OD;

That's exactly RIGHT!! It makes NO SENSE at all.

That's the way bureaucrats work, to justify their job, like Ray said. Also; The fines are higher for cheating on SMOG than cheating a customer for $$.

You can't introduce logic into this, sorry. I've been trying since 1968 when the first ones were forced upon us.

Jason S,I believe the tin is supposed to serve the same purpose as the lead in fuel did.It aids in conducting heat from the nearly red hot exhaust valve to the valve seat and heat.This happens when the valve is on it's seat,a very short length of time.The seat erosion comes from micro welding when the hot valve hits the seat,then the valve opens taking a little seat material with it.Over time,the seat is eroded away.
Generally,the harder the engine is run,more seat erosion occurs.This varies depending on engine design,some are worse than others.
I've worked on a few Chevy 235-261 and GMC 302's every one of these heads showed signs of erosion and the exhaust seats where pounded down from wear.
A machinist can "find" a seat when grinding the valves no problem,but the valve head is recessed in which will restrict airflow and have the valve stem standing to high,requiring a pile of spring shims to get the correct spring installed height.

Jason, it's not a matter of the combustion, but the catalytic reaction that takes place during the combustion... as I understand it.

And please don't think I understand it. As I've repeated over and over, I just know it stops the seats from disappearing... seats that show a willingness to go any time it's not there.

I had a brief introduction to some of this when I did my thesis on automotive emmissions gas sensors. But, am not a chemist, so I can't effectively argue it one way or another.

The other two points the chemist made made were that if it worked there would be papers describing its operation and the carmakers would be using them.

The other chemist at work said that there is a big difference between lead in formulated gasoline and tin solids in gasoline.

It is not important enough to me to research or discuss it any further. If it is to anyone else, I recommend a literature search at your local library.

Ok I'm finaly going to add my 2cent worth to this topic.
First Off There is a very good Risk to hitting water when going to install a Hardened seat.
#1 don't DO is have a Deep seat installed at ALL This will pretty much Guarantee your going to be Hitting Water.#2 Use a Shallow seat this will lesson the problem But still No Guarantee That you won't hit water.
When ever Your going to a Bigger Valve This becomes a ISSUE with Hardened Seats.AND The Biggest REASON for this is CORE SHIFT in the head casting.
So with SOoooooooooo Many lead additives Out there
Why Run the Risk if your that worried about Hardened seats USE IT. Why Run the risk of having a Head That has been CUT Right into the water jacket NOW your Back to Square ONE.
I ran My 64 FOR the Most Part which was at the Time a Daily driver/Racer To nothing But a FULL time Racer Nearing the end of 17 Plus years AND Never seen Or had a Issue with Out running Hardened seats.And Fuel octange ranging from LCheap 87 to 112 On the track.
So like i said My 2Cent oppion.

AMEN!!

Anyone with "good sense" knows; It's the heat from the unnecessary Cat. that causes the problem, NOT the fuel etc.

The Auto MFG puts them in to CYA.

Lets put this thing 'to bed'.

But if you could run leaded fuel with a cat,, you would not have that problem w/valve seats also.

But, I know, if you run leaded fuel w/a cat ,it will eventually plug it.

MBHD

OK Lets Just Get a Little More REAL for a sec.
HOW many of you guys are Putting a 230,250,292
Motor into anything THATs even NEW Enought to Have Had a CAT on the car OR TRUCK to start with?????????? ANYTHING For The Most part BEFORE 85 DIDN'T Have a CAT.
AND ONE THING EVERYONE has also Over looked is that any Motor That Had a CAT on it ALSO HAD A AIR pump Which did Double duty to the Best that i can remember #1 which was to help Cool the valve.#2 who knows what else as far as the exhaust itself goes.
But Personaly I think this is getting BEAT to death ,AND Nobody here is builting There MOTORS For Extreme DUTY But to Either Full Race Or a Nice reliable daily drivers. But it seems that many of the machine shop guys in & around town here (oppions)That if You not racking Up close to a 100,000 miles a yr Or Building FOR Extreme Duty,
OR HIGH RPMs (Long term) & maybe? turboed ( not much imput on the turbo)Don't realy feel a need
for them in a cast Iron Head.Some said Yes But Others say NO. SO my 2cents is I guess It's up to
The one Whos having a head Built Or to Which guy/Machine shop your asking?? I guess this could turn out to be a interesting POLE/survey for MOST machine shops.

Gentlemen;

The AIR "air injection reactor" aka 'SMOG pump' was just another government 'con job' from the 60s and forced upon us in 1968.

All it does is blow air into the exhaust manifolds creating a lower HC reading at idle while robbing 2-3 Hp. from the engine @ 'run' speed. Most were all 'trashed' when they came out.

Like Larry says, this was LONG before the the Cat. came on the scene, which isn't required on 1970 vehicles today and NEVER was.

When an engine is abused by operating it for long periods with one or more valves burned through or cracked, the seat for that valve (usually exhaust) is destroyed beyond 'normal' repair procedures.

There; a steel seat is used to "save the head" for the customer and NONE of this has anything to do with the fuel being used.

The Cat. being forced upon the American (motoring) public is just another form of engine abuse because of the extra/unecessary heat it creates in the combustion chamber/process.

It's this unusual operation/abuse that require these seats (sometimes) NOT the fuel.

Commercial 'fleet' vehicles use them for "preventive maintaince" is all (to save down time) on some of their vehicles only (not all) when they ALL use the same fuel.

Machine Shop personnel can often get these facts confused in their selling dialouge.

This; Coupled with decades of government propaganda on the subject is how the isssue(s) got swiched.

The Cat came first causing the engine damage, then 'unleaded' fuel which prevents damage to the Cat. Not the "other way" around!!

This is HISTORY not opinion.
"No brag son, just fact", Walter Brennen.

The EPA does not mandate the automotive manufacture's specification of equipment to meet emission standards. It does regulate the fuel. Air pumps were a stop gap measure by the automotive manufacturers to lower unburn hydrocarbons, HC. Air was injected in the exhaust port to enhance the final burning of the unburned hydrocarbons (fuel). Dilution of the exhaust gases does not lower the emission readings as it is measured on a grams/mile basis. Or as they say in industry:

Dilution is not the solution to pollution.

I am not aware of the automotive certification test required in the late 1960's.

As far as temperatures seen by the exhaust valve being elevated are concerned, I don't understand the direct connection with the catalytic converter, especially with the modern low restriction monolith convertors. The earlier pellet type converters had significant back pressure, which restricted flow. Air was also injected into some 3-way converters. Maybe this increased temperatures at the exhaust valve by reducing exhaust flow. Running very lean air/fuel ratios can extend the burn phase time, maybe also raising exhaust temperatures.

I'm one who's glad that automotive emissions have been reduced 90%. The reduction has been costly and a pain in the butt at times. With modern fuel injection systems, ignition sytems, combustion chamber designs, and the monolithic catalytic converter, engines are more efficient, pollute less, and last longer.

Ever stand behind a 1960's or 70's vehicle for long when it's running, especially one that's been hopped up? It will choke you up in more that one way. Yes, the EPA can be unyielding and draconian at times. So can the automotive manufacturers too. In the last several years a high speed test reaching speeds of 80 mph was added to the emission certification test cycle. The reason was that the prior certification test only called for speeds to 55 mph, and manufactures such as Cadillac had different fuel injection program maps for vehicles speeds above 55 mph that did not meet the intent of the emission standards.

I have worked with air and water emission standards programs in industry, and yes the EPA and state environmental programs can be bureaucratic, misguided, deceptive, naive, and lacking results/dollar value at times. They have made a tremendous impact on our enviroment. Remember when the Ohio River was declared a fire hazard.

You in the "Peoples Republic of California" have addition problems with 1) sensitive environmental conditons due to geographical concerns - winds mountains, valleys, sunlight and 2) being in the "People's Republic of California" where government is "suppose" to solve, and therefore have its hand in so many issues.

Related emissions websites:

http://www.epa.gov/reg5oair/mobile/history.htm
http://www.epa.gov/otaq/ld-hwy.htm

Mr. Winter;

The AIR system may be designed (in theory) to do that, but in reality it just 'stirs things up' or dilutes the exhaust to change the reading at idle (only) and does NOTHING to aid air quality as the volume and # of pulses @ run speed overwhelm it etc.

The excesssive temps caused by the Cat. used/required on later 70s & early 80s vehicles is what's under discussion and also caused the MFG to add steel seats at the factory back then.

As far as 60s vehicles having an odor; simply not true. However; I agree that any 'hopped up' engine will though, as the high speed camshafts used in them don't work well at idle.

The claim of a 90% reduction in emissions is "wishfull thinking" and impossible to prove/disprove as ALL the 'numbers' generated are the governments, or their "friends".

You are "right on" is stating that EFI & HEI systems (in unison) DO reduce emssions greatly and are welcome by everyone, mostly because they reduce fuel consumption.

Your analogy of the: "Peoples Republic of California" is 'right on' as well, but understated. Over 1/3 of the vehicles that fail our SMOG test do while passing the emmisions standard(s) for HC, CO & NOX. It's all about money/power and keeping it. We just had a ballod proposition (P-87) last election that would have taxed us 7 Billion ($) for a new breaucracy using air pollution/air quaility fuel (energy) usage as it's justification.

I believe that money would have been used to fight E-87 in the mid west, or create a government sponsored fuel consortitum there.

Your statement reguarding 'geograpyhical concerns' is correct (if) you are refering to the "South Coast Air Basin" in Los Angeles. However: Those conditions were there long before the internal combustion engine. The Indians named it; 'the valley of smoke'.

Happy trails.

Well to be real, out here in Calif. most vehicles post '75 have "cats" on them to pass smog test.

Is the smog pump diluting the exhaust gasses or cooling the exhaust gasses?

I was under the impression it was cooling the exhaust gasses which tend to be a little higher on a smog motor that usually has the carb leaned out causing higher exhaust temps.

The "SMOG pump" (AIR system) pumps air into the exhause manifold in an attempt to reduce HC @ idle speed. The injection point is near the ex. valve & may have a 'cooling effect' (of sorts) at idle only.

This stiring up/dillution of HC @ idle creates a lower reading during the test procedure as it "fools" the meter.

At 'run speeds' it robs horsepower and fuel mileage which is the oposite of cleaning the air because fuel is waisted.

The cost of it is a financial disaster too. Just think of a $100+ cost (per unit) times the # of cars made in the USA and eslewhere.

In addition: There's no way anyone can do any type of (objective) research on this situation as It's illegal to remove or alter the devices.

The games "rigged" by the government here.

Most states (the other 49) just do what the EPA says which is okay, as most vehicles will pass the test with their standards W/O the "devices". Especially those with EFI/HEI systems that are 'joined' via computer.

The really 'scarey' part is many believe the government after 45+ years of SMOG propaganda. Prop 87 almost passed due to it.

Thank GOD for almost.

While we're on the subject of valve seat material,it used to be that valve jobs were common on many engines after maybe 60,000 miles back when.Now,engines maintain proper compression with 200K+ miles on them.Is it the seat material?
The build quality of US engines in the 70's was poor at best.I personally remember the massive cam failures in GM V-8's,mostly Chevy.Head coolant leaks too,the coolant got into the oil,spun bearings.The car makers had the technology to prevent these problems,but they did nothing until the imports made a serious dent in sales.
Interesting,the inline 6's of that period didn't seem to have valvetrain issues,probably cause they were so gutless,lol.
It's no secret that heavy duty engines often had the seats hardened or replaceable seats made of more durable material.
Anyways,build your engine the way ya want.I will still have the inserts put in primarily to get the valve heads where they belong and the stems at the correct height.

Tony hit the nail on the head. The chevy and gmc sixes were economy engines. This is not to say that they were bad; they just didn't have the materials and technology of the better truck engines.

John, the purpose of the air injection is to promote burning of the hydrocarbons and conversion of CO to CO2 in the exhaust system; not to fool the tester.

John, why is it only at idle that the smog pump is effective?

Jason, how does the air promote the burning of HCs?

The air contains oxygen which oxidizes both the hydrocarbons and CO.

Engines are NOT designed to (just) idle, they are desinged to 'work' @ 'run speed'. When they idle, they are turning so slow that they don't burn all the fuel, creating an excess of HC & CO.

The AIR system (in theory) is suposed to function like many have said (burn up that excess). But in reality it just stirs up things making it appear to (lower reading).

(This opinion is based on decades of servicing the 60s & 70s era engines with & W/O the system, which BTW ONLY needed valve jobs @ 60,000 miles when abused by lack of maintaince.)

If; it were/did function as planned it could only work at idle speed because of the volume (air) the pump is capable of creating. The volume/tempature of exhause gases produced @ 'run speed' (or above) far exceeds what the pump would/could ever produce and it is totally "overwhelmed" in that mode.

Simply look at any AIR systems lines to the manifold vs the size of tubing (1"+) that headers use for exhaust relief.

Further proof is the fact that when removed; the vehicle always gains preformance & fuel mileage.

Like I stated before; It's a 'con job'.

I thought this title/subject is about hardened seats??
Not all this other C#@P.

MBHD

Thanks guys for answering my off topic question.

Sorry about that MBHD.