The good news is I got the motor in the car yesterday and shouldn't be long before we fire it up. The Bad new is.... #1 only has 30psi the rest range between 145-165. Oh well should be able to run and drive it with a low cylinder but its going to need some work before it sees a turbocharger.

Hey; "not to worry" you (most likely) set a valve to tight is all.

Re-adjust that cyl before you start it.

Good luck.

I will check them but we didnt touch the valves noone has since this engine came out of its original car. Who knows its worth a shot.

Well looks like its a case of the Old valves/seats being subjected to years of unleaded fuel. The #1 intake valve/seat is leaking horribly.

You might try this:

Turn entgine till that valve just starts to open. Then with a pair of 'channel locks' rotate that valve & spring retainer about 45 degrees and re-test compression.

If It's still @ 30# you'll have to pull the head & do a "valve job".

Good luck.

PS: Don't 'fall for' that steel seat BS as that's for aluminum heads.

From my understanding, you should put in steel seats.
Unless you are putting in some additive for a lead substitute.
The lead additive was used for cushioning the valves when it hit the seats.
Also to raise the octane.
Prevents the valves & seats from erroding eachother.

Yeah unless you plan on running a lead fual additive you really need hardened seats. They will work fine without but not as long.

Gentlemen;

In the 60s when those engines were designed/built the amount of lead (octane) in 'regular gas' was nill compared to todays fuels. :rolleyes:

It's true the seats last longer with the steel insert, but your "looking at" perhaps a 10% difference at best (maybe).

There primarly for aluminum heads is all.

The lead 'aditive' is for use in engines with the 'higher' (than stock) compression ratio(s) to avoid paying for 'premium' fuel.

"Hot Rod" (high reving) engines are always apart for valve work & they save time/labor in that application where compression, combustion tempature(s) and spring pressures are much-much higher.

For the basic (stock) Sixties or older engines don't waste your money; as the 'octane rating' of fuel then was LESS than 'unleaded' today.

"Think about it"; Will you ever put 100,000 miles on your engine rebuild, to gain the benifit??

Believe what you want !!! You should have seen the exhaust valves that came out of my 1970 350 v/8. Allthough it was used to pull a 22 ft. travel trailer all over the USA. Looked like someone tryed to be beat them out of the head the wrong way. The seats were beat flat and the valves junk.I didn't know if it was the seat or the valves that caused this (the old chicken or egg thing). I just replace both. The intake valves were just fine. Now the other side of the story...I drove my old 216 Chevy around 10,000 miles on unleaded gas with no ill effect.Like John said I think it,s the type of service you intend to use your motor for that will help you decide if you want to replace the seats...SCRAP

Scrapiron, your heads came apart due to hard use, just like they should have. Work them hard, they wear out. But for a every day, drive around car, you will never wear out a stock valve seat! The turbo engine might be hard on parts, but the amount of air coming past the valves will be enough to cool them and keep from burning the seats. As we all know its the heat that kills them, low rpm lugging heavy loads, the valves overheat and beat the red hot seats to death. Joe

i would say you need a valve job done.i have been doing heads for over 25years and done alot of testing on this issue of hard seats.one finding i have found is the guides wear out and then beat out the seats. some heads have softer guide then others. another is detonation that beats things up in a hurry.

now for this other b.s. about needing steel or hardened seats or additive. YOU DON'T. lead was added to gas to raise the octain rating that is all it was cheaper then other ways. even in the 50's and 60's there was ammaco which was unleaded and there was no problems then.lp. gas has no lead and it was and is used in fleet trucks with no valve problems. methenal has no lead and it is used in race motors with no valve problems.

a lot of valve problems come from not getting a good valve job to begin with. i have seen a lot of poor work from the local machine shop. you have to shop around. read about valve work then when you go to the shop ask questions.

i can tell you you will not get a good job unless you pay for it. and you will have to go to a shop that does hp work. not the nappa store on the corner where it is in by 9 out by 5.


scorpian your problem sounds like detonation. the wrog grade of gas or timing or over heating.but it was not the seat or valve fault.

Concerning valve guides and seals, what's the recommendation on rebuilding a 250 cylinder head with worn valve guides? The stock 250 does not have valve guide inserts, so is knurling of the cast ironguide bore then reaming acceptable or should bronze valve guides be installed? What about installing valve steam seals?

vlave guides are rebuilt with bronze walls. i use the walona system where the guides are taped and the a bronze insert is threded in then a expander ball is driven through to lock it in place then it is reamed to size. there is another sytem that is close to that it is called the nu-way.

now about knurling it was popular at one time but then people found out it lasts about as long as it takes to talk about it. think about it this way. you take an already over size hole run something through it that raises some high spots then you ream more metal out of that hole.

just putting seals on will last a little while till the valve rattleing around in the guide
wears them out too.

so the way it works is after takeing the head apart getting it clean the most important thing is the guides if they are not to size or rebuilt right then everything else is just throwing away good money

Ill have to see what the shops around here get for simple valve job. Just need to get this running right Ive got another engine I should be getting in a few months that is completely built, screw in's roller rockers, cam, ect....

Well said Bob & thank you.

For those interested; GM (& others) added the steel seats because the EPA forced the catalitic converter, which raised the head temp killing the valves & all related parts etc.

For a 'cheap valve job'; just go to a 'full service' Garage & fix the one in that cylinder. The other readings were okay for temp street use.

"Happy trails"

Yeah I think ill take it to the shop we have do all our service and have that one replaced.

As for the rest while the head was off I thought about just lapping the valves just to be on the safe side.

Sure, that's fine.

In the time you spend on that you could have it running tohough. Those valves were working fine.

The first rule of auto mechanics is: "If It's not broke, don't fix it".

Decided well just pull the head, have that one valve looked at and slap it back on with a new gasket.

Well we pulled the head and sure enough we have 4 exhaust seats that are sunk way into the head. So were having the entire head rebuilt. Even though it may be a temporary head id rather be safe then sorry. Especially if we plan on boosting this block.

RevOD,,,,
that is what happens when you do not have harden seats installed(w/no lead additive), it's not a fantasy, or a way of cyl. head shops getting money from you.

MBHD

I know.... and this engine only had 70,000 miles. Not out of the possibility of the mileage I put on my cars. My best friends 6 was the same way and hers only had 50,000 and they were both in Novas.

I have heard the argument before about not needing hardened exhaust seats but oh well...

Hey REVOD, you mentioned that four of the exhaust valves were sunk, was #3 and #4 the two that were still OK? Just curious.
Dan

nope #6 and #2 were in the best shape

and the myth goes on and on told over and over buy people that do not know what they are talking about. they see a problem and don't know what caused it so they lay the blame on something. and the guy that does the work knows nothing.

if you are beating the seats out you better find out what is causing it detination or preignition. and fix that.

I thought maybe the outer cylinders had run leaner/hotter, guess not though. Of the 5 Nova's I have owned the last three have been inline's and I have had no valve problems, I am not going to say that there is no advantage to hardened seats, (I currently run a non-integral smog head on my 250) but I have to agree with BOB308's advice because the same detonation/pre-ignition that sink's valves will "knock" loose hardened inserts too.

I have seen too many valves beat the crap out of seats because there is no lead.
GM later model heads, the seats are flame hardened (no harden seats installed)that is why the newer GM heads do not beat the seats in like the older GM castings.

Would it be possible to flame harden/temper older head valve seats instead of using inserts?? Just wondering for the sake of wondering.
Dan

I tend to believe the so called myth for one reason. We had the heads rebuilt on our old fullsize Dodge Van. The exhaust valve seats were beat up like mine were on the 6. That was at 85,000 miles. We had hardened seats put in it and drove it for another 200,000 miles, only had to replaced valve seals @ 190,000 and when it finally spun a bearing @ close to 300,000 miles, we pulled it apart the valve seats looked great... without them we would have had to do 2 more valve jobs.

yes you do flame harden them when you start them up and run them. another thing that beats out the seat is if the valve guides are worn that lets the valve rattle around and beat out the seats. on any head i have taken apart and the seat was bad the guide was shot too.

as far as beliveing tha myth go ahead it is not my pocket that $300 comes out of to pay for them.

Your still "missing the point" here.

Steel seats are good for commercial engines especially with the catalic converter. NO WAY was 300,000 miles put on a passenger car.

Most Hot Rods use them too.

But for a stock 250" engine, for use in a passenger car (W/O a 'CAT') save your money as you'll never get it back.

My original 327" Bell Air has 138,000 & never been apart and been using unleaded since it came out(60.000). Last tune up the compresson was close to perfect.

It's the usage or 'planned usage' that's the main factor.

Hey John I have to beg The differ here,My Mom had a 71 chevy Impala which Had over 300.000 Miles on it before She sold it to a friend And he put another 100.000 on it and it Only Had two timing chains replaced The first Chain had been replaced at 250.000. And at Normal oil changes The Motor was still pretty clean on the inside THAT was a surprize. I had a 87 sub. I had bought with 89.000
and I racked up 200.000 So when i sold it,It was Pushing the 300.000 mile mark.
So my 2cent point is It is possable TO rack
Up that kinda miles.

The old saying goes: "If you take care of something, it will last a long time".

Exactly 300,000 on a passenger car or in the case of our family van is not uncommon. Heck these even a Camaro around here that has 500,000+ on it.

As for $300 I would never pay that much to get a valve job on an inline 6 you'd have to be crazy. I'm paying $180 to get a complete head rebuilt and have hardened exhaust seats put in. The fact of the matter is they were going to have to be replaced anyways why not pay the few extra $$ for hardened seats....

Also john the exhaust seats on my 6 although beat into the head still showed fine compression on all those cylinders so even though you went 100,000 plus doesn't mean there isn't damage there.

This debate is not by any means specific to this site.
I googled -'hardened valve seats unleaded'- and there is no real consensus, Chevron claims all passenger cars and light trucks are safe from valve recession.
They even say that antique cars actually benefit from unleaded because of less exhaust corosion and oil contamination.
But we can't expect them to say "hey our fuel will ruin your ride".
And of course there are tons of articles that say exactly the opposite, I think it is safe to say that if you plan to operate under heavy loads or at high RPM's then hardened seats are a pretty good idea.

On the subject of leaded gas, check this timeline out. It will amaze you and even might make you mad.
http://www.thenation.com/doc/20000320/timeline
Back to valve seats, a little something from the EPA
http://yosemite.epa.gov/r10/AIRPAGE.NSF/0/adebd4b8879d36bc88256c0800760bf5?OpenDocument

Do I or don't I?

That is the question I've been kicking around.

My machinist says I shouldn't need them, as they are hardened from the factory. But then he goes on to say that as long as nobody did a valve job and ground through the hardening it should be fine.

So I'm still trying to figure out, do I or don't I?

I honestly think you have nothing to worry about.

if you don't need them to fix a bad seat don't put them in. look at it this way you are adding 12 more things that can go wrong. you ever seen a motor that a seat has poped out?

Not sure if you know this,,,,,,,, but you only typically need harden seats for the exhaust valves.
Only 6 are needed.

Put the seats in ,unless you are planning on not using the cylinder head that long.
Try & tell him to put the shallow seats in, so you will not get into the water jackets.

All the factory alum heads have seats in them, do you think they would be putting in seats if they would fall out?

If you install them correctly, w/enough interference fit ,you will not have any problems.
Goodluck!

Yeah ive never heard of someone putting hardened seats on the intake valves before. Don't see a need on those they are not exposed to the same heat/gasses/combustion as an exhaust valve. Also yes a valve seat may fall out but HONESTLY out of the # is hardened seats install how many have fallen out?

so i see you know it alls have never seen an intake seat beat out. may be if you bough the machinery and worked on heads for a few years and learned something you would know what you are talking about.

hey i don't need this B.S. or this club if this is all they do ask for advice then hack at it if it is not what they want to here.

Bob no one is saying you are wrong. No one is attacking you or your Experience so you need to stop taking it as that.

Everyone is free to express their own opinion. You gave yours and others have given theirs. You have had 25 years of experience and my machinist and close friend has at least that many years of rebuilding heads and engines and he swears by Hardened seats in the exhaust side, and has never once had one drop out.

We all appreciate your input and any knowledge you can share with us all but don't get upset if someone disagrees or has a different point of view.

If you trust your machinist in his work and he says you are not in need of them then don't bother. In my case i had a few that were going to have to be replaced regardless so I decided to have all my exhaust seats done. Its ultimately up to you if you are still unsure it doesn't hurt to take it to another reputable shop in the area and see what they say.

This is unfortunately one of those things that goes both ways you see varying reports from many sources that say one or the other.

I have the answer !!! if you are going to replace the intake seats, go ahead and put in 1.94 valves (350 chevy valves) and being you are doing the exhaust seats go ahead and use 1.60 valves. Now you have all new seats,valves,and a head that will breath a little better. YOU are happy, I am happy that you are happy,everbody is happy,this DEAD HORSE is happy we are finished beating him to death...SCRAP

Bob;

The 'kids' today believe everything they read or hear from their 'peers' & never people who have done it for years and "know the ropes".

Hard seats are ONLY needed if:

1) Your running a catilic converter.

2) Your running a commercial vehicle.

3) Your building a Hot Rod engine for racing.

A non-commercial, non-smog (used engine) in a passenger car doesn't need them.

This is the "general rule" for most and 'dreaming up' exceptions can't change it.

If you want to spend the money anyway, or call it "preventive maintaince" okay, but there still NOT needed. Engines rebuilt for antique vehicles rarely go 30,000 miles more; as their just driven to shows and other events and never abused.

Machine Shops put them in because they assume your going to run a 'Cat'.

Now; If your head is 'beat up' so bad that it takes one to fix a cylinder, that's the one you put it in is all. You DON'T need 6 or 12 new ones.

Get your car going & see if you like it etc. If you do; then build a custom engine for it, with ALL the "bells & whistles" you like from the ground up.

after all this reading,,, i have just 1 question., i have a 1976 pontiac ventura, came with 250 with integral head, has factory cat but the origional head had no hardened seats.... doesnt that contradict what u said here???
also, the origional motor when i pulled it had 135,000+ on it, and was origionally owned by an older lady who from what i found out did not take very good care of the car..had 3 cracked seats (got it hot i figured), and the seats were beat pretty bad. it is also an unleaded car. i trashed the head, bought a entire engine out of a 72 nova, built the head (without hardened seats) and rebuilt the origional shortblock.(took .040 just to clean up!!!) under the advise of my dad, i didnt go with hardened seats, or molly rings, and with regular maitenance, the motor didnt last. seats were sunk,(no i didnt get it hot, ran 180* thermostat) and the rings gone. bought a head of ebay during that time, had it built with hardened seats, and put in molly rings., oil is still pretty clean at oil change time, and not a drop of oil has leaked or burned out of this engine.. i learned the hard way, and others have learned things differently than others., it it works for u, great, but dont preach that what ur saying is fact, because i can obviously prove otherwise.. great site, and i love my inline!!! happy holidays all

Dear Mr. Smith;

No, not at all.

The MFG; GM & others didn't go with the hardned seats till they saw what the added heat (from the Cat.) was causing. It kills the guide then the seat.

Please read the posts again.

Hard seats ARE used with one.

Come on guys we don't need a ****ing match.
Everyone is entitled to their opinion here.

I want to get 200,000 miles from this build-up "with all the bells and whisles".
The van has a "cat" on it and it stays.

Just trying to get it right so I don't have to pull the motor a few miles down the road.
It ain't easy getting the motor in and out of a van,not much room to play.

I have been running 230's and 250's for many years
with no real valve seat trouble, but early Nova's are fairly light and I tune a little on the rich side.
I was wondering if lead was removed from fuel before or after the catalytic coverters came on the scene, or did it happen at the same time?? (I got my license and my 1st Chevy II in 1988)

Dan

Catalytic Converters were introduced in 1975, but lead production in ethanol,which began just after WWI,was allowed to continue into the mid to late 80's particularly by E.I.duPont, so as not to adversely effect the economy. Most of it, as is today was used in other counties. So yes, lead removal from "gas" and the cat came along about the same time.

Drew is right, by the mid 80's leaded gas was hard to come by at service stations in most major metropolitan areas. However, the total ban on leaded gas didn't acutally take place until 1996:
EPA Lead Ban

But this ban only applies to pumps providing 'automotive' fuels. It is still legal to this day to produce leaded gas for use in aircraft, race cars and in marine engines. For example, VP's C series fuels are all leaded:
VP Racing Fuels

and legal under the EPA 211n restricted use clause:
"Section 211(n) bans the use of gasoline containing lead or lead
additives for use as a motor vehicle fuel but does not restrict other
potential uses of gasoline containing lead or lead additives. The
definition of motor vehicle is limited to self-propelled vehicles
designed for transporting persons or property on a street or highway.
42 U.S.C. 7550(2). The regulations of 40 CFR Part 80, which are amended
by this rule, apply only to fuel that is sold for use in motor
vehicles. See 40 CFR 80.2(c). The petroleum industry may continue to
make and market gasoline produced with lead additives for all remaining
uses, including use as fuel in aircraft, racing cars, and nonroad
engines such as farm equipment engines and marine engines, to the
extent otherwise allowed by law."

Many guys carried plastic adapters to neck down the larger diameter leaded pump nozzle to fit into the smaller unleaded restrictor filler necks. This was great in places where there were no tail pipe tests, cause one could run cheaper 'Regular' gas. But the lead in the gas ruined the catalyst in the Converter - so as soon as the car found it's way into a metro area where tail pipe tests where enforced, the owner faced an expensive cat replacement. A real concern back then when buying a used car.

regards,
stock49

Does most avation fuel have lead? There is a small air field (Cable airport) near me that sells 100 octane right off the truck, they won't pump it into your car, but they are happy to sell it if you bring your own jug.

Dear Dan;

I believe so.

The aircraft industry has escaped the wrath of the EPA for years, because the FAA 'said so' and they have more 'juice' in Congress.

The "horizontal opposed" engine used in most small planes (Same as VW/Porsch & BMW bikes) was legislated out of the USA by Congress because it passed all the EPAs regulations W/O any 'smog' equipment.

Go figure.

FYI: Avation fuel commonly called AV-Gas has been used by Hot Roders for decades. "Try it you'll like it".......

100 LOW Lead Avgas has more lead in it than any automobile gas has ever had.

It is not a performance fuel.
I filled up a tank full of 100 LL Avgas into my 65 Malibu (got it free) that had 8.75 to 1 compression & it slowed my car down.

If you are going to use it, mix it w/your unleaded premium fuel.
I would not suggest you running it straight.
"Two cents"

MBHD

Did you guys check out that timeline on lead I posted earlier in this thread? We could've had a better solution 80 years ago. Once again, the golden rule applied: "He who has the gold makes the rules".

Dear Martin;

Sad but true.

Check the link under the (engines) title fuel additives just posted.

Happy trails.

No doubt that timeline is criminal strummin67 . . .

But so much comes down to ignorance. They used to use lead pipe for drinking water in the 1800s! The informed new it was no good for humans but no one bothered to remind the masses, and since lead pipe was easy to make, install and therefore the cheapest they just kept selling it and people kept buying it.

And sometimes it seems like a pendulum swinging from informed back to ignorant. When lead pipe was replaced with iron and galvi because it was 'safe' everyone seemed to forget about lead. When copper tube started to replace threaded pipe everyone seemed to forget that solder contained lead! And once again we had lead in drinking water because sweated copper was cheaper then fitted pipe . . . Now we have lead free alloys for solder - but why didn't we from the get go? Cause it was cheaper to use what was at hand.

In the end it comes down to consumers becoming informed on their own because we cannot not expect business to educate . . . they have no track record for it.

But I am way off topic here . . . this ain't Bench Racing . . .

Yep Stock49,

Similar to amalgam dental fillings for our teeth, which contain mercury. Dentist put it in our mouths, yet schools are on alert if someone breaks a mercury thermometer.

"Amalgam (at mixing) typically contains approximately 50% metallic Hg, 35% silver, 9% tin, 6% copper, and a trace of zinc."

John, I didn't know you could still get lead additves. I have to say in my own personal experience I have not had any problems running lead era cars and trucks with out lead.

M;

Neither have I, or anyone I've known.

That's what makes this hard seat business so stupid. It's the forced usage of the catilic converter (heat) that causes the damage.

Here is California the 'off road' places sell a "by pass" device that the hot Roders all use. They just replace their (unused) Cat. for the smog test & then go back.

On your adverage Jap car/truck it gives you 5-8 MPG improvement. So; If the Cat. helped the environment that wouldn't happen. The Cat. only helps remove HC/CO @ idle and engines weren't made to just idle.

If our 'public transportation' systems worked properly there wouldn't be highways turned into parking lots causing more smog.

Here the lead additive is called "octane booster" I think.

John, You need to start reading up on things before posting such B.S. Chemistry and physics would be a good start...

The current 3 ways catalytic converters reduce unburned hydrocarbons - HC (unburned fuel), carbon monoxide - CO (lack of sufficient oxygen at the fuel molecule burning burning), and oxides of notrogen - NOx (combination of nitrogen and oxygen from the inlet air when exposed to high combustion temperatures).


http://www.catalyticconverter.org/index.htm

http://www.howstuffworks.com/catalytic-converter.htm (use table of contents at bottom of page)

Gentlemen;

The vehicle that burns the least fuel, pollutes the least!!

You can quote all the chemistry & physics you like; but that's the "bottom line."

All the rest is just dialogue.

No, John that is not necessarily correct. Again, you need to research the this so that you have a better understanding.

I don't have a copy of my masters thesis handy but I do recall that there is a compromise between HC/ CO and NOx (NO and NO2) levels; that compromise is operating at stochiometric fuel/ air ratio. You could operate lean to improve fuel economy but this will worsen NOx production. So, we burn a little more fuel to ensure efficient operation of the three way catalytic convertor.

Carbon dioxide, C02, is directly related to the amount of fuel burned. It is also the gas animals exhale when breathing, and the main "greenhouse gas".

The other emissions are much more complicated.

I believe emission requirements are on a mg/mile basis, and not on a mg/gallon basis. Will verify later.

I have to go now till after Christmas. Ya'll have a safety and Merry Christmas.

Winter, you are mostly correct regarding the amalgam fillings. The formulation you gave is for one of the more common amalgams sold, but there are several varieties of dental amalgam. This is a very controversial topic in dentistry right now. Current thought says it may be more dangerous for the dentist that puts it in than the patient that walks around with it.

Stock49 - many business are very good at education - its amazing that "cheap" usually outweighs "good" in the free market place. Then consumers blame the business for their bad choices they knowingly made Its the deceptive business I have a grudge against.

Dear 6inarow,
I am going to need to agree with Stock49 concerning consumer education. I think the free market is the best way to go, but the less educated you are, the more dangerous it can be. (I too am off topic)

Dan

Dear Jayson;

I'm sure your correct.

My point is this; If the fuel isn't burnt in the first palce, the polluants arn't in the environment.

In 1960 the "automotive community" told everyone how to combat SMOG. They were ALL ignored by those with a vested interest in seeing the automobile "controlled".

The catalitic converter was 'sold' to Congress using (only) HC/CO 'numbers' from carbuerated engines at idle.

Since then; there have been so many lies & half truths piled on top of each other, that the facts are 'long gone'.

Recently the California Legislature passed a bill requiring a Cat on lawnmowers at a projected cost of $400 per.

This will never become Law, but you see my position.

At most of the meetings/hearings I attended (throughout the 60s) the ONLY intellegent thing said was: The pledge of alligence.!!

FUBAR

1990 Tier 1 exhaust emissions standards for 1998 - 2003 gasoline passenger cars and light light-duty trucks are as follows (first 50,000 miles/5 years):

HC: 0.25 grams/mile
C0: 3.4 grams/mile
NOx: 0.4 grams/mile

The Tier 2 regulations are being phased in from 2004 to 2009. They are much more complicated.

i think most of you guy's are far off topic. in the original post, he refered to his engine and seat problems. he is also going to use a turbo in the future. hardened seats are good insurance as well as good valves and good guides. if you want to start your own topics do it. the mentality of my way or the highway is fubar as john states. where does all the finger pointing get you or us as a organization? think about it. tom

Good point Tom.

Back to 'bench racing' for the Big Brothers SMOG. :p