pb4ugo
SILVER Star
Why did they have to install hardened valve seats when they started using unleaded fuels?
What have you done to your Land Cruiser this week? (37 Viewers)
- Thread starter IH8MUD
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Why did they have to install hardened valve seats when they started using unleaded fuels?
pb4ugo
SILVER Star
Not really, Its good to know your good to go for use under 3500 rpm with old style seats, but there's no mention as to why the seats could be damaged using unleaded fuel.
I think the seats were unintentionally protected by the layer of lead, so cheaper/ softer seats were then used. Removing the lead meant that they eroded faster at high temperatures.
delete
pb4ugo
SILVER Star
Unintentionally? Lead wasn't a result of the refining process, it was added for a reason. Growing up I remember there were signs on the side of the gas pumps, "Contains Lead" . I agree they had Softer seats.
pb4ugo
SILVER Star
So with very little searching, it was use to prevent knocking, helpful with the ability to raise octane, and prevent exhaust valve wear.
As stated in the linked information, it had to do with the original material used in the head. Some manufactures used better material and didn't have a problem with unleaded fuels. Other manufactures used softer material and when subjected to unleaded fuel, heat transfer was reduced and valves recessed into the head. For those heads replacement of the valve seats with hardened seats corrected the issue. If the engine wasn't subjected to sever load or high RPM then damage was slowed enough to not be noticeable.
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The "Roadster Shop" assembled the frame and all parts BARE METAL... Even though our customer ordered POWDERED and assembled. So, we will tear it completely down and get all the parts blasted, primed and powdered.
Paint shop in Sacramento put all the body mounts in the wrong places and ended up with some 2" body rake... So, yet another thing we have to correct. PAint shop also mocked up the motor, trans, tcase... BUT never installed the clutch, PP, flywheel or pilot bearing, fork... So again all comes apart.
This project was not started by us, but we will take it back to GROUND ZERO and rebuild.
Jason
TT
Yes, lead reduced engine knock. Read about Midgley. He’s the guy who figured this out.
Yes, the protection was an unintentional result of adding lead to reduce knocking.
Thank you for your great insight.- in my more then exhausting fact-finding mission research on this topic whole i learned more than a few very relevant facts
- that are intriguing as hell , and ones that were also absolutely mis-represented by that particular Fully Synthetic motor oils brand companies official web sites , and also HUMAN voice live TECH. phone support calls i made to them too ...!
- it was in no uncertain terms a eye-opening learning experience i am glad i found myself knee deep into , all for one single reason to begin , and find out what is the best Fully Synthetic Motor Oil for my 5/89 FJ62 with its super low mileage original 3F-E , that also met the krystal klear summer Viscosity Chart in my factory owners manual and FSM too of the REQUIRED 20W50 ....
- i did a back peddle in time to the 1962 FJ40 Siamese F Engine and moved forward year by year from there , F1.5 , 2F , 3F carb ( first introduced in 1984 ) and finally my 3F-E
- the fundamental areas of focus such as the SOLID Lifters , Cam Lobes , Solid Push Rods , Adjustable Rocker Arms to Valve tappets clearances etc, are same in kind , ...
- i do not know the whole Leaded Gas era Valve Seats topic , because that is the one topic here i did have going on ?
- i found more than a few 20W50 fully Synthetic Motor Oils commonly available at my local NAPA store , NONE of any kind or band at auto zone or advance , NOR could they special order a 20W50 of any kind at all ?
- one younger dude at advance , maybe early 20's ish told me he had never seen or heard on 20W50 motor oil before
- as wet my Carhart shorts laughing as that was , it also made me think WHY ?
- well i guess it's been a HUGE time window since a certain % of vehicles on american roads and there owner operators actually shopped for it and purchased it at a level that demanded auto parts stores justified carrying and stocking it at some level ?
- i learned that California , Arizona , and parts of URBAN Colorado around Denver , Colorado Springs , and one other high population density of registered vehicles still require yearly SMOG inspections , and that includes the good working order of all original factory Emissions parts such as the Catalytic Converters topic being present and doing its Job to a standard of air quality too ....
- this is where the ZINC and Phosphates / ZDDP additives are GOOD for older Land Cruisers as its commonly discussed here , BUT a 1/75 - 1990 and there Cats , they are required to still run NO F'ing WAY !
- as far as the ZINC RICH ZDDP Fully Synthetic motor oils out there , Amsoil , Royal Purple etc one HUGE RED flag became very real and apparent , NONE are actually API Certified in any way , they state on the back of the bottles that they meet all that API stuff , currently we are at the SP rating in 2023 , well if you SELF- CERTIFY your own brand or motor oil that you conjure up and brew ? then i guess you can claim anything you like on your own bottle too !
- the ONLY single Fully Synthetic 20w50 motor oil i could find that was 100% API SP Rated and Certified by the American Petroleum Institute was also the ONLY one that was NOT a intended to be ZINC and Phosphate rich ZDDP formula ...
- both Amsoil and Royal Purple TECH. Line customer service Reps , told me flat out 100% they were just that ?
Amsoil dude also made a point more then once that his bottles lacked the twin Circles DONUT official API logo and specs it meets like the SP grade etc , because all the brands that do have that official independent entity certification LOGO own a share or stake of ownership at one level or another of the American Petroleum Institute ?
- i called them and FAQ checked that claim , it's 100% Bull SH#T false in every way .....
- so my final conclusion is as follows :
- if you DO NOT have Cats still in place on a 1/75 - 1990 , or like in the GOOD SOLID point by @fj40fillet talks about , never had them to begin with , 1962 - 12/74 .....
- i would personally absolutely only use the same exact Valvoline Full Synthetic 20w50 Advanced i am NOW changing out on GHOST , then ADD my own preferred Zinc type ZDDP additive to it..
this way you achieve the best possible full synthetic 20w50 correct Summer Blend that meets all the Viscosity Chart spec,s , that is also API Certified too , combined with your Zinc ZDDP additive , you have a product keeping your Vintage Land Cruiser internal Engine Moving parts protected to a level that is basically a clever Preservation step , will freeze lifters and cam lobes , valve tappet normal wear and tear at its current state of being for the foreseeable future , if you use it for the foreseeable future ...
- the unique comment came up here above and requires Technical proven Science based answer to the best of my ability and current knowledge of the HOW and WHY i will touch on here ..
- once again @fj40fillet asks a interesting question that's answer is fairy short and simple here to dip into ....
- his quote : " have to wonder when our service manuals were written synthetic oils didn't exist... "
- YES , that is correct , MOBIL 1 came on the scene via PEP BOYS in the very early 1990's , they first initially offered only : 10w30 , 10w40 , and 20w50 ..........5w30 was also added to the line up soon there after
- the use of regular conventional motor oil versus a API certified FULL Synthetic , such as my example product i personally do use , Valvoline ADVANCE that also comes in 10w30 , & 5w30 also ...fyi
- has and is scientifically proven to reduce the normal average driving conditions wear and tear factor to all 4-stroke internal combustion engine moving parts ...... that key point might be a good topic for a stand alone TECH Thread for sure !
- all 4 above were and are still API certified from day 1 , and DO NOT have the zinc rich formula topic involved ....
since then 20w50 has been phased out approx. 5-8 years ago now , i recall clearly that day i went to my local NAPA and was told that fact , because i had always used that in summer driving season , and switched to 10w40 at Fall Maintenance . the mid atlantic climate here , supports those 2 different viscosities as the optimum choice / motor oil lubrication protection level . This tech above and how it applies to my climate zone does absolutely apply to all 1962 - 1990 Land Cruiser Gasoline F series engines ....
FAQ check your various model years glove box owners manuals please , this is good long-term internal Engine moving parts preservation related in a simple yes or no , black and white approach ...
THIS IS THE WAY ...
I worked at Dupont when the made leaded gasoline additive. I was mainly a anti-knock compound.
Yes, it was likely potential issues they discovered after unleaded fuel was introduced. TEL was developed the the 1920s as an economical additive to increase octane. Do you think the SAE was ahead of the valve seat issue?
Took it on a fire trail today. Ran great!
rkymtnflyfisher
Trout Bum
Gave it a little extra oomph.
Jvincig01
What color is your 40?
What color is your 40?
you are not alone....
rkymtnflyfisher
Trout Bum
I've noticed.you are not alone....
Honestly it’s a bit of a mystery color. Never knew the original color so I have been matching it the best I could when I paint part small parts and such.
JV
