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  •  » Unleaded valve seats on crate 302 motor??

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    6/11/2019 9:58 AM  #1

    gkm24
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    From: Winchester, Hampshire, England
    Registered: 6/08/2013
    Posts: 108

    Unleaded valve seats on crate 302 motor??

    I took my 1991 Ford 302 EFI Crate motor out of my Fox body mustang to go into my 66 Mustang. The engine has hardly been used despite its age but I decided to pull it apart to check everything. It is immaculately clean inside but I pulled the valves to replace the valve stem oil seals and decided to have the valves refaced and the seats re-cut.
    The engineer told me it would need new exhaust valve seats as they were not hardened seats.
    Considering that unleaded fuel has been around so long, surely this is not correct is it?
    Is he just trying to make some money??
    Interested in your opinions.
    Thanks for reading.

     

    6/11/2019 10:24 AM  #2

    red351
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    From: Carlisle, PA
    Registered: 5/31/2018
    Posts: 445

    Re: Unleaded valve seats on crate 302 motor??

    It would be a yes and no answer. Yes 91 heads would be surface hardened. No if he cuts deep to reface

     

    6/11/2019 11:15 AM  #3

    6sally6
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    From: Surfside Beach,SC
    Registered: 4/02/2013
    Posts: 6,874

    Re: Unleaded valve seats on crate 302 motor??

    I would be suspicious too.  I bet if you remind him by 1991 ALL valve seats on FoMoCo heads were hardened(especially on a "store-bought motor") and ask him how he determined these were NOT hardened seats. .. Bet he backs up real quick on his "recommendation" once you seem to know more than the average millineal(ever how you spell it!  .
    May need to keep a close watch on this guy. JMHO
    6sally6

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

    6/11/2019 1:46 PM  #4

    gkm24
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    From: Winchester, Hampshire, England
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    Re: Unleaded valve seats on crate 302 motor??

    Thanks for your replies.

       •Thread Starter
     

    6/11/2019 2:35 PM  #5

    TKOPerformance
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    From: Newark, DE
    Registered: 12/15/2014
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    Re: Unleaded valve seats on crate 302 motor??

    red351 wrote:

    It would be a yes and no answer. Yes 91 heads would be surface hardened. No if he cuts deep to reface

    And that's probably the kicker, because the seats are just induction hardened, down to a couple thousandths.  That's not hard to cut through if the heads have been rebuilt, and if its a reman engine then its been rebuilt.  Now, if its a new engine this shouldn't apply, unless he sees the need to cut enough out of the seats that the hardness is going to be lost.

    Also, did you put the engine in the '91, or was it a previous owner?  Wouldn't be the first time a PO stuck someone with a mutt engine to offload a car. 

     

    6/12/2019 3:40 PM  #6

    lowercasesteve
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    From: Auburn, Ca
    Registered: 4/01/2013
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    Re: Unleaded valve seats on crate 302 motor??

    TKOPerformance wrote:

    red351 wrote:

    It would be a yes and no answer. Yes 91 heads would be surface hardened. No if he cuts deep to reface

    And that's probably the kicker, because the seats are just induction hardened, down to a couple thousandths.  That's not hard to cut through if the heads have been rebuilt, and if its a reman engine then its been rebuilt.  Now, if its a new engine this shouldn't apply, unless he sees the need to cut enough out of the seats that the hardness is going to be lost.

    Also, did you put the engine in the '91, or was it a previous owner?  Wouldn't be the first time a PO stuck someone with a mutt engine to offload a car. 

    Pull the valve covers and get the part numbers on the heads.  That will tell you what you have.  Do it with both as re-man'd engines could be put together with heads from differing years.
     

    Original owner - 351w,T-5, 4whl disks, power R&P
     

    6/12/2019 3:53 PM  #7

    MS
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    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,297

    Re: Unleaded valve seats on crate 302 motor??

    I wouldn’t give it a second thought unless you are going racing or towing a trailer. I have pulled apart ALOT of 289, 302, 5.0 engines and have never seen any with excessive valve seat wear.  Just do a valve seat cleanup and run with it.
    If your heads have visually excessive wear, then maybe they need new seats. They are not that expensive unless your machinist thinks you think they are expensive.

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    6/13/2019 7:08 AM  #8

    TKOPerformance
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    From: Newark, DE
    Registered: 12/15/2014
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    Re: Unleaded valve seats on crate 302 motor??

    lowercasesteve wrote:

    TKOPerformance wrote:

    red351 wrote:

    It would be a yes and no answer. Yes 91 heads would be surface hardened. No if he cuts deep to reface

    And that's probably the kicker, because the seats are just induction hardened, down to a couple thousandths.  That's not hard to cut through if the heads have been rebuilt, and if its a reman engine then its been rebuilt.  Now, if its a new engine this shouldn't apply, unless he sees the need to cut enough out of the seats that the hardness is going to be lost.

    Also, did you put the engine in the '91, or was it a previous owner?  Wouldn't be the first time a PO stuck someone with a mutt engine to offload a car. 

    Pull the valve covers and get the part numbers on the heads.  That will tell you what you have.  Do it with both as re-man'd engines could be put together with heads from differing years.
     

    On later heads the numbers you will find under the valve covers are casting dates.  The casting number of the head is on the underside of the head cast into the area of the center exhaust ports.  FWIW, casting numbers are not part numbers, though most people reference heads by the first four characters of the casting number (E7TE, etc.).

     

    6/13/2019 7:11 AM  #9

    TKOPerformance
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    From: Newark, DE
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    Re: Unleaded valve seats on crate 302 motor??

    MS wrote:

    I wouldn’t give it a second thought unless you are going racing or towing a trailer. I have pulled apart ALOT of 289, 302, 5.0 engines and have never seen any with excessive valve seat wear. Just do a valve seat cleanup and run with it.
    If your heads have visually excessive wear, then maybe they need new seats. They are not that expensive unless your machinist thinks you think they are expensive.

    Yeah, a lot's been made about unleaded fuel in older engines, but I remember reading that the US Post Office did an in depth study when the switch was imminent because they had an enormous fleet of older vehicles.  They found that in the types of operation their vehicles we used there was no indication of accelerated seat wear.  Where I've heard you need to be concerned is with high performance engines that run high valve spring pressures and use aggressive cams with steep ramps. 

     

    6/13/2019 9:07 AM  #10

    red351
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    From: Carlisle, PA
    Registered: 5/31/2018
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    Re: Unleaded valve seats on crate 302 motor??

    Not to many awful years ago, the wife's 83 bronco had left bank valves sink to where the springs could be turned with just 2 fingers. May have been the 2V carb was a bit lean on that side. Nothing Hi perf about it. So I always had mixed feeling what to do with older engines

     

    6/13/2019 10:14 AM  #11

    MS
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    From: Canyon Lake, Texas
    Registered: 1/24/2013
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    Re: Unleaded valve seats on crate 302 motor??

    I just have not seen it as being an issue.
    Most of us are so anal about everything being perfect on our Mustangs that we overkill any potential problems.
    My vote is either leave the heads alone, other than a valve job, or just buy a new set of aluminum heads that already have hard seats in them, plus have some modern design efficiencies and lighter weight.
    And be sure to read my tag line at the bottom of my post.

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    6/13/2019 3:22 PM  #12

    TKOPerformance
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    From: Newark, DE
    Registered: 12/15/2014
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    Re: Unleaded valve seats on crate 302 motor??

    MS wrote:

    I just have not seen it as being an issue.
    Most of us are so anal about everything being perfect on our Mustangs that we overkill any potential problems.
    My vote is either leave the heads alone, other than a valve job, or just buy a new set of aluminum heads that already have hard seats in them, plus have some modern design efficiencies and lighter weight.
    And be sure to read my tag line at the bottom of my post.

    Couldn't agree more, and I personally wouldn't throw dollar one at an old set of iron heads.  If the heads are already off the engine and the bottom end is sound its time for a roller cam, lifters, timing set, heads, intake, etc.  I guess stock is fine for some people.  I'm just not one of them. 
     

     

     

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