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Featured Hot Rods How Difficult & Expensive to Replace Valve Guides at Home? Do a Valve Job?

Discussion in 'The Hokey Ass Message Board' started by bulletpruf, Jan 24, 2023.

  1. jaracer
    Joined: Oct 4, 2008
    Posts: 1,836

    jaracer
    Member

    Back in the early 70's Ford had a lot of trouble with their cast iron parts. Valve guides would wear enough to let the valve cock and not seat properly causing an intermittent miss. This was on engines with less than 12K miles (still under warranty). Ford's fix was to replace the head which may or may not be the same material. I got my hands slapped for sending a head to a machine shop and having a new guide installed. So Ford came out with a kit to drill out the old guide and press in a new one. There were a couple of bolt on fixtures to align with the center of the valve seat. You then used a 1/2 in electric drill to drill out the old guide. The local factory rep came to the shop and did an "after work" demonstration of how to use the kit. He then used a driver to pound in the new guide. The only problem was that the new guide fell through the hole he had just drilled. He packed everything back up and there were no more conversations about purchasing the guide tool.

    You still had to re-grind the seat after the new guide was installed. However, most dealerships had valve grinding equipment back in that time frame. We did a lot of valve jobs under the old 5-50 warranty. A lot of FE engines couldn't make it to 50K miles without burning an exhaust valve.
     
  2. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    I chucked up one of the galled valves in a drill and used 400 grit paper. I managed to polish the galling and grooves out. Need to mic it to see how much material I lost, but I think this is a viable route. EDIT: Looks like I took off about .001" of OD.

    As for enlarging the guides to the correct size, they're currently at .3885" or so, depending on the guide. I'd like to get them to .3895" or so on the intake (.0025" clearance) and about .3900" on the exhaust (.0030" clearance).

    Would I do this with a reamer or with a hone? Reamer makes me a bit nervous about having it perfectly centered.

    Thanks
     
    Last edited: Jan 24, 2023
    tractorguy likes this.
  3. jimmy six
    Joined: Mar 21, 2006
    Posts: 12,473

    jimmy six
    ALLIANCE MEMBER

    Guides are best handled by a shop. Positive seals can be done at home with the purchase of the proper tool and pretty easy to do if you know valve lift. Remember to lap the valves in before installing the seals.
     
    Truckdoctor Andy likes this.
  4. saltflats
    Joined: Aug 14, 2007
    Posts: 11,575

    saltflats
    Member
    from Missouri

    Keep an eye out for a seat and guide machine, they pop up here every now and then for decent price.
     
  5. TA DAD
    Joined: Mar 2, 2014
    Posts: 823

    TA DAD
    Member
    from NC

    How does someone learn anything if they pay someone else to do it ? Taking your stuff to a shop is no guarantee it will done correctly. This place is amazing.
     
  6. Truckedup
    Joined: Jul 25, 2006
    Posts: 4,648

    Truckedup
    Member

    exactly true......good valve work is a precision job.. getting the guide concentric with the valve to aviod excessive seat grinding that kills performance...You can do it at home, all depends on what you consider acceptable....
     
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  7. AccurateMike
    Joined: Sep 14, 2020
    Posts: 420

    AccurateMike
    Member

    I would use a reamer. They are piloted. I think it would be likely to get more out of kinder with a hone. You'll be doing a valve job either way. Mike
     
    bulletpruf likes this.
  8. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    My point exactly!!! Thanks for the comment!
     
    19Eddy30 and AccurateMike like this.
  9. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    Mike - thanks. I figured I would be doing a valve job, too, but why is that? Because even the slightest deviation in the angle of the guide will throw off the valve job? Thanks
     
  10. AccurateMike
    Joined: Sep 14, 2020
    Posts: 420

    AccurateMike
    Member

    Yes, both angle and concentricity of the new guide. A little ink/blue on the seat and spin the valve, will tell you how much. Mike
     
    bulletpruf likes this.
  11. atikovi
    Joined: Aug 9, 2013
    Posts: 30

    atikovi
    Member

    I can imagine them saying, Due to insurance regulations, we cannot allow customers in the shop. I mean, would you want people starring at YOU while you work?
     
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  12. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 3,298

    ekimneirbo

    I would get a couple sheets of 1000/1500 paper and then a sheet of crocus cloth to polish the stems with. 400 maybe for initial cleaning.

    A reamer tends to follow an existing hole. The specialty guide reamers have a "pilot" ground on their ends to make it follow the hole.....whereas a standard reamer will not have the pilot. A standard reamer would "probably" follow the hole ok if you are only taking out .015 or so because the teeth will "tend" to center the reamer because each flute will seek to have equal pressure as it cuts.
    The reamer with the pilot is the best way to go. Remember, when removing .015, the reamer is only cutting .0075 with each flute. Not very much chip load there.

    When a machinist at a shop does a job, he is not going to put as much effort into getting perfection as that takes time. Its more a choice of using known tools that provide a workable fit and fixing any complaints (if any) later.
     
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  13. SEAAIRE354
    Joined: Sep 7, 2015
    Posts: 496

    SEAAIRE354
    Member

    I just read through this kinda quickly but it looks like you only need to take a couple thou out. As mentioned the reamer is the better choice. A small flex hone will never get you there and the ridged valve guide hone setup is really expensive. And as also mentioned valve guid reams are piloted to keep you straight. Going back to the bronze guid liners. The Goodson setup looks like it changed. I have to older system and the cutter it uses is piloted and using it on a guid that’s already.015 over gets tricky as there’s a lot of slop for the pilot to manage. The newer system may work better but wanted to throw it out there.
     
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  14. Blues4U
    Joined: Oct 1, 2015
    Posts: 7,065

    Blues4U
    Member
    from So Cal

    I seem to remember there being a process of repairing worn valve guides that involved a process similar to installing thread repair inserts. The guide is drilled out with the proper size bit, then it is treaded with the tap provided in the kit and bronze wire insert is threaded into the guide and then reamed to size. This was decades ago and my memory is fuzzy, I never did the job myself and have no firsthand experience with it, but I do recall hearing and reading of this being done. One of those innovative repairs that people did when they didn't have the time or money to do the job correctly. It worked for a temporary repair.
     
  15. Valve job requires a valve grind machine to cut the seats.
    As for guides, we have been doing bronze guides for years with hand tools. You do not remove the old guide, you drill it out pass a knurl through it and install a bronze sleeve in it. Pretty common performance mod.

    You can get a kit from your favorite automotive catalog speed shop. I prefer a place in ohio but you can choose whatever one floats your boat.
     
  16. lostone
    Joined: Oct 13, 2013
    Posts: 2,264

    lostone
    Member
    from kansas

    I've never built a motor (+10) that I didn't have the machine shop install bronze guides.

    I one of those people that when it comes to building an engine that I plan on driving it a long time and totally hassle free. I hate putting good money into something just to have to take it apart several yrs latter.

    ..
     
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  17. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    Ok, the reamers that I'm looking at (someone posted a link earlier) are "Piloted for self-centering action." The only issue is the size. I was hoping for .389", but they have .388" and .390". The .390" should be perfect for the exhaust (leaving me with .003" clearance) but I didn't want to go to .003" on the intake. Anyway, I think I'll order the 3.90" and use it on the exhaust guides. On the intake I may just be able to hit them with a hone and call it good. BTW - the heads came off a turbo engine and it's getting a turbo again, but with a bit more fuel and about the same boost. That's why I want to make sure the guides aren't tight again on the exhaust.

    Thanks
     
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  18. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    Yeah the Sunnen valve guide hone setup is about $2,000 new. Budget can't handle that right now.
     
  19. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    Valve jobs can be done at home without a specialized valve grind machine. I'm not there yet, but that will be my next step.

    Thanks
     
  20. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    In the past, I have been a bit of a perfectionist when it comes to building motors. I'm trying to get away from that and at the same time, I'm trying to do more of the work myself. If that results in me pulling an engine to fix something that was jacked up, I have no one to blame but myself. I'm ok with that.
     
  21. seb fontana
    Joined: Sep 1, 2005
    Posts: 7,815

    seb fontana
    Member
    from ct

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  22. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    Yeah, that's the next purchase, I think. With the $800 I saved from not buying the bronze liner installation kit, I can pick up a valve seat cutter setup.

    Thanks
     
  23. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    I ordered the .390" piloted reamer.

    Need to order a valve guide hone; the 3/8" will be too small since I'm at 3/8" + .015" on the guides. Next size up is 10mm. That should work.
     
    ekimneirbo likes this.
  24. Budget36
    Joined: Nov 29, 2014
    Posts: 10,420

    Budget36
    Member

    You know what your next purchase will be right? A head resurface machine, well, 2nd in line after you get a precision straight edge;).
    I admire your DIY attitude, I can still do a lot of things, but now take a lot of things into shops that do it daily.
     
    Truckdoctor Andy likes this.
  25. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    Already have the straight edge; check out the video link I posted above to see it in action!

    I may end up using a "redneck resurface machine" -- sandpaper glued to some thick plate glass. One of my cylinder heads has just shy of .002" warp; still within spec, but I'd feel better if it was less than .001"...
     
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  26. bulletpruf
    Joined: Apr 15, 2012
    Posts: 128

    bulletpruf
    Member

    Got a few silicon carbide flex hones ordered in 10mm/.394" - one in 120 grit for intake guides that are a bit tight (I do realize that this is not likely to remove much material), and then 240 grit for a finish hone on all guides. Other option was 320 grit for finish hone but apparently diesel engines like a slightly coarser surface to better retain oil.
     
  27. sunbeam
    Joined: Oct 22, 2010
    Posts: 5,904

    sunbeam
    Member

    Budget36 and bulletpruf like this.
  28. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 3,298

    ekimneirbo

    If you check facebook for "glass tables" you can find a lot of "tempered glass" stuff very cheaply ($20 or sometimes free). Lots or different sizes.

    As for the hone sizes. Realize that they are not an exact size but rather spring loaded to have some pressure against the surface when honing. You should be ok with the ones you ordered, but the main concern is that they are small enough to insert in the guide. Personally, if you have a parts washer, I would create a flow through the guide while honing. That flushes the residue out and gives a better finish. All I can say is that in the machine shop we always used some fluid while grinding or honing anything. Whatever cleaning fluid you have in the parts washer should work fine.....don't need to worry about special fluids etc.
     
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  29. 1971BB427
    Joined: Mar 6, 2010
    Posts: 7,807

    1971BB427
    Member
    from Oregon

    Of course most of us love to learn something by doing it ourselves. But the lesson learned shouldn't be what to do to ruin parts, and waste time and money. If I had a junk head and plenty of time to play with it, I still wouldn't try to hand ream or fit guides to it. If the head had press in guides already I'd consider playing around with pressing in a new guide just to see if I could. But I certainly don't want to learn what not to do if it results in screwing up a pair of heads that could have been repaired correctly.
     
    Truckdoctor Andy likes this.
  30. 1971BB427
    Joined: Mar 6, 2010
    Posts: 7,807

    1971BB427
    Member
    from Oregon

    I've cleaned up the mating surface on heads using a large aluminum block wrapped with emery paper and some WD40 or kerosene to wet sand the surface. But the heads were true and straight before I started, so I wasn't truing the surface, just making it very smooth before installing new head gaskets.
     

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