Page 1 of 5 123 ... LastLast
Results 1 to 10 of 44

Thread: engine head parts-cast iron recommendation

  1. #1
    Join Date
    Nov 2011
    Location
    Chicago, IL
    Posts
    81

    Default engine head parts-cast iron recommendation

    I am currently working on an overhaul of my ford 1320 tractor (Shibaura 1.3L 3cyl diesel). I am about to bolt the head back on (for the second time) and I noticed that 1 of 3 glow plug holes have a plug & vent shown here:



    I think the intend purpose is to protect the head gasket & cylinder walls from the direct heat of the glow plug. I think this because of the damage seen on my original head gasket & the one I ran for <15hrs after the rebuild.



    But the fact that the original is damaged on #1 & 3, tells me there were no plugs to begin with (ie I didn't loose them). Additionally, the 2 photos I have from the manual both picture plugs in all 3 glow plug ports. This begs the question, why don't I have them? were they intentionally not installed? was this a manufacturing error?


    After seeing what it did to my head gasket after only 15hrs & very minimal glow plug use, I am leaning towards machining plugs to protect the rest. Does anyone think this is a bad idea? if so why?


    turning the plugs is well within my skill set, however, I lack the expertise to know from what type of cast iron these should be made? (i know nothing about the type of cast iron used in the head)
    Last edited by mtraven; 07-13-2017 at 10:15 PM. Reason: fixed image links
    "it is no measure of mental health to be well adjusted to a profoundly sick society." -- krishnamurti
    "look deep into nature, and then you will understand everything better." -- albert einstien
    "any intelligent fool can make things bigger and more complex...It takes a touch of genius - and a lot of courage to move in the opposite direction."

  2. #2
    Join Date
    Nov 2007
    Location
    Woodinville, WA
    Posts
    7,984

    Default

    How will you lock them in place?

    I love machining Durabar 80ksi, but I'm not sure it will matter much if you just use gray iron.

  3. #3
    Join Date
    Mar 2017
    Location
    central MA
    Posts
    137

    Default

    It looks to me like those plugs are used to create a pre combustion chamber. Are the injectors located in the hole along with the glow plug? If so, then I will suggest that this might not be the place to experiment with material, as this is where all the action takes place when the injector fires. You might be better off in the long run hunting down a set of plugs from a rebuild kit supplier.
    Last edited by tom_d; 07-13-2017 at 10:34 PM.

  4. #4
    Join Date
    Sep 2009
    Location
    NW Illinois USA
    Posts
    553

    Default

    correct. these are the pre chambers and I agree, be careful with material choice and the geometry.

    Compression must have been way down without those parts.

  5. #5
    Join Date
    Nov 2011
    Location
    Chicago, IL
    Posts
    81

    Default

    Quote Originally Posted by tom_d View Post
    It looks to me like those plugs are used to create a pre combustion chamber. Are the injectors located in the hole along with the glow plug? If so, then I will suggest that this might not be the place to experiment with material, as this is where all the action takes place when the injector fires. You might be better off in the long run hunting down a set of plugs from a rebuild kit supplier.
    the existing 1 is pressed in place and its the bottom of the head, so in service is sandwiched between the block & the head.

    As for them being pre-combustion chambers, I am really not sure, but I can tell you that I have run the tractor since 1990 without them and up until I lost an injector & cracked a ring, it had much more power than it has now. why would those plugs have any effect on a compression test?(which was down, but due to valves)...Even without the plug, you still have the glow plug itself sealing the chamber...

    I don't like experimenting in this case either, especial since the head gasket is $150, but I have searched high & low & cannot find OEM parts anywhere..so I am gonna have to make them.

    this is my first rebuild, so I am still learning, but it seems like everyone agrees I should put new one in, right? so far I am leaning towards class 40 cast iron, comments?
    "it is no measure of mental health to be well adjusted to a profoundly sick society." -- krishnamurti
    "look deep into nature, and then you will understand everything better." -- albert einstien
    "any intelligent fool can make things bigger and more complex...It takes a touch of genius - and a lot of courage to move in the opposite direction."

  6. #6
    Join Date
    Mar 2017
    Location
    central MA
    Posts
    137

    Default

    The plugs will have little influence on a compression test. The pre combustion chamber holds in the heat from the glow plugs which improves cold engine starting, and is integral to the overall combustion process when the engine is running.

  7. #7
    Join Date
    Nov 2011
    Location
    Chicago, IL
    Posts
    81

    Default

    Quote Originally Posted by tom_d View Post
    The plugs will have little influence on a compression test. The pre combustion chamber holds in the heat from the glow plugs which improves cold engine starting, and is integral to the overall combustion process when the engine is running.
    thanks Tom, im with ya so far....but why would the manufacturer leave 2 of the 3 out? could there be a real reason for this? if not, then was it just a mistake? and how the hell did the thing run well for 25years without them?
    "it is no measure of mental health to be well adjusted to a profoundly sick society." -- krishnamurti
    "look deep into nature, and then you will understand everything better." -- albert einstien
    "any intelligent fool can make things bigger and more complex...It takes a touch of genius - and a lot of courage to move in the opposite direction."

  8. #8
    Join Date
    Mar 2017
    Location
    central MA
    Posts
    137

    Default

    The engine must have been apart before you got it. I am not seeing the pictures that you had posted. Did you make a settings change, or add some photos? What I recall from the photos was some gauging marks around the pre chamber hole shown on the left. Maybe someone tied to replace a burned glow plug of injector, had to get aggressive in the removal, and wound up destroying the caps.

    I found some photos of replacement cylinder heads and it looks like the head was machined after the plugs were installed. This leads me to believe that the caps are not meant to be removed, at least not in a field overhaul. Do you have a good way to blend in the new caps to match the head surface? As for material to make them from #40 iron sounds like a reasonable choice.

  9. #9
    Join Date
    Nov 2011
    Location
    Chicago, IL
    Posts
    81

    Default

    Quote Originally Posted by tom_d View Post
    The engine must have been apart before you got it. I am not seeing the pictures that you had posted. Did you make a settings change, or add some photos? What I recall from the photos was some gauging marks around the pre chamber hole shown on the left. Maybe someone tied to replace a burned glow plug of injector, had to get aggressive in the removal, and wound up destroying the caps.

    I found some photos of replacement cylinder heads and it looks like the head was machined after the plugs were installed. This leads me to believe that the caps are not meant to be removed, at least not in a field overhaul. Do you have a good way to blend in the new caps to match the head surface? As for material to make them from #40 iron sounds like a reasonable choice.
    not sure what happened to the photos, here are different links:
    https://photos.app.goo.gl/7VfCK8RftlZK9UyJ2
    https://photos.app.goo.gl/Ua4nca15Dx96uS7q2
    https://photos.app.goo.gl/q2bNNIS6OhJ6UpgH2


    those marks made me think the same thing, but my father purchased this tractor in 1990, brand new & this is the first overhaul...they let me to think maybe they were installed @ the factory & removed @ factory for some functional reason. suppose I make "perfect" replacements, is there a chance they cause a problem?


    wrt the head being machined after the plugs installed, that may have been, though I doubt it as the one remaining is actually a touch high and the marks there are the difference between inside the chamber & under the gasket...as well as a bunch of residue from the last head gasket. i would think I could face it as close as the existing one, and the head gasket takes that up just fine. but i do want do it well, so if you have a suggestion on how to do it, I am all ears.

    and thank you so much for your help, i have been muddling through ever step of this overhaul, its very helpful to discuss with someone who knows what they are talking about.

    an
    "it is no measure of mental health to be well adjusted to a profoundly sick society." -- krishnamurti
    "look deep into nature, and then you will understand everything better." -- albert einstien
    "any intelligent fool can make things bigger and more complex...It takes a touch of genius - and a lot of courage to move in the opposite direction."

  10. #10
    Join Date
    Nov 2011
    Location
    Chicago, IL
    Posts
    81

    Default

    so I was poking around at that plug (as ya do..) and it popped up with the push of a pen...i just assumed it was pressed, but its actually I nicely machined fit with a little lump cast in to index the vent. Now that I cleaned it, the plug slides right in & out, so easy Ill have to do something so they don't fall out when I reinstall. so this rules out those markings being from a crude removal, still would like to know how they got there though. this changes things a bit, I am gonna sleep on it & see what everyone has to say tomorrow. thanks.
    "it is no measure of mental health to be well adjusted to a profoundly sick society." -- krishnamurti
    "look deep into nature, and then you will understand everything better." -- albert einstien
    "any intelligent fool can make things bigger and more complex...It takes a touch of genius - and a lot of courage to move in the opposite direction."

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •