Author Topic: GDB Inline 4 Cylinder OHV I.C.  (Read 24723 times)

Offline 90LX_Notch

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #180 on: October 07, 2021, 12:39:48 AM »
Thanks George.  My only shop time is usually on Sunday.  I just keep chipping away at this build.  I’ll get there one day.


Roger- The sliver got by my glasses and wound up under my eyelid, very near the eye socket near the eyebrow.  Usually, I blink into a glass of water to remove objects from eyes.  I eventually got it, but it was by far the hardest thing I ever have had to get out.

-Bob

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Offline 90LX_Notch

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #181 on: October 10, 2021, 11:29:48 PM »
Well….

A setback has occurred.  I allowed myself to get distracted for one second and I turned the handle the wrong way.  More than likely this is a catastrophic “f’up”.  The hurt area becomes a .100 thick wall for the valve cover.  The endmill traveled .065 into it.  I can bore a hole, turn a plug, press the plug in and machine it flush with wall.  How it will look is questionable.

At this point, I’m just aggravated with myself and don’t know what path I’m going to take (fix it or start over).

-Bob
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Online Kim

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #182 on: October 10, 2021, 11:34:36 PM »
 :facepalm:

Very sorry to hear that Bob!  I've certainly done that before and it is frustrating.

I certainly feel for you.

Kim

Offline Don1966

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #183 on: October 10, 2021, 11:44:37 PM »
Been there and know how you feel just take a step back and relax. Then when the head clears regroup. At least that’s what I do because tools start to fly if I don’t. Decisions decisions Bob you’ll get it done….


 :cheers:
Don

Offline steamer

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #184 on: October 10, 2021, 11:47:04 PM »
What part was that Bob?

Feeling it man!.....Sorry to see that

Dave
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Offline 90LX_Notch

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #185 on: October 10, 2021, 11:57:16 PM »
Thanks guys.  It’s the head.

-Bob
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Offline steamer

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #186 on: October 11, 2021, 12:10:27 AM »
Well   Tell ya what.     the only people who don't make mistakes are those that never do anything....


You have nothing to lose by trying to put a plug in, that reaches up to the top surface, and then machining it back...  You could thread it, but not sure you need to, especially without looking at the print.

Love is a wonderful thing, but Loctite is forever!!!   8)......but not tonight

Ifn I was you....I'd walk away for the evening and come back with a better mood....I know I get pissed at myself when I do it.

Dave


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Offline gbritnell

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #187 on: October 11, 2021, 12:56:16 AM »
Bob,
As long as it doesn't affect the structural integrity of the part plug it. One thing to consider is if you use a round plug just make sure that any intersecting edges are Fairley close to right angles otherwise you stand the chance of chipping the sharp corners. I have patched many parts in my career.
gbritnell
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Offline 90LX_Notch

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #188 on: October 11, 2021, 01:09:38 AM »
Thanks Dave and George I greatly appreciate your input.

I couldn’t just walk away from this.  I have already begun the repair.  I blued the mistake and turned the spindle by hand  until a scratch mark appeared.  Then I moved over another .001.  Next, the endmill was plunged to depth.  Then it was dinner time and I’m now watching a movie with my wife.  I’ll pick this backup at another time.

-Bob
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Offline steamer

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #189 on: October 11, 2021, 01:57:56 AM »
Way to go Bob!    and I'm glad you're watching a movie....You internalized a plan...and you are acting on it....nothing bleeds stress off better than that!

Goodonya mate

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline eccentric

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #190 on: October 23, 2021, 07:05:29 PM »
Bob,

What purpose do the indicated slots in the block provide?  Do they equalize crankcase pressure between the cylinder sections?  Are they for ease of assembly later?  And why are they needed on the ends of the block and not just between the cylinders.  They do not look straight forward so there must be a good reason.

Probably a simply explanation, but it has me scratching my head.


Thx

« Last Edit: October 30, 2021, 12:41:39 AM by eccentric »

Offline 90LX_Notch

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #191 on: October 23, 2021, 07:25:05 PM »
Eccentric-

Excellent question, George’s design uses a splash oil system.  Those slots allow oil to the main bearings. 

-Bob
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Offline steamer

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #192 on: October 23, 2021, 07:27:09 PM »
 :popcorn:
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline eccentric

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #193 on: October 23, 2021, 07:38:56 PM »
Oil to the main bearings, that makes sense. i see the oil feed holes to the bearings now.   ;D   :ThumbsUp:

Offline 90LX_Notch

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Re: GDB Inline 4 Cylinder OHV I.C.
« Reply #194 on: October 25, 2021, 03:12:20 AM »
Head continued-

Last weekend was the Jacktown show; so, I was unable to get into the shop.   This weekend was chock full family functions but, I did manage to get some shop time in.  I made a plug out of cast iron and pressed it into the head.  A toolmaker’s clamp was used to apply pressure against the plug, holding it firmly against the “boo-boo”. 

Under any other circumstance, I would feel confident that the repair would work after machining.  Unfortunately, after reviewing the print, the “boo-boo” is right where the spark plug hole will be located.  Time will only tell.  I do have an idea to help increase the odds and will be incorporating it into the “fix”.

-Bob
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