Borescope for M38 engine
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Borescope for M38 engine
Anyone have input on a good borescope that can be used to view the pistons in an L134 engine? The one I got the camera is too long and won't make the bend towards the piston. I'm tired of finding TDC using the finger test and want something more objective.
Scott
Scott
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Re: Borescope for M38 engine
I am wondering how you will be sure visually with the borescope that your engine will be @TDC, because the valves needs also to be closed on the right cylinder, normally #1.Scott in NM wrote: ↑Fri May 27, 2022 3:29 pmAnyone have input on a good borescope that can be used to view the pistons in an L134 engine? The one I got the camera is too long and won't make the bend towards the piston. I'm tired of finding TDC using the finger test and want something more objective.
Scott
I use a used plastic medical syringe of the appropriate diameter inserted in cyl.#1. You can force it easily into the spark plug hole
When the syringe piston jumps to the roof with a big bang, no doubt that you are @TDC on the right cylinder
I have drilled a little hole in the syringe piston pusher in order to attach it with a little wire to the syringe cylinder.
Really simple ti use : remove spark plug #1, replace it by the syringe, turn the engine manually until ...bang ! You are @ TDC
I have an endoscope/borescope and I have the same problem. The camera housing with the led lights is too long.
Also I’m wondering if it is safe for the optical fiber to be sharply bent to 90 degrees.
Yves
Last edited by YLG80 on Sat May 28, 2022 8:01 am, edited 2 times in total.
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Re: Borescope for M38 engine
There are several cheap under $20 cable camera kits for smartphones that will work. The cables are long but they work well are waterproof and have good lights at the lens end.
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Re: Borescope for M38 engine
Had not thought of the cable cable camera kit. Excellent idea. Now I just wish I could find one with a small enough head so I can bend it and view the piston.
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Re: Borescope for M38 engine
What???
That won't tell you when the piston is at TDC and both valves are closed!
That won't tell you when the piston is at TDC and both valves are closed!
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Re: Borescope for M38 engine
Really hard to see the piston top through an L-134 spark plug hole with the head on.
If you get at just the right spot with a small LED pen light, you can just barely see the edge of the cylinder and piston when it is up. Not easy.
Option two: The front crankshaft pulley groove. Take the nut off and see where the groove is positioned. With the pistons up and cyl. 1 & 4 or 2 & 3 at TDC, the groove will be at the 90' position.
Option 3: A piece of soft plastic string trimmer line. Stick the line into the spark plug hole so it will be on top of the piston, between the flat piston head and the cylinder head. Not much space there when the piston is on TDC. The line will get pinched in place but is soft and won't cause any damage.
If you get at just the right spot with a small LED pen light, you can just barely see the edge of the cylinder and piston when it is up. Not easy.
Option two: The front crankshaft pulley groove. Take the nut off and see where the groove is positioned. With the pistons up and cyl. 1 & 4 or 2 & 3 at TDC, the groove will be at the 90' position.
Option 3: A piece of soft plastic string trimmer line. Stick the line into the spark plug hole so it will be on top of the piston, between the flat piston head and the cylinder head. Not much space there when the piston is on TDC. The line will get pinched in place but is soft and won't cause any damage.
Mike Wolford
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CJ-2A
VEP GPW
Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB
- dpcd67
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Re: Borescope for M38 engine
Or just use your thumb and have your neighbor turn the crank. If you remove the valve cover you can see what the valves are doing. We didn't have no borescopes back in the hills. You young guys kill me with all your new fangled technology trying to solve problems that people routinely did decades ago.
As I type this on my apple with a connection speed of a quintillion quarks per millisecond.
As I type this on my apple with a connection speed of a quintillion quarks per millisecond.
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Re: Borescope for M38 engine
Excellent.
Waooh, that must be very fast.
Yves
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Re: Borescope for M38 engine
You are the Nuclear Engineer so I knew you would understand what I was talking about!
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