Valve Adjustment info from P15-D24

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refit1701
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Valve Adjustment info from P15-D24

Post by refit1701 »

After much googling this morning, I found these instructions. Seems legit to me and the website has other info on our 230 flatheads

P15-D24.com

Valve Adjustment

Proper valve adjustment is critical for quiet and efficient operation of a flathead six and is the first line of defense against burned valves. Compared to overhead valve engine the flathead is a very simple design. A tappet follows the contour of the cam lobe pushing a valve up and open at the appropriate time. The only adjustment is the clearance between the tappet and valve stem. Accurate adjustment can only be made while the engine hot. To complete the job you will need a valve gasket set, set of go/nogo feeler gauges, pair of tappet wrenches and a pair of gloves to protect you from burns on the exhaust manifold. While the valve covers are readily visible from the top of the engine, don’t attempt this job from above the manifold. Instead raise the right front on a jack stand and remove the right front tire. Inside the wheel well is an access panel approximately 3 feet wide and 18 inches high. Remove the bolts holding the access panel. When removed you will have straight on access to the valve covers. Start the engine and bring it up to operating temperature. After the engine warms up, stop the engine and manually turn it over to Top Dead Center (TDC). Verify piston #1 is in firing position by checking the position of the distributor rotor. If should point around 7 o’clock. If it points to the 1 o’clock position, you have piston #6 in firing position. Manually turn the engine one full revolution and you are ready to start. Remove the valve covers and use the following sequence for the order of the valves to adjust.

Exhaust valve clearance .010
Intake valve clearance .008

Stage A, #1 and #6 at TDC, #1 in firing position
Stage B, #1 and #6 at TDC, #6 in firing position
To move from Stage A to B, manually turn the engine 1 revolution.

Stage A – Adjust #1 Both valves, #2 Inlet valve, #3 Exhaust Valve, #4 Inlet valve, #5 Both valves.
Stage B – Adjust #2 Both valves, #3 Inlet valve, #4 Exhaust valve, #5 Inlet valve, #6 Both valves.

Using the two tappet wrenches you can use one hand to adjust the tappet, leaving the other hand free for the go/nogo gauge, The go/nogo gauge has three steps cut into it. If the adjustment gap is too wide, you will be able to slide it to the third step. If the gap is too narrow only the first step will slide between the valve and tappet. What you want is the middle step to fit snugly. Adjust each valve as specified in the adjustment sequence. It is better to err on the side of too much clearance versus not enough. Too much clearance may result in a slightly noisy tappet, while too little may burn the valve. After you finish the adjustment, reinstall the valve covers with the old gaskets. Bring the engine back up to operating temperature and you will notice the engine is much quieter. Sometime you will need to readjust a single noisy valve. Just make sure it is fully off the cam lobe and totally closed. If everything is OK remove the valve covers and install the new valve cover gaskets (780-469) with sealer. When re-tightening the valve covers don go overboard. They just need to be snug, letting the gasket and sealer do the work. Too tight distorts the sheet metal cover and usually results in leak. Reinstall the access panel and tire and you are back on the road. Properly adjusted valves result in a quiet running engine and help protect against damaged valve train components. If you have done the job right it will be difficult to tell if the engine is running from five feet away because it so quiet!
-John
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1953 USAF M37 wow, restored
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NAM VET
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Re: Valve Adjustment info from P15-D24

Post by NAM VET »

all good information. I did my valves using Charles Talbert's cold engine. And yes, when the valves are set right, the engine really is quiet, just the exhaust and fan noise. I stopped by the local MAC tool truck to get the correct thin tappet nut wrenches. Hal
refit1701
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Re: Valve Adjustment info from P15-D24

Post by refit1701 »

Oh, I am doing his cold engine method. I knew that there was a method of doing half of them at a time based on what was at TDC.
-John
Member of Dixie Division MVC

1953 USAF M37 wow, restored
1962 M151 Ford Production, on the rotisserie now
1953 USMC M37 w/w -in storage
1942 M6 Bomb Service Truck (sold to UK collector)
1967 M116A1 Pioneer Trailer
1968 M101A1 Trailer
S-89 Comm box
John Mc
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Re: Valve Adjustment info from P15-D24

Post by John Mc »

Does anyone have a link to a description of the cold engine method?
1951 M37 "Brutus" w/Winch and 251 engine
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Re: Valve Adjustment info from P15-D24

Post by Cal_Gary »

Yep, right here from Charles-
http://www.g741.org/PHPBB/download/file.php?id=2615

Click, or Paste that into a browser-it will open a PDF....
Gary
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Re: Valve Adjustment info from P15-D24

Post by John Mc »

Thanks for that Gary... & Charles.

Do you know if the cold clearances are the same for a 251 engine?

[EDIT]
The more I look in to this, the more confused I'm getting.

Charles' write-up notes
.010" intake & .013" exhaust is a good COLD set up. The actual
hot setting you need is .009" intake - .011" exhaust, the cold settings will tighten
to the proper hot setting as the engine warms to normal temp due to heat
expansion.
TM 9-8030 says you need .010" intake and .014" hot (pg 138)

The Canadian manual (CDN-VEH-D114) says (Instr 1, Table II Engine Specs, pg 57):
Intake Valves
.....Clearance-Stem to tappet (Hot) .010"
............................................. (Cold).010"

Exhaust Valves
.....Clearance-Stem to tappet (Hot) .018"
............................................. (Cold).020"
So at least that source shows a significant difference for a 251,

Charles' write up also mentions it's for a T-137 engine. I thought the 230 engine in an M37 was a T-245? (I can't for the life of me remember the model number of the 251 engine, nor can I find it in the Canadian manual.)

Most of this is curiosity on my part. I'm going to leave setting this to someone who actually knows what they are doing (unlike me).
1951 M37 "Brutus" w/Winch and 251 engine
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Re: Valve Adjustment info from P15-D24

Post by RCrombie »

Canadian motors are T249 :)
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