You often mixed up identifying the intake and exhaust valve locations. Also, there is no way a worn valve will "grow" in length and hit the cylinder head. Weak or broken valve springs will cause it though. Thanks for the video P.S. The cylinder is cracked between the valves, look at the video around 10:20.
Valves do stretch over time from millions of cycles. Springs lose their tension and seats wear deeper. Those ground valves lost their hardness at point of impact… wont last long
Nice video. Any time that the valves aren't fully seated when at TDC your valve clearance is zero. It's a waste of time trying to insert a feeler gauge.
Thank you for making this vid.....great job.....lve liked and subscribed as you asked.....helped me out lots......wishing you and your loved ones all the best
Appreciate you making this vid. Id never seen the valve adjustment procedure on that little engine....having one similar myself. Sure looks like they could have come up with a better way than grinding. Im wondering if there is a problem with it holding its adjustment once ground for clearance. Lots of parts now are just surface hardened and once you remove material (grinding) you look at accelerated wear. Any input on this? Again... thanks.... might try it on one om my engines that's running rough... could be the exhaust valve clearance is out of spec.
I think intake is .008 and exhaust is .012. I think he said it backwards near end of video. I wish he’d shown the grinding process too. I may need to do my 8hp Tecumseh.
Intake and exhaust clearance was spoken and checked reversed, don't do this. Also, clean up valves and lap them in while your are doing valve clearance.
Once you grind these valve stems they won’t hold that clearance very long… maybe a season, depending on usage. Valve stems are obviously hardened by heat treat and you just ground it away right at the tip and point of impact. Also, the heat from grinding will usually compromise the remaining hardness of the rest of the valve. These flathead engines valve clearances were basically made unserviceable… you gotta buy new valves and springs. The valves stretch over time from hundreds of thousands of cycles and the springs lose tension.
At first you stated that the "Intake had .008 clearance, and the Exaust was at .012 clearance. Later in your video you set them in reverse to what you fist said the clearance was where Inatke you set at .012, and intake at .008. Which is it? I believe it's set at what you stated at the beginning Intake at .008 and exhaust at .012. You set your valve setting wrong in reverse. Intake is always open a wee bit longer than the exhaust valve, so the intake valvehas the greater setting (.012), by a few extra thousands of an inch than the exhaust setting..
What happens, physically, that causes the valve to need to be ground down? I get that the clearance is off, but it fit before with the same length, so why does it now need to be shortened?
Since you had it all apart, Should have ground the valve and cut the seats before you redid the clearance. I work for a rebuilder many years ago in my youth. I am old school..
what's the symptoms of needing to check the clearances? I have an 8hp that has spark,fuel, compresson,fresh gas,and new carb. ...will not fire..even with stating fluid.
the way to tell if it is the valves or rings causing low compression take a compression reading the remove the spark plug add a spoon of oil in spark plug hole retake compression reading did it help if so its the ring are going bad if it didnt help its te valves need grinding simple???
the feeler gauge should have a slight drag on it while pulling through the gap when the clearance is correct. not enough force to lift the valve but a bit to let you know it is not too much clearance.
in a normal valve in head engine the exhaust often has larger clearances due to the added heat they sustain but with a valve in block engine that should not be necessary imo. as you well know metal expands with heat so the hotter valve will expand more thus warranting additional clearance. of course you know this but others may not. maybe that is why he said the exhaust has a larger clearance.
Didn't show you checking for top-dead-center compression leakage, insuring your made good contact with each valve-to-valve seat after doing a lap job. A poor lap job means leaks and loss of compression and a loss of horsepower while running.
the 10 horse L head engine has the same clearance which is .008 -.012 inches. metric equivalent would be .203 - .305 mm. the tecumseh L head service manual can be found at the link below. www.allotment-garden.org/rotavator-manuals/Techumseh-L-Head-Engines-Manual.pdf
Yes there are two . The top of the compression stroke is where you want to be. In the other position (Exhaust stroke) the exhaust valve could still be open slightly at TDC.
i think he is worrying with bottom end of the valves as long as they arent tuching on the bottom the valve will seat but he failed to grind them a comressin test will show if they are leaking
For a flat head engine, replace valve with a new one but this time take only a little off the ends at a time and recheck with feeler gauge often till correct clearance is got. Too much clearance means too much has been removed off the stem. That means replace valve.
@@waynedavies3185 OK, Thanks for that. I'll see if these valves on my very old MTD ride-on mower are still available. It's got an 11hp Briggs and Stratton engine at the back.
I think intake is .008 and exhaust is .012. I think he said it backwards near end of video. I wish he’d shown the grinding process too. I may need to do my 8hp Tecumseh.
You often mixed up identifying the intake and exhaust valve locations. Also, there is no way a worn valve will "grow" in length and hit the cylinder head. Weak or broken valve springs will cause it though. Thanks for the video P.S. The cylinder is cracked between the valves, look at the video around 10:20.
old vid but wonder if thats why he replaced the valves lol no compression due too big ass crack in his block lol
I never noticed that at all, good call
the valve seats are probably sunken in
Valves do stretch over time from millions of cycles. Springs lose their tension and seats wear deeper. Those ground valves lost their hardness at point of impact… wont last long
Nice video. Any time that the valves aren't fully seated when at TDC your valve clearance is zero. It's a waste of time trying to insert a feeler gauge.
thanks for this video... its big help for me as a beginner.
Thank you for making this vid.....great job.....lve liked and subscribed as you asked.....helped me out lots......wishing you and your loved ones all the best
So if you repace the springs and the caps would you have to grind the valves? It just don't make sense that the alve stems length could increase.
Appreciate you making this vid. Id never seen the valve adjustment procedure on that little engine....having one similar myself. Sure looks like they could have come up with a better way than grinding. Im wondering if there is a problem with it holding its adjustment once ground for clearance. Lots of parts now are just surface hardened and once you remove material (grinding) you look at accelerated wear. Any input on this? Again... thanks.... might try it on one om my engines that's running rough... could be the exhaust valve clearance is out of spec.
I think intake is .008 and exhaust is .012. I think he said it backwards near end of video. I wish he’d shown the grinding process too. I may need to do my 8hp Tecumseh.
Yes, intake is .008 exhaust is .012. He reversed them.
At 2:00 he has it correct.
Lay a file down on a table, make a couple passes with the valve flat against the file. Check clearance after every pass or so.
Intake and exhaust clearance was spoken and checked reversed, don't do this. Also, clean up valves and lap them in while your are doing valve clearance.
@@DAS-Videos No. That is Max Min. Minimum of .008 to Maximum of .012 or anything in between.
Once you grind these valve stems they won’t hold that clearance very long… maybe a season, depending on usage. Valve stems are obviously hardened by heat treat and you just ground it away right at the tip and point of impact. Also, the heat from grinding will usually compromise the remaining hardness of the rest of the valve. These flathead engines valve clearances were basically made unserviceable… you gotta buy new valves and springs. The valves stretch over time from hundreds of thousands of cycles and the springs lose tension.
What about the valve caps? Do they distort after years of use?
@@mattyal9347im not sure about distort, but maybe if overheating occurred. They will ware down after hundreds of hours of use
Thank you. That makes a lot of sense. I did not understand why it would need to be ground.
Use a magnet for the pin so it won't fall into the hole.
my old 10hp Tecumseh doesn't have pins the valve seat is slotted so must compress spring then remove seat .
At first you stated that the "Intake had .008 clearance, and the Exaust was at .012 clearance. Later in your video you set them in reverse to what you fist said the clearance was where Inatke you set at .012, and intake at .008. Which is it? I believe it's set at what you stated at the beginning Intake at .008 and exhaust at .012. You set your valve setting wrong in reverse. Intake is always open a wee bit longer than the exhaust valve, so the intake valvehas the greater setting (.012), by a few extra thousands of an inch than the exhaust setting..
good video i ground stems with flat side of cut off wheel and mic'd before and after and he did say backwards near the end
10:15 is the cylinder wall cracked?
Looks that way, or badly scored where camera shadow makes it appear as if the wall is cracked. Most likely it's scored
What model number of engines have the .008 .012 valve clearance?
Great video buddy
What happens, physically, that causes the valve to need to be ground down? I get that the clearance is off, but it fit before with the same length, so why does it now need to be shortened?
Since you had it all apart, Should have ground the valve and cut the seats before you redid the clearance. I work for a rebuilder many years ago in my youth. I am old school..
They should be ground nice and square on valve grinding machine not bench grinder , thats why they wont last long nut good video
what's the symptoms of needing to check the clearances? I have an 8hp that has spark,fuel, compresson,fresh gas,and new carb. ...will not fire..even with stating fluid.
Hey you need to check compression and a leak down test to see where you might be loosing compression
And now your valve seal is cut. Good one. People dont do this. Do it right
Nice video. Where you buy that c-clamp?
the way to tell if it is the valves or rings causing low compression take a compression reading the remove the spark plug add a spoon of oil in spark plug hole retake compression reading did it help if so its the ring are going bad if it didnt help its te valves need grinding simple???
Hey just curious but why did you not lap the valves?
What should it feel like when the space between them is gapped right???
the feeler gauge should have a slight drag on it while pulling through the gap when the clearance is correct. not enough force to lift the valve but a bit to let you know it is not too much clearance.
Always file the burr before ya rip it through the guide.
Probably was not a burr, but rather carbon buildup along the valve stem. Happens on the exhaust sometimes.
is the crankcase breather installed upside down? Mine has tiny drain holes on bottom?
MUY BUEN TRABAJO 👍
Both intake and exhaust are the same. .008 is minimum and .012 is maximum.
in a normal valve in head engine the exhaust often has larger clearances due to the added heat they sustain but with a valve in block engine that should not be necessary imo. as you well know metal expands with heat so the hotter valve will expand more thus warranting additional clearance. of course you know this but others may not.
maybe that is why he said the exhaust has a larger clearance.
Didn't show you checking for top-dead-center compression leakage, insuring your made good contact with each valve-to-valve seat after doing a lap job. A poor lap job means leaks and loss of compression and a loss of horsepower while running.
Put the breather cover on backwards.
Valve lash is... .008 min to .012 max. Nothing under...nothing over.
What would the gap be on the 10hp tecumseh!!!
the 10 horse L head engine has the same clearance which is .008 -.012 inches. metric equivalent would be .203 - .305 mm.
the tecumseh L head service manual can be found at the link below.
www.allotment-garden.org/rotavator-manuals/Techumseh-L-Head-Engines-Manual.pdf
Are there not two instances of TDC, one where the clearances should be measured and one not?
Yes there are two . The top of the compression stroke is where you want to be. In the other position (Exhaust stroke) the exhaust valve could still be open slightly at TDC.
@@geobrown9413 Thank you. Not mentioned in the video.
i think he is worrying with bottom end of the valves as long as they arent tuching on the bottom the valve will seat but he failed to grind them a comressin test will show if they are leaking
Why doesn't anyone say what to do if the clearance it too big! I can't find answer anywhere on RUclips
For a flat head engine, replace valve with a new one but this time take only a little off the ends at a time and recheck with feeler gauge often till correct clearance is got. Too much clearance means too much has been removed off the stem. That means replace valve.
@@waynedavies3185 OK, Thanks for that. I'll see if these valves on my very old MTD ride-on mower are still available. It's got an 11hp Briggs and Stratton engine at the back.
Breather back on wrong side up
Where's the vale grinding
One minute you say intake is 8000th. Then you later you say 12000th.
Respectfully, which is it?
I think intake is .008 and exhaust is .012. I think he said it backwards near end of video. I wish he’d shown the grinding process too. I may need to do my 8hp Tecumseh.
It 10 thousands on both.Or. 8 on both.depends on hp size.
You're can set them at .008 the lowest and .012 the highest as long as you are within specs you're good
@@michael-ki4sr hi tecumshe. Manual says 7 hp 10 thousands on both valves
@@jeffazarva6549 awesome I was always told if you're within those specs you're good thank for the info
200 or less to change it out for a repower, these old engines are just that old.
Dude.... you need to lap the valve too. You only did half of the job
i am glad i was not the only one to notice that he fail to grind the valves with compound.
This solotion of a engine going over all bad solotion , not normaly to grind the end of the valves , to get the right valvecleranse.