For my 80's snowblower Tecumseh engine they used to sell exhaust valves with oversized stems to øet you service the motpr whem clearance was exceeded. You simply left the worn guide in as is and resized to match the new oversized stem (1/64).
Another option for non-replaceable valve guides are valve guide liners (or sleeves). But those should be installed by experienced machinists or the results will not be great.
Loved it, great stuff and a great explanation of things, subscribing for more ! Also Im glad to see you have oil stained fingers even though you tried to clean them up.
I have a Ford 3000 3 cylinder diesel tractor with the issue you are describing on the center cylinder on both the intake and exhaust valves. This engine does not have replaceable guides so if the valve guide is out of spec a new brass valve guid can be installed so not the end of the world. I can also get oversized valves with stems .003 over and .015 over. I am going to see what a new stock valve feels like and try the .003 oversized stem. Cylinders 1 and 3 seem to be ok but I can have them checked by someone with the correct tools and that knows what they are doing more than me. For sure I need to lap the new valves in but more research is in order. I am afraid it is not as easy as I hope it to be.
Well with the guidance of this video I determined that my best course of action was to take my tractor head to a professional automotive machine shop. O ordered new replacement valves of stock diameter and the shop installed valve guides of the correct dimension. The seats were done and the new valves and springs installed. I got it all back together, bled the fuel system and the tractor fired up in short order. Do pay attention to the rockers to valve interface which will have some amount of wear the diameter of the valve stem leaving a ridge on either side. This ridge will give you trouble when you go to set your valve lash. Your feeler gage is generally a 1/2 inch wide and wider that the valve stem.with your feeler gage bridging this wear area it will give you a false reading, a larger gap at the valve stem to rocker interface. It would be best to replace the rockers while you are in there and start out fresh on both valve stem and rocker interface. After the top end was completed and all back together the engine uses engine oil but the wet stacking issue of unburnt diesel fuel being blown out of the exhaust and down the side of the engine has been stopped. New injectors did the deed but I am sure the new valves seating correctly with new guides helped out too. Next year I will see what I can do about new pistons, rings and a bore job.
so you're saying if the valve guide is an intregal part of the cylinger head, and it out of specs, the cylinder head must be replaced? is there no way to recondition it? just curious.
There is a knurling process that can be done. I'm not aware of any modern engines manufacturer that recommend knurling. I primary teach modern engine repair practices that would be performed by a dealership technician.Knurling does not get the guide back to it's original condition but does recondition it. This video talks about knurling. Knurling Pt 1
I know this is an old topic but be aware that some engines used valve guides as inserts that can be found finished or semi finished and this are pressed fit so you need to pressed them into the head and then reamed to the OE specifications measured with the hole gauge as shown in this video, also there are valve guides insert for engine that have guides worn out and you can take it to STD or oversize valves
Would I be able to feel 1.5 thousandths on an intake valve by rocking the stem. Springs removed. I have a single cylinder 4 stroke 250cc motorcycle which needs valve stem seals. Blue smoke until warm. I feel some play in all the stems, but really do not want to remove the head. It is a low budget build for now. Thank you.
It would be challenging. Comparing all of them and looking for any that are significantly different is a good start. I would use some lapping compound to get the best seal possible if you can't measure.
Great video and I subscribe to your channel--love the work and the camera takes. I have the m54b30. i started the car, switched it off went to lock the gate, got back and it would not start. Got a local mechanic to check it out. He stripped it and the valves bent on cylinder 6, replaced and built engine back. Started the engine and it was smoking like a chimney with oil dropping from the exhaust and oil light flashing on the dashboard. Please help what can i do. it idles very well and does not seem to lose power when idling but lack power when being driven. please help i am in Nigeria so not a lot of specialist tools or expert like you here. thanks, the car did not overheat even after he coupled the engine back,
atobsky a valve gets bent when it comes into contact with the piston. That usually happens when the timing chain or belt breaks. If the engine is running now then that's not likely the reason it was bent. Another possibility is that the valve was stuck open because there was excessive buildup of carbon on the valve causing it to seize in the guide. This is the most likely scenario. If the valve guide wasn't properly cleaned and or repaired it's possible the valve is not properly sealing the combustion chamber. A cylinder leakage test is probably the only way you will be able to figure that out.
Thank you, sir, for your reply. One thing I forgot to mention is that a cover lid behind the cylinder head ( part number BMW 11121733403) had come off some 4 days after driving into a deep pothole before the no start issue, I kept on driving that way. This caused the engine to lose compression and, not only was it very loud, the car moved very sluggishly indeed and was leaking oil through the hole. I believe it is from this that excess carbon built up especially in cylinder 6 where the valves bent as it was the closest to the cover lid. The mechanic who then took care of it, claiming to be an expert, only changed the bent valves and not realising that the valve guide too could have been damaged. Although he complained that the chain guard broke, I believe this was during removal as they become brittle over time and not as a result of the bent valve, do you agree? And I go with your analysis that the valves were stuck open when I went to restart the vehicle. I have decided to order a used cylinder head. No point to try to fix it for the reasons that we don't enjoy or have within my reach precision equipment that you enjoy in America and the expertise to operate such precision equipment that you have shown in your amazing video, also I learnt from BMW that the guides that they stock are oversize guide and would also require an oversize valve etc which in the long run could be excessive and not economical approach . Thank you so much, I truly appreciate. Please if there is anything you think I should know or you like to add, I will appreciate those too
This video should have about 5 million more views....straight to the point and spot on knowledge
Demonstrating the clearance with the cutaway head really made this concept understandable. Thanks.
Straight to the point and smooth talking. Great job!!
For my 80's snowblower Tecumseh engine they used to sell exhaust valves with oversized stems to øet you service the motpr whem clearance was exceeded. You simply left the worn guide in as is and resized to match the new oversized stem (1/64).
Still how its done to this very day. Machine shops have suppliers who sell these.
15 to 35 ten thousanths (.0015 to .0035) for the intake clearance is actually MORE than .001" - .003" you mentioned for the exhaust.
Exactly what I was thinking. Its larger not smaller
That is exactly how I do it, I port and rebuild a lot of cylinder heads.
Another option for non-replaceable valve guides are valve guide liners (or sleeves). But those should be installed by experienced machinists or the results will not be great.
K Line bronze guide liners
Excellent video Mr. Scott. Congratulation....
If you can't push it through it's to tight. If you dip the valve tip in thick grease and drops in all the way on its own it's to loose
Perfectly explained
Thank you very much, for great tutor n video...
Loved it, great stuff and a great explanation of things, subscribing for more ! Also Im glad to see you have oil stained fingers even though you tried to clean them up.
I have a Ford 3000 3 cylinder diesel tractor with the issue you are describing on the center cylinder on both the intake and exhaust valves.
This engine does not have replaceable guides so if the valve guide is out of spec a new brass valve guid can be installed so not the end
of the world. I can also get oversized valves with stems .003 over and .015 over. I am going to see what a new stock valve feels like and
try the .003 oversized stem. Cylinders 1 and 3 seem to be ok but I can have them checked by someone with the correct tools and that knows
what they are doing more than me. For sure I need to lap the new valves in but more research is in order. I am afraid it is not as easy as
I hope it to be.
It sounds like a good time. Good luck
Well with the guidance of this video I determined that my best course of action was to take my tractor head to a professional automotive machine shop.
O ordered new replacement valves of stock diameter and the shop installed valve guides of the correct dimension. The seats were done and the new valves
and springs installed. I got it all back together, bled the fuel system and the tractor fired up in short order. Do pay attention to the rockers to valve interface
which will have some amount of wear the diameter of the valve stem leaving a ridge on either side. This ridge will give you trouble when you go to set your valve
lash. Your feeler gage is generally a 1/2 inch wide and wider that the valve stem.with your feeler gage bridging this wear area it will give you a false reading, a larger
gap at the valve stem to rocker interface. It would be best to replace the rockers while you are in there and start out fresh on both valve stem and rocker interface.
After the top end was completed and all back together the engine uses engine oil but the wet stacking issue of unburnt diesel fuel being blown out of the exhaust
and down the side of the engine has been stopped. New injectors did the deed but I am sure the new valves seating correctly with new guides helped out too.
Next year I will see what I can do about new pistons, rings and a bore job.
Wonderful Explanation!!!
Thank you.
Very interesting, thanks!
so you're saying if the valve guide is an intregal part of the cylinger head, and it out of specs, the cylinder head must be replaced? is there no way to recondition it? just curious.
There is a knurling process that can be done. I'm not aware of any modern engines manufacturer that recommend knurling. I primary teach modern engine repair practices that would be performed by a dealership technician.Knurling does not get the guide back to it's original condition but does recondition it. This video talks about knurling. Knurling Pt 1
Okay. thank you!!! :)
Sometimes there are inserts that can be used. You can also have them reamed and fit valves with oversized stems
I know this is an old topic but be aware that some engines used valve guides as inserts that can be found finished or semi finished and this are pressed fit so you need to pressed them into the head and then reamed to the OE specifications measured with the hole gauge as shown in this video, also there are valve guides insert for engine that have guides worn out and you can take it to STD or oversize valves
Very informative video. Thanks!
Would I be able to feel 1.5 thousandths on an intake valve by rocking the stem. Springs removed. I have a single cylinder 4 stroke 250cc motorcycle which needs valve stem seals. Blue smoke until warm. I feel some play in all the stems, but really do not want to remove the head. It is a low budget build for now. Thank you.
It would be challenging. Comparing all of them and looking for any that are significantly different is a good start. I would use some lapping compound to get the best seal possible if you can't measure.
Yo what year, make, model, vin, and engine type and size is this vehicle? My teacher made a assignment for us
Sorry, I can't recall that info, it was some time ago. It was probably an 05 SOHC
Scott Hadzik thank you. My teacher must be wildin.
what
Great video and I subscribe to your channel--love the work and the camera takes. I have the m54b30. i started the car, switched it off went to lock the gate, got back and it would not start. Got a local mechanic to check it out. He stripped it and the valves bent on cylinder 6, replaced and built engine back. Started the engine and it was smoking like a chimney with oil dropping from the exhaust and oil light flashing on the dashboard. Please help what can i do. it idles very well and does not seem to lose power when idling but lack power when being driven. please help i am in Nigeria so not a lot of specialist tools or expert like you here. thanks, the car did not overheat even after he coupled the engine back,
atobsky do you know what caused the valve to bend?
no sir, The mechanic reckons because i tried starting it many times which i dont agree with it unless you are suggesting otherwise
atobsky a valve gets bent when it comes into contact with the piston. That usually happens when the timing chain or belt breaks. If the engine is running now then that's not likely the reason it was bent. Another possibility is that the valve was stuck open because there was excessive buildup of carbon on the valve causing it to seize in the guide. This is the most likely scenario. If the valve guide wasn't properly cleaned and or repaired it's possible the valve is not properly sealing the combustion chamber. A cylinder leakage test is probably the only way you will be able to figure that out.
Thank you, sir, for your reply. One thing I forgot to mention is that a cover lid behind the cylinder head ( part number BMW 11121733403) had come off some 4 days after driving into a deep pothole before the no start issue, I kept on driving that way. This caused the engine to lose compression and, not only was it very loud, the car moved very sluggishly indeed and was leaking oil through the hole. I believe it is from this that excess carbon built up especially in cylinder 6 where the valves bent as it was the closest to the cover lid. The mechanic who then took care of it, claiming to be an expert, only changed the bent valves and not realising that the valve guide too could have been damaged. Although he complained that the chain guard broke, I believe this was during removal as they become brittle over time and not as a result of the bent valve, do you agree? And I go with your analysis that the valves were stuck open when I went to restart the vehicle. I have decided to order a used cylinder head. No point to try to fix it for the reasons that we don't enjoy or have within my reach precision equipment that you enjoy in America and the expertise to operate such precision equipment that you have shown in your amazing video, also I learnt from BMW that the guides that they stock are oversize guide and would also require an oversize valve etc which in the long run could be excessive and not economical approach . Thank you so much, I truly appreciate. Please if there is anything you think I should know or you like to add, I will appreciate those too
I agree that another head is probably the best option. Good luck.
👍👌
Tool name?
Small hole bore gauge
My customer just kicked my ass. Cause I cut his cyl head in half
Dont use this head, its cracked.
nothing a little bit of jb weld won’t touch up 🤣
@@JayDeeFrm7400 yup lol
Exactly, I hope this is just for instructional used