When designing camshaft profiles, the stage where the exhaust valve has not quite closed when the inlet valve begins to open is called “overlap”. Due to the momentum created by the exhaust gases leaving the system at high speed it creates a partial vacuum behind the exiting gasses, and by opening the inlet valve prematurely it helps to suck in the new fuel/air mixture faster, and therefore slightly more gets into the combustion chamber before the inlet valve finally closes and the mixture is compressed. This improves power. However it does waste a little more fuel and when the overlap is large, rough running or poor idling occurs. Subsequently large overlaps are only generally designed for fast road, rally, or full race camshafts.
Oh, he is just kidding. I know he can do it if he has to. But he prefers to let me do it and make fun of me when his engine doesn't start during a live stream LOL
Yeah, I guess, they didn't pay attention to the relation of the holes to the teeth. They only followed the 89/91 relation or whatever the angle is. I find that reproduction gears are different to each other even. Some "land" right on 110, some are either 106 or 114, some are 108-116.... They vary a lot, so I guess they don't have a jig that holds the gear in certain orientation while drilling the 4 center holes.
@@RustyBeauties I was thinking the same thing.. The fault 'couldn't' be on the teeth otherwise Mr Cock-up would come a visiting withing a few miles of getting the car mobile again. Judging by the damage to the timing chain cover and backplate the car already lost a timing chain in the past. Cog to cog was always the answer. I thought timing gears would be more reliable, but there would be bearings involved and cost would no doubt be another issue on ordinary production vehicles. Belts & chains are cheaper and supply maintenance income for repair garages and sometimes a replacement engine !
Nicely explained Elin. That last little bit about flipping over the cam gear was nice to see you finally address. (You must have heard me yelling at you from Australia). Most back yard mechanics would have no problems following what you have shown. Even though I an a MOWOG man I enjoy your videos. Thanks for sharing.
This video was...well timed 😁...as I was just putting together a '63 TR4 engine and scratching my head at why I couldn't get 1/4 tooth adjustment by flipping the new cam gear over. It appears I have the same aftermarket cam gear as you, and something definitely has changed with them since I last rebuilt a TR3 engine in late 2019.
Thank you very much for a college grade video!! I have a bit of a headache now, but it is a good one. I haven't come across a video like yours that explains timing so well. Again, thank you very much and technical colleges should include your videos in their curriculum.
You really explained this very clearly. I like your custom printed compass wheel, I laughed out loud when it fell off and I got soaked!! This engine is going to fly when your finished, these small adjustments will make a great difference. I'm sure I saw somewhere a split sprocket that allows very fine adjustment. When I rebuilt my spitfire engine I put a new high lift cam in using the standard timing marks. It made the idling really lumpy. It wasn't until I spent a bit of time adjusting it with a dial indicator that I got into to perform well, but it still remained lumpy. I would have been better off sticking with the standard profile!! Great video, well done Good luck from Spain!!
thanks Elin. Now you've got me thinking. When I rebuilt TS 394 LO in 1967, it was new crank, pistons and cylinders (87mm) and valve grind. I did not change timing gears and am sure I installed them by lining up the marks. I drove the car many miles over the next 20 years and there was lots of torque but I could not get it over 100 mph. Road tests from the time got TR2s up to 110. Maybe the valve timing was slightly off and I flipped the cam gear ? Getting back into the car this summer and will check the valve timing. From rural Manitoba. Full winter is back !
Yes, lining up the marks is tricky. I had absolutely no experience on that first engine I rebuilt and I was off by a tooth. But even with the experience I have now I wouldn't trust myself to line up the marks. It is possible that you are off a little on your car. You can easily attach a degree wheel on your crank pulley and check the timing with the head on even.
@@RustyBeauties thanks Elin. I will give it a try once we get the car uncovered, after being used as horizontal storage in the shop for 20 years. Currently, in prep, I am working through your's and ChefTush videos done a while ago.
If anyone has a problem getting a new cam gear which can be adjusted by turning 90 degrees or by turning round (ie 8 different positions) then get a Ferguson TEA tractor gear - its exactly the same gear and still made with the adjustment facility.
Yes, but then you have to rely on the bolts to hold it in position, which requires a lot of torque. There are adjustable gears available, but too expensive. For a stock engine like this one 3-4 degrees advance are not even noticeable. It is worth timing it to the spot if it was a racing engine with a performance camshaft.
I have a question. I am working on a 1960 TR3. As far as I know my cam is stock. I used your video to to set the valve timing. When I check my valve timing fully open I get 134 degrees and 84 degrees respectfully at 50 thousandth. Your cam was 168 and 68 degrees. Obviously my intake valve full open was way different that yours. Do you think that could be correct or did I do something wrong. I did the piston stop method to get to TDC. In my case I replaced the timing change, marked chain and gears and counted the teeth aligned the marks on the original gears and when I put it all back together checked the valve timing, did the calculations and my valve timing was 109 instead of 110 degrees. Again my only concern is the difference in the degrees of fully open on my intake valve of 134/84 degrees compare to yours at 168/68 degrees. I did my check with the head on and measures at the top of the valve spring retainer not at the pushrod as you did.
Well explained Elin. I don't have a Triumph, but if I did....... Anyway, just a thought, could you not slot two of the holes in the cam gear slightly, set the timing bang on, then drill through the gear and flange and install a cotter pin to lock them in position?
In theory everything is possible, but it is not worth for a stock engine like this. 3-4 degrees in advance are tolerance for a stock camshaft. For a performance camshaft , where it is important to be spot-on, there are adjustable gears available. But they are pricy
I have watch twice already so impressed and I feel more confident now I will need to do this on my MK2 2ltr Vitesse engine. Once mine is returned from the machine shop. From not realising you need to do this following your videos stripping inspecting measuring, I have successfully measured the cylinders, Camshaft etc. I had 2 cylinders 3.8 thou out of spec the others 1.5 thou. The crankshaft all in spec, The camshaft I have exchanged for a new cut one. The point is the machine shop rechecked my measurements and imagine how pleased I was they were all correct. This is all down to how you teach and show how to do it. Is there a printable copy of your new degree wheel vernier, if you do how to print one? Thank you so much.
And here I thought the timing was about when the distributor sends the spark... which of course has to match the crank and the cam at the proper point in the rotation.... but I thought it referred to the timing of the spark sent to burn the gas.
When designing camshaft profiles, the stage where the exhaust valve has not quite closed when the inlet valve begins to open is called “overlap”. Due to the momentum created by the exhaust gases leaving the system at high speed it creates a partial vacuum behind the exiting gasses, and by opening the inlet valve prematurely it helps to suck in the new fuel/air mixture faster, and therefore slightly more gets into the combustion chamber before the inlet valve finally closes and the mixture is compressed. This improves power. However it does waste a little more fuel and when the overlap is large, rough running or poor idling occurs. Subsequently large overlaps are only generally designed for fast road, rally, or full race camshafts.
Very well done and explained. Dave, I seriously don't understand how you don't find this interesting. Thanks Elin for a great tutorial. Cheers
Oh, he is just kidding. I know he can do it if he has to. But he prefers to let me do it and make fun of me when his engine doesn't start during a live stream LOL
You are a natural teacher.
Very clearly explained, again. Thanks, Elin.
Great video! 👍🏼👍🏼
I'm still recovering from the numbers.
I love the colors on this engine
👍Never boring listening to your detailed procedures. This engine should purr like a kitten now. 🙂
Excellent explanation! I learned a lot!
Interesting that the new gear has a small difference from the original. Despite this you've 'nail' it Elin.. Excellent tutorial ..
Yeah, I guess, they didn't pay attention to the relation of the holes to the teeth. They only followed the 89/91 relation or whatever the angle is. I find that reproduction gears are different to each other even. Some "land" right on 110, some are either 106 or 114, some are 108-116.... They vary a lot, so I guess they don't have a jig that holds the gear in certain orientation while drilling the 4 center holes.
@@RustyBeauties I was thinking the same thing.. The fault 'couldn't' be on the teeth otherwise Mr Cock-up would come a visiting withing a few miles of getting the car mobile again. Judging by the damage to the timing chain cover and backplate the car already lost a timing chain in the past. Cog to cog was always the answer. I thought timing gears would be more reliable, but there would be bearings involved and cost would no doubt be another issue on ordinary production vehicles. Belts & chains are cheaper and supply maintenance income for repair garages and sometimes a replacement engine !
Wow! Thank you. I've learned something today. Excellent explanation. 🙌
Nicely explained Elin.
That last little bit about flipping over the cam gear was nice to see you finally address. (You must have heard me yelling at you from Australia).
Most back yard mechanics would have no problems following what you have shown.
Even though I an a MOWOG man I enjoy your videos. Thanks for sharing.
Helpful video series. I’m rebuilding a tr3 with TR4 innerds and will be getting to the timing in the next month I figure. Cheers.
Yes now the Mud is much clearer. Thank you for clearing the way to my understanding it. Great video.
Great practical video, thanks
This video was...well timed 😁...as I was just putting together a '63 TR4 engine and scratching my head at why I couldn't get 1/4 tooth adjustment by flipping the new cam gear over. It appears I have the same aftermarket cam gear as you, and something definitely has changed with them since I last rebuilt a TR3 engine in late 2019.
O so good. Really appreciate the time and energy and the transmission (pun intended) of knowledge.
Thank you very much for a college grade video!! I have a bit of a headache now, but it is a good one. I haven't come across a video like yours that explains timing so well. Again, thank you very much and technical colleges should include your videos in their curriculum.
You really explained this very clearly.
I like your custom printed compass wheel, I laughed out loud when it fell off and I got soaked!!
This engine is going to fly when your finished, these small adjustments will make a great difference. I'm sure I saw somewhere a split sprocket that allows very fine adjustment.
When I rebuilt my spitfire engine I put a new high lift cam in using the standard timing marks. It made the idling really lumpy. It wasn't until I spent a bit of time adjusting it with a dial indicator that I got into to perform well, but it still remained lumpy. I would have been better off sticking with the standard profile!!
Great video, well done
Good luck from Spain!!
Yeah, adjustable gears are available, but quite pricy
Nailed it Elin. Thanks!
thanks Elin. Now you've got me thinking. When I rebuilt TS 394 LO in 1967, it was new crank, pistons and cylinders (87mm) and valve grind. I did not change timing gears and am sure I installed them by lining up the marks. I drove the car many miles over the next 20 years and there was lots of torque but I could not get it over 100 mph. Road tests from the time got TR2s up to 110. Maybe the valve timing was slightly off and I flipped the cam gear ? Getting back into the car this summer and will check the valve timing. From rural Manitoba. Full winter is back !
Yes, lining up the marks is tricky. I had absolutely no experience on that first engine I rebuilt and I was off by a tooth. But even with the experience I have now I wouldn't trust myself to line up the marks.
It is possible that you are off a little on your car. You can easily attach a degree wheel on your crank pulley and check the timing with the head on even.
@@RustyBeauties thanks Elin. I will give it a try once we get the car uncovered, after being used as horizontal storage in the shop for 20 years. Currently, in prep, I am working through your's and ChefTush videos done a while ago.
I need an Advil 😉
I will make a special video for you one day LOL
@@RustyBeauties does it involve gasoline and matches? 😉
I love your timing videos. Be watching this with my afternoon tea.
@@RustyBeauties This one? :)
ruclips.net/video/QFp__eBSWAA/видео.html
If anyone has a problem getting a new cam gear which can be adjusted by turning 90 degrees or by turning round (ie 8 different positions) then get a Ferguson TEA tractor gear - its exactly the same gear and still made with the adjustment facility.
Good video Elin! In theory, couldn’t you slot the holes on the cam gear a little bit and get the exact timing you result you want?
Yes, but then you have to rely on the bolts to hold it in position, which requires a lot of torque. There are adjustable gears available, but too expensive. For a stock engine like this one 3-4 degrees advance are not even noticeable. It is worth timing it to the spot if it was a racing engine with a performance camshaft.
I have a question. I am working on a 1960 TR3. As far as I know my cam is stock. I used your video to to set the valve timing. When I check my valve timing fully open I get 134 degrees and 84 degrees respectfully at 50 thousandth. Your cam was 168 and 68 degrees. Obviously my intake valve full open was way different that yours. Do you think that could be correct or did I do something wrong. I did the piston stop method to get to TDC. In my case I replaced the timing change, marked chain and gears and counted the teeth aligned the marks on the original gears and when I put it all back together checked the valve timing, did the calculations and my valve timing was 109 instead of 110 degrees. Again my only concern is the difference in the degrees of fully open on my intake valve of 134/84 degrees compare to yours at 168/68 degrees. I did my check with the head on and measures at the top of the valve spring retainer not at the pushrod as you did.
Wow, you're smart as well as talented! Who knew?!
LOL I went to the RUclips university :)
Well explained Elin. I don't have a Triumph, but if I did....... Anyway, just a thought, could you not slot two of the holes in the cam gear slightly, set the timing bang on, then drill through the gear and flange and install a cotter pin to lock them in position?
In theory everything is possible, but it is not worth for a stock engine like this. 3-4 degrees in advance are tolerance for a stock camshaft. For a performance camshaft , where it is important to be spot-on, there are adjustable gears available. But they are pricy
I have watch twice already so impressed and I feel more confident now I will need to do this on my MK2 2ltr Vitesse engine. Once mine is returned from the machine shop. From not realising you need to do this following your videos stripping inspecting measuring, I have successfully measured the cylinders, Camshaft etc. I had 2 cylinders 3.8 thou out of spec the others 1.5 thou. The crankshaft all in spec, The camshaft I have exchanged for a new cut one. The point is the machine shop rechecked my measurements and imagine how pleased I was they were all correct. This is all down to how you teach and show how to do it. Is there a printable copy of your new degree wheel vernier, if you do how to print one? Thank you so much.
Nice to her you find my videos helpful. Send me an email to elin.yakov@rustybeauties.com and I will email you back with the PDF of my wheel.
Hello, even if this is not a precise method, can you explain how to adjust the timing with just the shims? THANKS
And here I thought the timing was about when the distributor sends the spark... which of course has to match the crank and the cam at the proper point in the rotation.... but I thought it referred to the timing of the spark sent to burn the gas.
There's ignition timing, valve timing and if you are really lucky there is also TR6 fuel injection (PI) timing
That is timing too - ignition timing, so you were not wrong
Any chance you can share your Rusty Beauties degree wheel?
Sure, send me an email at elin.yeakov@rustybeauties.com and I will email it to you.
First one here, brownie points please.
You got them :)
Du er god på matematikk
Det var ikke det læreren min på videregående sa :)