Timing cover is now modified by welding. It has enlarger couple of mm's (<0.1") at the area where there was marks of chain.
Result: It is silent.
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| No, it is not a Noisy cam button but the new roller chain is https://slantsix.org/forum/viewtopic.php?t=54570 |
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| Author: | lgu32 [ Sun Feb 09, 2014 3:29 am ] |
| Post subject: | No, it is not a Noisy cam button but the new roller chain is |
I did the "cam button", an aid to keep camshaft moving forward for my slant. There is just a M8 nut welded to the timing gear cover and there is M8 bolt. I adusted it so that it does not touch to the camshaft bolt. There is probably 1mm gap in between the parts. Basically no touch to each other. When the engine is gold and idle bad the timing gear cover sounds like hammering a steel bucket with a spoon. Light knocks every this and then. When the engine heats the noise goes away. WHat I have been thinking for the reason is the oil thickness. As there is oil channel for each camshaft bearing the oil could go behind the last bearing at the clutch end of the engine - by pulling the cam to the front. And when the engine get warm the oil comes thinner and the hammering stops. I am 100% sure that the noise comes there. I used a stethoscope to test the noise source. The noise is almost continuous when I start from outside with dead cold engine. When I do it in garage there is just few hits. And with the warm engine none. Oil is GULF 5w-40 for "old cars". Other theories, please! |
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| Author: | Rick Covalt [ Sun Feb 09, 2014 4:35 am ] |
| Post subject: | |
If the cam bolt head is smooth and the end of the bolt is smooth then there should be no knocking, I would think. I always use a rocker arm adjusting screw that has the rounded head. Rick |
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| Author: | DusterIdiot [ Sun Feb 09, 2014 8:37 am ] |
| Post subject: | x2 |
Quote: If the cam bolt head is smooth and the end of the bolt is smooth then there should be no knocking, I would think. I always use a rocker arm adjusting screw that has the rounded head.
Yeah, the key is to grind the cam bolt head smooth, and I use the rocker arm screw as well...my last timing cover cam bolt mod I added a washer to the inside of the cover where the rocker arm screw comes through, this helps make the cover a little more rigid if the cam has a fair amount of 'walk'. (My next improvement was to add a strip of .0625 steel to the cover going edge to edge for roller cam use since the lifters can't take any side loading variances and to completely eliminate the "pucker"/pounding if the cam bearings are "loose").-D.Idiot |
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| Author: | lgu32 [ Wed Feb 19, 2014 5:28 am ] |
| Post subject: | |
I did tests with and without the bolt acting a cam button. Not really a big difference. Sounds to me now like the chain is hitting to the timing cover. It does it only when engine is cold. I will open the timing cover as soon the car season is going to change to the motorcycle season and I can garage my Dart for a while. There is a roller timing gear inside. Driven only few thousand kilometers after rebuilt.Probably the chain is little bit wider than the original silent chain. Yes, original is silent... |
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| Author: | lgu32 [ Sat Feb 22, 2014 4:17 am ] |
| Post subject: | Timing chain cover |
Are all timing chain covers the same design? My roller timing chain knocks to the cover when the engine is cold. Everything inside seems to be fine except there is marks below the bigger chain wheel of chain hits. Timing chain is bought from Clifford performance many years ago and it has only couple of thousand kms on it. I have either modify the cover or find another with little more space inside. |
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| Author: | DusterIdiot [ Sat Feb 22, 2014 8:11 am ] |
| Post subject: | Yep... |
Quote: Are all timing chain covers the same design?
Physically yes the cover is pretty much the same...what changes is the timing tab/mounting/ and location of it...If the cam gear is knocking on the cover, then you have other problems, either the cam button is not doing it's job, or the timing chain is loose enough (and bearings) to let the cam slide forwards out of it's bearings... Quote: Timing chain is bought from Clifford performance many years ago and it has only couple of thousand kms on it.
Wonder what brand it was when Clifford bought it...
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| Author: | WagonsRcool [ Sat Feb 22, 2014 8:55 pm ] |
| Post subject: | |
Quote: If the cam gear is knocking on the cover, then you have other problems, either the cam button is not doing it's job, or the timing chain is loose enough (and bearings) to let the cam slide forwards out of it's bearings...
I'd read somewhere years ago that flat tappet cams were designed so that the lifters spinning in their bores "pulled" the cam towards the rear of the engine. That changed with the use of roller lifters so engineers added cam thrust plates to prevent cam walk. I don't know if what I think I know is correct, but I have never heard of any flat tappet (stock/street) engine that had problems with the cam walking out or hitting the timing cover. |
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| Author: | lgu32 [ Sun Feb 23, 2014 1:50 am ] |
| Post subject: | |
No. The cam is not coming out of its space. I have tested this engine with and without "cam button". As told I have there metric 8mm acting as a cam button. It has been its mark to the bolt fixing the cam and chain wheel to each other. To make me sure I have tried to close out the possibility that my cam button bolt is the source of the noise: I did tests with no gap between cam button and with small gap and also without the cam button at all. The sound is there in all of the three cases so we can forgot the "cam button" for this inspection. The only shiny mark inside the cover, which I have registered to be the noise source (with a stetoscope and my ears) is just below the bigger chain wheel. The shiny mark is against back of the chain, not the side. The cam is not walking out but the chain could reach to the cover especially when the engine is cold. Chain is still tight compared to used timing chains I have seen past. So I am thinking this roller set is a bit larger in diameter compared to the OEM chain set and this could be the root reason there. I'll make some measurements there. I bought the timing set about 5 years ago when Clifford still had these. My trash can has been cleared many times since that, but I am sure this set was born in Australia. |
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| Author: | lgu32 [ Sun Feb 23, 2014 3:51 am ] |
| Post subject: | |
It is not possible to see inside the cover how much there is free space between the cover and the chain. But when I put approx 1mm (0.04") tape inside the cover at the place where there were wear signs, I felt that the cover with tape and the chain get a contact when installed. It is really not enough for any chain IMO. I did another test with running engine. Without the cover there was absolutely no mechanical noise at the timing chain area. If removing of the cover takes the noise off, it has to be a part of that "music" I am solving? The chain and chain wheels were running smoothly with no eccentric vibration or shake. I am going ask a mechanicst to modify the cover slightly larger by cutting and welding. |
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| Author: | sandy in BC [ Sun Feb 23, 2014 7:39 am ] |
| Post subject: | |
I would be tempted to carefully hammer it out till it clears. Hammer ....reinstall,,,,check,,,,hammer again .... |
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| Author: | hantayo13 [ Sun Feb 23, 2014 9:35 am ] |
| Post subject: | |
I am with Sandy on this one ...grab the BFH and go to it....fit ....hammer ...fit |
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| Author: | lgu32 [ Sun Feb 23, 2014 11:02 am ] |
| Post subject: | |
Yes it could be possible to hammer it. But because the complete testing needs installation with gaskets I rather made it "big enough" once. The mechanist is my friend, so it is not big issue to do it by cutting and welding. |
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| Author: | Ron Hamby [ Mon Feb 24, 2014 3:18 pm ] |
| Post subject: | |
I have had a couple of different engine builds where I had to create more clearance between the chain and the cover. Each had the cam button adjusted to keep the cam from moving out. The Aussie timing set is the only one I have had that problem with. I always check the clearance now before buttoning it up. Ron |
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| Author: | lgu32 [ Mon Feb 24, 2014 9:11 pm ] |
| Post subject: | |
Quote: I have had a couple of different engine builds where I had to create more clearance between the chain and the cover. Each had the cam button adjusted to keep the cam from moving out. The Aussie timing set is the only one I have had that problem with. I always check the clearance now before buttoning it up.
Thanks. I was already thinking "why this happens just for me". It is the otherwise great timing set, which requires some attention for the cover.
Ron |
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| Author: | lgu32 [ Thu Apr 03, 2014 4:32 am ] |
| Post subject: | |
Timing cover is now modified by welding. It has enlarger couple of mm's (<0.1") at the area where there was marks of chain. Result: It is silent. |
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