emagdnim Posted April 30, 2008 Report Share Posted April 30, 2008 I don't know what the stock one is made of, haven't really looked at it, but a place local to be will custom make my timing chain into a 304 stainless steel double roller chain... I'm not sure if the stock one is a double roller or not. These have different ratings on them as well. Anyone ever dabbled into this? Link to comment Share on other sites More sharing options...
Chad Posted April 30, 2008 Report Share Posted April 30, 2008 I don't know what the stock one is made of, haven't really looked at it, but a place local to be will custom make my timing chain into a 304 stainless steel double roller chain... I'm not sure if the stock one is a double roller or not. These have different ratings on them as well. Anyone ever dabbled into this? I have never heard of upgrades, but 304 is not the strongest stainless anyway. 304 is deffinalty stronger than mild steel, but weaker than a good carbon or alloy steel. Does this shop cater to motor cycles? BTW, it's a double roller. and in teh 10 years on this site, I've never heard of a chain failure. Link to comment Share on other sites More sharing options...
emagdnim Posted April 30, 2008 Author Report Share Posted April 30, 2008 No, its a weird kinda "we do it all" shop... They make Carbon double rollers as well, and the spec's on those are way better. (Like ft/lbs it holds.. all that) Stock ones stretch ever? Link to comment Share on other sites More sharing options...
Chad Posted April 30, 2008 Report Share Posted April 30, 2008 there have been lots of rumors, but no one has ever documented a stretched chain in any way, shape, or form, let alone by how much they stretched. Even if it did, if you have an adjustable cam gear you could compensate. Not a bad idea, but it woud be upgrading a part that isn't defective. Link to comment Share on other sites More sharing options...
emagdnim Posted April 30, 2008 Author Report Share Posted April 30, 2008 I like to over compensate.... rumors are enough for me to upgrade it. I'm trying to push the head threw the hood. Link to comment Share on other sites More sharing options...
Technology Posted April 30, 2008 Report Share Posted April 30, 2008 just run it stock till it pops. Link to comment Share on other sites More sharing options...
emagdnim Posted April 30, 2008 Author Report Share Posted April 30, 2008 (edited) Here is some information on our timing chain, Its a "British Standered Roller Chain" Remeber, ours are double... these specs are for one side... Chain Type: 06B-1 L, Pin Length:0.500 Pitch: 0.375 Roller Ø: 0.250 Pin Ø: 0.129 Width: 0.225 Height: 0.323 C: 0.403 "in a roller chain, the outside diameters D of the rollers and the outside diameters d of the pins extending through bushings on which the rollers are disposed satisfy the relationships 0.72P≦D≦0.79P and 0.40P≦d≦0.44P where P is the pitch of the roller chain. The height H of the inner plates of the chain satisfies the relationship 0.96P≦H. The elongation ratio of the chain is significantly reduced, and improvements in breaking strength of the pin and in the rotational fatigue of the chain are realized. Consequently wear resistance, strength, and endurance of the chain are significantly improved, making the chain suitable for use as a timing chain in an engine that rotates at high speed." http://www.freepatentsonline.com/7121969-0-display.jpg Inventors: Kaga, Arimasa (Osaka, JP) Shimaya, Kazuhiko (Osaka, JP) A B-type roller chain, designated a “06B” chain according to JIS B1801 (coincident with the ISO number) has been used commonly as a power transmission medium in an automobile engine. This chain has a pitch of 9.525 mm, an outside roller diameter of 6.35 mm, and an outside pin diameter of 3.28 mm, It has been reported that, when the above-mentioned conventional roller chains are used as timing chains in automobile engines in which high loads, for example 4 kN, are encountered, some of the roller chains do not exhibit the expected endurance. Therefore, enhancement of reliability of the engine and of the endurance of the roller chain, has become an urgent problem. As a result of continued study, we have found that the “elongation—wear resistance” of a roller chain is exceeded when a high speed engine applies an unexpectedly high load to the pins of the roller chain. The conventional ratio of the outside diameter D of a roller, to the pitch P, and the conventional ratio of outside diameter d of the pin to the pitch P (D/P and d/P), which were set in accordance with the conventional size balance, are not always the optimum values. The general object of the invention is to solve the above-mentioned problems encountered in a conventional roller chain, and to provide a roller chain with enhanced wear resistance and strength, and particularly good endurance when the roller chain is used as a timing chain in an automobile engine which rotates at high speed. More here.... http://www.freepatentsonline.com/7121969.html Edited April 30, 2008 by emagdnim Link to comment Share on other sites More sharing options...
emagdnim Posted April 30, 2008 Author Report Share Posted April 30, 2008 The part number for the stock chain is MD021230 Link to comment Share on other sites More sharing options...
Whiplash Posted April 30, 2008 Report Share Posted April 30, 2008 British Standard was dropped from OEM during WW2. Link to comment Share on other sites More sharing options...
TainterRacing Posted May 2, 2008 Report Share Posted May 2, 2008 I dont think its something you need to bother with unless you making a high reving motor say 8K. But as we know a 2.6 is not a high rev motor. Link to comment Share on other sites More sharing options...
emagdnim Posted May 2, 2008 Author Report Share Posted May 2, 2008 I dont think its something you need to bother with unless you making a high reving motor say 8K. But as we know a 2.6 is not a high rev motor. Eh, I'm worried about stretching it at 10k if I accidentally don't hit the electric shift button at 9K. Link to comment Share on other sites More sharing options...
Technology Posted May 2, 2008 Report Share Posted May 2, 2008 get a scattershield for the timing cover. lolz. Link to comment Share on other sites More sharing options...
TurboRaider Posted May 3, 2008 Report Share Posted May 3, 2008 Eh, I'm worried about stretching it at 10k if I accidentally don't hit the electric shift button at 9K. The average torque required to turn the cam should fairly be constant over RPM. The power required to turn the cam goes up with RPM since power is a function of RPM and torque. The stretching load does not double becasue you go from 4000 to 8000 rpm, just the power to turn the cam. Basicly, the cam should not require more force to turn at 8000 rpm than at 9000 rpm. That said, a valve train setup the requires more spring pressure to prevent valve float at higher RPM would increase timing chain loads. As a referance point we have a double roller chain running a 4 cyl valve train. How does our chain compare to a SBC opening 2X the valves with a lot more sping pressure? Also if you have rollers rockers chain loading will be lower and as RPM goes up inertia helps even out the torque pulses. Nice to know you can get a custom part made, I would break a stock factory chain in (thats when the most change occurs), degree the cam and see how much the chain is moving on you over several runs. You might find that the factory part is very well built since it was designed to last at least 140,000 miles. If you decide to go forward an interesting test would be to cut one apart and have the shop tell you if they can do any better. Kevin C Link to comment Share on other sites More sharing options...
emagdnim Posted May 3, 2008 Author Report Share Posted May 3, 2008 Thanks Kevin, Thats just the kind of response I was looking for. I just like to go over every part on the car and look for improvements to be made before i run it. Thanks again. Link to comment Share on other sites More sharing options...
Tim_C. Posted May 6, 2008 Report Share Posted May 6, 2008 Would a lighter chain help? Link to comment Share on other sites More sharing options...
emagdnim Posted May 6, 2008 Author Report Share Posted May 6, 2008 Would a lighter chain help? I like the sound of that. Link to comment Share on other sites More sharing options...
TainterRacing Posted May 6, 2008 Report Share Posted May 6, 2008 (edited) If it was lighter it might help But.... I Say you would be a lot better off with say AL rods in the motor Just my thoughts Edited May 6, 2008 by TainterRacing Link to comment Share on other sites More sharing options...
emagdnim Posted May 6, 2008 Author Report Share Posted May 6, 2008 If it was lighter it might help But.... I Say you would be a lot better off with say AL rods in the motor Just my thoughts The car will have them. exhausting all options... BTW, Stock chain weighs in at 1lb 9.6oz Link to comment Share on other sites More sharing options...
Tim_C. Posted May 7, 2008 Report Share Posted May 7, 2008 The car will have them. exhausting all options... BTW, Stock chain weighs in at 1lb 9.6oz Wow! I could swear it weighs more than that, but I'm sure you are correct. Yeah, with AL rods, why try to go lighter on the chain. And why try at all I guess when you go with AL rods and lose a lot more with much more positive effect on the ability to stay in the desired RPM range. Link to comment Share on other sites More sharing options...
Shelby Posted May 15, 2008 Report Share Posted May 15, 2008 load on the chain will be greatest durring rpm increase , esp durring the higest rate of rpm building sort of like when pulling a car with a rope, it takes a lot less effort to keep it moveing then you try to increase the speed your going or slow it down , roller rockers would deff lessen the strain on any chain set up Link to comment Share on other sites More sharing options...
TurboRaider Posted May 16, 2008 Report Share Posted May 16, 2008 load on the chain will be greatest durring rpm increase , esp durring the higest rate of rpm building sort of like when pulling a car with a rope, it takes a lot less effort to keep it moveing then you try to increase the speed your going or slow it down , roller rockers would deff lessen the strain on any chain set up What Shelby is refering to is inertia loading as the cam accelerates. IMHO its not an issue since the inertia loading is small compared to the force required to overcome the drag from the valve train. There are two reasons why its not a big factor: 1: The cam is accelerating at 1/2 the rate of the crankshaft, and 2: The cam is small in diameter so tis moment of inertia is small. Combine a small moment of inertia with low acceleration rate and you dont get a very large force. You can cut some weight out of your motor if you center drill the cam. Kevin C Link to comment Share on other sites More sharing options...
Tim_C. Posted May 16, 2008 Report Share Posted May 16, 2008 Well, when you campare what it takes to turn a roller cam by hand on a head (off the engine) with 110 Lbs of seat pressure, against a stock cam with stock slip rockers (hyd or mech), and stock springs, you can easily see it takes much less effort to turn the roller cam. Plus, the steep lobe actually helps the cam to pop forward on the way down the lobe, which helps other rockers that are on the way up. They probably defeat themselves so to speak, but you can feel a much more prominent opening and closing of the valves for better, more precise action than a gradual type in the slippers. I can stand over 15 feet away from my exhaust and it pelts my pant legs visibly. It is quite amazing, but moreso reassuring to know it is opening and closinig the valve faster for more time fully open than a slipper can offer. My machinist was very amazed at the difference in force required to turn each type. When doing it by hand, the cam pops your arms forward with the valve action on the roller, and is quite mushy and uneventful with the slipper. Link to comment Share on other sites More sharing options...
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