Hey guys,
So I've recently had some issues of my car going through timing chain tensioners abnormally fast, and i actually had an instance where my car jumped time on startup due to a failing tensioner. Im running Kelford B cams supported by Supertech 95lb springs and associated VT so there is obviously a much heavier load on the chain and tensioner. I read that some of the earlier grinds of the Kelford A's and B's had some issues in causing tct's to fail, however I have no way to confirm if mine are bad or not so before replacing the cams, i decided to modify the OEM one.
Upon doing some research, I found that the tensioners in these k-series motors are one of the biggest failing points even without upgraded cams and vt. Obviously with upgraded cams and vt its just that much more common for them to fail. I looked into the Toda and HR tensioners, and the HR looks to be a wonderful design, with a steeper price tag. The Toda is pretty much a stock tensioner with a heavier duty spring and a hard stop. I read on a forum where someone disassembled a Toda tensioner, and they stated that it didnt seem like the spring that was in it was much if any stiffer than stock, however they didnt have an accurate way of measuring it.
I decided to try and modify an OEM tensioner, and since i had so many failed ones laying around, i wasnt worried about opening one up and hurting it. After getting everything apart, i took some measurements of everything and ordered springs from McMaster with much noticeably heavier spring rates than the OEM, and then I turned myself a hard stop. (I believe the stock spring rate is somewhere around 10-12lbs/inch and the springs I put in are around 22lbs/inch.)
The part that fails on these tensioners is the ratcheting mechanism, which is really the root of the tensioners issues i believe. Most engine failures or when the chain jumps time is seen in low oil pressure situations, or cold start ups. The upgraded spring is to help in this situation, offering more resistance in comparison to the stock spring. I added the stainless hard stop so that if the ratcheting mechanism fails, AND you have a low oil pressure situation, the piston will only retract so much into the housing, keeping enough tension on the chain for it not to skip teeth. The stock tensioner allows the piston to retract almost fully into the body of the tensioner, however with the stop, it allows it to retract only enough to install the tensioner. I have read that some people aren't a fan of the stop as it could possibly lead to chain breakage, but when the stock tensioner ratcheting mechanism is fully operational, it performs pretty much the same thing as the hard stop would; however time will tell.
I installed the modified tensioner into my car yesterday evening, and so far so good. Time will tell how long these will hold up, but i don't see there being any issues with them, however anything can happen. Just figured I'd share my most recent project with you guys!
Pictures below; I am not an expert nor do i know everything about these things so I am 100% open to any comments/criticism, I'm always up to learning.
So I've recently had some issues of my car going through timing chain tensioners abnormally fast, and i actually had an instance where my car jumped time on startup due to a failing tensioner. Im running Kelford B cams supported by Supertech 95lb springs and associated VT so there is obviously a much heavier load on the chain and tensioner. I read that some of the earlier grinds of the Kelford A's and B's had some issues in causing tct's to fail, however I have no way to confirm if mine are bad or not so before replacing the cams, i decided to modify the OEM one.
Upon doing some research, I found that the tensioners in these k-series motors are one of the biggest failing points even without upgraded cams and vt. Obviously with upgraded cams and vt its just that much more common for them to fail. I looked into the Toda and HR tensioners, and the HR looks to be a wonderful design, with a steeper price tag. The Toda is pretty much a stock tensioner with a heavier duty spring and a hard stop. I read on a forum where someone disassembled a Toda tensioner, and they stated that it didnt seem like the spring that was in it was much if any stiffer than stock, however they didnt have an accurate way of measuring it.
I decided to try and modify an OEM tensioner, and since i had so many failed ones laying around, i wasnt worried about opening one up and hurting it. After getting everything apart, i took some measurements of everything and ordered springs from McMaster with much noticeably heavier spring rates than the OEM, and then I turned myself a hard stop. (I believe the stock spring rate is somewhere around 10-12lbs/inch and the springs I put in are around 22lbs/inch.)
The part that fails on these tensioners is the ratcheting mechanism, which is really the root of the tensioners issues i believe. Most engine failures or when the chain jumps time is seen in low oil pressure situations, or cold start ups. The upgraded spring is to help in this situation, offering more resistance in comparison to the stock spring. I added the stainless hard stop so that if the ratcheting mechanism fails, AND you have a low oil pressure situation, the piston will only retract so much into the housing, keeping enough tension on the chain for it not to skip teeth. The stock tensioner allows the piston to retract almost fully into the body of the tensioner, however with the stop, it allows it to retract only enough to install the tensioner. I have read that some people aren't a fan of the stop as it could possibly lead to chain breakage, but when the stock tensioner ratcheting mechanism is fully operational, it performs pretty much the same thing as the hard stop would; however time will tell.
I installed the modified tensioner into my car yesterday evening, and so far so good. Time will tell how long these will hold up, but i don't see there being any issues with them, however anything can happen. Just figured I'd share my most recent project with you guys!
Pictures below; I am not an expert nor do i know everything about these things so I am 100% open to any comments/criticism, I'm always up to learning.
Modified/Upgraded my OEM TCT!
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