Built Motors and 2 -steps: Tensioner arms

[RedVenom48]

So Im starting to acquire parts for my engine build up. One of the goals I have is to use the 2-step feature on my WOT Box. So far I have Accufab pivot pins and Cloyes billet secondary gears. Im going to pick up a TSS billet lower gear, Accufab oil pump gears, Accufab secondary tensioners and chains, Accufab cam spacers and ARP cam bolts. Im strongly considering JDM S/S cams in the future.

I want to know if you guys think the factory primary chain tensioner arms are strong enough for 2-step use? Do you think cryo treating factory tensioner arms and guides can make them stronger?

I ask because someone who I very much respect in the Mod motor world was... not a fan of the quality of the most widely available Ford Mod engine parts when asked.

Car will be at the track 4-5 times a year but mostly a street bruiser.

 

[Catmonkey]

Shelby Mike Racing also makes chain arms.

 

[RedVenom48]

Shelby Mike Racing also makes chain arms.

Looked at their product and Im impressed. Not cheap, but the quality of machining looks top notch.

 

[Catmonkey]

Cryo may help add strength to the stock components, but won't be as strong as billet. The stock arms look fragile next to these. You know 2 steps are hard on these pieces, so put your money on known problem areas. The Shelby Mike arms are in my engine.

 

[RBB]

I wouldn’t trust the OEM arms and guides with repeated use of a 2 step. Get the Shelby Mike or MMR (a little cheaper) arms. They're a little pricey, but just another drop in the bucket as far as engine builds go, and good insurance. I'd hate to skip out on something at that price point and have it lead to a much bigger and costlier problem down the road.

 

[RedVenom48]

I put them on my list of "To buy" parts. Definitely have no plans to let cast arms be a weak link. Big thanks to you all and @JB_2010GT500 for pointing me to the Shelby Mike units!

 

[JB_2010GT500]

Sure thing, Ed! As others have said, it's one of those parts that sucks to spend extra money on, but is really affordable compared to buying and building another motor! Shelby Mike pieces are top notch, and he's a nice guy to boot.

 

[biminiLX]

Do we have evidence of arm failure? I plan to use the WOT box 2-step occasionally but didn’t go with the billet arms. My tuner and JDM didn’t think they were necessary or mention failures.
They do look serious compared to the stockers.
-J

 

[Catmonkey]

Do we have evidence of arm failure? I plan to use the WOT box 2-step occasionally but didn’t go with the billet arms. My tuner and JDM didn’t think they were necessary or mention failures.
They do look serious compared to the stockers.
-J

I have seen a few pics of broken components, but no saga's written. While this isn't a chain drive system, just look at the abuse this belt tensioner takes on the line with a 2 step.


This has got to be hard on engine internals.

 

[RBB]

Do we have evidence of arm failure? I plan to use the WOT box 2-step occasionally but didn’t go with the billet arms. My tuner and JDM didn’t think they were necessary or mention failures.
They do look serious compared to the stockers.
-J

I’ve never actually seen anyone post a thread with a failure....

 

[98 svt]

I was considering a 2 step on my new build as well. Having second thoughts now.

 

[biminiLX]

I was considering a 2 step on my new build as well. Having second thoughts now.

If you truly drag race for good times with a stick car you almost need one.
-J

 

[RBB]

If you truly drag race for good times with a stick car you almost need one.
-J

Agreed, I wouldn't even consider it optional for drag racing our heavy stick cars. If you want quicker and consistently repeatable ETs then it's the only way to go.

 

[RedVenom48]

I was considering a 2 step on my new build as well. Having second thoughts now.

Im not going to lie, its a commitment to getting strong parts. The alternative though is that little nagging voice in the back of your head and a potential boat anchor under your hood. 2 steps are pretty rough on the timing system. The lower crank gear and oil pump gears should be on there as a minimum.

What should be considered MANDATORY is the tensioner arm pivot pins. Standard aluminum block pins are 8mm dowels with 6mm threads. They can shear off at the block under abusive stress (2-step, high RPM and load etc). Upgraded pins will require machining the block to accept 8mm pin threads. Available from Cobra Engineering, Accufab and I believe JDM Engineering sells a set of ARP produced pins.

Picked up the TSS lower crank gear and the Accufab Pump Gears. The price on the Accufab OPGs is.... breathtaking to say the least. But after getting them in my hand, and knowing its made out of precision machined tool steel I can accept their cost. I picked up a Ford Performance GT500 oil pump. Fresh housing and high pressure valve with a steel backing plate and the Accufab gears should mean no issues with oil pressure. The Accufab dowels and cam spacers are REALLY nice pieces too.

I need new primary chains, secondary chains and passenger tensioner, cam bolts and arms. My timing system is complete after that!

 

[RBB]

Im not going to lie, its a commitment to getting strong parts. The alternative though is that little nagging voice in the back of your head and a potential boat anchor under your hood. 2 steps are pretty rough on the timing system. The lower crank gear and oil pump gears should be on there as a minimum.

What should be considered MANDATORY is the tensioner arm pivot pins. Standard aluminum block pins are 8mm dowels with 6mm threads. They can shear off at the block under abusive stress (2-step, high RPM and load etc). Upgraded pins will require machining the block to accept 8mm pin threads. Available from Cobra Engineering, Accufab and I believe JDM Engineering sells a set of ARP produced pins.

Picked up the TSS lower crank gear and the Accufab Pump Gears. The price on the Accufab OPGs is.... breathtaking to say the least. But after getting them in my hand, and knowing its made out of precision machined tool steel I can accept their cost. I picked up a Ford Performance GT500 oil pump. Fresh housing and high pressure valve with a steel backing plate and the Accufab gears should mean no issues with oil pressure. The Accufab dowels and cam spacers are REALLY nice pieces too.

I need new primary chains, secondary chains and passenger tensioner, cam bolts and arms. My timing system is complete after that!

Thinking about getting the timing components cryo treated and microblued as well?

 

[70SCJ]

Thinking about getting the timing components cryo treated and microblued as well?

I went ahead and cryo treated my gears and pins. Cheap insurance.

 

[RBB]

I went ahead and cryo treated my gears and pins. Cheap insurance.

I felt the same way. Cryo, REM polish, and microblue for all timing components.

 

[RedVenom48]

Thinking about getting the timing components cryo treated and microblued as well?

Sorry for the delay in response!

Ill be getting the Primary gears, chains, Cloyes secondary sprockets and all my transmission parts cryo treated. All my Accufab parts and TSS Lower gear Im leaving alone. Much smarter people designed some very robust pieces. Ill leave em be lol.