Adjustable rocker arms
Thread Starter
Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,166
From: Dyer, IN
Adjustable rocker arms
I still have not seen a single post on a performance increase associated with using adjustable rocker arms. For those that run them, exactly what benefit have you realized ?
Burning Brakes
Joined: Apr 2009
Posts: 946
Likes: 2
It's a hard question Lucky -- most of them are not a straight-up comparison to stockers. For example, Crane race gold 1.7 arms are actually 1.75:1 ratio and have "accelerated lift". The real benefit in adujstible arms IMO is the ability to adjust the valves rather having to guess at preload, etc. Performance-wise the better pieces (without the other stuff) might be worth 3-5hp (just guessing).
Due to the design of the stock rockers, I do, however, think everyone benefits from aftermarket rockers, based on seeing what happens when the stockers impode (needle bearings in you ears...). It's not a big enough deal that everyone should run right out and do it, but if you are doing a cam and springs anyway...
In that case, IMO, spend the few extra bills and get adjustibles. We're not talking shaft mounted billet Jesels here -- $700. The extra money means a dead nuts valve train, and the other performance benes -- accelerated ramp rates, bigger ratios, whatever.
Due to the design of the stock rockers, I do, however, think everyone benefits from aftermarket rockers, based on seeing what happens when the stockers impode (needle bearings in you ears...). It's not a big enough deal that everyone should run right out and do it, but if you are doing a cam and springs anyway...
In that case, IMO, spend the few extra bills and get adjustibles. We're not talking shaft mounted billet Jesels here -- $700. The extra money means a dead nuts valve train, and the other performance benes -- accelerated ramp rates, bigger ratios, whatever.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
The main advantage I see in adjustable rockers is when running something like Comp R lifters, that have a very narrow and precise preload requirement or when running a solid setup.
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Usually only needed with solid roller setups.
But for anyone else, I suppose the benefit would be not needing to alter pushrod length to get lifter preload set correctly.
But for anyone else, I suppose the benefit would be not needing to alter pushrod length to get lifter preload set correctly.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Its kind of a mixed bag, at least with stud mounted, because the pushrod also sets geometry so both need to be examined together.
