TF 190 Heads
I have the Hughes 1.6: 1 aluminum rockers on my cast iron heads. I was wondering if you had any experience with these rockers on aluminum heads? I've heard several engine builders talking about comp, PRW, Harland Sharp, ect..
I was wondering about geometry as they seemed to have bolted right on stock heads without any need for correction..
I guess what I'm asking is if you think they would be worth trying on the new trick flow heads or should I just add the cost of those as well? And like stated before thank you for your time if you get a chance...
Yep, I have experience with them. As far as whether they "need correction", I suppose it depends on one's definition of geometry. If getting the pattern centered is the goal, that can be done by changing the length of the rocker, but the engine doesn't care whether the pattern is centered or not. It only cares what the valve is doing and the cam is dictating that through whatever the rocker geometry is, whether good or bad.
The rocker is not the issue for getting the rocker sweep minimized, it is the stand height, which means the head is the problem. Every roller rocker, including the Hughes rockers, will need that adjustment to the head, but the rocker design and net valve lift determines how much.
The rocker issue is in the pushrod side, and I've seen Hughes rockers drop a bunch of ratio when the other corrections are made. They aren't the only ones with the issue, but the angles and adjuster placement is so bad, that a lot of motion is lost from over arcing the adjuster at full lift. That leaves you with a choice. Do you A, leave it alone and have rpm limiting valvetrain instability and possible parts failure, or B, make the adjustment and lose some lift and higher lift duration, but have a reliable, stable valetrain? There is always C, which is pay extra for a properly designed custom rocker, make the shaft adjustment, and have the best of both worlds.
From my perspective, on a relatively low budget build, the best answer is B, because the valvetrain will be stable, and I've never had a motor noticeably lose power from loss of lift. My own dyno testing showed a power increase from increased rpm capability.
Sorry if I got a little of track here, but I wanted be informative to anyone reading. The older Hughes rockers were pretty short, so they may not fit as well, but the newer small block rockers I've dealt with are made by HS and are quite a bit longer. Regardless, they can be made to work. It just might take some manipulation.
