Trickflow Valve springs & Scrub pattern
I think the pushrods are okay. WE have like 2 to 2 1/2 adjustment screw threads showing. Tried to set it up how Smith Brothers called for.
The car wont be raced a lot but now and then in the summer. I grew up with this stuff with my dads Roadrunner and my brother Satelite. We would go to Mopar nationals and some other races years ago with their cars.
I can not see well enough to drive the Duster so my brother is my driver. I had a chance to built an engine how I wanted for it and I really wanted to built a very strong engine. Don't really care if its real streetable. Putting this together and picking all the parts I would expect in the 550hp range at peak. I would think it would get the car in the low 11s easy and maybe if the chassis and converter is right be capable of high 10s. I don't know that I want to put a roll bar in so I figured we would need to put street tires on if it did well and track MPH like a dyno. So seeing the MPH so far off I really felt something had to be wrong with the engine. So this is where I am.
Here is a link to my post with the build.
Stroker Performance Review
Im not sure who told you the adjuster needs that many threads showing, but that is dead wrong.
The ball of the adjuster should be down .281 plus .050 minus .000 and that’s where they should be.
When you hang the adjuster that far down, a few things happen.
One, the cup of the pushrod is so low, that the oil that should be coming out of the rocker to lube the adjuster and cup that the cup doesn’t get direct oil. You are now relying only on splash oiling and the mist that is blowing around in the valve cover.
Two, by making the adjuster that far down, you actually slightly REDUCE the rocker ratio. On most rockers, the adjuster is at an angle away from the shaft. Probably not saying it the best way, but look at the adjuster and it’s relationship to the tip of the rocker. Rocker ratio is simply the difference in the length from the center of the adjuster to the center of the shaft, and the length of the center of the shaft to the tip of the rocker.
So, dropping the adjuster usually makes the distance from the adjuster to the center of the shaft LONGER, thereby reducing the rocker ratio.
And, hanging the adjuster that far down changes the geometry on the pushrod side of the rocker. There isn’t much you can do about the geometry on that side of the rocker, but misadjusting the length of the adjuster just makes the geometry on that side of the rocker worse.
I suspect by the time you get the valve side geometry correct, you’ll need new pushrods anyway, so when you measure for them run the adjuster out .281ish.
Also, at some time in the past, someone made the command decision to change the RADIUS is the seat in the lifter. Virtually every new lifter I’ve seen lately (since I started paying attention anyway) now has a 3/16 radius and NOT the common 5/32 radius that most pushrods have.
When I put my junk together I caught it, and said piss on it and let it slide, and it bit me right on the ***.
What happened is I needed to pull the rockers off for some reason I no longer recall. A simple task to put the rockers back on became a giant crap sandwich.
That small radius on the pushrod end allows the pushrod to drop down out of the seat, and if your not careful, you set the lash with the pushrod sitting on the edge of the seat.
Since my valve to piston is kinda tight, and I missed the couple of pushrods that slid out of the cup, I got bent valves.
When you get the correct radius on the ball of the pushrod, they about can’t slide down like that. Plus, it’s the correct radius on the pushrod for the lifter.
We (FABO member lead69 and I) just did a tunnel ram 340 and his lifters had the big radius. You could almost stand 10 feet from the engine and throw the rockers on and the pushrods stayed in the lifters.
If you don’t have a radius gauge, call Smith Brothers and ask them to send you one. Then you can measure the radius accurately and get the correct ball on the pushrods for the lifters you have. I’d be surprised if you do NOT have the 3/16 radius.
EDIT: the 9/32 adjuster distance (.281) is for BALL adjusters and NOT for CUP adjusters. Just want to be clear on that, and PRH pointed out in his post below.
