Thank you for sharing your attention to detail.
It's the little things some of us never think of that make a difference.
It's the little things some of us never think of that make a difference.
400/450 stroker....Cheap parts, lotta work.
- Thread starter IQ52
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The first 400/451 stroker that we did needed the block ground along the indicated red line at the junction of the main webbing and the bottom of cylinders 4 & 8. This being necessary to clear the modified 440 crankshaft counterweights. With this engine I have .050" of clearance from the crankshaft counterweight. If it hits with that much clearance I have some other kind of really big problems going on.
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Did you turn down the couterweights, and you still only have .050 clearance?
Jim, cool build. Thanks for sharing all this.
I think I remember Jim sayin his pappy whipped those up.
See post #47............
Oh ok. Thanks. How are they made? Hard to see the inside. Is it a threaded sleeve welded to the rockers? Pretty cool idea.
It looks as if it is a threaded insert shaped like a mushroom tappet that is pressed into the rocker arm from the underside. I don't see any welding and there is proud metal pushed up around the outside of the insert on the top of the rocker arm.
Wow and it stays put. Imagine that. I'd be skeered.
Cody and I have done some strange things with those rockers. In 2007 or 08 we used them on a 7.5:1 compression, stock rod, cast piston, 383 that made 525 HP at 8,000 rpm on the Westech Performance Group dyno in Mira Loma. It was the same day our '71 Road Runner with a pump gas 451 made 554 RWHP on the chassis dyno there. My boys and I were dashing back and forth between the engine dyno and chassis dyno wearing out our track shoes.
I went back and reread. You say the mushroom is on the BOTTOM side and they are pressed in FROM the bottom? That would work then, since that's the wan the pushrods' force is. Or did I read that wrong? Interesting for sure.
You have it correct Rob. They are pressed in from the bottom.
Ok, then I might not be as skeered. lol
You guys paying attention? Wow!
Imagine, using the Crane Gold Race rockers we had to make a rocker shaft relocation kit here at the shop to move shaft this much. It will reduce the sweep across the valve tip from .110" wide to .040" wide.
Offsetting the holes in the shaft...........
We ended up with this.........I can make the upper clamps this beefy because the lash adjusting screws on the rocker arms stick up higher at full lift than the rocker clamp nuts do.
Offsetting the holes in the shaft...........
We ended up with this.........I can make the upper clamps this beefy because the lash adjusting screws on the rocker arms stick up higher at full lift than the rocker clamp nuts do.
Lordy, knocking all the burrs off by hand wasn't fun. And I had to do six of the bottom spacers again because they came out .035" too tall and moved the the pattern off center towards the exhaust port exits and spread it out to .050".
You can kinda see the pattern on the left valve without the correction kit. It is off center towards the intake port openings and .110" wide. The valve on the right, using the correction kit, has a sweep pattern of .040" and is centered on the valve tip. Bad picture but it is the best I could do for now.
You can kinda see the pattern on the left valve without the correction kit. It is off center towards the intake port openings and .110" wide. The valve on the right, using the correction kit, has a sweep pattern of .040" and is centered on the valve tip. Bad picture but it is the best I could do for now.
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U will have more hours in this build than ur customers race builds. Kim
LowDeck451
Well-Known Member
A few years ago, I think it was you or Challenger340 that posted pictures of how and where to grind the block and crank for a 400/451. The counterweights had a 45* cut on the edges and the block was ground in the area you’re showing IIRC? His point was, a guy could do this part at home and not pay the machine shop. Does this sound right? Thanks.
Are these corrections to stock length valves? Or should we be checking factory setups to see how far off they are?
Seems like anytime you go to a roller tipped rocker arm there will be corrections to be made. These are very close to standard length valves.
I've seen the post to which you refer but I had nothing to do with it. The method I've posted is the only way I have done it.
I thought all that was required was turning the counterweights down. Is there a reason you do it differently?
I'm guessing that Chrysler didn't always machine the 400 blocks exactly the same. Sometimes just cutting the counterweights down clears and sometimes you grind the block or the edge of the counter weights also. Supposedly some just do a major 45 degree bevel on the counterweights by number 4 and 8 cylinders and don't cut them all .120" in radius on the lathe like I do.
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