400/450 stroker....Cheap parts, lotta work.

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Thank you for sharing your attention to detail.
It's the little things some of us never think of that make a difference.
 
Can you post a close up of those converted rockers?
Sorry for the delay............

400-450 rockers 004.JPG
 
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.

400-450 crnk clearance 005.JPG
400-450 crnk clearance 006.JPG
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Did you turn down the couterweights, and you still only have .050 clearance?
 
Yep. They hit on a previous engine that had the crank ground exactly the same way. Life can be so damn cruel.
 
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I wonder if those rockers are home made or factory experimental?
 
Jim, cool build. Thanks for sharing all this.
 
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.
 
It looks as if it is an 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.
 
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.
 
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.
 
Any con-rod you install in your engine must be prepped. I don't mean just wash it, I mean prep it. Factory, rebuilt, or new aftermarket must be prepped. One exception I've found was a set of new Molnar rods that had already been prepped.

You need to separate the cap from the rod and lightly file all the connecting machined surfaces. The edges where the bearing surface and the cap and rod meet have a sharp edge that could strip some of the metal bearing back off when you push the bearing into the cap or rod.

View attachment 1715697348

This picture shows the small triangular file I use to do the operation. I'm not putting a bevel on the rod/cap just gently rounding the mating surface all around the ends of the cap and rod to remove any small chips that may get into the engine. Additionally, more often than not, the register that the bearing tang rides in will have a sliver of proud metal inside the register. Often I cannot easily get the file to remove that sliver and I have to rely on my trusty Buck pocketknife to cut it out.
View attachment 1715697349

I also lightly sand, using flat surface with 280 grit, the sides of the caps and rods looking for any proud edges that may interfere with the side clearance or mess with the adjacent rod or the crank. I'm not sanding them smooth, just looking for high areas that may need attention.
View attachment 1715697350

I even lightly sand the corners of the cap and rods when possible to get them a little smoother for bearing installation
View attachment 1715697351
Now we wash everything up and install the bearing into the rods and measure the rod bearing clearances.

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.
400-450 rocker correction 009.JPG


Offsetting the holes in the shaft...........
400-450 rocker correction 001.JPG
400-450 rocker correction 003.JPG


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.
400-450 rocker correction 008.JPG
 
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".

400-450 rocker correction 002.JPG


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.
400-450 rocker correction 006.JPG
 
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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.

View attachment 1715701566 View attachment 1715701567 .
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.
 
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...

Are these corrections to stock length valves? Or should we be checking factory setups to see how far off they are?
 
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.
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.
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.
 
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.

View attachment 1715701566 View attachment 1715701567 .

I thought all that was required was turning the counterweights down. Is there a reason you do it differently?
 
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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