'72 K5 - Greg's @MightAsWellK5 Build

[Greg72]

As I mull it over more it seems like I can probably push the axle side mount back 1.5" and keep the PHB parallel to the axle.

The only question is if I can still clear the 3rd member? The further back I go the more it will interfere with the PHB... It's rotated up at about 10* to line up with the front Atlas output.


-G

 

[shady]

Any reason you cant bend the end of the bar up and change the bracket?? I'm sure theres a way to do it and keep the same geometry

 

[Greg72]

The height of that link is important. You don't really want to go higher unless you have no other choice. Plus, that poor PHB is going to look like a pretzel with the additional bend in it. At some point I get concerned about its strength and ability to still locate the axle under dynamic driving loads.

-G

 

[folkenheath]

Any reason you cant bend the end of the bar up and change the bracket?? I'm sure theres a way to do it and keep the same geometry

Thats a good idea, but if you raise that link up then you need to raise the pitman arm up too, and that could pose a problem.

 

[Greg72]

...looks like I'm going to be notching the oilpan.

I set the suspension at full bump again last night and found that I still had more trimming to do on the PS frame rail. Last time I did it the axle wasn't 100% centered under the truck, but it is now.

The frame side PHB mount will fit it exactly 1 spot (non-negotiable) due to the interferences of the lower link mount and the CNC adapter. It will end up about 2" from the frame edge and about 2" below the bottom of the frame rail.

The 3rd member really blots-out all the space on the PS now. There isn't even enough room now to put a small slug of 1.75" DOM between the two even just to test it. I will have to nip off the square corner of the oilpan and plate it back in. Anyone know how much "extra room" exists between the crank and the pan at those forward corners? If I can steal 1" I'd probably be golden.

Here's a good shot of the area I'd need to trim. There is a black Sharpie line on the oilpan a couple inches forward of where the clearance need to improve....

Feels like I may have lost some forward momentum last night with these issues.


On a more positive note, I found an old Scout II steering box less than 20 miles from me for cheap.

The splined portion doesn't reach below the frame. Guess the Scouts used shorter frames than Chevy? Anyway... It's good to have a sample part to work with now.


-G

 

[4X4HIGH]

Greg, make a mark in the exact location you would need to cut out on the pan, there isn't much room though in that front area of the pan and highly doubt you'll get anywhere near 1" of room.

 

[Greg72]

In the spirit of "low tech" renderings like PencilCAD...... here's a rendering of where the passenger side framerail might be heading...

You can see the original framerail in the background, with the new shape as an overlay.

I'm gettting concerned about the amount of cutting that I've had to do to fit the pumpkin fully-stuffed (at 6" of bump travel) and with the panhard bar needing to squeeze into that area as well, it is starting to feel like I'm giving up too much frame strength even once I plate it all back in....

The idea is to raise the framerail about 2-1/2" in the center where the pumpkin and PHB need to fit, with susbstantial care given to grafting the new parts in place and making sure it's all nice and strong once the new frame sections are installed.


-G

 

[folkenheath]

I'm with Scott on this one, there isn't much room in the front behind the oil pan, if you take the curve and continue it back, you have a little room in the sharp corners, but that's only if you don't have a windage tray, which you likely do on that 502. I would leave the oil pan alone there.

Also, now you are considering moving the whole frame up over 2" in one section? You are crazy I tell you, crazy. Not saying it won't work, but damn is that a lot more work.

 

[NorCal_Chris]

Might as well cut the front of the frame off and run tube up there

 

[Greg72]

Heath,

There is a small "bump out" on the oil pan where the clearance is needed.... Not the big deep part of the pan, just a subtle bump with a square-ish shape.... The pan starts out fairly cylindrical near the balancer, then transitions to a slightly deeper, more square shape....then finally transitions to the really deep area. The interference is in that first transition from cylindrical to square-shaped.

You can see that it's almost directly underneath the motor mount bolt holes in the image.


EDIT: Photo attached...

I don't know what to tell you about the frame mod..... That kind of a change (and the subsequent work involved) doesn't even phase me any more. You can tell I'm not a "for profit" fabrication shop .... If the idea makes sense and solves the issue (or at least moves the build forward) I just keep my head down and log the necessary hours to get it done.


-G

 

[folkenheath]

Heath,

There is a small "bump out" on the oil pan where the clearance is needed.... Not the big deep part of the pan, just a subtle bump with a square-ish shape.... The pan starts out fairly cylindrical near the balancer, then transitions to a slightly deeper, more square shape....then finally transitions to the really deep area. The interference is in that first transition from cylindrical to square-shaped.

You can see that it's almost directly underneath the motor mount bolt holes in the image.

I don't know what to tell you about the frame mod..... That kind of a change (and the subsequent work involved) doesn't even phase me any more. You can tell I'm not a "for profit" fabrication shop .... If the idea makes sense and solves the issue (or at least moves the build forward) I just keep my head down and log the necessary hours to get it done.


-G

I added a smiley because I didnt want to sound too serious when I called you crazy, maybe it should of been like Kert says, "kwazy!".

As for the oil pan, not sure if it helps you picture the clearance, but here are some pictures of my BB before I put the oil pan on...some have the windage tray installed. I also added one with the moroso pan installed. Make sure you keep at least .050" absolute minimum between anything and the rotating crank and rods if you decide to do it.

 

[ryoken]

Greg, would it help if you moved the PHB point in and down just a touch, like this?

 

[MNorby]

Prob need to hang it off the side of the frame as far as you can to try to keep the length of the phb and draglink somewhat close or is that not going to be able to happen?

 

[Greg72]

I added a smiley because I didnt want to sound too serious when I called you crazy, maybe it should of been like Kert says, "kwazy!".

As for the oil pan, not sure if it helps you picture the clearance, but here are some pictures of my BB before I put the oil pan on...some have the windage tray installed. I also added one with the moroso pan installed. Make sure you keep at least .050" absolute minimum between anything and the rotating crank and rods if you decide to do it.

Heath, no worries... I get most subtle humor around here, and certainly can take a joke even if it's on me at times.

It's funny though, looking at your engine photos it looks like there is a main bearing cap aligned perfectly with the 3 motor mount holes..." which might suggest that there are no rotating parts in the exact spot I'd want to put my small cutout. An inch either way and I'd have to be worrying about the counterweights of the crank.... But miraculously it looks like I might actually be able to pull this off! The windage tray is toward the flywheel side of the motor, which will also be out of the way for my cutout.

Greg, would it help if you moved the PHB point in and down just a touch, like this?

Paul, you nailed it! Thats the exact spot I ended up with last night. Roughly 2" out from the frame and roughly 2" down.... With the suspension stuffed there is literally only one small pocket there where I can hold a bare heim.... And that's it.


-G

 

[Greg72]

Prob need to hang it off the side of the frame as far as you can to try to keep the length of the phb and draglink somewhat close or is that not going to be able to happen?

I keep struggling with this one.

If the lengths are identical, then the frame side PHB mount should be out there pretty far....... The draglink goes all the way out past the knuckle pivot to the steering arm which adds length that has to be accounted for in the PHB somehow.

The only other option I can think of is to do an "inside the frame" steering box. That would shorten up the draglink and even if I only build a small frameside PHB mount, the lengths could end up the same.

Keep in mind, the two bars would be the same length but would NOT be aligned at the heims (squarely). The draglink would be shifted a few inches forming more of a parallelogram shape if you connected all the heim and link points together.





-G

 

[MNorby]

It would nearly be very hard to have the draglink and panhard directly in front/behind each other and be same length unless you mount axle phb bracket over the top of the kingpin area, seems like most are offset from rigs I've paid attention too.

edit one for reference: http://www.pirate4x4.com/forum/11428849-post195.html

 

[4X4HIGH]

It's funny though, looking at your engine photos it looks like there is a main bearing cap aligned perfectly with the 3 motor mount holes..." which might suggest that there are no rotating parts in the exact spot I'd want to put my small cutout. An inch either way and I'd have to be worrying about the counterweights of the crank.... But miraculously it looks like I might actually be able to pull this off! The windage tray is toward the flywheel side of the motor, which will also be out of the way for my cutout.





Paul, you nailed it! Thats the exact spot I ended up with last night. Roughly 2" out from the frame and roughly 2" down.... With the suspension stuffed there is literally only one small pocket there where I can hold a bare heim.... And that's it.


-G

Better look again Greg, that oil pan bolt hole just below the engine mount hole is directrly in line with a counter weight.

 

[Greg72]

I guess I'll have to just cut that counterweight off and keep the engine RPMs down.......


















-G

 

[4X4HIGH]

I guess I'll have to just cut that counterweight off and keep the engine RPMs down.......-G

I was going to say that I did remove 3/8" off the counter weights already but then I remembered that was on the 496 stroker.

 

[Greg72]

OK....found a good photo from the original 502BBC build.

Here's a clearer shot of how everything lines up:

The main bearing cap IS slightly offset from the motor mount holes.... but not too much. It looks like the best reference is actually the oilpan bolt holes. The perfect spot for clearancing the pan would be between the 3rd and 4th oilpan bolt when counting from the harmonic balancer side.

For reference, here is the original mark I made with the new numbered bolts overlay...

This seems totally do-able... Given that I cut the pan directly over that main bearing cap, what sort of clearance do you all thing is realistic?


-G