'72 K5 - Greg's @MightAsWellK5 Build

[kgblazerfive]

A shorty reversed would do that. Or a custom built reversed would work too.

My HP front had issues with my oil filter because I had to much up travel, no bump stops. If I had headers the front drive shaft would have mashed them long ago. The only headers that I think would fit with a HP would be shorties or custom built ones.

 

[BUDDY]

Why not use a block hugger or even manifolds and run passenger exhaust around front of oil pan and tie into the drivers side. Even maybe a drivers side manifold on passenger side so it dumps at front of engine. .

I love this guys thinking!!

Even maybe a drivers side manifold on passenger side so it dumps at front of engine. .

This especially, is genius. Very nice. Now I need to find a drivers side manifold for the passenger side of my blazer.

I need to get this done pretty shortly. I'll try to take pictures & post what happens.

Later,
Buddy

 

[4X4HIGH]

Greg, are there any custom fab shops around you that build headers? It would probably be eaiser to design your suspension then have a set of headers built around your suspension/driveshaft. Obviously a custom set of headers isn't going to be cheap (I paid $1000 for the headers on my race car years ago) but sometimes spending more money on a part and less time trying to fab everything is worth it in the end. If you're comfortable enough you could even buy a header kit and build them yourself if you have the patience.

 

[Greg72]

Thanks everyone!

Lots of great information and suggestions in the last 24 hours...

The header thing is going to be a struggle. Flipping one to run forward is probably not going to work though. Remember, there is only 6" of clearance between the shallow portion of the oilpan and the top of the axletube at ride height. The portal axle eats up a lot of this room; if I was using a D60 there would be almost 12" of clearance there. The only option would be to go even further forward and cross to the drivers side closer to the crank pulley (or in front of that).... It's starting to look like a violation of "KISS" at that point.

Last night I did some quick calculations on my front axle track width. I plan to match the same 82.625" as the rear axle. Obviously, with the steering knuckles there will be a lot less axletube showing on both sides. In fact, if I weld the Scotty CNC adapter as close as possible to the pumpkin on the passenger side the axle position (as shown in my last photo) is about 4" too far right. Even in the bast-case scenario, that pumpkin has to go further under the framerail to center the axle. This has the side effect of lining up the Atlas output almost PERFECTLY with the front pinion! (front driveshaft length is roughly 52" long BTW). The bad part, is that the driveshaft needs to run closer to the transmission than the framerail.... So the header mods I just did are 100% wrong. Ultimately, I learned too late what some of you suggested; build the suspension and driveshaft first....then modify the headers to fit the remaining space.

I took a look at the ORD website last night, and studied their front suspension kit. It looks like a quasi-parallel 4-link with panhard bar if I'm seeing things right, and the bars run basically at frame width up to the attachments points on the axle. Very elegant in its simplicity and implementation. I need to do a little more digging for source photos and threads about 3 & 4 link (with panhard bar) setups... Maybe with enough studying I can save myself some aggravation and mistakes along the way.


-G

 

[folkenheath]

I took a look at the ORD website last night, and studied their front suspension kit. It looks like a quasi-parallel 4-link with panhard bar if I'm seeing things right, and the bars run basically at frame width up to the attachments points on the axle. Very elegant in its simplicity and implementation.

Thats exactly what I was thinking, parallel laterally, but not vertically so you can tune anti-dive, etc. This could be stronger with an extra link to control the axle while not interfering with your engine as much.

And buidling the headers to suit is awesome, gives you a lot of options. In my uncles drag cars many times he fabs the headers to fit the custom chassis. However, that's also where I differ from most of you guys on here. For rock crawling its obviously better to have a lighter small block with shortys and a Y pipe to get a lower ride height, and you don't need much power for crawling. But being a drag racer , and the wheeling I do is mostly hill climbs and sand drags, the speed demon in me just won't let me cross the line into shortys, especially with a Y pipe, too much of a choke. The closer the restriction is to the engine, the more it hinders performance because the hot gas takes up more volume until it cools further down the pipes.

So I know it may sound crazy, and I'm all 4 building custom headers if you need to, but for me they still have to be long tubes with dual exhaust, I just can't do shortys, there's like a hidden force inside me that won't let it happen. But if you think you'll be doing more rock crawling and don't mind the power loss and the flex from a 3 link vs a horizontally parallel 4 link is more important to you, then go for it, it all depends on how you are going to be using the rig the most and where you want to make the trade-offs.

 

[MNorby]

Not to degrade this build but what are your ultimate goal/ambitions for this rig? A fullsized, big block power, linked on mogs. Would now be the time to make the k5 into a nice streetable rig with the big block and a set of tons pulling a trailer with a tube based rig with mogs that you can beat on and have more fun? I was in the same boat the last few years with essentially a buggy with a cab built into the middle. It wheeled OK for the most part and I didn't care about and cosmetic damage. Still wheeling something that big presented its limitations and now I sold majority of everything off and building a tuber. With your sweet list of parts maybe the K5 isn't the greatest setup, but would make a nice DD/towrig for a lightweight buggy on mogs/oris/etc. Just throwing it out there from my own experiences.

 

[Greg72]

By most CK5 standards, this truck will ultimately end-up as a pretty "soft core" wheeler. Having the ultimate offroad machine was never the objective of this build.

For a period of time, I did the whole Towrig/trailer/wheeler thing and I could see that it wasn't going anywhere good for me.... too much money to build up the towrig, and WAY too much space to store all of those "extras" somewhere on my property.

Ultimately, I just want to DRIVE this truck and enjoy it again. That's my objective, especially now that I have a young son to go cruising around with!! There are a lot of K5 experiences I want to have that don't involve being on a rockpile, or wedged between boulders in the mountains somewhere. I'd like to go camping with it, or just exploring open spaces. I'd like to not worry about whether I have to drive on a highway, and if it rains I still want to be comfortable inside. I'd like to be able to pack my essentials with me (sleeping bags, coolers, campstove, etc) and the full-size K5 is awesome for that. In fact, it's one of the original things that attracted me to Blazers in the first place.

Don't get me wrong, I am looking forward to getting this truck out to Moab as soon as possible too... I really love it there. There are still a lot of trails I've never run, and as I go through the list I'm sure there will be opportunities to do body damage along the way. If I'm lucky, the "transformer K5" idea will allow me to minimize the damage by making the whole vehicle a lot narrower and easier to maneuver... but even if I end up with some damage, it's not the end of the world to me. If there's one thing I've learned over these last MANY years of building this truck it's this:

"It's only metal"


That's it in a nutshell. I have a feeling guys like Ryoken learned this one years ago as a bodyman. So much of what makes a truck "pretty" is superficial and if it's dented or damaged, it can be cut-out and replaced quite easily. I'm not going to cry over cosmetic damage once this truck is running again, but I'm also not going to be "that guy" looking for opportunities to damage my truck to amuse the spectators either.

Based on what I really want the truck to do, I'll admit the parts list is WAY excessive. But remember, I wanted the experience of designing and building something almost "from scratch". In my mind, it's not about the destination... it's about the journey to get there and enjoying the entire process, not just the end result. I guess that's about as simple as I can express my feelings about it.


-G

 

[miniwally]

Greg

This will be my last long distance quarterback post (I hope).

What about not doing portals in the front? Stephen and I have had the conversation several times about how easy it is to place the front axle where it needs to be because it steers and that's what we consider normal. It's the damn rear axle that's hard to position in a way that avoids rocks. You have the portal rear why not just blow off the portal from and get moving forward?

Right now if you took your current axle, put spidertrax inner C's and knuckles on it, mega high nine with an ARB and some axle shafts and make it happen. This solves a lot of problems in the build. Admittedly it changes the journey though. Yo could use 16" travel shocks/ORI's and if needed bumpstop and limit strap that to what ever you can get usable with the steering.

OR like has been said get out there and install a suspension that works with a bit of thinking along the way as to what you are going to do for headers. Get the suspension right then either build headers or get it to someone that can.

Tim from liquid iron industries is somewhat near you I think, he is building some headers for Erik Millers new Ultra 4 car and it appears he has some skills.

I would triangulate the lowers of any suspension you do, play with the calculator and you will see that the roll steer changes, this has good effects. Between caster changes and triangulating the lowers on the race car we went from a handful at 100+ to feeling confident at those speeds so that you can breath and do something else besides drive and pray.

Ask questions and I will help however I can, if you want advice I seem to always have an opinion but this is your deal and you need to do it how you want to, not how you imaginary internet friends think you should do it.

 

[Greg72]

Greg

This will be my last long distance quarterback post (I hope).

Awesome! Does that mean you're flying out here? The plane ticket is on me....



I definitely will listen to your advice and take it to heart. Can't guarantee that I'll use every suggestion but everything will be considered for it's "tradeoffs".

Here's an easy one to start:

When trying to study a 4-link with panhard suspension (like the ORD one) which Excel tool should I use? The basic 4-link calculator doesn't seem to be the right one, since the panhard bar postion plays a big role in establishing roll center (I think!).... would it be better to use the 3-Linkv1.0b (Triaged's 3-Link with Panhard) and just not draw in the 4th link? That seems to be the more "correct" way, though I won't be able to trust the load calculations.... there might be some other side-effects as well?

Honestly, I've got SO much invested in these Mog-9s (both financially and emotionally ) that it would be hard to consider taking the build in a different direction. I get what you're saying about the clearance problems being mostly "out back", but at this point I think it's time to explore the best possible solutions based on the axle I've got.


-G

 

[miniwally]

Awesome! Does that mean you're flying out here? The plane ticket is on me....



I definitely will listen to your advice and take it to heart. Can't guarantee that I'll use every suggestion but everything will be considered for it's "tradeoffs".

Here's an easy one to start:

When trying to study a 4-link with panhard suspension (like the ORD one) which Excel tool should I use? The basic 4-link calculator doesn't seem to be the right one, since the panhard bar postion plays a big role in establishing roll center (I think!).... would it be better to use the 3-Linkv1.0b (Triaged's 3-Link with Panhard) and just not draw in the 4th link? That seems to be the more "correct" way, though I won't be able to trust the load calculations.... there might be some other side-effects as well?

Honestly, I've got SO much invested in these Mog-9s (both financially and emotionally ) that it would be hard to consider taking the build in a different direction. I get what you're saying about the clearance problems being mostly "out back", but at this point I think it's time to explore the best possible solutions based on the axle I've got.


-G

You would need to talk with someone a lot smarter than I on which calculator to use. I would guess the three link myself. Honestly Stephen is the one that does the enginerding, I get impatient and start building.

At the end of the day the way this really works is that you get some rough ideas of general areas that you can place components based on the vehicle configuration. Then you use the calculator to tell you what kind of numbers you have with those locations.

Then you start building it, putting parts and things where they work, and in the end you put the actual numbers into the calc. to tell you how bad it is.

It seems like a circular process but it's needed. You find things like an inch here is a huge deal, but four inches there doesn't change much. That way you can move things with some sort of an educated guess as to what that change will do to the numbers.

I think it's roll understeer that you want in the front, a few degrees is best. roll oversteer will make it to where when the body rolls the axle steers you into the turn harder. Understeer will always try to turn the vehicle out of the turn with body roll, this is MUCH easier to drive. 6 to 8 degrees of caster Pinion pointed right at the transfer case at ride height and get it done.

I am not a fan of four links because they put a lot of stress on the housing. From a manufacturing standpoint they are nice because one bracket does multiple things, and the stresses in the links goes down. For a mass produced and "bolt" on install the only way to make something work well is a four link and with the right ends there is enough compliance in the system to be okay.

 

[Greg72]

OK.... Last night I took a bunch of measurements and took a chance that the 3-Link calculator is the correct one to use (even if a throw in an extra upper link later on)

Here's what I've got:

A couple of things that I think are important:

Anti-Squat (Anti-Dive) is a reasonable value + 61%
My Roll Axis is slightly toward understeer = -1.40*
My Roll Center Height is pretty close to my assumed CG Height = 31.80" vs. ~ 34" CG

For comparison, my REAR values were:

Anti-Squat = 68%
Roll Axis = 0.0* (Neutral)
Roll Center Height = 26.5 vs. ~34" CG Height


In both cases, the Instant Center and Roll Axis points are well beyond the wheelbase of the truck... I'm not sure how that plays into any of this exactly, but it seems like most designs I study seem to have that characteristic also.

Dan (Triaged) coached me that a little negative roll axis up front is good and that a relatively high roll axis is also good, and if the front roll axis was a bit higher than the rear roll axis, that would probably be a helpful as well.

Looks like I have a lot of those items covered well with this latest attempt, but as Brandon just mentioned.... it ain't built yet, so it's anyone's guess if it will actually fit / work / flex without hitting important stuff.

Until I can actually get into the garage to try some of this, I'd be happy to keep the general comments and discussion going.

-G

 

[folkenheath]

I think the 3 link calculator is fine to use Greg, except for the link loads like you stated. But you need the track bar in their for sure.

Also, if you were to add a 4th link to that triangulated configuration, it would bind with the track bar. Also, it appears you lower link would be below your axle tube? Or is it an illusion? You may have to do that a little to get the results you need without the upper tube above the starter!

Also, I am of the belief that the location of your IC effects the reaction on the truck in addition to the actual anti-dive % in this case. So with it so far back it won't have much effect on the truck, which will be very soft and with that % should be very supple during braking.

Ask questions and I will help however I can, if you want advice I seem to always have an opinion but this is your deal and you need to do it how you want to, not how you imaginary internet friends think you should do it.

Thats funny right der. Brandon, your advice is always important because you are one of the people that goes slow and fast and uses your rig on a regular basis, even on stuff like KOH and other races. So it's always good for me to see your perspective, and I'm sure Greg likes it too.

 

[blazinzuk]

The best advice I could give you here is to not let the numbers mess with you too much.

The numbers you have are acceptable for sure. Remember there are as many opinions about links and what works good here and there as there are rigs out there.

It seems to be that with your numbers it will be what I refer to as a neutral suspension setup, there won't ( or shouldn't) be any really screwy handling characteristics, shouldn't be massive body roll, shouldn't be too much dive or lift under braking and acceleration.

The numbers tell you what it should do, but I have seen a couple suspensions where the numbers were awesome according to most and it just didn't work on the rig. Just the fact that the rig is heavy means that some changes will affect it more, some less. Track width, wheelbase, tires, weight bias ( side to side and front to rear).

I built a front 4 link on a scout where most guys thought I was nuts cause the anti squat number was high, don't remember what it was, but I had a thought that because it had leaf springs that it would help it climb a little bit, get the front end a bit lighter but not so light that it would flip over backwards. Plus the rig had a huge wheelbase (120). With the numbers I got on the link calc it really should not have worked as well as it did. But that rig would climb anything, never got unstable on climbs. Worked well everywhere. Hard braking was screwy though it did not drop the front end at all, a little disconcerting.


So all the best advice given and 49 times out of 50 if the numbers look good it will work good but there is that one time where all you calculations say awesome and the real world says you suck.

Now get to building

 

[Greg72]

Also, it appears you lower link would be below your axle tube? Or is it an illusion? You may have to do that a little to get the results you need without the upper tube above the starter!

Correct. The bottom of the axletube is 20.5" and those links are a bit below that. however, they are also pushed ALL the way to the ends of the axletubes (right next to the knuckles) so they should have decent protection from rocks.

It's awfully hard to get 9 - 10" of vertical separation without losing clearance somewhere!


-G

 

[blazinzuk]

Its pretty easy to do a rear suspension but a front is full of compromises. Even on tube buggys they are somewhat of a compromise. Unless they are stupid high, stupid high makes it easy.

 

[Greg72]

THE CK5 BLACKOUT OF 2012

....22 hours without CK5. It wasn't pretty

Unfortunately, about 3 days worth of posts were permanently lost in the server crash too. Bad timing, we had a pretty lively discussion going on here at the time.

In any case, I'll be heading out to the manspace in the next hour or so, and I'll see if I can get some new status and photos to get this thread moving forward again.


-G

 

[cybrfire]

Greg,

I didn't have time to catch up on all the reading this morning for you build, just enough to see the discussion about the Dshaft and headers and some of the talk about over the frame rail headers.

I've built a few different sets of headers. Never anything normal because.... well, you can buy those.

My blazer has over the frame rail headers. I saw some of your comments about the hurdles with these kind of headers. IMHO there are far more advantages than disadvantages to this setup. I won't bother listing them all out, you can easily see alot of them. Chat with you anytime about them. Not that terrible hard to build. Can be time consuming but.... They're worth it.

 

[Avery4jc]

I bet leaf springs and some obnoxiously loud and awesome zoomies out the hood are looking pretty good about now.

 

[Greg72]

Greg,

I didn't have time to catch up on all the reading this morning for you build, just enough to see the discussion about the Dshaft and headers and some of the talk about over the frame rail headers.

I've built a few different sets of headers. Never anything normal because.... well, you can buy those.

My blazer has over the frame rail headers. I saw some of your comments about the hurdles with these kind of headers. IMHO there are far more advantages than disadvantages to this setup. I won't bother listing them all out, you can easily see alot of them. Chat with you anytime about them. Not that terrible hard to build. Can be time consuming but.... They're worth it.

I'll keep them in mind... Might not have a choice depending on how the suspension work goes!

I bet leaf springs and some obnoxiously loud and awesome zoomies out the hood are looking pretty good about now.

Yep. Tempting!


-G

 

[Greg72]

FYI...

It appears that the Unimog front knuckles have no caster built into them. I was getting ready to tack weld my CNC adapter plates to the axletube today, and squared the plate to the ground. Thankfully, I decided to bolt the knuckle on just to see what sort of caster there would be once I set the pinion angle correctly. Turned out the caster is 0.0* if you don't rotate those backing plates a bit.

Fortunately I caught it in time, set the top of the CNC plate for 8* of caster and kept on pressing forward.

Now you know.

-G