'55 Chevy 3800 Cummins - Page 2

6DoF · 11-23-2020, 10:50 PM

a lot happened today

6DoF · 11-25-2020, 03:57 PM

a few missing details, but i think this chassis is close to wrapped from the firewall back. now time to focus on the front. the odd channel brackets are for saddle style fuel cells.

nblehm · 11-26-2020, 03:22 PM

This is going to be rad.

6DoF · 11-27-2020, 04:22 PM

i think that's pretty much a wrap! got all the IFS crossmember mounting dialed in and the frame connectors built. now to start detailing out drawings and such to have all the plate cut.

Cobound · 11-30-2020, 02:51 PM

That is going to be so bad ass

Oh, and again, that jack :drool:

6DoF · 12-03-2020, 09:01 PM

ordered all the steel for the chassis today! was $536 delivered from MetalDepot.com, $527 picked up locally, or $385 picked up an hour away. i'm driving for it!

tires get put on the wheels Tuesday, that's when i can final double confirm the chassis and start the fab. had to move the rear most bags inboard b/c of a wheel clearance.

Colin said he could cut all my plate early Jan, but that shouldn't hold me up at all getting things together.

Cobound · 12-04-2020, 12:48 AM

6DoF · 12-07-2020, 08:49 AM

started actual chassis fab yesterday with the tube work. got everything bent, notched, and cleaned up. even bent up some stuff for a buddy to build a TJ belly pan / engine skid.

xj_man_646 · 12-07-2020, 10:53 AM

Did you model the engine and rear end or was that sourced from somewhere?

Looks pretty sweet!

Baby peez · 12-07-2020, 11:38 AM

What kind of joint do you use between the diff cover and that z thing to have play due to the fixed mount on those "lower" links?

What do you call that style suspension?

6DoF · 12-07-2020, 03:21 PM

Quote:

Originally Posted by xj_man_646

Did you model the engine and rear end or was that sourced from somewhere?

Looks pretty sweet!

found em online! the 14b was from the FB group for offroad CAD, while the cummins was a dropbox link i found in a forum from like 2015 that still worked!

xj_man_646 · 12-07-2020, 04:07 PM

Quote:

Originally Posted by Baby peez

What do you call that style suspension?

Watts link suspension! Basically does what a panhard bar does, without any lateral movement of the axle with suspension travel.

6DoF · 12-07-2020, 04:09 PM

Quote:

Originally Posted by Baby peez

What kind of joint do you use between the diff cover and that z thing to have play due to the fixed mount on those "lower" links?

What do you call that style suspension?

this version of a radius arm suspension is generally called a "truck arm" setup. factory to C10 trucks, and used in NASCAR. my links are actually only 6" longer than a factory C10. the little extra length was what allowed me to dial in the anti-squat numbers.

just to try something different, and because i wanted a lot of suspension travel with the tires tucked tight to the fenders, i went with the WATTs link instead of the panhard bar. over 15" of travel, my links induce only about 0.07" lateral motion. it has standard poly bushings on the frame side of the links and heims at the pivot link. the center pivot is a big-ol Johnny joint. was easy to fab with, and allows the link to rotate some with the travel while still being a stiff joint. when i was designing it i went back n forth with Sean over that fact that it being able to pivot could also induce some extra lateral motion. per the geometry, it's less than 0.1" so i suspect no bad effects. but i've been wrong before, and we are going to find out!

that part of the suspension i designed and built in 2017

it'll be moved over to the new chassis.

Baby peez · 12-08-2020, 10:06 AM

Nice! Thanks

6DoF · 12-12-2020, 11:10 AM

got the chassis wrapped up in 3D and got the steel a few days ago. did a quick mock-up for motivation and to check a few last minute dim's before cutting the last chassis in half to save a few bits. the C30 IFS is 3"+ narrower than the ram suspension currently under the truck. the mock-up picture is at that chassis' max drop, what should be about 3" below ride for the new chassis. not going to say i'll never rub a fender with the tire, but shouldn't be too bad.

i'm also super glad that i'm taking the time to properly slam this truck. i think i'd have always been pissed driving around with that as my max drop. having spend all the time building to have only gone half way.

nblehm · 12-13-2020, 09:32 AM

So are the rockers going to touch the ground on the new chassis? Thanks for the build thread, it is motivating me to get out in the garage and work on some projects. Also this is further fueling my want to build a jeep cab ramp truck, that will sadly have to wait til I have a different house, I have nowhere I could park or build something like that here.

6DoF · 12-14-2020, 08:26 AM

go build! i'll race ya to first drive.

Quote:

Originally Posted by nblehm

So are the rockers going to touch the ground on the new chassis? Thanks for the build thread, it is motivating me to get out in the garage and work on some projects. Also this is further fueling my want to build a jeep cab ramp truck, that will sadly have to wait til I have a different house, I have nowhere I could park or build something like that here.

"yes" ... i'm building it to have the rocker 0.5" above the bottom of the frame, and the frame on the ground at the same time as suspension end of travel. i'll then add 0.25" bump pads in the suspension above bind for a minimum level of safety against uneven parking.

as of the mock-up, i'm hoping to set the ride at about 8" above bump for more steering clearance. really there shouldn't be anything mechanically limiting me from that, but we'll see how it rides and the geometry changes once aligned.

6DoF · 12-14-2020, 10:04 AM

did some smashing on steel this weekend to get the huge sticks off the floor. even remembered to lay out the riser so that the seams would line up.

ordered 1 stick of 6x2x0.25, came in 24ft mill stock. i never actually measured it, but we're good, i only had 1" left over!! damn thing is that 1" cost me $1

i nested all the 22.5deg cuts to save steel and make less cuts and it's a good thing. i knew i'd consume 23'6" ish before cut widths.

putting a full round on 4" c-channel is kind of a b!tch, but i think the effect was worth the effort. it's for the body mounts, so that cut will be hanging out on it's own. i also hate grinding this much, but without a huge drop-arm band saw i wasn't getting the cut precision in the 6x2. the ceiling mounted air filter was a HUGE win.

Cobound · 12-14-2020, 12:22 PM

Lining the seams up, next level detail...super nice!

Cool sweatshirt, bro...see you there in February?

6DoF · 12-14-2020, 02:11 PM

Quote:

Originally Posted by Cobound

...see you there in February?

i'd like to, but probably not

11-30-2020, 02:51 PM	#25
Cobound - The Don - Join Date: Sep 2002 Location: MN Posts: 49,188	That is going to be so bad ass Oh, and again, that jack :drool: __________________ To each his own. Not all those who wander are lost. The great irony - triggered snowflakes accusing triggered snowflakes of being triggered snowflakes

12-04-2020, 12:48 AM	#27
Cobound - The Don - Join Date: Sep 2002 Location: MN Posts: 49,188	__________________ To each his own. Not all those who wander are lost. The great irony - triggered snowflakes accusing triggered snowflakes of being triggered snowflakes

12-07-2020, 10:53 AM	#29
xj_man_646 Senior Member Join Date: Oct 2004 Location: MN Posts: 27,752	Did you model the engine and rear end or was that sourced from somewhere? Looks pretty sweet! __________________ - James I like diesels

12-14-2020, 12:22 PM	#39
Cobound - The Don - Join Date: Sep 2002 Location: MN Posts: 49,188	Lining the seams up, next level detail...super nice! Cool sweatshirt, bro...see you there in February? __________________ To each his own. Not all those who wander are lost. The great irony - triggered snowflakes accusing triggered snowflakes of being triggered snowflakes

11-23-2020, 10:50 PM	#21
6DoF AKA: jeepnski Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 16,901	a lot happened today

11-25-2020, 03:57 PM	#22
6DoF AKA: jeepnski Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 16,901	a few missing details, but i think this chassis is close to wrapped from the firewall back. now time to focus on the front. the odd channel brackets are for saddle style fuel cells.

11-26-2020, 03:22 PM	#23
nblehm Needs moar dagger Join Date: Feb 2004 Posts: 26,785	This is going to be rad.

11-27-2020, 04:22 PM	#24
6DoF AKA: jeepnski Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 16,901	i think that's pretty much a wrap! got all the IFS crossmember mounting dialed in and the frame connectors built. now to start detailing out drawings and such to have all the plate cut.

12-03-2020, 09:01 PM	#26
6DoF AKA: jeepnski Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 16,901	ordered all the steel for the chassis today! was $536 delivered from MetalDepot.com, $527 picked up locally, or $385 picked up an hour away. i'm driving for it! tires get put on the wheels Tuesday, that's when i can final double confirm the chassis and start the fab. had to move the rear most bags inboard b/c of a wheel clearance. Colin said he could cut all my plate early Jan, but that shouldn't hold me up at all getting things together.

12-07-2020, 08:49 AM	#28
6DoF AKA: jeepnski Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 16,901	started actual chassis fab yesterday with the tube work. got everything bent, notched, and cleaned up. even bent up some stuff for a buddy to build a TJ belly pan / engine skid.

12-07-2020, 11:38 AM	#30
Baby peez Senior Member Join Date: Nov 2019 Posts: 1,068	What kind of joint do you use between the diff cover and that z thing to have play due to the fixed mount on those "lower" links? What do you call that style suspension?

12-08-2020, 10:06 AM	#34
Baby peez Senior Member Join Date: Nov 2019 Posts: 1,068	Nice! Thanks

12-12-2020, 11:10 AM	#35
6DoF AKA: jeepnski Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 16,901	got the chassis wrapped up in 3D and got the steel a few days ago. did a quick mock-up for motivation and to check a few last minute dim's before cutting the last chassis in half to save a few bits. the C30 IFS is 3"+ narrower than the ram suspension currently under the truck. the mock-up picture is at that chassis' max drop, what should be about 3" below ride for the new chassis. not going to say i'll never rub a fender with the tire, but shouldn't be too bad. i'm also super glad that i'm taking the time to properly slam this truck. i think i'd have always been pissed driving around with that as my max drop. having spend all the time building to have only gone half way.

12-13-2020, 09:32 AM	#36
nblehm Needs moar dagger Join Date: Feb 2004 Posts: 26,785	So are the rockers going to touch the ground on the new chassis? Thanks for the build thread, it is motivating me to get out in the garage and work on some projects. Also this is further fueling my want to build a jeep cab ramp truck, that will sadly have to wait til I have a different house, I have nowhere I could park or build something like that here.

12-14-2020, 10:04 AM	#38
6DoF AKA: jeepnski Join Date: Sep 2002 Location: Pittsburgh, PA Posts: 16,901	did some smashing on steel this weekend to get the huge sticks off the floor. even remembered to lay out the riser so that the seams would line up. ordered 1 stick of 6x2x0.25, came in 24ft mill stock. i never actually measured it, but we're good, i only had 1" left over!! damn thing is that 1" cost me $1 i nested all the 22.5deg cuts to save steel and make less cuts and it's a good thing. i knew i'd consume 23'6" ish before cut widths. putting a full round on 4" c-channel is kind of a b!tch, but i think the effect was worth the effort. it's for the body mounts, so that cut will be hanging out on it's own. i also hate grinding this much, but without a huge drop-arm band saw i wasn't getting the cut precision in the 6x2. the ceiling mounted air filter was a HUGE win.