Pipe Notch

[SCOTI]

DWright,

Sorry about pirating your thread. I hope the info shared w/my combo helps others avoid the same mistake.

[DWright]

Originally Posted by SCOTI

DWright,

Sorry about pirating your thread. I hope the info shared w/my combo helps others avoid the same mistake.

i'm actually enjoying the discussion. i thought i would be lucky to get an answer on this thread and then i get excellent advise and cad drawings from an engineer ; i couldnt be more grateful. not to mention how many other people who were wondering how to build a dependable, "concealable" notch are now armed with the correct info as to how to go about this safely. Thanks again Lakeroadster.
DWright

[Malibob]

Wow, does a step notch help any of this? I am thinking about notching my rear to get the frame down (want to lay rockers), guessing this is a little OT but, is a step notch better? Can you get to the ground with a pipe notch or an aftermarket "kit"?

[DWright]

Originally Posted by Malibob

Wow, does a step notch help any of this? I am thinking about notching my rear to get the frame down (want to lay rockers), guessing this is a little OT but, is a step notch better? Can you get to the ground with a pipe notch or an aftermarket "kit"?

no, a pipe notch wont lay rockers. my frame is about 4'' off the shop floor with a pipe notch. i wasnt trying to put my scrub line on the ground and this was the stance i was after. laying frame is cool and all but when it happens on the road because of a busted bag or line then its no longer fun. but to each his own. all thats important is having a good time and doing it safely.

[DWright]

i thought your truck was notched. it looks awesome by the way

[Malibob]

Thanks man. Got the bug now so until it hits the floor I don't think I will be happy, it is really sad but I want to be able to cruise the way it sits in the pics and figure if I notch the bed and put in my chopped crossmember, I will be able to. I will keep everyone up to date.

[DWright]

Originally Posted by Malibob

Got the bug now

i know how that goes. 'i'm just gonna level it out, just a little lower, just a little bit more...' next thing ya know you're digging a trench in the driveway so that your truck sits lower than you buddy's ride when he comes over.

[gopokes]

I was just doing some searches for low budget c-notch ideas when I came across this thread, this is great information. I do have one question though. When cutting the frame do you need to make the cut as large as shown? The line in red in the pic below is what I'm a little confused about. I was thinking it would be easier to only cut as much as necessary to fit the pipe in and leave the part of the original frame in and put the reinforcement over it. Hopefully this makes sense.

[SCOTI]

Originally Posted by gopokes

I was just doing some searches for low budget c-notch ideas when I came across this thread, this is great information. I do have one question though. When cutting the frame do you need to make the cut as large as shown? The line in red in the pic below is what I'm a little confused about. I was thinking it would be easier to only cut as much as necessary to fit the pipe in and leave the part of the original frame in and put the reinforcement over it. Hopefully this makes sense.

Yes, cut the frame only as much as needed & weld in the pipe section. Add the reinforcement plate after the pipe portion is welded to the frame.

[SCOTI]

Originally Posted by Malibob

Wow, does a step notch help any of this? I am thinking about notching my rear to get the frame down (want to lay rockers), guessing this is a little OT but, is a step notch better? Can you get to the ground with a pipe notch or an aftermarket "kit"?

A step notch would be the way to go but most of them that I know of also require relocating the springs (bags) because that portion of frame area gets cut.

I didn't want to relocate my bags & w/my rear end spaced back to center the wheels, an off the shelf bolt-in c-notch wouldn't work. Since I raised my bed floor, I was able to add material above the notched section of frame to reinforce things as strong as original (& keep my bags close to the OE position).

[darkhorse970]

Originally Posted by lakeroadster

Yep, from a "calculation standpoint" adding the structural steel member is about the same as welding in a boxing plate. Most of the bolt on kits use a steel plate that is considerably thicker than the stock truck frame thickness. That helps but I still would like to run the numbers on one of the kits to see if it is as strong as the original uncut frame when all is said and done.

As for the bolt holes, they don't effect the strength very much as long as they are spaced away from each other.

I took a little time this morning and made a solid model using Inventor Cad software. (See attachments below)

First I made a model of a stock frame rail.

Second a model of a c-notched rail using 4 inch pipe (0.237 wall) as the notch. This configuration is about 75% weeker than the stock frame.

Third was the c-notch with a 1/4" thick boxing plate. This configuration is about 25% weeker than the stock frame.

Using FEA is more realistic than the simple channel and tube calculations that were discussed in the previous posts because it looks at how all the parts work together as a system. And the cool thing about this type of analysis is it gives you a warm fuzzy feeling about how different modifications effect the strength of a part.

Kind of neat, don't ya think?

This is very nteresting reading...

John, did you run the numbers on an "off the shelf notch"? (I wanted to attach a pic of the one I have from Early Classic Enterprises, but can't find it on their site now) I'm very curious to see how this stacks up the to other designs shown here.

I have not installed it because I decided that it probably wasn't necessary on my '63. I was thinking about using it on my '68, but I'm not sure if thats a good idea or not now.

[joe231]

This thread is great, very informative!
Thanks guys!
I wanted to kinda throw in that all the added structure is only as good as the welds attaching them.
I also had a question that I have been curious about, how does the heat put into the steel while welding effect the strength of it?

[joe231]

Thanks John!
Very helpful!

[DWright]

[gopokes]

Originally Posted by lakeroadster

The "best" way from a stress and corrosion perspective is to cut the entire frame side piece out and replace it with the reinforcing disc, as shown in the diagram. This allows a full penetration weld to be made at the o.d. of the reinforcing pad and the pad becomes integral with the frame. This also eliminates the corrosion that can occur when materials are sandwiched together.

That being said, adding the repad without cutting the frame is still a good compromise and a huge improvement in strengthening the frame.

I assumed the diagram was correct since the rest of your information is so great! Thanks for all the time you have spent on this.

[darkhorse970]

Originally Posted by lakeroadster

The "best" way from a stress and corrosion perspective is to cut the entire frame side piece out and replace it with the reinforcing disc, as shown in the diagram. This allows a full penetration weld to be made at the o.d. of the reinforcing pad and the pad becomes integral with the frame. This also eliminates the corrosion that can occur when materials are sandwiched together.

That being said, adding the repad without cutting the frame is still a good compromise and a huge improvement in strengthening the frame.



I would need detailed dimensional data of the off the shelf kit to do an analysis. I am curious, does the information you got from them say anything about how strong the kit is or have any "legal" stuff about not being legally responsible for damages, etc., etc?

The reality of the situation is the bolt on kits I have seen just don't add the needed sectional strength back into the frame.

I have them in a storage unit away from my house. I will go take some pics and measurements and let you know what I've got. They were purchased from Early Classic Enterprises over 5 years ago. I will look at the paperwork that came with them.

[LOW DOUGH]

Great info lakeroadster! Also, way to keep it going Scoti!

[SCOTI]

Originally Posted by darkhorse970

I have them in a storage unit away from my house. I will go take some pics and measurements and let you know what I've got. They were purchased from Early Classic Enterprises over 5 years ago. I will look at the paperwork that came with them.

I've got some 'bolt-on' notches on an extra frame. I could prob get the dimensions if I know exactly what we're looking for. I'm assuming:

• Material thickness

• Length of material under frame?

• Dimensions of notch (height, width, length)

• Length of material on side of frame?

Anything else?

[SCOTI]

Originally Posted by lakeroadster

OK guys, the bed is off my 65 C10 SWB right now so I can make a model of the actual frame configuration, instead of the straight configuration I did for the previous FEA.

Then if you guys could make a sketch with enough information such that you could build a set of "bolt on notch brackets" then I would have what I need.

This should result in a real world CAD Model and thus the FEA results should be pretty dog gone accurate.

Now that we have this discussion and I have done a bit of surfing, looking at some of the kits being marketed, they don't appear to have enough height. Based on the previous results we have already discussed I am betting these bolt on bracket kits will be weaker, much weaker, than the original frame.

Lets put it to the test and find out. What do ya think?

I'm really wondering.

I towed my 74 on my 18ft steel-floor trailer behind my 68 short fleet w/a bolt-in style c-notch. I did weld the outside perimeter of the notch along w/the GRADE-8 installation hardware but that's not worth much if the structural strength is diminished significantly. FWIW I never had any issues @ all & the frame is still intact & square....

[8mpg]

Ok... so I have some rough dimensions of an off teh shelf kit... .250" hot rolled steel, fillets look to be .500" with .500" holes. To many dimensions to put in one drawing so there are two:



I can send a CAD file if needed. Im not great with it, but I was able to hash it out. Been 10 years since high school when I messed with it.

[Malibob]

Anyone got any pics of the CPP notch and how their truck sits with it? I am trying to decide which way to go and don't want to buy things twice like I have this whole build.

[Hottrucks]

Holy crap I read 4 pages to get here and now you have me nervious....I have a 1/4" x 4" pipe notch...its welded in and out and the back side is boxed with 3/16" plate from X memeber back about 12"...I tow a 21" checkmate boat..guess would be about 3600lbs with 300lbs tongue weight...I do it with a bumper pull..

I tow ALOT besides the issue of trying to stop it (disc brakes soon) it seems to "look" ok and I felt good when building it but now????? I do inspect it offen but I could use a pat on the back or something...my truck is bagged and I use it to haul firewood too which I thnk is more stressfull on the frame???

[8mpg]

Originally Posted by Malibob

Anyone got any pics of the CPP notch and how their truck sits with it? I am trying to decide which way to go and don't want to buy things twice like I have this whole build.

In my opinion it fits well...but please weld the inside seams:
http://67-72chevytrucks.com/vboard/s...d.php?t=402527

[Malibob]

Originally Posted by 8mpg

In my opinion it fits well...but please weld the inside seams:
http://67-72chevytrucks.com/vboard/s...d.php?t=402527

So how does your truck sit all aired out? That is what I need to see to decide.

[Hottrucks]

John any thought on what I did?? I have fabbed a ton of heavy equipmnet and heavy truck stuff but its always good to get a second opinion from people that accually know how to run the #'s...besides heavy equipmnet is a diffent animal..everything we do is over kill for the most parts but stuff still breaks..I just think its more forgiving because of the redundant systems