A discussion about safe chassis repairs, welding, fitting and finishing Options

[rick 918-S]

I try to check the resto threads and titles that have to do with chassis repairs and welding. I have been playing at and learning about auto repair, auto body and welding since the age of 12. I am self taught and learned enough in my youth by watching others and practicing what I learned to eventually open a collision/resto shop. In my hay day I had 6 full time guys, a computerized office, a Celette in the shop and all the headaches that go with it for 18 years.

I have been out of the industry now for 20+ years. But over that time I have still worked to hone my skills. I'm not posting all this to boast. I just want you to know when you read the following where I gained my knowledge and why I suggest this method of repair.

I have read many threads and see the same questions asked as guys learn how to go about repairing the projects they start. I have seen some threads started and questions asked after things went too far south that recovery was not possible. I hope to help some of you from making that error.

I have to say I see the most inventive and industrious guy on this forum. Lots of knowledge here. I've see cars repaired that other non 914 guys would have scrapped. Nice repairs too.

Here is where I wanted to start. The right rail and jack post. The easiest and hardest part of the chassis to repair. Here is a link to a repair I did on a factory 6 I did for Ben.

http://www.914world.com/bbs2/index.php?sho...26585&st=60

I wanted to expand a little more on why I did what I did.

Specially when it comes to the double layer. I installed a double layer in the rail on Ben's 6 when I did the rail repair. This serves two functions. One, less important but functionally as important is heat transfer. This will allow the single outer layer to transfer weld heat into the thicker two layers slowing the transfer and help reduce warping and shrinking.

The second and most important reason in a unit body car is structural. When your talking about trying to butt weld a rail section and count on your weld to carry a vertical, horizontal and angular flexion you will very likely not succeed. By adding the stiffener or backer you ensure the joint is safe.

One word of caution though. The ribs on the outer panel serve two functions. One is strength the other is weakness. Strength in the stamped design, but a designed weakness as a crush zone to allow the chassis a place to give and absorb energy in a collision. The energy transfer passes around you instead of into you. You will not want to bridge these or eliminate them. They serve a function.

I hope this helps others just getting started with a new project and others that are in the midst.

[Elliot Cannon]

I try to check the resto threads and titles that have to do with chassis repairs and welding. I have been playing at and learning about auto repair, auto body and welding since the age of 12. I am self taught and learned enough in my youth by watching others and practicing what I learned to eventually open a collision/resto shop. In my hay day I had 6 full time guys, a computerized office, a Celette in the shop and all the headaches that go with it for 18 years.

I have been out of the industry now for 20+ years. But over that time I have still worked to hone my skills. I'm not posting all this to boast. I just want you to know when you read the following where I gained my knowledge and why I suggest this method of repair.

I have read many threads and see the same questions asked as guys learn how to go about repairing the projects they start. I have seen some threads started and questions asked after things went too far south that recovery was not possible. I hope to help some of you from making that error.

I have to say I see the most inventive and industrious guy on this forum. Lots of knowledge here. I've see cars repaired that other non 914 guys would have scrapped. Nice repairs too.

Here is where I wanted to start. The right rail and jack post. The easiest and hardest part of the chassis to repair. Here is a link to a repair I did on a factory 6 I did for Ben.

http://www.914world.com/bbs2/index.php?sho...26585&st=60

I wanted to expand a little more on why I did what I did.

Specially when it comes to the double layer. I installed a double layer in the rail on Ben's 6 when I did the rail repair. This serves two functions. One, less important but functionally as important is heat transfer. This will allow the single outer layer to transfer weld heat into the thicker two layers slowing the transfer and help reduce warping and shrinking.

The second and most important reason in a unit body car is structural. When your talking about trying to butt weld a rail section and count on your weld to carry a vertical, horizontal and angular flexion you will very likely not succeed. By adding the stiffener or backer you ensure the joint is safe.

One word of caution though. The ribs on the outer panel serve two functions. One is strength the other is weakness. Strength in the stamped design, but a designed weakness as a crush zone to allow the chassis a place to give and absorb energy in a collision. The energy transfer passes around you instead of into you. You will not want to bridge these or eliminate them. They serve a function.

I hope this helps others just getting started with a new project and others that are in the midst.

(IMG:style_emoticons/default/agree.gif) OK, I'm going to go out on a limb here and agree with everything said. (IMG:style_emoticons/default/laugh.gif) I've seen Rick work first hand, so pay attention.

[914_teener]

Yep...between Rick and Mark bumping out and shrinking Jaime's rear quarter on his car in the parking lot at the WCR...that was cool.

[mb911]

I teach welding and fabrication at a local college and teach the very same principles.. I am working a very rusty 914 currently but have implemented the very same things you wrote about..

Great write up.

[Olympic 914]

One word of caution though. The ribs on the outer panel serve two functions. One is strength the other is weakness. Strength in the stamped design, but a designed weakness as a crush zone to allow the chassis a place to give and absorb energy in a collision. The energy transfer passes around you instead of into you. You will not want to bridge these or eliminate them. They serve a function.

If I understand you then, the outer long pieces such as the ones from 914LTD that bridge the stamped ribs defeat the crush zone?

this is what I have and believe it is much stronger than stock.
but possibly less desirable in a collision?



I am missing the triangle sill panel supports shown in this picture.



are these something I should add? I wasn't going to, but could.

[rick 918-S]

One word of caution though. The ribs on the outer panel serve two functions. One is strength the other is weakness. Strength in the stamped design, but a designed weakness as a crush zone to allow the chassis a place to give and absorb energy in a collision. The energy transfer passes around you instead of into you. You will not want to bridge these or eliminate them. They serve a function.

If I understand you then, the outer long pieces such as the ones from 914LTD that bridge the stamped ribs defeat the crush zone?

this is what I have and believe it is much stronger than stock.
but possibly less desirable in a collision?



I am missing the triangle sill panel supports shown in this picture.



are these something I should add? I wasn't going to, but could.

My text has to do with stock appearance and restoring the chassis to be visually as well as structurally safe. It's true Brad's kit adds strength to the stock chassis. I like Brad's kit. It makes the most sense to me of all the chassis kits out there. It's like adding a roll bar to your car. It stiffens the chassis. Not really needed in normal driving. In fact it could be dangerous if your head comes in contact with the bars during a collision. That's why you wear a helmet and a harness to keep you off the bars and the bars keep other race cars out of your cabin. As an added benefit you gain a stiffer chassis which aids in the ability to achieve predictable suspension and consistent drive-ability.

You may or may not need the triangles. They only serve to help prevent the top panel from bending if you step on it. They are stock but in your case may not fit with Brad's kit.

[76-914]

So what negative effects will stiffening the longs or other stations have upon our cars, Rick. Kent (IMG:style_emoticons/default/beerchug.gif)

[BeatNavy]

So what negative effects will stiffening the longs or other stations have upon our cars, Rick. Kent (IMG:style_emoticons/default/beerchug.gif)

Yes, I'm curious as well as I'm planning on putting an Engmann stiffening kit in as part of my repairs. Rick, your post is very timely as I'm getting ready to address this on a driver's side long repair very soon (I've done the basic lower part of the inner, but I am wrestling with how to repair and reinforce the jack point area structurally). The only way it would have been timelier is if I had seen your other post before I did the passenger's side. (IMG:style_emoticons/default/dry.gif) May have to look at that again...

[rick 918-S]

Other than changing the physics of the car in a pedestrian crash I would say there is no real negative effect. Possibly with a 40 year old chassis it could actually make it safer. You be the judge. I'm not going to comment on modifying the chassis beyond my earlier statement about Brad's kit. It is my opinion that a chassis stiffener that passed the weak place (the jack post) just makes the most sense. Although Mark Engman was an engineering genius. I was fortunate enough to sit with Mark once and listen to him talk about the zero steer riding mower design he was working on. Impressive. There are plenty of guys on the forum that build race chassis' and can comment on chassis stiffening and the pros and cons of roll cages in street cars. I'll leave that to others.

[cary]

Bump

[mb911]

Does anyone have a better picture of brads kit.. I have considered something like this during my rust repair..

[BeatNavy]

Does anyone have a better picture of brads kit.. I have considered something like this during my rust repair..

This thread may help, and includes a discussion of the different kinds of kits. It's a little dated, but I think most of the info is still valid:

http://www.914world.com/bbs2/index.php?sho...100567&st=0