How I Built Custom Frame Rails For My Datsun 280z Project

It's time to build some frame rails for the 280z! In this video I will show you how I fabricated custom frame rails out of 2.5" square tubing. This really stiffens up the chassis over the OEM frame rails. If you want to add some strength to your Datsun consider copying my build!
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[@stevef1076]

Just a safety tip when using a thin cutting disc, never hold metal with your hand in front of the blade (23:51), if it grabs the steel itll drag your fingers into the blade and the gloves won't stop any damage to your hand, 35yrs using these machines and no accidents until a yr ago and a stupid mistake almost cost me my thumb, be safe. a new subscriber.

[@BLOKgarage]

Sorry to hear about your accident! Yeah, I know cut off discs can be dangerous. I should probably put my guard back on, I took it off because I couldn't get in a corner to grind a weld a while back. And probably should have used a c-clamp to hold that square tubing to the bench instead of holding it myself. Thanks for the subscribe!

[@ChiemyChanga]

Nice! C-clamps ordered lol@@BLOKgarage

[@moesizlac2596]

I like how you edit your videos for maximum info and minimum time wasting. To the point commentary, no repetition, yet great detail. I will be referencing this video as a guide for how to make detailed DIY videos that are engaging. Cheers!

[@robertdonnell8114]

There you go! Cardboard Aided Design!!!!

[@jimalexander9230]

Bravo on going back and full welding the rail to the body!!!

[@BLOKgarage]

I think it was the right call.

[@ze_german2921]

Having owned a 74 240, I would suggest adding a full cage because at impact , you will be shredded chicken. That metal is thinner than a Harbor Freight tool box.

[@BLOKgarage]

It's been a thought but I haven't made a decision yet.

[@amundsen575]

good job, seam sealer and weep holes, water always finds it way in!

[@BLOKgarage]

Definitely will be using seam sealer on every seam!

[@Dancing_Alone_wRentals]

You've got that rotisserie dialed in!

[@BLOKgarage]

It's amazing. I couldn't imagine doing this laying on my back. Well worth the effort to build it.

[@Dancing_Alone_wRentals]

I have an Austin Mini that I would like to put up on two old engine stands. @@BLOKgarage. I agree with you...I think the project of fixing the car will seem much easier once you can spin the shell. Great job. After the video I called a friend and told him about what you had done and how you worked through some of the steps.

[@BOGCUSTOMSTIMEATTACK]

Keep up the good work mate.

[@BLOKgarage]

Appreciate it

[@thomas50208]

Just a note to help the algorithm. I see the subscriber count is still growing.

[@jgraham8248]

Very commendable job on the frame rails. That is one solid chassis now! You can put a jack anywhere under there and not worry about crushing them. Glad you went back and closed in with continuous welds. I'm doing something very similar on my '72 240Z Turbo Z. Oh, and, good editing as well. Subscribed!

[@BLOKgarage]

Thanks! These frame rails really should stiffen the car up a ton.

[@jeanlawson9133]

Worthy of watching, great video Thanks for sharing.

[@BLOKgarage]

Glad you enjoyed it

[@ronwalsh]

Had to subscribe. Not working on a Z, but an MGB.

[@CrazyCat229]

My dad had a 79 280z the T-tops kept getting stolen in the 80s. It was the first car I ever got to drive and shift.

[@garymucher4082]

Very impressive... And I am not easily impressed either. Looks like you are doing a top notch job bringing this 280Z back to life... Thumbs Up!

[@BLOKgarage]

Appreciate it a lot!

[@deciplesteve]

If you want to add a last bit of stiffening, get non-water absorbing expanding foam and fill those rails with it. Acura does this with their cars and it is crazy what a difference it makes. Lemons racers do this with generic expanding foam, but they aren't worried about the long-term water absorbsion.

[@BLOKgarage]

I actually did that years ago when I built my LS1 swapped S13.

[@deciplesteve]

@@BLOKgarage oh, cool! Great work, by the way.

[@superdave2403]

Nice job buddy!! Fully welded and stronger! I like the way you did the rails! Should be a much more rigid cat. Trust me I had a 240z. They need all the help they can get!!!!

[@BLOKgarage]

Thanks! I've never actually driven one so I'll have nothing to compare it to but I think it'll be worth it!

[@frizae86]

So that 2 1/2" tubing you got, how thick is it?? I need to do the same on my 76 z lol

[@BLOKgarage]

@@frizae86 I believe it was 1/8" wall.

[@frizae86]

@@BLOKgarage awesome thanks!!

[@lila8687]

And..... snap..... it's done!

[@delarok1977]

Nice work brother! this is my plan for my 240z.

[@BLOKgarage]

Go for it!

[@damiansmith5294]

Oh, you have one of the little fans for your stove that I've got!

[@landonmarx4753]

What keeps water and debris from getting inside that frame rail w it stitch welded? Beautiful work btw!! Love what you’re doing!!! I’m just wanting to understand your thinking and explore options ideas for my 240 project

[@BLOKgarage]

Seam sealer! Every seam should get seam sealer just like it did at the factory. Although I did end up fully welding the frame rails I'm still going to seam seal them.

[@WildAzzRacing]

I would probably add some drain holes just in case water does get in to those rails. Great vid and good fabrication.

[@brianbloom1799]

When I restored my 67 Chevelle, I also Built a Rotisserie, I built it Just like your's But I put a Flex plate, With Starter Motor with motor controller, So it would turn Real slow, and stop were need be , just thought I would share, Looks Great, God Bless

[@BLOKgarage]

Damn that is a really good idea! I've been trying to think of a way to do something like that, tried a couple things that didn't work. I might have to try that.

[@charlesclarke9430]

Awesome job on those frame rails!!

[@BLOKgarage]

Thanks 👍

[@AW_DIY_garage]

Great work dude! My first time coming across your channel.

[@BLOKgarage]

Thanks!

[@jakethepeasant]

Fantastic work, I'll definitely be using this as a reference when I weld new floors in my 510 in future!

[@bmurphy8946]

Nice video thanks for sharing your ideas on how to do this

[@BLOKgarage]

Thanks!

[@NOTSOSLIMJIM]

Next time you use the handheld sand blaster. Tie a shop vac hose pointing at the area you are hitting. It will suck up 80-90% of the sand or baking soda.

[@BLOKgarage]

Hmm I did try that once and it didn't seem to help much. I'll give it another try!

[@DontCallMeGarage]

you can make an attachment for that sand blaster out of a PVC tee and a bushing so you can use it as a spot blaster

[@BLOKgarage]

Got any more details on that? I'm having a hard time picturing it.

[@DontCallMeGarage]

@@BLOKgarage then you can stuff a piece of radiator hose on the end for a seal.

[@BLOKgarage]

I looked them up, that definitely seems useful.

[@prorebuilder]

Nice work

[@BLOKgarage]

Thanks!

[@fasteddie9475]

Great video, your skills are amazing, THX.

[@BLOKgarage]

Appreciate it!

[@DustyMacsGarage]

Crushed it bro!!! I liked how you used the old frame rail to trace the curves and layout the cuts so it fit nice. Also loved the templates you made to tie into the front frame rail and the template you made to tie the rear frame rail into the rear subframe area!! Great progress bro!! Im hoping to finish my truck soon, so I can get back to work on my wifes Datsun 240z!

[@BLOKgarage]

Thanks! Hopefully you can get back to the 240z soon so I can steal ideas 😆

[@DustyMacsGarage]

@@BLOKgarage lol 😂

[@HybridGt2052]

Just found this channel, love the content. My dad restored and modified a 260 here in the UK back in the early nineties. I have fond memories of that car, my dad once dropped me at ice hocky training, all my mates though my old chap was the coolest as he did a nice fat number 11 out the car park😆

[@BLOKgarage]

Thanks! Those memories are what I hope to have for my kids with this car.

[@HybridGt2052]

@@BLOKgarage It rubbed off, i have a modified 1967 mini now. I am creating different memories with my kids as they race karts. Good luck with the build, i will be following with interest.

[@GeorgeEI7KO]

Nice work bro. The guy you linked is a friend of mine!

[@BLOKgarage]

His idea helped me a bunch!

[@millertimebmw]

How does this channel not have 100k subscribers? Clear and entertaining. If you ever want to create some content on an older BMW, I"ll send it along! Nice work.

[@BLOKgarage]

100k would be insane!

[@jz-ez7wx]

Awesome work, looking good!

[@BLOKgarage]

Thanks!

[@marknewman2641]

Nice job !

[@jamesdisney9150]

If you were going to use the car for racing, you could’ve Slotted the floor and put 2 x 3 and connected the cage off of it Super nice job 👍

[@BLOKgarage]

I'll most likely do some auto-x and drag racing but it's not what I'm building the car for. Might still want a cage in it though, I haven't decided on that yet.

[@grahambrown7720]

Really enjoyable informative and entertaining thanks

[@BLOKgarage]

Glad you enjoyed it!

[@miguelpagansr6128]

I don't think that the factory could've done it better even down to the quality of the metal, excellent job on the car so far. Looking forward to the next video.

[@BLOKgarage]

Thanks, I really appreciate that a lot!

[@rickyfulks889]

U can make a u shaped bracket then tack to ur floor, then use a wege to pull it tight to ur frame also

[@BLOKgarage]

Not a bad idea!

[@martinharris5017]

Nice work. Sensible upgrade tying into the rear, makes you wonder why the factory didn't do it that way!

[@BLOKgarage]

I'm sure it was some cost cutting and they didn't expect us to be driving these cars 45+ years later 😆

[@arrindaley3714]

Not sure but the brackets near those rear frame rail extensions look like they're for the rear sway bar, just wondering if that's why the factory didn't extend all the way to the rear. Looking at pictures, this is the case but they also show swaybars mounted behind the diff / rear suspension, so perhaps production changes later on?

[@martinharris5017]

@@arrindaley3714 Sounds logical Arrin :)

[@BLOKgarage]

​@arrindaley3714 yeah that's the swaybar mounts. You can get aftermarket bars that go to the rear. I'll either do that or possibly notch my frame rail extensions a bit, depending on how much would need to be taken off.

[@ZachSmith-gm4sq]

Hell yea

[@daleolson3506]

Nice

[@konradweniger3141]

😢you should try a vacuum cleaner head with brush end drill hole for sandblaster nozzle it will blast contain and vacuumed all at once saving the clean up and mess. They make a commercial unit but you problem own a vacuumed already.I use for window track cleaning.

[@BLOKgarage]

I did try once with my shop vac but it didn't seem to help much. I'll probably revisit it though.

[@MrFunnyDad2024]

Sweet - Save the Zee's... LOL Good video work too. What you done and what your about to do updates.

[@BLOKgarage]

Thanks!

[@giniblais]

Nice.

[@taccom1617]

Nice job! Maybe add some drain holes so water can't get trapped and rot your new rails 👍

[@BLOKgarage]

I haven't decided if I'm going to do that yet. I will have to drill a hole regardless because I'm going to coat the inside of them with Eastwood internal frame coating. Not sure if I'll plug it or weld it back closed.

[@ELOFTW]

You make it seem so easy, fantastic work man.

[@BLOKgarage]

The magic of youtube! I try to keep in the issues I run across so everyone can learn from my mistakes but there's so much that I have to cut to get the videos from being super excessively long.

[@ELOFTW]

@@BLOKgarageI will definitely save this video for the day I work up the courage to redo my banged up frame rails on my '82 280ZX Turbo, you're doing the lord's work my guy.

[@FixTechStuff]

Excellent video. This is one of those things that ends it for a lot of old cars. Your video doesn’t make it look easy, but achievable.

[@BLOKgarage]

Appreciate the sentiment!

[@davidmacpherson6155]

Just found your channel, great video, looking forward to seeing more, but put the damn guard back on your grinder! 😂😂😉.

[@BLOKgarage]

I have it back on now! Took it off to fit in a tight area and got lazy.

[@DontCallMeGarage]

dude, your old frame rails are in better shape than mine. lol

[@BLOKgarage]

The one on the drivers side was probably usable. I almost just patched that floor but figured I'd rather just replace everything while I'm there.

[@DontCallMeGarage]

@@BLOKgarage i think the floor pan is the only thing holding my diesel 280z together. i don't think my 260z is any better. i was able to score some aftermarket rails and rocker panels from a local guy that was moving to Alaska, he had welded them onto his car then cut the car up to sell off the good panels. luckily his booger welds arent very good so reclaiming the pieces wont be hard.

[@BLOKgarage]

Diesel 280z?!

[@DontCallMeGarage]

@@BLOKgarage yep theres a couple videos on my channel, and links to my IG. i used to have a lot more on my instagram but i got hacked and my FB and IG accounts got shut down and erased.

[@BLOKgarage]

I'll check it out!

[@AdamsTubing]

nice job! way to get it handled! i need to do this to my 260z. about how much tubing was needed overall? what wall thickness? ty

[@BLOKgarage]

You need approximately 60" per side. The stuff I used was 1/8" wall.

[@captainlandyacht1328]

If there's a next time use a compass. Drag the point down the surface you wanna copy, pencil or sharpie on the surface you wanna copy to. Check/refine with a tape measure.

[@BLOKgarage]

I'll keep it in mind but I hope to never do Datsun frame rails again! Although I'm sure it could be useful in other situation.

[@quademasters249]

Amazing cutting. I'd have probably let it protrude a bit through the floor instead. This is more factory for sure.

[@BLOKgarage]

Yeah I've seen/heard of other people doing it that way.

[@rickyfulks889]

Nice job

[@jorgerosales609]

Got to ask......did you use weld through primer? Or if just primer, how come you were able to weld right over it without issues? Like you did not have to expose the metal (bare metal) for the weld area? If I try to do that my MIG will splatter and create this like "lava balls" that sometimes burst.....😢

[@BLOKgarage]

Yes I used weld-through primer on the bottom of the floor pan and backside of the frame rails.

[@RA-uj3nm]

Outstanding 👍👍🍺🍺

[@ppss6220]

The gap between the floor and the rail is from the thickness of the flange/flared out bit of the original rail?

[@johnbloomer7210]

Great work. Getting ready to tackle KlassicFab floor pans and frame rails on my 77 280z. Will be doing the work with the car up on 15 inch cradles. Will be doing one side at a time so hoping it will not require welding in supports. Still has engine and trans etc... Do you see any issues with car flexing/twisting or should I be Okay? Thanks.

[@BLOKgarage]

You're definitely going to want to support the car in the middle too while you have it cut apart. Not just on the end. It'll really depend on how good your rockers are as that is where a lot of the strength is on these cars. I would want to plan for worst case scenario because if the car flexes its going to be really hard to get it back straight after.

[@jonathan1989torres]

Great work I always wounder if I could do this to my 77 Celica , one qustion thou what gauge is the floor sheetmetal, and any tips to no blowing any holes because when its a thicker metal to a thinner one this is a problem at least for me , cheers ! and again great work

[@BLOKgarage]

The Klassic Fab panels are 18ga, OEM sheet metal is 20ga. Doesn't sound it but there's a big difference. You really need to dial in your welder, that's the biggest tip. Practice on some scrap. Then you need to concentrate your weld on the thicker panel.

[@jonathan1989torres]

@@BLOKgarage thanks! Can't wait to see the next video awesome work Dude

[@brianbloom1799]

You Did a Great Job, That car won't know how to act, You can put a Ls in there and would be fine.

[@mix1806]

i thought of the same thing for my s13, but now i think it might be too heavy, i also wanted to bend out it like OEM look (not excatly but the lips that are spot welded)

[@BLOKgarage]

I don't think its much more weight. The square tubing is only 1/8" wall, which is more than the OEM sheet metal rails, but I don't believe by a lot. Plus its all down low and you gain a ton of stiffness, which I would say is a good trade off. I thought the same thing about putting the lips on the edges of the rails but don't think its necessary. They are only there from the factory because everything is spot welded, so you need a lap joint.

[@mix1806]

@@BLOKgarage i thought the lips with holes, then weld them like oem because it might rust less in the future, still debating on that, but you're right about stiffness and such!

[@BLOKgarage]

I'm sure it would be fine either way but I'd be more worried about rust on a lap joint.

[@mix1806]

@@BLOKgarageyes! that's another point to look on, it can be grinded and painted but, i think best to do would be just shape new sheet metal

[@BOGCUSTOMSTIMEATTACK]

Just keep at it chip away 2-3 hours a day and it will be sorted before you know it. I’m just waiting for my new spay gun.

[@BLOKgarage]

I wish mine was ready for paint like yours!

[@ronielcrewe1277]

Just a suggestion next time just do the frame rails first that way the floor moves easier

[@user-bg8bz4uf8s]

Was wondering why you did not just slice the floor and run the full-size rails. Much easier and stronger. I've done it many times and it disappears under the carpet.

[@BLOKgarage]

I bet that works well doing it like that!

[@homepup72]

About to do the same to my 240Z replacing the entire floor pans and frame rails, but will be underneath it as I don't have a rotisserie and the engine and transmission are staying in it. Great tips, thanks for sharing. About how much did you have to pay for the metal tubing in total? Debating trying this method instead of purchasing frame rails from kfvintage.

[@BLOKgarage]

I don't envy you!

[@squirrelsworkshop]

Very nice. That's a nice straight shot from front to back. How thick was the wall of the tubing?

[@BLOKgarage]

It is 1/8" wall.

[@stevenketchum6593]

what brand of cutoff wheel are you using? even my metabos are eaten up faster than that one.

[@BLOKgarage]

Just some cheapo Amazon discs. www.amazon.com/gp/product/B09DYQD55R/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&th=1

[@roym.9875]

Would it be easier to make a cardboard template off the old rail? Then use that to trace out the shape on the new piece of tubing.

[@BLOKgarage]

I bet that would work well!

[@daleolson3506]

That’s cad. Cardboard aided design. Very high tech

[@BLOKgarage]

😆

[@Scott_G]

I'm a little late to this video, but how do you determine where to put the pivot point on the rotisserie? Is it just a trial and error type of thing, or is there a way to figure it out mathematically?

[@BLOKgarage]

So I did it incorrectly at first. Initially I put it approximately half way between the bottom of the frame rails and the top of the roof. This made it too bottom heavy as there's more weight on the floor. I'm sure there's some math that could be done. What I did when I moved the pivot was to watch someone else's video that had it pretty well balanced and then did some guesstimating. Luckily it worked out well. On rotisseries that are purchased, they generally are able to move the pivot up and down. You could fab yours with that ability, I just don't find it necessary on a one-time use rotisserie.

[@Scott_G]

@@BLOKgarage Thanks for the info!

[@StraightLineCycles]

cool

[@jayinmi3706]

Nice work! What tubing thickness did you use?

[@BLOKgarage]

It's 2.5" x 1/8" wall.

[@justharry305]

Dam I wish my mx5 was that easy to spin but unfortunately I can add any weight too the roof that it doesn’t have 😂😂😂.

[@Blueturtlej47]

What thicknes is the 2.5 tubing

[@BLOKgarage]

1/8"

[@senbin]

Do mine 😊

[@BLOKgarage]

I hope I never have to do this again 🤣

[@stan525]

nice work. i added frame rails with my Son in his 67 mustang years ago Fun Stuff. good content and delivery. my2cents

[@BLOKgarage]

Very cool! Family projects are great.

[@LorinaKilledButch]

Looks good, really should have a flat section running against the for pan to spread he load through the floor pan. more so if the new rail is heavier wall than the the old rail

[@BLOKgarage]

I thought about that but figured it wouldn't be necessary.