What to look for when buying a used chassis...

[1000hpJohn]

I thought Would start this thread to help myself and others that are looking into buying a completed chassis that has been used.  This thread isn't intended to cause a contest, but a fact finding thread to help locate areas on a chassis frame, rear axle housing, steering and so on to look at prior to laying cash down.

I have some experience looking at things such as chassis, rear axle housing, 4 link bars and hiem joints, brackets and a few other systems but for the most part I look for strange things...cracked paint, bent metal etc.

So, with that being said, I would think to inspect the rear axle housing itself, and the attached brackets that secure it to the frame.  I would check each bolt hole for movement and elongation, ANY loose hardware and I will zoom in on that area unless specified by seller, that's just me though...  next would be the rear & front motor plate locations and surrounding tube and support bars.  A magnaflux tool would be perfect in this whole process too, we all have one of those in our tool boxes right?  Lol. A black light and some floresant die will work too...

I would then just continue a frame inspection of all welds, joints and any holes that are in the chassis.  The steering attachment areas would be next along with the complete system itself.  Check for any looseness at heim joints, and any component that moves purposely.  I would finish with the back of the cage and lower chassis if wheelie bar/s were located for again elongated holes, fractures in paint...  what else on the steering system needs to be looked at closer?  Of course fuel tank, battery, fuel pump/filter, radiator, ign. Box mounting brackets and rubber mounts, what else did I miss?  Along with most of these components, the wiring, fuel lines, hoses etc., etc...

Now here is a question or two for the builders of these wicked macheeens

Where do a majority of fractures/ cracks show up on the chassis itself?  I would think in the center and towards the front near the steering from wheel torture from launches.  Are top bars more prone to cracking or bottom bars?  Support bars???  Is there other areas of concern to target more closely like the slip joint areas?

So, if you masters of chassis construction and repair could step in, I'm sure it would be much appreciated.

John

[George]

 A SFI spec book would be a good start. http://sfifoundation.com/drag-racing-chassis/

[hemidakota]

exactly what George said...sfi book is worth its weight in gold.

[1000hpJohn]

Awesome, add that to the thread beginning
Which copy do you guys find easier now a days, PDF file or paper?
I will get the paper copy.

[noslin]

get pdf that way you always have a copy and then just print off whenever you need to. 

[dreracecar]

First and foremost, any used chassis even Worthy a look must have an SFI date tag on the frame , those tags have been around to close to 20 years now. The tag does not have to be current, updates to a older chassis that has been tagged are minor compared to an old chassis that never had been inspected

[1000hpJohn]

First and foremost, any used chassis even Worthy a look must have an SFI date tag on the frame , those tags have been around to close to 20 years now. The tag does not have to be current, updates to a older chassis that has been tagged are minor compared to an old chassis that never had been inspected

Ok,  correct me if I'm wrong, the inspector from SFI or any other authorized inspector from NHRA or the IHRA looks for the correct tube dimensions per location surrounding the driver on each chassis being certified per that chassis spec.   The chassis inspector Pete Woodriff near Norwalk, Ohio mentioned to me that as long as the correct bar sizes are in the correct locations around the driver and have the correct supporting bars, all the other bars are just going for a ride...meaning the rest of the bars that support the rest of the chassis are not inspected!!!!

That being said, with a dragster which I believe have more to inspect from front to rear, what does the actual inspector look at besides correct size and correct  location per the chassis as per the et range and speed?  All the inspectors I have ever had only measure around the driver area.  So, am I under the assumption that all inspectors check welds too!!!!   Maybe I'm not up on this with a dragster, but they don't inspect welds correct???  So just by having a chassis number means that chassis is ok...  that is what I am concerned with, and why I asked these questions when buying a used chassis.  I'm not asking about a chassis that was built in the 60's to pass spec in today's world, but a chassis that is built in the 70's and later, has passed tech numerous times along with the needed upgrades.  So, unless the buyer checks each weld them selves, couldn't they be buying a chassis that MAY have fractured welds somewhere???    I can't believe every chassis ever built will not have any fractures anywhere whether it is 30years old or 2 years old....  I'm asking this because I just don't know, I'm ignorant to the dragster chassis itself and of course I will buy the SFI spec info., but that doesn't tell me if the chassis cracked somewhere or not.

This thread is not about tube size or placement, but about where to inspect a used dragster chassis for possible stress fractures over time racing and traveling to and from tracks... I sure wouldn't buy a tube chassis door car unless I crawl underneath and inspect welds myself which I do, so is a dragster chassis different in that respect?

I'm not trying to create a crap storm here ok?, I am only asking where to inspect as a buyer to make certain that chassis does not have fractures, That's it!   If I'm going to be running quicker than 8.50's and over 155mph, my chassis better be done right and have ZERO fractures.  I asked this question to find out if there are areas I need to look for first before purchase.  I apologize if it read differently.

John

[Paul New]

I e seen several FEDs show up at the track with the lower team rail sitting on the trailer and they had to fix the chassis prior to racing again. One of the guys we race with showed up that way and we just told him to haul the car to our shop and I will weld it up tonight this was a long Friday night as I had to splice the frame rails and replace an upright or two. So what I am saying is look over the complete car!

[aafa760]

John
Most likely you should buy a known builder if possible

if you have ever seen how powder coating hides cracksvery well.
most 6:00 cars will not be powder coated if it is walk away.
Strip it down to bear metal look over every weld after you buy it. Every hiem joint should be replaced with high Quality ones no grease zirts  new washers, all bolts and washers with grade 8 new ones nice new washers new nylons nuts. Unless you safety wire each one.

pull each king pin check for wobble.
new front tires if you can
The Chassis inspectors I dealt with are very good the will find small tubes thin tubes need for Kidney  bars.

[JrFuel Hayden]

Yes, Paul is right,  inspect ALL of the car. The cracks that showed up on our JF was in the front, the support for the steering bellcrank,& uprights, it has cracked/broken at least two times, requiring bigger supports. That's why some chassis builders prefer drag link direct to the spindle.  We have also broke a rear motor plate and a 11-12" windsheild. We think it was from tire shake, as we made more power and worked on the converter combination we get more shake. I have seen cracked/ broken chassis rails & uprights, just from towing in the trailer, if the chassis is not supported enough. More racecars are stressed/cracked from towing than racing.
You will have to check even more closer if the chassis is painted dark colors because it's harder to see. Our chassis is orange, easier to see cracks. We wax the chassis before leaving home, it makes us look at the whole chassis.
I'm sure Rooman and Bruce can give you more info about the SFI specs, I think a chassis that was build in the 80's can be brought up to current SFI. Keep in mind having a SFI number is not enough, it needs to also have a date as to when it needs to be re-certed. The Jrfueler that Don Enriquez drives was built in the early 80's, matter-a-fact, in nostalgia racing that car has run, and won more races than anyother car racing in Bakersfield, Bruces car is no doubt close but even when I asked Mike Algire that owns the Enriquez chassis to count how many runs and wins are on the car Mike said I couldn't even guess, just too many. Anyway after Scott Parks has welded up their chassis a few times at the track, mostly in the front rails, Mike finally decided to front half the car with all new tubing from the motor on. John Farr, the JF racer that does all our chassis work agreed to front half it. BTW when John had  it on the jig he found out the rear-end was not straight in the chassis. Since the chassis update Don says it never ran so striaght, he always had to fight the wheel some. But my point is even an old chassis can work good if the motor is in the right place, ie not too far back, like they used to build them in the 60-70-80's. Mikes car is 42" out, ours is 48" out, and has been when built in 1995. Parks build their cars at least 50" out, their car was 54" out.
Keep in mind the tubing can have stress cracks too, I'm sure you have seen the video of Larry Dixon's big show top fuel car coming apart about half track, and not at the welds.
Chassis inspectors also check for tubing thickness. The way I understand chassis specs is SFI only has specs in the driver area, anything goes from the motor forward. That's why when we had John Farr front half our car so we could run our Hemi or our SBC we also had him increase the wheel base from 200" to 225" , 200 was the limt for the JF clas when it was built in 1995. John put smaller dia tubing in the front to hopefully keep the car weight down, even tho we were adding 25" to the WB. BTW the Hemi is 100 lbs more than the SBC. The last JF championship we won was with the Hemi.
I still think buying a already built car is less expensive than building your own.       
Jon, 805-444-4489

[George]

We bought a FED in 2009 with an expired NHRA chassis tag. It was expired by several years. I called the NHRA office and was told expired chassis certifications were not on file. After the chassis failed an inspection I doubt the tag was legal and if it had been inspected at the time the tag was installed it got a "special deal". So, my take on a used chassis is: make it a current cert or know the SFI spec for the build. As for cracks and any other flaws it's buyer beware. I have only a few cars to draw real knowledge from. A point to consider is the transporting of the car/chassis can be a serious concern as far as chassis fatigue. It would be a good question to ask a seller as to how the car was secured and supported in transport. The used car is the best deal out there if you know what you are looking at. George

[1000hpJohn]

Paul, aafa, John & George,

  That's what I was looking for as far as info.   I'm not a genius, but I kinda know what metal does and doesn't do under certain conditions and it is really neat to see it move and the reasons why.

You guys more less hit the nail on the head.  It's the locations of (where to look) for a possible issue.  If or when I buy a dragster, I will be anal about certain things, the chassis will most likely be stripped so I can inspect every joint and where everything meets.  I also agree on replace the wearable items such as heim joints, hardware and so in.  Working on heavy trucks off and on during my career in the auto industry has taught me a few things and many are a direct crossover to my race vehicle, my trailer and my dualie. 

Is there such shops that can inspect a chassis once stripped for issues or is that an (option) type job for a chassis shop or other shop that would charge extra for just that?

I also agree with you all about finding out who built the chassis, and the names I cannot even afford to call and talk to such people  as N&P, Uyherra(sp), and some of the other top name builders as they are who I would go to for a scratch built to me chassis and a small loan would make that happen.  So I am one of those guys who needs to know as much as possible before I dive head first into the digger world and you all have helped soo much so far and I want to thankyou all again...one of the better sites I've been to with less arragonce ...Great job guys keeping it real, and real cool (insert thumbs up emoticon here) lol.

John

[olddiggersrule]

Thanks for starting the thread John. I learned a ton with you, I am in a similar situation as I  have been shopping for my first FED. Unbelievably knowledgeable and patient posts from all of the contributors.
The biggest thing I am running up against is the majority of the cars I've looked at just weren't built for an NFL linebacker sized driver. The most important thing I have learned is that there is reasons for all of the bargain cars available and I will most likely have to really reconsider my budget.
We are still kicking our selves for missing out on few cars that were within a days drive but at same time very thankful now that we didn't hastily buy a few others that we would have most certainly regretted.

[dreracecar]

My point being that even if the NHRA/SFI tag is expired, there has not been many updates to the specs that should be a big concern on a once stickerd chassis, helmet bars, kidney uprites, front roll bar uprite support (those chassis without the inner sleeve). Looking at a never been tagged old chassis runs the risk of too small of dia or too thin a wall of the major componants that would either be too expensive to fix or just require a new chassis to start with, The sticker just saves you from wasting your time--- ask the seller if the chassis has ever been inspected and tagged and what the spec and date is. From that point if it was stickerd, then see if you even fit in the drivers seat. bring or borrow a 15 or 20 suit and helmet and sit in it, if you do not fit or your are cramped up, pass its over, if you cant get your helmet inside the cage enough to pass track tech, you should pass also, now you can always put a new cage on the chassis, but here at my shop you can be looking close to $750 or if the cage needs to be over 18" tall then the shoulder hoop might have to be changed to .065 (most are .058).
  In a perfect world, the seller would be more than pleased to strip the entire car down to bare frame so that you can inspect each and every weld-- not happening and one must assume that there may be some spots that need touch-up. patches, splices, clamshells are indications of problems. If the chassis is build like an oil derrick, then inspection of the up-rites towards the front will often show signs of repair, because of this style/design, more traditional (all rails converging to the front torsion) have much less tendency of cracking.
 Chassis inspectors only check for placement, diameter, wall thickness---period!!! Not the welds unless the condition is so bad (bubble gum, bird shite, wire feed on moly) that he will fail the tag. To ask the inspector to look at all the welds is beond his capacity as an inspector, He has no way of determining if the weld is sound or not and you are not going to strip and blast the chassis for him either if he is doing the inspection at the track/event. 2 months after he inspects the welds and one happens to crack/break , do you still blame him??? inspection of the welds is your maintenence/job.
 I built my chassis 20 years ago, and have never had to weld any of the basic structure, ohh  and ocasional motor mount tab and the updated helmet bars along with another firebottle mount, but never broke a frame rail or up-rite, but have done a few other peoples chassis

[cad500justin]

Hey guys, I'm a bit of a lurker here. I'll post an intro when I get a min. But I'd like to chime in on my chassis experience.

My car was originally built in '71, it's been front halved and back halved leaving only about 2' in the middle of ugly work.

Chassis cracks are not something to be too concerned with when buying a used fed as long as you're buying a good car. Hopefully you have a mill, lathe, and tig welder. I couldn't imagine racing without them.
The problems I've encountered with an older car are:
The shoulder hoop is really narrow (I barely fit) making it harder to sell should I ever want to.
The motor is really far back making the car want to wheel stand and more difficult to remove the tranny. (Mine is 30-1/2" out, I have a shorty glide, with a shorty coupler, right into the rear end.
Most older cars were built with Chrysler 8-3/4" rear ends. This is good and bad, they're lighter and use less hp than ford, but there's less gear ratios available. A bit of a problem for me with a low redline rpm.
If the frame rails were used for breathers, alcohol and moisture may have rotted the inside of the frame in places.
It would be too much work to make this car cert to 6.0 so I am limited to 7.50.
Old cars just aren't as well thought out, so things don't always make sense.
Although they sometimes look cooler.
Spin the front tires and look for flat spots in the rims. New hoops ain't cheap.

My advice is to buy the most modern lightweight car you can afford. Parts will be easier to get. It takes less hp to go fast in a light car. Less hp is less maint and less money. Maybe look for a guy that runs jr fuel and is upgrading to an on-kill N&P chassis.
If you don't have a good trailer, in the long run, it will probably be cheaper to buy someone's whole operation with spares, etc. all those little things add up to time and money.
See if it comes with a chassis stand.
Fwiw, if you get an altered, you can also run in a,b,c gas if they don't have the NE classes. And altereds fit in standard garages and trailers. But dragsters are sexier
When you do finally get a chassis. Take it all the way apart-every single nut and bolt. Literally. You want everything that is wrong with that car to be your fault. Not the last guy's. Lord knows I found a few things that might have literally killed me.
I stripped the paint off the chassis too so I could look everything over carefully.

Good luck in your adventures.