Projects Front Engine Dragster (FED) Build Ideas

http://www.jalopyjournal.com/forum/threads/nhra-says-ok.862146/ this one looks good I really hope the OP in that thread makes plans for the chassis. as far as a rad go's most modern tracks you will have to sit in the staging lanes for a few minutes id go for a small dragster style rad. you will also have to start on your own this means a starter and a battery. your budget of 10k id forget it as for me safety counts when you are sitting behind the engine with you're feet/legs alongside the transmission and you are sitting on the rear end being cheap is not always a good idea

 

True, I ran a 96" wb TE-440 with an Ardun on straight nitro, it always went straight. I kept it that way by ajusting tire pressure -- if one tire bit more than the other I just adjusted tire pressure - more air, less surface, less bite. Also ran lots of caster, helped to keep it straight at the top end.

It sounds like your real purpose is to have fun, that was what drove us old timers to drag racing, you've got the right attitude!

 

Lots of very good replies. The difference between running 9's and 10's is probably about $1k in safety equipment alone. Safe with going from 11's down to the 10's. Which was one reason I never made any changes to my OT race car.... it was a lot of fun running low 11's concidering the price of the safety equippment to run 10's !

96" wheelbase is pretty short. If you get the steering ratio a little too quick it can get away from you in a hurry.

I think I would shoot for 10's, lengthen your shed with the money you will save on safety equipment and build a 120-140" chassis. You will really feel safer in it.

 

What sort of ET did you run then ?

 

High 9's at its best, low 10s more often...a good stocker could have run me down now but then it was ok for an engine with blower pistons (all I could afford) but no blower...

 

You could build a Hamb Style dragster chassis, use a shorty body, and add an altered body if you choose. Using mild steel, properly built, it would certify for 7.50. This one is 116" WB.

 

that is also a really cool chassis I like the idea of having the diff behind me kind of like some of the early rail jobs but 1000% safer where do I get chassis plans

 

Gotta love front engine dragsters even thou they could be a hand full to drive at times.

Jimbo

 

On your question about chassis plans, I didn't draw up any when I built three of those chassis a few years back. To get started, I generally block up an engine and trans on the floor, then position a front and rear axle, both with the diameter of tires I plan on running. That way you can determine the width and length of the frame along with the driver's position. Here are some shots of one of the cars without the body.

 

Heres the problem--
NHRA is starting to sonic all tube framed chassies and what we normaly call .120 wall tubeing (.118 minimum as per rules) is much thinner. A new piece of 1" x .120 wall ERW mikes out a .108 and 1 5/8" x .120 wall is around .114. Most chassies made with ERW are .134 wall tubing (accually mikes out at that) and since its a mill run supply not every metal house stocks it and you have to buy it from a chassie shop for $8 to $10 a foot. Other choice is to use DOM tubing as the wall thickness is consistant with lableing, it too is in that 8 to 10 a foot range. I can buy Moly cheaper, but as per rules ,must tig weld the joints.
As I have said before in other posts, It is not a good idea to have a un-supported bend in the upper framerail. moving that bend foward to the motorplate uprite is a much better design.
By building the frame with the minimum spec CM tubing, is eaiser to construct, lighter in weight(free HP), depending on where you buy-can cost the same or even less. The only difference is the weld skill and time.
If you run tracks that turn their backs on minimum chassie spec. or do not require chassie tags, consider yourself lucky and go have some fun

 

sure DOM is heavier then CM but its also more ductile and the welds are less prone to cracking/braking if the NHRA was smart they would allow oxy/fuel welding CM that's what alloys like 4130 were originally made to be welded with it produces a normalized joint that is much less prone to stress

 

Yep, was told my 10.20 fed needs cert, getting it done next Friday, older bottom but cage redone to current spec's...hope this goes well.

 

Mine is 96 inch and runs a straight as an arrow. Like it was on rails. Without me weighs 1406. I drive it to the line and back the return road. Typically it stays under 170F I have $4000Can invested over a 8 year period. That includes a new set of spare slicks (tried a shorter tire but gained zip so put the 29.5 X 10 back on. ) Never had so much fun for so little. Car has been in several magazines (Current issue of Chrysler Power for one. ) Been on TV (Gearz) and I only built it for something to do in retirement.
I like your thinking. You will never be sorry. I run steel rims and will not spend a nickel on chrome. (Sparkle will eat up more money then solid performance ever could.) Car is competitive. I can run with the V8s and not be embarrassed (however sometimes they are. ;>)

 

NHRA is very smart on this , Airframes were meant to be welded with gas for feild repair, easy to get and would not need electric power. However these were people who were trained to do this type of welding and were very good at it. But to allow some clown to go into a HF store and buy a $40 gas rig to weld with because he is too cheap to pay a qualified welder to do it is insane. Their way of thinking is that if you can afford this type of welder (tig) that you might/will have taken a class or two to get good at it.
DOM in the same minimum wall thickness as CM does not have the same strength so one has to increase the mass/wall thickness to be equal.So in other words the thinner CM equals the strength of the thicker and heavier DOM. If one prices out DOM its about the same as CM
Cracking/breaking tubing/welds are a design/builder issue and not the fault of the material used.
Please dont bring in NASCAR into this, those cars have to weigh a 3600# and have to be built and repaired quickly and they are built rather ridgid so that the suspension will work proper and accept tunning adjustments. Drag cars having no or very limited suspension rely on chassie flex and CM provides this along with repeatability, Mild steel or DOM has a limited amout repeatability before it just sags and stays there.
20 years of racing and have never had any tubing or weld crack.Thats because it was engineered and welded correctly

 

I never brought Nascar into it I did how ever bring Metallurgy into it CM dose not respond well to the high heat and somewhat quick cooling of any sort of electric arc type weld tig is used because of the smaller zone affected by the heat but it still produces a hard and sometimes brittle weld. with oxy/fuel we can let the weld cool in a more controlled manner(read slowly) giving it a more ductile weld. mild steel such as 1020 that most dom is made of does not have the same amount of carbon and chromium as CM so welding with mig will not affect it much. if someone had the money they could build a chassis size heat treatment furnace to normalize a CM chassis that will produce a chassis that is the same hardness throughout it may not need it but every time that chassis flex's it puts more stress on the welds they will start cracking no matter how good the person that is welding it is or how much is spent on the machine

 

Takes me about a week to weld up a Funny Car or Dragster chassie with a tig, not a lot of heat and really slow so my HAZ carries further and I usually do it with the doors closed and guests out of the shop to keep the air still, Really fat welds to boot(none of that FI fusion shit)so the load area is increased - tube is 1" dia but the weld makes it act like 1 3/8".
People have thought about SR the chassie after welding before , determind it was not practical do to the high cost of the tooling involved and the procedure for so little positive bennefit

 

Come on guys. This is a 96 inch wheel base car that might run in the tens. DOM is far more durable the CM. Just heavier. How much heavier . In car like this it isn't even relevant. It lends itself well to normal welding methods Mig or Tig. As for short cars don't handle. Nonsense! None of you have a car that runs straighter then the one on the left. And not one single chassis issue the 8 years of racing. Made strong to last long. Some don't get it. These are NOT top fuel cars. They are safe fun FEDs for moderate performance without breaking the bank. I built mine using the rule book at the time. It is actually above spec being 1 5/8 mild steel rather then the minimums. And yes it does have front suspension. It also has Ackerman. Something many chassis builders do not comprehend. It makes front tire wear almost non- existent and makes loading unloading and driving on and off the track a pleasure rather than a torture test of steering and suspension components. It has nothing to do with slip angles and bla bla at 200+ miles per hour. It has a lot to do with negotiating the pits , staging lanes and return roads where a car spends the largest part of its time.
I see this thread and am glad I just opened the rule book and built. Otherwise I would be so confused I probably wouldn't have bothered.
I hope you aren't and go ahead and build and run it. The rewards are great.
don

 

The welds are only less prone to cracking and breaking if they are done correctly. I have seen plenty of horrible MIG welds on DOM/ERW frames that had too little penetration or were not in the root of the junction. It is all in the skill of the weldor. As Bruce noted in his reply to your follow up post the procedure and equipment required to normalize a dragster frame is totally unnecessary. I have a 1969 Don Long car that had a fairly short history as a top fuel car followed by a long stint in sportsman competition as an A/D, A/ED and then bracket racer as it worked its way down the food chain. Despite the fact that it has been butchered in the engine bay area it does not have a single crack anywhere on the chassis. This is a car that has the typical Long tiny uprights and diagonals forward of the motor and the shallow frame spacing that is characteristic of the torsion bar suspension era. A properly executed TIG weld (correct filler rod and enough of it) is at least as good as your oxy weld example. I would also suggest that the operator skill required for an acceptable TIG weld is less than that for the same with a gas torch in this case.

Roo

 

and I'll bet a 10 ran in an open rail sitting close to the ground feels like your running a 5 at 300mph!

 

My intended purpose was not to get into a debate on the virtue of MOLY vs DOM/ERW, both has their place. But if a newbie has plans to build a car and accepts the ERW dimentions for which the metal house sells it as, then the chassie will not meet min specs.and fail chassie cert. The next step would be DOM for more consistant wall numbers, However the trade-off is weight (with everthing being .120 wall)and cost(the same as moly) and the only possitive for some is that one is allowed to use a mig to weld it, I have built a few ERW/DOM cars but still prefer to us a tig

 

You may be able to compensate for the short wheel base by moving the engine forward.

In Tommy Ivo's book, one of his dragsters he was building liked to do wheelies a little too much. So he welded a little more length to the front end, tested it, added a little more, etc., until he had the exact length that provided the best weight transfer without doing a wheelie. His dragster told him exactly how long it needed to be (not his garage).

You may have to experiment to accomplish the same thing by moving your engine.

 

The cars I posted earlier, were both built out of .134 ERW and tig welded. The price on 1.75 tube was around 3 bucks a foot, and is readily available around here. The main reason I used mild steel was, it allowed the customer to mount body panels,tanks, and complete the car himself. Along with the fact that these are ten second cars at best, with six cyl engines. If weight was a big issue, we wouldn't have mandated OEM front axles in the rules. There are 6 of these cars running in this area, and they are having a ball !

 

Did the OP take the wonderful advice? Or is he in the shed building?

The HAMB is full og talented guys that does this kind builds for a living.
But when it comes too low-buckes fun in a straight Line, Racing with out doors 6 cyl FED SWB is the way to go. Dom or cm comes down to can you weld?

I really likes the ones Marty Strode build! Do you have more pics?

For the longest time I've been thinking about building a FED. Having wet dreams about it actualy. ;-)
Only held back by the lack of hands on help around here. :-( I no nothing about dragsters, except from pictures and a NHRA/SFI handbook.
And the Dolmetch FED has been the fuel of my desire in a long time!

He had a Web page about the build. Go read it and learn some. He is the grand Master of low buckes, all fun I6 FEDs.
Maby he can post the link.

 

105" wheelbase 417 Hemi on NITRO clicked it @1000'
Anyone that says short cars dont handle have never driven one and are perpetuating a myth or their car was built by an amature

 

It's not a FED, but I'm a little under a 96" wheelbase. I haven't run it with the new engine yet but have run it for years with a stout 454 & power glide with a brake & 4.11 gears. It works way better than I ever expected. Well enough that I wanted more power than my last 454 LS6 with a 200 h.p. shot of nitrous. I also wanted it to look more traditional. I have a hidden radiator, fans, water pump, fuel tank & fuel pump under the turtle deck.


Posted using the Full Custom H.A.M.B. App!

 

Posted using the Full Custom H.A.M.B. App!

 

Dolmetsch or Marty has posted a couple of examples of where you probably want to be OP.

To me the biggest question in building a FED is how period correct do you want to make it.

To be under your $10k budget you will have to do most of the work yourself but if you keep the power down then it will help all the way around.

I'd look at a TE-440 or Dragmaster type frame and then do a cheap SBC with a hilborn setup if you are going to run methanol. I have no idea where some of these guys get their numbers from. I bought a $50 9-inch truck housing off craigslist, sandblasted it, I cut the ends off and approximately where I thought it needed to be and then took it to a guy with a jig who charged me next to nothing since most of the work was already done. The 9" parts are going to be cheaper than almost any other rear end out there and are easy to come by.

Build a mild 350 and you'll be able to make ~450-500HP for probably the same amount you will have in a roller.

$75 set of slot mags at your local swap meet or craigslist, sandblast and dry graphite lube em, run piecrusts . . .

The hardest part of the whole build is going to be the cooling situation and the fact you'll need a primer setup to start it or a friend who can squirt some gas in the injectors. You will have to have a radiator if you are dead set on driving it from the pits, waiting in the staging lanes for joe blow to let you go, and then driving it back to your pit.

 

Is 10K your total budget or just the price of the car? You'll need a trailer and also a bunch of tools. I'm glad your storing the rail in a 10X10 shed and not trying to build it in there. Much too small a space. You need to be able to move around the car easily or it will take much longer to build. also you need work benches,parts storage,tool storage. Welders,acyleteen tanks,cut off saws,vices,grinding wheels tke up a lot of room.

 

First let us kill the concept short cars don't handle. The little begger to the left is 96 inches and none of you have a car that runs straighter. I just posted a video of senior dragsters first and last passes.
The last video in the group is probably the cars fastest pass ever and it is taken down track so you see the whole run. It could not run straighter or handle better as you can plainly see in the video. Funny cars are usually 125 inches or less and run as fast as top fuelers. If you design your car using proper automotive principles it will handle well. And that does not mean 10 degrees of caster and no Ackerman. BTW Willys from the 40s are 100 inch wheelbase and have no trouble running big numbers so lets stop the nonsense.
Next the "can't use a big converter myth." I run a Frank Lupo Dynamic converter custom made, 8 inch 4700 stall converter. It will leave so hard it will give you a headache. I leave at whatever the track will hold on that day.
Next no room myth. I run a full rad and a big fan and the gas tank in front of that and still have room for a picnic lunch if I wanted to. And my engine is a long one, 6 in a row. My trans is a full length 904 torqueflight which is quite bit longer then a shorty glide. I think I could drive it on the street and it would stay cool. As for temp I have never seen it over 170F yet that I can recall and at the airfield I have to drive quite a ways around the whole airport to get back to the pits. (I run gasoline)
Build it strong, by the rule book, have good brakes (and a chute would be wise.) Make sure you are well supported and comfortable. Pad under your bum well with thick hi density foam. Your back will thank you if you have an "incident."Use a steering damper if you run on rough tracks like 1940s airfields. Probably a good idea anyway. Mine is Mild steel and above spec dia wise. Because I am very comfy welding that material and lacked experience with CM but that is just me. I wanted to KNOW it was good so stuck with what I was comfortable working with for my own piece of mind and safety. A decision by the way I am very satisfied with. Weight empty without me is 1404 lbs.
Mine looks a bit funny because of the huge roll bar but I am 6 ft 306 lbs with a busted ribcage and 29 inches at the shoulder so I had no choice. After 8 years of running I am more then happy with the car.
Never once had to repair anything on the chassis. I just retired from driving it as I am getting too old for this speed and too stiff from my ribcage injury to get in and out of it.
don
Oh yeah, with 10K I would build almost 2 of them!