Homemade 125" FED Twin-turbo SBC

Awesome.

 

Good for 7.50 in the 1/8 mile? I would think because of the Henry stock pinion support with the little ball saver lip on top? The little ball saver top pinion support has nothing on a replacement Life and Ball saver billet pinion support and necessary replacement parts needed.
I'm not the rule guy, but I have customers that have grenaded stronger factory Henry parts in drag cars with lesser engines as the turbo engine in this thread.
How do tires and chassis react to Pinion Escape Stew 101? How about farther down the track?
Got balls? Wanta keep them?

 

Mctim64's rearend is not going anywhere. It is solid mounted to the chassis. With the correct size steel plates and 1 extra bolt per-side. Even if the 9'' did spit the pinion out the front isnt gonna make it spin around and make him loose his balls. The anti-rotation deviece is there incase the welds or bolts holding the rear get ripped out.

Yes I do think that the rearend in Jim Mitchell's project needs work. Jim you should copy what mctim64 shows. And listen to what Rooman , HemiRambler, Toymaker and mctim64 suggest. This is a serious thing. A dragster is a whole different world than a door car. And where you are sitting makes what they suggest even more important. This area of every dragster I build I over do with wall thickness of the up right that the rearend plates are welded to. This is the last thing you want to rip out.

 

i wanna see how ur turbos end up getting mounted. i was drawing up some ideas with a straight six twin turboed roadster

 

I'm just a newb here and getting my feet wet. But listen to what some of thses guys are saying about the rearend mount and think of the overall picture, the combo you want to run wills build a bunch of tourque and that put stress on alot of things.As a tech for our local track I see alot of stuff and things get overlooked safety wise. I like the project and look forward to the updates.I use to know some sand racers tht had a about a 125" fed with a small block mopar and a single blow thru turbo and once they got it figured out it was animal even in 300' of sand. Also for info on setting up blow thru carbs etc if you haven't been to the site yet I recommend Turboforums.com

 

For the record I am taking you guys advice and will be redoing the rearend mounts. Im going to wait until I have my top hoop bent and in place so I can put in the uprights. Thanks for the clarification on this issue and thanks for the pictures, it helps. For the time being Im gonna finish up the turbo fabrication then get the hoop bent and we will go from there. Thank you guys! Im gonna slow down a bit and try to take more pictures to post up here so the next time I do something stupid you guys will catch it.

 

Not a problem. I will be building the headers or manifolds for the next couple weeks and will keep this thread updated with progress pictures.

 

Looks like you're going to have a lot of fun with that thing!

And it's cool that you are doing it yourself.

I wouldn't have used square tubing on the lower rail.

I did on a drag car... and thought it would be easier... it wasn't.

When it came to fitting the tubes that came in at a compound angle... it was a bitch.

And then, once it was all ready, the lower rails didn't end up totally perfectly upright, and there was a bend from the heat of welding the front hoop into it.

Lastly... without support past the front firewall hoop... the front flexes like a mo-fo when it goes down the track.

The solution is to triangulate the front... which is a pain in the ass on a dragster. Our car is an altered, so it isn't as hard to do, and doesn't look as out of place as it would on a dragster.

Lastly... square tubing is heavy, ugly and wasn't ever really commonly used on front engined dragsters back in the day.

Maybe some hilljack who had shit lying around may have used them... but even then.

Back to your project.

If you're not going to shit can what you have and build a tube lower rail...

Please do something about that rear end mount.

Personally, I would get your shoulder bar installed, then your uprights... and then mount the rear end.

When you do... make sure to weld the the strap steel from the lower rail to the shoulder bar.

The way you have it, the shoulder bar would have to be awefully low.

Remember, we just want to see you build something safe and fun.

Sam

 

Cool. No problems here with the blow-thru stuff, tuning them is easier than falling off a horse.

 

Yes the rearend is gonna be redone. I know this dragster is ugly and tasteless but I like it and I cant see any reason to throw it away and start over. I have 25-30 hours invested in it as it is.

 

Oh yea...
One more thing, that axle wase originally used with a long upper support.

That little arm might work... but I think it should probably be used with a long arm like it was intended to be used.

What I am thinking is that the longer arm helps to keep the front end from flopping side to side... I dunno... I'd have to see what you have going on, in person.

Sam

 

The look of the car's front half is Bitch'n IMHO, now build that back half Hell I think I'm going to weld the housing into my car as the rear end is going to be unique and pretty much useless in anything else. I was told by an engineering kinda of guy that if we wanted to stiffin our REC Tube (1 1/2 x 3" .120 wall) frame on our HAMB Dragster just stitch weld a piece of strap along the bottom, of course I'd wait to see if you had a problem first

 

Sam, I dunno but it looks like Jim used a complete vintage unit and I think I've seen cars with that design, Rooman or someone can confirm I'm sure.

 

RE: rearend mounts:


1) Wow i'm glad i brought it up. And i didn't bring it up to critique either----i had no idea this was unsafe. Actually the real reason i brought it up was because i'm a little stumped on my own project as far as how to mount the rear diff , (a project i can't divulge yet although here's a hint---i'll be sitting in front of the rear diff).

a) Now in regards to this:

i understand what you're saying about 2 pts of attachment vs. 1= more strength. However for one would you have to cut a slot in the tube to accomplish this? And secondly would this be acceptable(even preferred over cutting a slot) in terms making a stronger mount?



In other words, weld the tab/bracket to the side of the tube. More surface area to weld=more strength? P.S. i meant to draw the bracket so it's flush with the bottom of the tube.

Is either of these was "legal?" nhra etc.?

b) i'm not saying i would do this, but just out of curiosity would using large u-bolts say 1/2" or greater diameter in this manner be ok and/or legal? i mean using u-bolts instead of all that bracketry. You would have to drill holes in the frame of course. Sorry for the crappy drawing(s).




2) Apparently square tubing, at least for the "bottom" tube ("F" in the rule book diagrams) can be used as long as the rest of the cage from firewall back looks kosher and is the right diameter and thickness tubing?

The rulebook wasn't real clear about this. And if this is true, what wall thickness and size must the square tube be?

 

I have built both square and round. I prefer square but only use iin altereds. Regardlesss of the rules I use no less than .125 wall. With square I fasten to the lower rail but with the same style bracket as when using round on the uprite. Usually a 3/8 steel U with a good angle both ends. LIke the black diagram above except under the axle instead of in front of it. It isnt going anywhere. Or one can leave the front of the bracket square and weld an upright there as well. Whatever you do overkill beats gettin killed everytime.
Don

 

The chassis that I pulled this rearend out of had 2 uprights per side of the axle tube with 2 bolts per upright. It was raced this way for years. Thats what I was gonna duplicate with this new chassis, the short plates are there for mockup. I plan to use full length plates welded to the uprights and Im going to continue the housing 360 degrees around the rearend. There will be 6 bolts per side when Im done and the rearend will not be removable unless the frame is cut.

 

Thanks, Im glad you like it. Im not sure if you read my earlier post but this chassis is a run off of your sketches. I have allways loved the look of a single rec tube altered and when I came across your FED sketches here during a search I decided to try it.
I have seen a picture of a long wheelbase altered with a 2"x3" frame and they welded a 6' length of .120''x2'' strap under the motor section of the frame.

 

Yeah thats how the bracket is mounted to the rearend is a big U shaped piece of 3/8" plate welded 180 deg around the axle tube from the bottom. Its a little different than most of the setups I have seen but our local chassis guy said its kosher as long as you have the proper built plates on the chassis.

 

I almost hate to jump in, seems like most of the other pros have jumped you pretty good already.

anyway building the frame and rearend so that the housing cannot be removed without cutting something isnt a great idea either. If your going to go that route forget about the bolts and just weld it in.

 

Yep I read that and hope I'm not held responsible LOL, I'm not sure if "Stitch" welding is the right term maybe it's "Skip", but short welds spaced evenly anyways. I'm not an engineer or certified anything, just a guy with some basic skills and wanting to build some of my own stuff. I was going to use something narrower than our frame so it would be hard to see as it would be welded to the bottom surface and not "Trussed". Lovin' the build Jim and now that we have the rearend mounts covered "Build Baby Build", I wanna see some YouTube of that Monster in action Rocky

 

I'll probably get "Flamed" on this but I agree with Da Tinman. It will take me a good amount of time to make all the brackets to bolt the Rear End in my car and I'm not Chroming it or do I plan on ever taking the housing out so I'm planning on welding it to the chassis.

 

I can understand the desire to do things simpley but I don't think it would take too much time or effort to make the rear end removable. I think in the long run you will be happier and it looks good bolted rather than welded in. If in the future you find a need to take it out you will be glad you went that way.

Just remember if you weld it there will be a need to take it out, if you bolt it in and make it easy to remove you'll never have an issue that warrents taking it out.

 

Last year I found out what it's like to break a rear in a f.e.d. It tore the pinion support right out broke every tooth onthe ring and pinion pushed the motor forward and bent both motor plates . Not trying to scare you just build it strong

 

Would it be legal to weld the rearend into the chassis? Technically it wont have any bolts so Im guessing it would fail.

 

What did you do to destroy a rearend that bad?

 

Very nice. This is gonna be a nice rail.

 

I sure hope so.

 

Jim- Its great reading about your build-up ! Its quite difficult to build something from an era that you were not even born yet! At forty four years of age, I was not even born yet when the altered wheelbase cars I build for customers first started laying rubber at the drags!! I have to say that it looks great so far what you are doing. I'm also interested in your "recipe" for your old twin turbo 302. I recently built an altered wheelbase Comet that may need some inventive motivation in the near future!!

http://public.fotki.com/teddisnoke/the-rosedale-rocket/page12.html

Can I contact you via a PM?

Thanks!
Dale

 

Unplanned better hook than normal. Engine torque and direction of gear cut causes the pinion to push toward the front of the car, breaking the five tabs off the pinion support. A nodular case and billet support are a lot more resistant to this than average stock Ford parts.
With a hob setup, escape is pretty well prevented, but doesn't mean something catastrophic can't happen. With a door car, the resulting spinning/swinging parts have a lot of destruction capability.
FWIW, I have one customer with a NHRA stock legal 69 Mustang that puked the pinion support and destroyed the first driveshaft I build for the car.
Keep up the good work. You have a lot of guys here that can give good advice. Hope you have a lot of fun building and driving the car!

 

My motor makes about 800 hp plus I was spraying it with a 150 shot of nitrous .It pulled the helicoil's right out of the alluminum case . This year we are putting a heavier duty Mark William's case and pinion support in it. I think the reason it broke was I was using bolt's in the front support should have used studs threaded all the way in . Good luck with your project . I alway's liked the idea of a tubo powered car . It should make some pretty good horse power.