Potential FED Build

[225digger]

if you did not come across glenns personal site, check out the build of his digger by rooman   some pretty good pics on there... also take note to his chassis table

https://www.lever-family-racing.com/lever-family-racing-home/family-vehicles/2010-front-engine-dragster/2010-front-engine-dragster-week-2010-02-06

[Rat]

Hi Lynn, One of my favorite sayings is "The only stupid question is the one not asked". I also learned a long time ago what works for one does not work for another. I may not work for you but never dismiss their idea it may come in handy later with another combo. Listen to everyone one and make up your own mind from the info gathered. When it works/doesn't work it was your decision. This forum is a great resource for differing ideas and information. Ultimately have fun. Cheers Rat. 

[Curly1]

I have learned a lot with my 225" front engine dragster and few if any are the same. Part of the reason for that is the length of the frame, how it is braced in front and the flex of it. Tire choice, tire pressure may not work on two different ones that appear very similar.
Most of the Rear Engine Four link dragsters have become pretty generic and others can get you a close set up on them. There is NOTHING Generic about a front engine dragster, they are like women and have multiple personalities. Some of those are not pretty and hard to tame.

My dragster is working good now but it was a fight and she did not give in easily. When I throw more horsepower at it we may be in for another fight.......

[Don Munyon]

First time on the forum. Anyhow my spare 8 3/4 chuck measures 11 5/16 from axle center to the end of the pinion thread, hope that will help. My dragster is 145 inch wb with the motor out 31 inches, the motor center line dumps down about 7 degrees. I believe it to be a mid 60's dragster but it was a bare bones used chassis when I bought it. It now has a 8 3/4 rear end, shorty glide, hand brake and the driver sits low in the seat. I have had over 40 years of fun with this car at the local strip

[lake_harley]

Don....Thank you for your post. I appreciate the measurement on the 8 3/4" rearend pinion length. Your car certainly speaks to what I hope to build and I thank you for the photo of it!

I saw the car's performance figures listed under your user name and as I suspected it's much quicker than the carbureted mild SBC car that I envision.

Lynn

[lake_harley]

Don I tried sending a PM to you and wonder if you received it. I can't find anything in my "sent" box, but maybe I forgot to save a copy there?

I had a number of questions specific to your car and thought contacting you directly might be better.

Lynn

[lake_harley]

I'm still in the "potential build" stage on a FED, but just in case this actually moves forward I bought a 8 3/4" Mopar rearend housing with axles and brakes today. It came out of a A100 "Little Red Wagon" sort of truck and although I didn't measure the brakes it appears they are 10" X 2.5". I settled on a Mopar as opposed to a 9" Ford for the simple reason the axles can be cut/re-splined quite a bit cheaper than buying a set of aftermarket axles. To do the same with a 9" I'd have to find something with 31 spline axles and everybody seems to really be proud of them. Seems that someone also mentioned that the Mopar rearend is slightly less bulky in size to give a bit more room in the cockpit. I can handle narrowing the Mopar housing myself when that time comes.

A friend mentioned he had a 3rd member that I can get at a really reasonable price. I believe it's a 741 housing, but I'm not positive. I'll probably pick that up too thinking even if it's a 741 it would hold up to my projected 300-ish HP SBC.

Another thing I've been watching for on Facebook Marketplace and Craigslist is a used pair of slicks and wheels of appropriate sizes for mock-up purposes. There seem to be a lot of used and abused 10.5 X 15 slicks out there but wonderif I'd really need that wide of a tire to hook up only 300 HP in a FED? I'm thinking a relatively tall tire, perhaps about 29" tall? My un-educated gut feeling is that a 29 X 9 X 15 might get the job done with my projected HP and the car wouldn't be dragging the extra width and possibly weight down the track. I'm looking for input here, so fire away.

Anyway.... although a baby step it was the first step toward a FED build. Now if I could just sell my Willys to make room and free up capital.....

Lynn

[THE FRENCHTOWN FLYER]

I know a guy with an inline-powered altered who uses 9 x 29 slicks.
It runs 8.30s in the quarter.

He is the reason I'm downsizing from 12 x 31.5 tires next season.

[dreracecar]

You want either a 742 or 489 case, the 741 pinion is the weakest of the three

[Don Munyon]

Lynn
I did receive your email and took a few days to reply, hope you did get the answers to your questions. That being said, you mentioned that the 8 3/4 that you have has 10 x 2 1/2 brakes and respline the axles. Do you plan to use the drum brakes, if so I have a few suggestions if your interested. I'm saying that as a budget builder who had to make a lot of parts rather than buy them.

[THE FRENCHTOWN FLYER]

I remember that some dragster builders preferred drum brakes because they could be set to have zero drag, as opposed to some drag from disc pads at the hit. The reasoning was that they were good for one high speed stop before they faded - and one stop was all they needed.

[lake_harley]

Frenchtown Flyer.....One good stop before brake fade logic makes sense to me.

Don.....If you have suggestions regarding brakes, or anything else for that matter, please post them!

Lynn

[Don Munyon]

I don't remember having a problem with brake fade but I do use the chute most of the time. What I do remember was the first time at the track with this car. I couldn't stage or hold it in staging lights without it creeping which really got the starter POed at me. Anyhow (here is the tip) I changed the master cylinder to a smaller bore 3/4 or 7/8, put larger wheel cylinders from the front of a AMC and got rid of the metalic linings. After that no problems, I only changed to disc a few years ago to get rid of all that weight of the drums backing plates etc.

[lake_harley]

Thanks, Don, for the reminder on using a smaller MC to increase pressure to the brakes. Would about a 6:1 or 7:1 brake lever or pedal ratio be about right? I've used that pedal ratio on hot rods in the past.

Also, any particular model AMC and/or range of years that will fit the 8 3/4 rearend 10" drum backing plates without a lot of changes?

Lynn

[dreracecar]

Zero drag with the drumbrakes vs disc drag??? bunch of "Hooey" Disc brakes are lighter and lower reciprocal weight than heavy drums that take time and HP to get going. Call it like it is "Some people are not smart-just cheap"