Projects Northwest Vintage Dragster Group Build.

I'm going to have to come to your meeting nights ... just to eat LOL

 

Were all just in it for the food too!

Thought I would put this up before our panel of judges before we start cutting cross tubes. the blue would be 1" -1/8" wall and the red would be 1.5" -1/8" wall. Any issues spotted or advise is appreciated.

 

Don't paint'em blue & red, looks silly.

Sorry, Sir. Just couldn't resist.

 

These should help with the bar placement (see they do come in various colors):

 

And a real one:


Also a note about another possible steering box Rob asked about earlier. Since we're not going for the absolute minimum weight on these cars, I used a reversed Mustang box. It wasn't as hard to find as the aluminum MoPar box.

 

I would reverse the angle of the forward red diagonal (as per CASUAL6's frame).

Roo

 

great idea on the color coded tape thanks loads for a cool idea

 

A couple of comments. I ran a mild flathead dragster in late '60. Had 276 cu in, side shift ford trans, and 4.11 rear end.
With 26" tires ran out of engine at 1000' but got out of the hole well. With 29" tires could nt get off the line but pulled thru the 1/4 mile. Ran in low 12s I hope your not going to run that T front axel over 60MPH. When welding in the diagonal braces one of the vertical draces has to be loose of you have to have excessive fish mouth on the diagonals. Don't ask how I know. Also short wheelbase cars can get squarrelie at speeds.

 

Walt, did we learn anything new yesterday at the meeting?

 

Rob - No major changes. Just updating a few things to encourage the use of old speed equipment. I'm tiding up my notes today and will send them out for review. After I get any feedback we'll be ready to get things posted.

 

Sounds good Walt, will the 8"-28.5"-15 cheater slicks from towel be the right ones?
http://www.towelcityracingtires.com/site/mobile?url=http://www.towelcityracingtires.com/Pie_Crust_Cheater_Slicks.html#3079

Edit..Nevermind, i just go the email with the rules preview. thanks.

 

Yes. For those who are interested.

 

Not a ton to show this week other than mustard sauekraut pizza is pretty tasty and coping the cross braces is time consuming....

 

Wow never heard of mustard sauerkraut pizza. Going to have to try that it sounds like a good combo. Maybe with a little ham or kielbasa.

 

And some beer.

 

Rob, You might check the roll bar specs as per height and tube diameter. Here is a couple of shots of one with a 300 Ford, just for reference.

 

As an aside, I think FEDs have to have 6-point cages per NHRA rules, if that is of concern. I had to change over a perfectly good 5-point to a 6-point a few years back to stay legal for NHRA.

The 5-point became yard art - "Left Turn Louie":

 

If you look at Section 20.23 of the current NHRA rulebook, for a Funny Car/Altered chassis, a 5 point roll cage is still permitted for 10.00 seconds and slower. Maybe it changed for 9.99 seconds and quicker?

http://www.nhra.com/UserFiles/file/General_Regulations.pdf

 

How about a little info on your chassis. Wheel base, engine location, weight of chassis.

 

So if I'm reading that right, we should be good with 1/8" wall 1 1/2" MS no matter if we are over or under 18"...? Seems kind of odd that they would make a height statement if it doesn't change the material spec.



Btw Casual 6 and I have been putting up some pages for the class. Everyone can see our progress here www.nwvintagedragster.com let me know if you think of some links or other helpful info we should include.

 

You need to use 1/8" wall 1-5/8" OD (CODE B) for the roll bar hoops (labeled 1) on both (over and under 18" tall) for a 5-point cage.

And then 1-1/2-inch x .065-inch CM or .118-inch MS (instead of the 1-3/8") for the upper framerail/shoulder hoop (labeled C) is also required for both over and under 18" tall 5-point cages.

And remember, you can always use larger tubes if you want. These are just the minimums. We used 1-5/8" tube for the framerail/shoulder hoop (labeled C). That way the roll bar hoops match the framerail/shoulder hoop when welded together.

We also spliced a 1-1/2" tube into the framerail/shoulder hoop 2" in front of the rear motor plate going forward to the front axle. That 2" is also a requirement if you neck down the framerail/shoulder hoop.

 

Ok i can see how i was reading that wrong. We were planning on sticking with the 1 3/4" anyhow.

I think once we get some cross bracing in the bottom of the car we are going to tack the rearend in and build a seat so we can start figuring out roll bar heights off our tallest driver.

 

After you mount the rear axle, I would mount the engine and trans. Then, with the driveshaft loops and tunnel cover in place, build the seat and determine the roll cage height. Your chassis layout looks great !

 

Yeah we have been back and forth on that, we have a basic idea of where the engine will be and in the cad we have a for sure crankshaft angle in relation to the lower rail. Our thought was that with the seat in we might be able to cheat the engine back a couple more inches but it was pretty hard to tell with half assed mock ups so we drew it up somewhat conservatively to make sure we had enough leg room.

 

Yes, I was running quicker than 9.99. I did not realize you could still run a 5-point if you are slower than 9.99. That, plus not having to re-certify the chassis every two years for a car slower than 9.99 is a good reason to stay slower than that e.t.

 

Actually a five point is legal in front motor dragsters as quick as NT/F as per the SFI 2.2 spec. As for the engine location you really should mount it with the rear of the block in line with the appropriate upright (that is why it is called the motor upright in the spec). That way the engine load is transferred to the frame where it is supported and the motor plate acts as a firewall. I have seen numerous cars with the motor mounts "out in space" between the uprights and the results are usually not good, especially once the car gets a few laps on it.

Roo

 

Dad showed up last night with the roll bar pre-made. (Exaust tubing for another project)


We got the last two cross braces made up for the sides of the chassis.

That makes sense and is good news. I had it drawn up to be a couple of inches past that upright. We cut the chassis off the table and put it over our mockup motor. Then made up a plywood mockup seat that looked like it would work with the driveline hoops. Sitting in the car we were able to move the engine back a little over 2 inches which put the front of the bell housing right on the upright. So we decided to go ahead and run a mid motor plate.




We did notice that the next upright back probably should have been about 4" farther back so a straight cross tube could have supported the front of the seat. As it is right now if it went straight accross it would have to go threw your calves. I think we can get by withsome bent tubes to get it back. And then make the alteration on the next chassis.



It does work out nice for the trans crossmember, but i would think it would be ok if it were mounted ahead of that upright 4 inches.

 

If you are running a mid plate and front motor mounts the trans cross member is unnecessary (and may cause problems) At the most use a factory style soft mount pad if you feel the need to support the trans but all of my dragsters/altereds just hang the trans off the mid plate/block. A lot of people worry about the trans hanging out there but in the factory installation the whole package is supported at the ends (trans mount and engine side mounts) so the bellhousing is plenty strong enough.
If you are going to use a front plate (from the front face of the block) it would pay to mock up the engine in the next car and place the upright in line with the front of the block. That way the engine weight and torque load) goes into the frame where it is supported (and is also spread into the lower rail as well). At the performance levels that you are planning what you have will work but I have seen lots of issues with the motor "hung out in space" in higher powered cars.
As for the seat cross member I would use a piece of 1" tube bent to land on the lower of the rear "K" tubes so that it is at least 6" to the rear of the driver's knees.

Roo

 

Fair enough, one question, looking things over, the car would be pretty comfortable with the floorboards down at the level of the bottom of the trans pan. Can the trans be in the cockpit if it is covered with a blanket or shield?

 

If the trans only has a blanket or shield, you'll need to wear a SFI-15 or better suit. I don't think you want to do that (~$1500+ and certs required).

So, you'll need a complete sealed metal firewall and floor. Then it's Levis and tennis shoes.

If you run the 12 Second ET, you won't need a trans shield. Then you can wrap the trans tunnel real close to the trans. The floor where my feet are is about level with the bottom of the trans (pics). My seat platform is about 3 inches higher. I also made the trans tunnel in 2 pcs so it is easy to remove.