Jump to content

512 cid C series on Dakota chassis- build thread


Recommended Posts

Looks good and the best part not spending money. You won't be starving the engine with that beast!

What did you use to plug the original dipstick hole in the block?

I was thinking of using a short chunk of aluminum rod?

Link to comment
Share on other sites

Thanks! I used a stub of oem dipstick filled with silicone. I left just enough nub that I’ll be able to yank it if I ever want to (dunno why I would?). 

 

My rear sump offroad pan is an older one the screw in dipstick is on the passenger side. The pics of a similar pan on summit etc show a driver’s side bung on the pan. My pan also doesn’t seal the stock dipstick hole so it did need a plug. 

 

I’m playing with gauge ideas today. I would like modern gauges to protect my investment in the motor but I definitely want a vintage look. Here’s a mockup- it doesn’t get much more reliable than autometer. Mechanical Oil psi, electric water temp, mechanical speedo/odo.

611AB549-FE03-428E-89E5-602F62D4E4D9.jpeg

Link to comment
Share on other sites

I’m all ears if anybody has other gauge suggestions. A little cheaper would be nice! The stewart warner stuff is also pretty expensive and I didn’t see much that had a nice vintage feel. 

 

Edit: I pulled the trigger and ordered this setup. Nobody else makes anything this good looking which also has rolling odo numbers.  I can cut this truck up till the cows come home but I’ll never put a chevy motor or a digital readout in it!

Edited by Radarsonwheels
Melted my visa card
  • Like 1
Link to comment
Share on other sites

7 hours ago, Plymouthy Adams said:

just what kind of steamship engine you got in there that you need 950 CFM double pumper......

 

Well I think an 8.4 liter v8 should make a *little* bit of steam! I was planning on using a 750 double pumper that I had laying around but when I went to go through it I discovered it’s really a 950hp. Jeez I’m not old enough to be forgetting what parts I have laying around!

 

Funny thing about the older holley 950 though- they actually have smaller bores than the holley 850 carb! I think there is some magic in the sculpting of the main body but they’re only supposed to flow 830 or so. The 950 label is just marketing hype to keep up with all the other manufacturor’s shiny exaggerations. The primaries should see plenty of signal from the big stroker to have decent manners. 

 

I’ve learned the hard way over the years how to wire down the idle feed restrictions for the transfer slot circuit and idle discharge holes to get a clean low throttle cruising afr on a race holley.  As long as I don’t mind pedaling the car to warm it up with no choke I should be able to make it work on the street. Plus I don’t think a choke horn would help flow in my wierd dual snorkel carb hat air cleaner.

 

I also kind of enjoy how the double pumpers can be ‘driven wrong’. They remind me of a shovelhead I had with an S&S super B carb. It was a great performance carb but had no accelerator pump so you had to ease into it just right until you got it singing- then you could whack at it and get amazing throttle response.

Link to comment
Share on other sites

I have been dreading messing with the power steering pump. The one off the 400 had nice big block brackets that looked like they’d swap right over but sometimes ‘looks like’ bites your butt. Both pumps were maximum filthy! I scraped degreased sandblasted and painted the BB brackets and washed the dakota pump with a gasoline soaked rag (I know I know but it works the best and it is outside still attached to the rack & pinion).

 

The dak pump did indeed take the painted brackets perfectly and after modifying the bracket to move the pump/pulley 1/2” forward it fit a 1977 d150 400cid non AC ps/wp v-belt just right. The alternator works great with a belt I had in my collection which has seen better days but still has part numbers very legible on it :)

 

The alternator has to move another 1/4” or so to get the belt alignment perfect but that’s just juggling some washers since it’s all shimmed in there anyway. 

 

The amount of work left is still daunting but some details are starting to come together which is nice.

BB8E8C90-7B13-487E-9D67-5B534015DDEE.jpeg

Link to comment
Share on other sites

Got the shroud/fan sealed to the radiator with foam side rails and attached the B&M oil cooler to the front of it last night. Tonight I chased the 3/8” fine thread holes in the rad support with a tap, mounted the aluminum radiator brackets and hung the whole mess in the front clip. 

5ED4F8E0-769F-4C10-82D8-759B8CC75B7A.jpeg

  • Like 1
Link to comment
Share on other sites

I got my ratchet/detent shifter assembled, and bolted my brake pedal/mc setup together. 

 

Also chased the starter threads in the bellhousing, installed a stud in the top hole  almost like stock but not 1/2 fine thread, and wrestled with the mini starter for a bit before realizing it was hitting because it had a wire stud extention bolted on to it for some other model mopar engine- probably a v6 or 5.2. Now that the starter is on I’ll know how to route the downpipe from the shorty header. 

 

One of the hardest things about the truck’s  former incarnation was that I am over 6’ tall. It was always a workout bringing my knees to my chest to work the pedals. Since the bench seat can’t move back any farther without losing the springs and going with a hard thin foam over church pew or bucket race seats (ouch and barf) I am thinking about pushing the footwell forward a little bit to get more legroom. Now’s the time since I have to re-imagine the firewall. I’m going to frame it out with 1” .120 wall square tube and skin it with mostly flat panels of probably 16g. A little on the heavy side but it should be strong. 

 

I’m trying to decide if I want a support structure for a ‘floating’ shifter, or if I just want to build the trans tunnel up into a console. A cupholder is always a nice thing to have too but not so traditional. I found this pic of a pretty clean solution but I really have to sit in there with the bench seat column and shifter to see where my right hand wants to end up. And also to make sure I don’t punch the dashboard to go into Park.

9703EC18-0723-4681-8C66-901F8013DDE9.jpeg

Link to comment
Share on other sites

I sat in there with the shifter- it was only really comfy kind of butted up to the bench seat. I guess I will make it a little console or maybe hang it up on a gusseted pole like a mailbox. 1/2” or so clearance to the upholstry should keep rubbing wear to a minimum. It’ll be a while before I get to mount that anyway- floor first.

 

I also got working on my air over leaf adjustable suspension with the 2500lb load leveler bags. I called the airbag manufacturer and got all the specs on the bags and brackets I ordered. First I dropped the rear down to the bump stops and measured the clearance, then measured at my proposed ride height, then at max extension before the leafs unload the tires. Then I knew how much travel the leafs ‘wanted’ before they would be fighting the bags.

 

I sat down and drew a bunch of scale drawings of my ride height, frame height, and bracket positioning. 

 

It looks like if the lower bracket that sits on the axle tube is 4” tall then I can make the top bracket sit level with the top of the frame and everything will work out perfect. I’m anticipating it will be less than 4” so I’ll be able to drop the top bag bracket down by whatever the difference is. 

 

This bag placement should give me 1 1/2” clearance at the lowest and 7” at maximum psi/inflation. I’m looking for 4 or 4 1/4 gap at ride height but the beauty of it is I’ll be able to put it where ever I want. It’s supposed to arrive around halloween so I have plenty of time to mess with the pinion angle, leaf perches, and driveshaft before then. I want a front driveshaft loop too.

 

 

Link to comment
Share on other sites

Thanks GGdad!

 

I got the rusty spring perches out then sandblasted and painted then chamfered and sanded the weld edges, spun the axle 180° and sanded to bare metal where it’ll be welded, and re-assembled it all. The perches are perfectly centered and I’m at ride height. The driveline (motor & trans) are at 1° down (driveway’s on an incline) and I am ready to preload the slappers, set the pinion angle, and tack the perches in. Then I ran out of time and found out it’s supposed to rain all tonite and tomorrow! I want to take my time and get it right next dry day I have some wrench time Should be ok...

9B9B5AA5-60B0-411C-A5DF-2A09BDE8E83E.jpeg

  • Like 1
Link to comment
Share on other sites

Had to run home real quick- got a ups notification that my airbags came almost a week early! Go brown truck! They look nice. The bottom brackets are cut for a smaller axle than mine and have plenty of meat to shorten them and make them fit my 3” axle perfectly- my axle actually tapers so I’ll have to account for that. 

74B916EE-7EC9-48BC-9AA1-D219F1318FCE.jpeg

  • Like 1
Link to comment
Share on other sites

This is why I didn’t want to build headers- my exhaust welding always works but doesn’t get pretty till I’m almost done and get in a groove. There is enough left to do that I should see some improvement! 

 

Anyway, the downpipes need to angle 48° out because the collectors shoot in toward the oil pan and 24° back to clear the engine crossmember. It’s tight but not bad at all. I think the back half of the system needs to get mocked up so I can start having dots to connect. 

 

The stainless headers came with angled bolt up flanges with downpipe stubs but I don’t know why I would use them- they neck the 3” collector immediately down to 2 1/2” and my system goes from 3” to 3 1/2”. 

B0F3C4AC-124D-481D-8A13-11AC6EDA98C5.jpeg

Link to comment
Share on other sites

I also ordered a new tube flaring tool. It was kind of hard because all the $15-$50 tools are pretty much the same quality as the made in usa bar clamp one I already have. I got pretty good at using it- it’s all in the prep work chamfering the tube and making sure the bar sides are exactly even when you clamp them down. I still hate it though and don’t get a perfect flare every time.

 

Plus if you clamp the tube hard enough to not slip it leaves puckers near the flare that either make the nut harder to turn when you’re trying to start threading it in, or get filed down smooth which removes the rust protection. 

 

The next obvious step in quality to professional tools seems to be $300 for the master cool kit which has more durability for every day use than I need as a hobbyist. The $50-200 middle range seemed to be a minefield of imported pot metal junk that should cost much less or won’t hold up unless you only flare copper.  I ended up buying a cal-van set for just over $100 that has nice deep clamps and even a hydraulic ram instead of a screw down mandril. It had good reviews so I’m hoping is works out for me. 

 

By the time I get this exhaust done I’ll be ready to plumb the transmission hard lines. I’m planning on all new brake hard lines too so there is plenty of plumbing to do which I am now looking forward to.

EE311670-B0D0-4407-8DB8-BFBF875C7EBE.jpeg

Edited by Radarsonwheels
Added pic
Link to comment
Share on other sites

It was a toss up between the cal van and the eastwood which looks like yours- more of a turret setup. A bunch of folks sell them- I don’t know if the quality is all the same or if some are knockoffs? In any case we’ll see soon if I chose well or not.

 

Several companies use this design with the deeper single hole clamp blocks that have the male threaded boss on top to receive the ram- hopefully the cal-van version is closer to tool steel than pot metal.

Link to comment
Share on other sites

I saved a Dakota Chassis for 15 years.  I finally gave it away last year.  I dreamed of using the chassis with a 1957-60 cab and bed.  Family life said...  No!  LOL

 

I am enjoying watching you figure it all out.  Not always easy to fabricate stuff.

 

I will try to stay tuned, just busy trying to get my new building up...  Not much time to good off online.

  • Like 1
Link to comment
Share on other sites

The bags took about five hours to install today.  I boxed the frame, re cut the bottom brackets with 3” and 3 1/2” circles so they would sit down and flat, got it all welded in, painted, plumbed, and messed with the air. It seems to be holding just fine. 

 

The truck sits very low and flat with no pressure in them and at a tall ride height with 30 psi which is still nice and squishy. They get a couple inches taller but over 40lbs seems pretty stiff. The bags will take 550lbs in case I ever need to haul a safe with an elephant in it.

 

I was originally going to go with a T and a single schrader but I was reading that it accentuates roll in a turn as the stressed bag squeezes air over to firm up the other bag. 

 

Now I can set my pinion angle without fear that my ride height will change again with the ipe bed and a tank of gas. It is tempting to put dumps and an air tank and compressor on it but that’s not what I’m trying to do here plus that is expensive!

CC632817-18D7-49BE-9632-A1215F8CEDEC.jpeg

9ED1D538-17D1-4B27-8978-A7F811D92DF1.jpeg

Edited by Radarsonwheels
  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Terms of Use