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512 cid C series on Dakota chassis- build thread


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Almost done breaking in the cam/lifters but my lower rad hose sprung a leak so I idled it down so it wouldn’t diesel on shutdown. It only idled for less than 10 secs but I recorded it!

 

I can see the conversation now- “what’s that got in it?!” “It’s a (cough cough) stock flathead motor with exhaust and a cold air intake” hahah 

 

It sounds a little nastier than I expected!

 

 

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9 hours ago, Frank Elder said:

what's your favorite gas station.........I think I'll buy some stock......lol!

When you’re right you’re right. It was running super rich which I corrected but I burnt up 5-6 gallons of gas just on break in! After getting the high rpm break in period overwith I tuned the idle then went to try out my fresh transmission. The tires didn’t move at all, no jolt into gear, nothing. Then the afrs started going lean, the motor struggled, and died. Those glass fuel filters get a bad rap as fire hazards but they sure make it easy to see if you have fuel! I was out. I got some more gas and got the four corner idle happy around 1000 rpm which is just slightly choppy with the cam in there, checked and added a quart of atf idling in N, still nothing. 

 

My mistake: I did the whole break in with the trans in Park. I now know that the pump doesn’t run to fill the converter or lube anything unless you are in Neutral or a gear. I’m thinking I smoked it. 25-30 mins of varied rpm around 2500-3000 with a dry converter. The cooler lines are cold and shifting is doing nothing. I figure maybe I bungled the valve body rebuild but it’s looking more like I’m going to be pulling the trans and buying some new parts.

 

At least the motor seems real happy. I gotta hurry up and get this trans right so I can give this motor some work to do!

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If you smoked the trans, you should be able to see and smell it in the fluid.  You did remember to install the converter bolts, right?  Easy enough to forget to put them in when putting big pieces together and thinking I'll remember to do that later.  Fluid level has to be checked with trans in neutral on the 727 since the converter returns some to sump when in park, giving a false level of full.  Recheck your band adjustment as well.

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Fluid looks new but there’s no flow to the cooler in any gear. I ran back and forth through the gears slowly a bunch. I have 9 quarts in it so it should have done something by now. Stupid dipstick is impossible to read- after adding atf thru the dipstick hole idling in N it just always comes out wet. Even with a deep sump the pickup is extended to the bottom- it should have tried to shift or spat out the cooler lines after a minute in N with one line in a bucket.

 

The torque converter install took a while- I didn’t pour a quart in like I usually do because I had the trans tipped up to get gravity on my side and didn’t want to make a mess. It took a lot of spinning around, pulling up and re-clocking to get the converter to drop all the way down but there wasn’t any force involved and after the trans bolted to the block the converter had to slide back forward a smidge to bolt to the new flexplate. So unless the pump and keyed TC snout are made of tissue paper I’m thinking it’s good. 

 

I know the flexplate is bolted onto the converter because I forgot to mark which of the 4 bolts was offset and it took four tries to get it- just my luck haha also I was amazed that it uses such tiny bolts compared to the ones that hold the flexplate to the crank and I wanted them nice and tight but took care not to snap them off. I used blue loctite. That was a long night I remember very clearly rotating the crank over and over trying to find the offset bolt and bolt it up. I wasn’t pulling the trans back off the motor though after how long it took to get the converter to drop into place into the trans!

 

The only thing that messed me up reassembling the trans was I had the kickdown piston upside down or something and the little nose was sticking way up. I slept on it and figured it out the next day- something was upside down iirc. Everything else seemed pretty simple except for the valve body. 

 

The tf2 shift kit instructions were super clear and easy but some of the smaller valve body pistons were hard to figure out where they should go- the stock ones I cleaned and reinstalled. I could easily have installed one backward or on the wrong side of a spring. Or maybe a check ball went where it shouldn’t.

 

I am tempted to just buy a tci streetfighter valve body and throw it in to see if that solves everything but when I built the trans I figured if I bungled the VB it’s easy enough to pull off compared to pulling the whole trans. I also crossed my fingers it would just work out...

 

Anyway tomorrow I’m buying a brand new drain pan so I can salvage all this B&M trick shift ATF, draining the trans, pulling the VB, and looking for any problems that jump out. I’m going to carefully disassemble the VB and possibly blow air in the holes in the trans to make sure it applies the bands etc- especially if I find no problems with the VB. 

 

I’d like to use this to learn since I’m new to working on auto transmissions but if I have to throw $300 at a new hotrod VB it’s a better looking option than pulling my trans or driveline.

Edited by Radarsonwheels
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Thinking my 86 ford van with the C-6 trans took 12 quarts to fill it .... when I swapped the trans and installed dry torque converter.

But I looked that up on line somewhere .... you sure you have enough ATF?

Maybe I am wrong and was not that much, but it was a stupid amount needed to fill it.

 

I hate checking trans fluid, when you add a little bit, you have to let it sit overnight to drain down the tube and check it again in the morning.

I would think that you would get some flow through the lines with 9 quarts though.

But if you are 2 quarts low, I know my ford would not move without adding to it.

Should be some site online that would tell you exactly how much your trans holds.

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I believe there were shallow and deep pans.  Your article says 9 and would be typically for a shallow pan if the pic in the article is any indication.  Deep pans or an aftermarket deep pan are going to take more.  Did the  pickup have an extension to drop it to the bottom of the pan?    

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Apparently it’s possible to install the atf pickup backwards and run the filter up to nothing, leaving the suction hole unfiltered and above the fluid level. 

 

I installed it as a unit with the filter and gaskets on the screws- never checked to make sure the passage went somewhere! Kind of an optical illusion that the center screw is not centered, but it is.

 

Flipped it around. Cheapest fix ever still gotta go back together and fill it back up, and see if it will work now.

 

It’s funny if I had overfilled it it probably would have worked until it sucked enough unfiltered ATF to clog someday.

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2 hours ago, Merle Coggins said:

Now, hopefully you didn't smoke the pump running it through the cam break-in period without any oil going through it.?

Yeah I was pretty worried about the pump converter, & seals. I felt much better when I dropped the valve body and the trans above it drained a couple pints of fresh fluid. It did pull some up but it didn’t have enough to make pressure. I also always use plenty of grease when I rebuild rotor pumps both for lube and so it will have good suction. 

 

Honestly I had no idea what I could have smoked in there when it didn’t work! 

 

My first freak out was when I read that the pump doesn’t flow in Park which is how I did the whole break in. Then I felt a little better when I went back and re read my tf2 shift kit instructions- with the kit it fills the converter etc in park not just Neutral. 

 

The rear main seal definitely leaks and I need to put a new gasket between the head and passenger header but I’ll probably romp around the neighborhood soon to seat the rings and get an idea of the baseline tune. Then a post preak in oil change and back to sheetmetal work.

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I'm glad you got it figured out! Simple fix!

I rebuilt the 727 in my 71 satellite and I wasn't sure if I'd ever find where all the pieces went.  I didn't have any leftovers and it worked,  but I was a bit nervous at the initial startup.

Have a safe romp around town!!

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I checked the brakes and steering and went down to the corner and back. It is not always easy to start so I didn’t want to walk home and my kid is in the house watching cartoons after dinner. I was more than a little nervous but the rusty rotors worked ok and the steering was pretty good too- a little more effort than the over-assisted 70s muscle cars I’m used to but nice.

 

I live on top of a small hill in the middle of my block and it’s a 2 lane street that narrows when people park on the sides so I was just concentrating on making it home without killing the motor or finding a terrible problem the hard way. 

 

It’s got a loud thrum at idle that will take some dynamat to cure but it never threatened to die. The turning radius was decent (should be for a shortened dakota) and the power brakes seem to be working ok? Not amazing. Breaking them in from their slumber will help but the actual braking happens after a good bit of free travel and requires some force on the pedal. Maybe I will eventually go to a smaller bore master but time will tell. I’m super glad I extended the floor forward under the pedal so it could have more travel without a higher starting point. 

 

I hardly looked at the gauges but on the way back up the hill I gave it half throttle and good lord she’s got some stink!

 

BIG milestone today.

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Edited by Radarsonwheels
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Gotta make a little tool roll to take on shakedowns!

 

And I have to remember to tie the shifter cable farther from the headers- it was close before I took the trans apart ghis morning and I forgot to check it after. 

 

I’ve used peel & seal before, and fatmat too- never ponied up the big bux for the brand name before but this time I did. I’m gonna do everywhere under the rubber floor and behind & under the bench seat where it won’t be seen. Should make a huge difference in the resonance. I’d like to wrap the whole firewall but I don’t have a plan to hide it and the truck still gets water inside when it rains- I need to seal everything up. 

Edited by Radarsonwheels
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I ordered some fancy percys soft aluminum exhaust gaskets for between the head & headers- # 1 is ticking pretty good and I isolated it with a hose in my ear.

 

I also found that I stripped the hose clamp to the thermostat neck. I don’t want to open the system again- I’ll probably cut the stupid chrome streetrod cover off with a dremel and replace the clamp with two new ones for insurance.

 

The steering had a couple notchy spots so I moved the bearing support down a touch more- didn’t try it yet.

 

And I remembered to zip tie the shifter cable off the headers too. 

 

It’s a chilly rainy morning here- hopefully tomorrow before work I’ll get a minute to wrench and shake down some more.

 

Gotta get zinc, oil & a filter for her first oil change to get all that break in glitter out of there. Probably do plugs too unless they look great which is a possibility. I haven’t started tuning in earnest except for the timing, curb idle, and idle afr which all seem pretty happy.

 

Also it seems to start pretty well if I spin it before squirting a little gas. When I prime it with a pump shot it seems to flood or generally be stubborn. 

 

I’m also pleased to find that I have a two finger margin before tire rub at full lock. Have to go slow turning into driveways with a bumpy enterance but totally drivable.

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Oh and funny story- I tried to flip it around in the driveway and after I got into the street it wouldn’t go into Reverse. After my first trip it was reluctant to catch R as well-  I figured the linkage was maybe not indexed quite right. Turns out the trans & cooler had burped and it wanted some more atf- after adding some it works like it should. 

 

Anyway, since I couldn’t back up but Drive seemed to work perfect I took a trip around the block- my longest trip yet ;) 

 

The funny part is when I got back I stopped in front of my house and did a tiny burnout- just a quick spin no real tire smoke or high rpm. Whew! Felt good! But after I turned into the driveway I noticed smoke coming out of the passenger defrost vent- oh no emergency action mode! 

 

Turns out that when you have rain water leaks and it’s cold out the heater core steams a little when it gets up to temp! No sweet smell, no electrical smell. A good scare though! All that’s over there is the two guages and the heater fan which collectively have three fuses one of which would have popped before letting smoke out but I got a good scare. 

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I got that water neck tightened up and had to add more a/f than I lost from popping off the top hose which I ended up doing. I guess without an overflow/reserve tank hooked to the line on the rad bung it’ll always ends up having some air in the top tank of the radiator. I’ll have to rig something up. It’d be nice to see any ideas anybody’s got.

 

Maybe I should just weld up a bracket with some foam in it to hold a glass bottle and hang the hose into the bottom of it? I have a universal ugly milky plastic one around on the shelf that looked right on a 70s mopar.  I’ll have to look around google hamb ebay etc for ideas too. 

 

Also got my fancy percy’s exhaust gaskets in the mail this morning. That’s somewhere between an annoying chore and a fun upgrade. It’s just the #2 cyl that tics so I’m not fixing the other side just to have matching gaskets- I’ll save the extra one. Might put on a jacket and do the passenger side tonight so it’s done. 

 

My wife’s out with friends so there will be no hotrodding around the neighborhood tonight- not leavin my kid alone in the house.

 

Tomorrow I wanna see if the steering is cleared up, re-check the atf level hot in N, see if it still reliably goes into reverse, try revving up 1st and seeing if 2nd & 3rd upshifts will bark if I run thru the gears manually with the slap shifter above stall speed rpm, check afrs at different rpms & throttle openings, mostly fun stuff.  I’m a little scared about hot starts. If it doesn’t fire after a few good cranks it starts to drag the battery down. I got a fancy bracket to hold a red top battery sideways when this one goes or if it’s not strong enough for this duty. I thought about running two batts but I think there might be a reason only RVs and winch trucks run them.

 

The first trip to buy high-test will need to be soon. She took gas as fast as I could get it out of a 5 gallon can so my fill tube is working, and no leaks, but will running the vent about a foot higher than the fill actually allow the pump to shut off before anything spills? Or will it keep shutting off and need to fill annoyingly slowly? Or will I have to watch for when it starts filling the fill tube and shut it off then? Fingers crossed my ‘engineering’ works like I want. 

 

It’s been registered and insured for months but I’m a little giddy that I am allowed to just go ahead and drive this thing around. 

 

One more thing- my buddy had a pinstriper make this plate for me. The ‘dude magnet’ was a name coined for this truck by my buddy who originally owned it. The truck always draws a crowd but they ain’t women. I am secure in my manhood but I think it might send the wrong message- can’t bring myself to put it on the front bumper even though it’s hilarious. I’d prefer it to stay an inside joke. Maybe it’ll fit on the firewall inside the glovebox door. Gotta make a new glovebox too! And a dry stash spot for my paperwork

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Welp the exhaust ports on my stealth heads are definitely bigger than stock! I can’t believe more cyls weren’t leaking on the passenger side. You can see the black squares on the old stock gasket- #2 was a straight mismatch and never didn’t leak. #8 was a short & curly away from burning through, and #s 2 & 4 were not much better. 

 

I took that passenger side on & off so many times to ding it for clearance I guess I just grabbed a stocker and thought I’d see which style lasted longer. I didn’t realize the heads & headers were so hogged out from stock. Both sides are good now with port matched gaskets. 

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