Zac_F71's 71 Demon

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Well guys been going hard since the 4th on the car, lots has happened -

Patched the trunk, hung, and fully plumbed the fuel tank
Installed the wideband o2
Replaced the brake prop valve as the rear brakes stopped working
Found a metal on metal grinding sound, tore down the front of the motor, found the crank pulley bolts hitting the timing cover, re-assembled that.. added washers, and milled the inside of the pulley to fit better

Fired the motor last night had it running for 15-20 minutes, running great, it back fired thru the carb- huge fire ball, died, would not turn over, locked up.. not sure what happened yet but probably not good.. hauling the car home from my friends shop Sunday to tear it apart
 
Crank bolts rubbed the timing cover when the temp moved things around. Same on my 540. ATI makes spacers to get the balancer/pulleys out further from the timing cover.
 
Locked up? You can't even turn it with a breaker bar? Good luck buddy keep us informed.
 
Is there a chance that you stored the crank on it side, instead of on its end? I had a friend do this and the crank warped. 3 minutes after first start up, it locked up. The heat warped the crank just a little bit and it would not turn all the way around.
 
jrlegacy23 said:
Is there a chance that you stored the crank on it side, instead of on its end? I had a friend do this and the crank warped. 3 minutes after first start up, it locked up. The heat warped the crank just a little bit and it would not turn all the way around.
Click to expand...
Nope was stored on it's end until it was in the motor..
 
I'll let the pics speak for themselves..





Luckily it wasn't running when it locked up so hopefully everything will be ok..
 
that didn't take long. hope that's all. good luck
 
Welp after much discussion, a plan is forming! Let me know what you guys think?

68 383 - milled as close to 0 deck as possible
KB162 pistons .030" over
stock forged crank (.010" mains, .020" rods)
stock rods w/ ARP bolts
ARP main studs
Summit billet double roller timing set
Comp CL21-228-4 cam
New or stock pushrods
Stock rockers
Rebuilt stealths, with a little porting/milling
Good valve springs
Mopar M1 intake
same Holley 750 carb/spacer it has
MSD 6AL box
 
Well got the motor out, discovered it's not as bad as we all thought - the 71 motor is staying a std bore 383! - My machinist agreed to fly cut the pistons, degree the cam that's in it, give a general inspection, and go thru the heads - need new intake valves, get some porting while they're apart, and probably talk about better springs/retainers/keepers

I'm dropping everything off Saturday morning at Sampson Racing Engines, put some cash down, and come up with a final plan - I'll post the carnage pics Saturday night or Sunday..
 
just read the whole thread. you busted ur *** on this car and for that to happen just sucks. dropped a valve with new everything?? nice job on all and keep going.
 
Thanks man! Should be going real good here in the next couple months! Looking at a parts order here probably Sunday
 
Hopefully going out to the garage now to get everything ready for tomorrow (dropping everything off at Sampson Racing Engines to get fixed! )
 
Well the motor build is sorted! Got the first parts ordered last night as well. Here is the plan..

71 383 block .030" over, 0 deck
Mic stock forged crank, ARP main bolts
Stock rods with ARP bolts
KB400 -5cc domed hyper pistons
Comp timing chain it had
Comp 280*/.480" - 110*LSA cam it had - will be degreed this time
Stealth heads are getting 8 new valves, ported, and new springs/retainers/locks
Edelbrock Performer RPM intake w/ a 1" open spacer
Same 750VS Holley it had


Should have a true 10.5:1 static compression with a typical .040" head gasket

Jake at SRE says we should be good to get it going by May - so I should make Mopars in the Park car show in June..
 
The engine rebuild has begun! Motor has been torn down, and baked/cleaned I just ordered a few parts for it -

440source dual plane valley plate (yup going with a Performer RPM over the Torker 383)
few gaskets not all
KB400 .030" over 5cc dome pistons
Mahle piston ring pack
Clevite P series .010" under main and rod bearings
ARP main and rod bolts

A solid start to fixing this thing! It's everything for the short block anyway.. I was told all 16 valves are bent even though there is no signs that the exhaust valve even hit - so 16 new valves, and a good spring kit will be in order with a mild porting of the heads here.. now to come up with a little extra cash so he can keep working on it LOL
 
Well guys, got most all the parts dropped off over last weekend, the block has been boiled, line honed crank bore, and the decks milled. The crank was polished as it's all it needed (was already ground .010"/.010")

Ordering the Performer RPM intake, 1" phenolic carb spacer, MP/Felpro head gaskets, and 2 oil pan gaskets. As well as a set of PRW 1.6 stainless rockers

Been selling most all the stuff from other hobbies (RC's, slot cars) to help pay on the machine work tab - which after assembly, and dyno'ing the motor will be around $4,500-$5,000. Of which I currently have $900 down - going to put another $200 or so down this weekend when I drop off the Summit Racing order I make tomorrow or Wednesday night
 
Hey back with another small update!

Cancelled my offer on a set of PRW rockers, as I found Pro-Comps for $200 less and wouldn't ya know it they look identical

Did a wide search on eBay, found a set of used Crane 1.6's, and a set of unknown Harland Sharp's

Won the Crane's for $360 shipped that came early today!! Got the update that the crank was balanced, and I got a new Edelbrock Performer RPM intake as well as a new high rise throttle cable bracket with an integral mount for a Lokar kick down cable!!

Just splurged last night and bought a US Car Tool bolt on driveshaft loop as well!

So I'm home sick this weekend and going to sell a thew more things to recoup some money here to make a large payment on the machine work tab!



 
Back with another small update!

Went to SRE yesterday, the block is in final assembly, stuck on the No.4 cam bearing - the set I bought is a std set, and the No.4 bearing was a over size from the factory, so had to have a custom bearing made. Waiting on that, and then together it goes! He had the rings out as well I assume to gap them.. getting nervous and excited! LOL

Nervous as I bought a truck and am running out of money but excited to be getting it done!
 
nice Demon.....I love their subtle differences from the Duster

too bad your valves decided to stick....or whatever they did, but better now then later (I guess).

looking back a couple of pages I saw the crumple in your header tubes.....those offenders can be cut out and with a slight e-route....better than new. If you can tac, get some U bends, tac it yourself (duct tape even works)...and have the tig welded. I have re-routed many a offending tube....easy-peasy

your labor .....a few bucks to a good welder (if it is not you)....and good to go.

other than that....keep up the great effort. Already starting to pay off.
 
Thanks! Ya all 8 intake valves hit the factory flat tops cause I used the wrong 0 on the crank gear to time them up, 1 ended up dropping in the chamber..

Got all my pics uploaded finally and I'll see if I can post the shitty video of it running..

Enjoy!

Tearing the engine down to find the metal on metal grinding (was crank pulley bolts) -


All back together -


Spare tire well marked before cutting -


Cut out and fitting the patch I got from Tony and Kathy Defeo for super cheap!


My good friend Shannon welding the patch in! -


Starting the rear axle housing fitting housing was 44" center to center, leafs were 43.5" center to center-


Not pictured but we elongated the mounting holes in the Allstar 1" lowering blocks 1/4" in each one to bring them out to 44" centered -


Ride height as it sits -


Priming the oil to start it!


Final is starting the tear down, after it blew up..


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Finally pics of the damage -

Motor out! -


There's the valve! -


carnage under the valve -


Valve hit the head a couple times -
 
The video!

[ame="https://www.youtube.com/watch?v=3rWZXom80Yk&feature=youtu.be"]1971 Dodge Demon first start with 383 big block - YouTube[/ame]
 
Wow man. Now this is a build. Great job. Thanks for the info on my thread by the way.
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