Blown 400..few questions

So, I have a super low milage 400 that I acquired. And I decided to take a bunch of extra parts I have and put a Dyers 671 Blower on it.. Yes useing stock pistons, rods and cast crank.. I know there's so many red flags already. But this is LOW budget and really if/when it grenades I'll gaurentee I'll be cheesing ear to ear.. The 671 will be heavily underdriven and wickidly low boost approx 4-5 lbs. And I'll keep the timing retarded so it Might (?) Last ha-ha.. Anyway my main question is the 400 is externally Balanced, and I have a hub for an internally balanced 440, so I assume it'll viberate quite badly.. So next option anyone have a recommendation for a 400 externally balanced harmonic Balancer.. That'll hold up to a 3" Blower belt. Or any input on it? I know it should be dual keyed but... I'll chance it. (2 friends of mine both run blowers..Street use.. With one key and hasn't failed them yet) again this is a fun low budget, bunch of crap I have laying around, Street Engine that will see 5000 rpm max.

Try your luck with a stocker?? This whole build reminds me of an episode of Roadkill which is awesome. Sound like a blast man

Just sell me the block, and I will put it to good use....lol, and I thought I was cheap.

I paid $50 for the complete 400 with 22,000 miles on it.. The intake I'm using is a $100 383 tunnel ram milled down with a 3/4" aluminum plate on it. The Blower ive had the Crower cam (low miles used) I've had, took in on trades for paint work and truck parts. The dual 750 Eddy's 1 I've had and 1 was given to me. All junk I have kicking around might as well do something stupid and fun with it.. Cheap is fun.. Most of the time

I would take a little time now and buy a ATI dampener that will work with the blower drive and have the motor either rebalanced externally or internally before hurting it messing around with a unbalanced blown pump gas motor Cheap can be fun when done correctly Not so much when the car is on fire from a rod exiting the block at 5500 RPM BTW, a low compression motor, under 8.0 to 1 with low boost, under 7.0 lbs doesn't need the timing retarded, at least the last blown pump gas hemi motor I dyno tested didn't 33 degrees with 7.0 lbs at 7300 RPM made 924 HP on CA pump swill a bunch(2002 or so) of years ago

Haibach,

I think it will be fine, I have run a nitrous fed cast crank stock rod 440 in a 63 Plymouth to a best of 9.69 135 , that was 15 years ago, I belted piss out of it and the engine still lives. It has been semi retired now running NA 11.00 in my sons Aussie Valiant street strip car, all good.

5 lbs go for it !!!!

Cheers

The stock crap in those engines is bloody bombproof. I know guys here that used to buy 'em up and gas the hell out ov them, 300HP shot. It was never the pistons or bottom ends that quit. STOCK pistons mind you... and they made this distinction... jobber or rebuild pistons never lasted apparently. I've talked to a couple different guys that did exactly what you're doing... dumped a big ol' roots on top ov a stock low-comp 400 or 440, and they had probably more fun than anyone else i've ever known with a Mopar. You're good to go. I think you could easily get away with more boost and RPM...

Think is was Chrisf (the guy with the blown 383 Challenger) here that dumped a 6-71 into a bone stock mid-70's NewYorker and had a pile ov fun too...

You should be fine (after you get a balancer) I ran a stockish cast piston 440 w/ 6 psi of boost. I added a 8psi pulley but sold the car before I could run it. I ran an MSD boost delay box. I dropped 1 * of timing per lb of boost. The only time I burned up a piston was when I forgot to turn on my fuel pump. I'm sure you'll have fun.

Thanks for the input guys, its all going to be slapped in a 66 4-door Coronet with pie-crusts on the back, it's all for Fun,

you should win the burn-out contests for sure.

For a Balancer, do I just bite the bullet and get an ATI or try an "economy" SFI approved one from like Summit or Mancini?

RUN AWAY from the Summit balancers. I've owned 2 and on both the rings have become separated from the hub. Caught both before a disaster, and of course Summit was told and couldn't have cared less.

I don't believe in skimping on balancer quality, but if you are watching your budget I've heard nothing but good things about Pioneer balancers.

Valid point, somethings need to be high quality. I guess I can slurge on one thing.

We have a Summit one down at the shop...Total junk. Timing marks are way off.

Not sure if this is an option for you, but uhh,...why not just use a factory 383 steel crank & loose the cast flexi' stuff? Dunno..just a thought?

And if you end up grabbing a 383 crank, just use the hub, wouldn't spend the $$ on a balancer, the belt should absorb the harmonics (as long as everything is weight wise equal enough) not building a 2,500 HP nitro engine ya know, & I wouldn't be scared of 8 to 12 psi boost, use ARP studs & the good fel pros,... I'm doin same thing to my dad's duster..lol