Joined: Sun Sep 24 2006, 10:33PM
Location: Lisle, Ill.
Posts: 168
I have a '66 Chrysler New Yorker. 440 727 8.75, supposedly 55k or so on the clock. I knew from some pencil in the doorjamb that it had been overhauled and bored to some worn away number. So now that I have it in the garage, I pulled the heads to find it had been bored .040 over. Ok, no big deal. cc'd my 516 heads, 84cc. Ok, fine. Measure that the pistons are .165" down the bore at TDC. That looked like a lot to me, so I did the math only to find my current compression ratio to be 7.84:1. Holy crap! No wonder it ran fine on pump regular! Why on earth would someone want to drop the compression that much on a rebuild?! So now, instead of just throwing a top end at it, I'm gonna have to throw a bottom end at it too. I'm thinkin 500 stroker kit from 440source.com. The scary part is, it still seemed to have tons of power and torque as it was. Maybe it was just in comparison to my crappy old Oldsmobile. Now I'm so looking forward to my real compression 566hp 588ftlbs! [numbers from my DynoSim software] I mathed the new CR to be in the neighborhood of 10.43:1 with 88cc Eddy RPMs. Has anybody used these 440source kits? And with how much success?
Joined: Mon Oct 10 2005, 01:49PM
Location: Grand Rapids, MI
Posts: 421
About the rebuilt pistons. Prolly just replacement parts, every stock one I've seen come apart has all had em down in the hole, no where near the advertised compression ratings. Doesn't suprise me in the least in what you found.
Lots of happy guys over at Moparts who are using the whole kit from 440source and that is where I will be looking once my 440 needs its next major upgrade. 505" would suit me just fine
With zero deck and 76 cc Edelbrocks I'm at just over 11.2 on my 440. I run pump gas in mine but do toss in a few gallons of the good stuff every once inawhile.
Depending on the cam, I'd think that torque will prolly be even higher than what your program predicted... !drive
Joined: Sun Sep 24 2006, 10:33PM
Location: Lisle, Ill.
Posts: 168
Wow, that's a lot of compression! I thought in the neighborhood of 10.5 was the highest you could go on pump premium. That'd be freakin nice if I had more torque than that. I chose a cam that was more for the top end, because I wanted the mean idle associated with it. Looks like it's gonna make plenty of power and torque still tho. Here's a screenshot of the dyno.
Joined: Mon Jan 16 2006, 02:52AM
Location: Vantaa,Finland
Posts: 379
I would not use the 88 cc edelbrocks, instead I would use the 84cc heads. With zero deck and the 88's, you should have about 10.7:1 CR, and with the 84 cc versions 11.2:1. But with the smaller ones, you would have "quench", which will make the engine more resistant to detonation than the 1/2 point drop in the CR by increasing the gap between the piston and head. Still a bit on the high side in my opinion. I have about 11.3:1, and with a 255/265 at .050" cam it runs without any problem on 93 octane. This is with a solid distributor and 35 degrees of advance.
Joined: Sat Apr 29 2006, 05:11PM
Location: Cincy
Posts: 269
daveakre wrote ... I have a '66 Chrysler New Yorker. 440 727 8.75, supposedly 55k or so on the clock. I knew from some pencil in the doorjamb that it had been overhauled and bored to some worn away number. So now that I have it in the garage, I pulled the heads to find it had been bored .040 over. Ok, no big deal. cc'd my 516 heads, 84cc. Ok, fine. Measure that the pistons are .165" down the bore at TDC. That looked like a lot to me, so I did the math only to find my current compression ratio to be 7.84:1.
The 84 cc seems high to me. My 65 516 heads measure 76 cc and give me a whoppin' 8.34:1 compression. The pistons were dished from the factory.
Joined: Thu Oct 13 2005, 08:23PM
Location: Beautiful Down Town Roebuck Ontario
Posts: 227
I have a 440source kit in my 66 New Yorker. 493 cube 9:1 comp zero deck with 84 cc Eddies and a .509 cam with 1.7 rockers and Holley Commander TBI. It did 600 lb/ft at 4000 and 500 hp at 5000. It carried over 500lb/ft from 2000 to 5500. We dynoed it with 91 octane but at that comp ratio it should just about do it on anything better than kerosene. Brandon has a dished (30ish CC) to get zero deck ( an absolute must IMHO) and 9:1 for no extra charge. 88cc Eddies are open chamber so you get no quench with a flat top piston.
Joined: Sun Sep 24 2006, 10:33PM
Location: Lisle, Ill.
Posts: 168
Yeah, 84cc seemed high to me too, but the measurements shouldn't lie. I believe I did it right. I think the seats have been replaced...but that shouldn't make that much of a difference. Seems like I'm gonna be goin with 84's now that I know I can.
Joined: Mon Oct 10 2005, 04:16PM
Location: Ann Arbor, Michigan
Posts: 18
Wow, you guys have some pretty sweet combos! My 496 makes about 9.8:1 compression with stock Eddys, 509 cam, Performer intake and a Holley 770 Street Avenger carb. My mechanic was reluctant to raise the compression any higher, which I find a bit odd since the Flyin' Whale had 11.2:1 and ran fine on pump gas. I have no idea what the dyno numbers are for my stroker, but I imagine it should be making around 500 ponies. Any guesses, guys?