Joined: Fri Aug 05 2011, 08:06PM
Location: Brisbane Australia
Posts: 132
I have this up on moparts as well, but you guys would have more experience with our heavier cars...
Vehicle: 68 Fury HT aprox 4000lbs with me in it Usage: Almost daily driver in country area (lots of 65mph) with a few trips to the track per year Drive line: 727 with a 2.76 open, have a 3.23 open for track - possibly may get a full spool at later date Heads: Sidewinder or Stealth Cam: Comp XE268h 224/230@50 .477/.480 lift Carb: large t/quad or street demon (850 either way) CR: 10-11:1 (somewhere in there)
Soo Im using a cut down 440 crank and have the option of using my 383 6.358 rods (816gr) and some Diamond 1.72ch pistons (597gr) OR some new 440 Source 6.76 rods (740-750gr) and diamond 1.32ch pistons (500gr). There is the option to go lighter pins too, the shipped ones are 172/176gr, but they make some D13 thin wall ones that are only 126gr
Comparing the weight differences vs a STOCK 440 and using the std pins, the short rod crank would be around 1170gr lighter and the pistons/rods 2241gr lighter. The long rod combo would be 2068gr lighter on the crank and piston/rods 3544gr lighter
Obviously the long rod & lighter weight piston would be great for a revvy engine, but would that be a miss match for my barge?
I have read a few different pages on short vs long rods and the short seems to win in a few areas - better cylinder filling with the larger than stock cc inlet ports, potential detonation resistance and the possibly of more torque down low.
I've seen it said that the differences would be in the single digits hp and torque wise though? that said it's also good to get the combination of components working together
From what i have seen of other builds the combo should be good for 400+ hp and 500+ ft lb
So I am after some thoughts/opinions/advice from people who actually drive these motors on the road, will the light weight combo be too peaky for my cars weight and average street driving? or would the peakiness be good for slowing the beast down when i have to?
Joined: Fri Aug 05 2011, 08:06PM
Location: Brisbane Australia
Posts: 132
Reasoning's to date:
I live in Australia and mopar parts don't grow on trees
Spend money once
Stroker - my 383 motor is not numbers matching, dead 440 motors are about a $1k buy here, so $150 for a crank that needs grinding and a set of pistons that are dearer than normal is value for $$ for a given Ci/output. The 383 built up will have way less torque and upper hp and cost me not significantly less
Cam - middle of the road, wont need a set adjustable rockers or heavy springs for lift and rpm range, step under needing a torque converter change
Carb - could more than likely go a 750 and not miss the difference
Heads - cant just go down to a swap meed and grab some 915's, which would be my choice if available, cutting my existing 906's down for quench will have me cutting them more than .070 and waiting for them to crack at some inopportune moment (see point 2)
CR - 10:1 will give me a dynamic of 8.1 for our version of your 93 octane, was looking to maybe bump it up a bit cause of the reputed ally head cooling effect
There is method to my madness - what don't you like Uncle Joe?
Joined: Thu Mar 22 2007, 08:13AM
Location: In the workshop
Posts: 1063
I'm in Sweden, so parts availability is the same here.
Going off what I know from dyno runs with perhaps half a dozen 440's (sorry, not 383's) over the past couple of years alone...
The 268 cam has a good reputation out there, but in reality, it could be a lot better. Unless the profile has been reshaped over the past couple of years that is. Trouble is, there are no really good C-body suitable cams out there. As you might have noticed, I look for torque rather than horsepower.
I've used 452 aluminium heads on a couple of builds, and 452, 516, and 906 irons on others. given the chance, thats the order I would use them with the E10 we have here.
Carbs. The 496 build I posted only uses an 800, so for yours, I would be going smaller.
But, after having said that. The most important thing is to carefully match all the parts, be obsessive as to putting everything together, and be realistic regarding youself. My preference is torque, but others prefer top end. Neither is right or wrong, its just the choice of the individual.
Joined: Wed Nov 17 2010, 03:28PM
Location: florida
Posts: 1311
Ive built a few motors but i have to say for the best bang for the buck and proven outcome , a crate motor was worth every penny. 600hp outta the box , complete carb to pan , no wasted time on unproven combinations of parts and a guarentee of workmanship. It will cost more than sourcing parts and assembling yourself but again worth it in the end.maybe worth looking into
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
I'd say maybe a smaller cam might be a better choice with 2.76, I've always been a fan of the Lunati 60302 (or whatever number they give it now).
If using a TQ or StreetDemon, I'd say either size should be a safe choice. IMHO carb sizing is less critical on spreadbore carbs. Smogger 400-440s got the 800 size, and 318s got a 625 size, and traditional thought says both of those are over-carbed.
A big variable here is the lightweight 431 pieces, which will allow it to rev faster and possibly get up into the Comp cam a bit better on acceleration. Although at steady speed that's not involved, and you're stuck with whatever behavior the cam/converter/gearing gives you.
Here's a out-of-box thought if your resources can support it - wide-ratio planetaries for your 727. They'd take your 2.76 up to the equiv of 3.08, and you'd have the benefit in street use while still maintaining 1:1 3rd gear for highway -- and save you swapping gears several times/year to go racing. I don't know how much those gears cost now, but average it vs ~15 gear swaps over 6-7 years and put a $$ value on your time?
Joined: Wed May 23 2007, 10:30PM
Location: Far North Queensland Australia
Posts: 78
Hi Alchemi, I run a 65 Fury with a 438 stroker stealth heads, performer RPM, 274XE cam with a 750 vac, about 10.25 to 1. very happy with the combination. I run a 3.23 sure grip with 2500 convertor and 26 inch tyres, very streetable but it does struggle to get off the line. Engine is very responsive from 2800-6200 and really livened the C barge up. Havent had it dynoed but it ran an 8.81 on the 1/8th at Warwick, which shows an honest 385 HP. I would thouroughly recommend the engine for a cbody but you will regret having a single spinner in the Rsend!