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Discussion Starter #1
Has anybody heard of the power building technique of using longer than stock rods, custom pistons and a stock stroke crank? I have read two build-up articles on the subject but I would like to hear some real world or if someone has built an engine that employs this.
I know that the theory goes that the power is created by holding the piston longer at TDC and BDC for more efficiency/power/longevity. One article touted the advantages as more power, greater fuel efficiency, smooth idle, plenty of manifold vacuum and greater motor longevity. I guess this way of increasing power is out-dated due to the advent of reliable stroker motors?
I guess I am in the dark as to where to turn. Is this worth the extra cost for the benefits? One article used a 302 block, Chevy 400 connecting rods and custom Ross pistons. The other article followed the build-up of a 1969 351 Windsor block, Ford 400M connecting rods and custom JE pistons. I have both blocks, a stock 1983 5.0 block and a stock 1969 351W block on an engine stand. I would like to know if anybody here has done anything like that before or is currently doing so now. I can email one or both of the articles to someone who might like to take a look at them. It would be a scan though.

Thanks,
 

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I run a 6.8" rod with a 3.9" stroke in myy 460 based engine. The longer rod ratio does allow a longer dwell to enable a better cylinder fill. It also allows less ignition advance and still enables complete combustion with the longer dwell at TDC.

The more advance you "need" to run to complete combustion at TDC, the more energy is waisted trying to compress an expandign gas.

Many of the 5.4" (long rod) combinations are a waiste of time. A .1 of an inch of rod length wont net a lot of difference. a 1/4" or more can make a lot of differnce.

Biggest benefit is to a class with a head restriction, or an engine build with a budget, where a small cross section head is used. The dwell allows the high velosity charge to overfill the cylinder.

Most guys in classes where unlimited heads are run will run a short rod combination to achieve maximum piston speed as fast as possible. All depends what your doing.
 

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Discussion Starter #3
The 351W article used the 400M rod (6.580" long) which is about .6" longer than the stock rod. I think the rod ratio (big debates there) came out to 1.88:1. The resulting power output was [email protected] and [email protected] These numbers, according to the article that is now almost 10 years old, were attained using 87 octane fuel. I think that is pretty good for 9.5:1 compression, smooth idle roller cam (278/286 adv dur.-.520/.542 valve lift and 112 deg LSA) and a 650 vacuum secondary carb on a Weiand Stealth intake. The heads were old Crane Fireball iron heads. What would be a good replacement? Iron or Aluminum? The good part about the buildup is that the 400M and 351W rods are about the same on the big end. Same journal diameter and width. The balancing is the trick. I guess I am trying to get a consensus if this technique is worth the extra machining and custom piston costs. From what I read in the article it seems like it is but articles are just one person's opinion. What is your opinion kim? Anyone else too?
My goals have changed to streetability and not stupid fast power. This combo seems to fit the bill/budget. Am I wrong?
 

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I am in the process of building my own long rod 351w. I was convinved that this was a very viable option after driving (for 2 weeks) my uncle's 85 stang with the same engine. As it sits right now - complete from pan to heads. (no intake, water pump etc...) I have less than 2,200.00 invested. I had the machine work at a place called "The Car Shop" in Moline Illinois. The balancing and machining expenses were 860.00. The pistons I paid 265.00...and other necessities to assemble the short block came to 1567.67. I paid 400 for stage 2 ported World Sr Heads (used of course...but in great shape). Its balanced to 28oz.
The 85 stang had an unbeleivable Tq curve....it was always fat all the time. I used to own a 70 GTO...and this thing was tquier. So abundantly fat like it had a 427 in it. I got 22.8 mpg (average) with the car....it had about 30,000 miles on the build with no trouble whatsoever. If you have any specific questions...email me.
 
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