stock 340 rods

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rumblefish360 said:
Safe! at first base! You nailed it. I have no idea what THAT was all about.
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Ok. I'm glad senility hasn't set completely in. I thought that's what you meant.....hell, I thought it was clear as a bell, actually. lol
 
hi, I run 72- 73 340 stocker engines, I have YET to find a press pin rod in any of them, all are bushed from the factory. as for a good stock rod, the 68 to 70 is better. its the 496 forging. later 340/360 rods are 645 forging.
 
StrokerScamp said:
No it will not. It will get you a set of chinkese knockoffs that may or may not be good metalurgy. Scat, Pro Comp and the like are ALL made in China. There have been huge issues with the metalurgy coming from there. I would stake my motor's health on a good set of reworked factory Chrysler rods any day of the week rather than junk. I can get rods reworked like I outlined for around 300 bucks. What'd your eagles cost?
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400 (got it on a discount day).
 
rumblefish360 said:
I have no idea why you quoted me or why you would post such a comment as if I think you could make a 1,000 HP on a stock rod and have it live.

Do not quote me and make dumb statments that may confuse somebody into having them think I made that comment or think that.
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Sorry. I completely read that wrong. I had a migraine coming on yesterday when I wrote that and must have had a complete brain fart. I thought you said that power does not have an affect on longevity. My apologies.
 
I have stock 340 rods with arp bolts been spining it to 7000 for 13 yrs. 71 scamp 344cu.
 
bones427 said:
I have stock 340 rods with arp bolts been spining it to 7000 for 13 yrs. 71 scamp 344cu.
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I wanna see them chebbie boys do that with them powder rods they love so much. lol Ain't happenin.
 
perfacar said:
hi, I run 72- 73 340 stocker engines, I have YET to find a press pin rod in any of them, all are bushed from the factory. as for a good stock rod, the 68 to 70 is better. its the 496 forging. later 340/360 rods are 645 forging.
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They still let you run stock rods in Stock? LOL
 
The issue with mopar rods is never strength nor cost...lol. It's weight. IMO, by liberating the very heavy factory pistons you make a factory rod much more viable. They will take any rpm the block will with good bolts and better pistons. It costs me $300 to have a set of factory rods redone, new bushings, resized, ARP bolts. Shot peening is part of the cleaning process for them so that's in there too. A set of SIR Eagles, probably the weakest and most iffy quality rods now available, are $300/set and a LOT lighter plus use a smaller big end footprint for block clearance on strokers. I avoided them when they first came out as they used to have a problem with quality related to metalurgy and some were pulling apart at the beam. That seems to have been addressed as I havent heard of it for several years now and there's a lot in service now. H beams are more depending and many of them need to be resized after you cycle them a few times. So the cost starts going up. IMO, if you haev them, and the labor's cheaper, use the stock rods. They will take most of anything a NA engine could throw at them.
 
Absolutely perfect. Couldn't have said it any better moper.
 
I wonder how much the Eagle I-beams weigh? They're $250 @ mancini.

I spun some of those well past 8000 in a 302 ford (420 rwhp), but that was with sub 500 gram pistons, low tension rings, good bearings, blah blah. Shorter stroke so slower piston speed than a 340/360 also.

light stuff makes horsepower, but broken stuff makes for a really bad day.
 
LXguy said:
I wonder how much the Eagle I-beams weigh? They're $250 @ mancini.

I spun some of those well past 8000 in a 302 ford (420 rwhp), but that was with sub 500 gram pistons, low tension rings, good bearings, blah blah. Shorter stroke so slower piston speed than a 340/360 also.

light stuff makes horsepower, but broken stuff makes for a really bad day.
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eagle I beams are listed as 605 grams..

Scat I beams are at 595 grams...
 
Scat i beams are better than eagles. scat is 4340 not 5140 have arp cap screws and are 7/16 not 3/8. mike at MRL say's real good rod. and almost 100 grams less weight than stock rod.
 
LXguy said:
I wonder how much the Eagle I-beams weigh? They're $250 @ mancini.

I spun some of those well past 8000 in a 302 ford (420 rwhp), but that was with sub 500 gram pistons, low tension rings, good bearings, blah blah. Shorter stroke so slower piston speed than a 340/360 also.

light stuff makes horsepower, but broken stuff makes for a really bad day.
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lighter stuff makes the same horsepower.

And the thing is...if you are going to rebuild and use 'todays pistons'...then those stock rods have even less to worry about.

Stock 340 pistons weighed 700+ grams...

Todays common replacement KYB243 'considered heavy by some' only weigh around 576 grams.

Just things to ponder.
 
LXguy said:
light stuff makes horsepower, but broken stuff makes for a really bad day.
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My vote for quote of the year. lol


Piston weight is the biggest conern. Properly prepped stock rods with a light weight piston will last in a lot of cases. As for rod failures, they happen but not from breaking. Usually when the big end has spun a bearing it's either lack of oil or the rod egg shaped under a heavy load, the rod bearing then bites the crank and it spins in the rod. This would be my concern with stock rods in anything other than a healthy street/strip car.
 
green1 said:
It wasn't the rods, it was balancing, or heavy azz pistions, or clearancing in general.
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Yeah, I blew up three stock rodded motors, always due to something else, even though the rods were busted in half. Them were some expensive lessons.

1) Big old heavy TRW pistons, with too much cylinder wall friction, and I aint telling why. (ok, I was having trouble seating the plasma rings, so I did the old babo trick.) Bad idea!
2) Oil restrictor plug added to passage before I got the block, didn't see it, and it starved the motor at rpm.
3) Hydrauliced my alcohol injected flying toilet 440 in the 67 R/T

Like others have said, less is better, get the lightest piston hanging on the end you can afford.
 
My 62 Valiant runs 10.70's in strip trim. I'm converting it to street use, and adding a plate system. 4 bolt X block, 3.79 stroke, Ross pistons, Hughes solid cam, ported J heads, and stock rods. All my buddies keep yelling at me to get them out of there before I tear up my good block!! Perhaps I will before I switch to the W-5s.
 
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