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#1
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eBay 4340 Connecting Rods
Anybody use these?
https://www.ebay.com/itm/PONTIAC-400...AAAMXQjq5RAx40 Looking at these for a budget build. 4.21" stroke, Old, heavy L2359F 030 TRW pistons. Mopar 0.984 "lighter" pins. Thoughts? Results? Any Experience? Stuart |
#2
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Look like the same CAT rods I paid 290$ for years ago. Mine had to be honned on the big end as they were tight. But I have had mine well over 500HP for a long time now. Might buy a set myself just to keep around.
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#3
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Things to think about... can you return them, for any reason? For full refund?
As Dragncar mentioned, his needed work to make useable. You could run into same, or worse have a small end too large. I don’t know how all the other import rods fare, as far as accuracy. If you do buy them, get them checked by a legit machinist, ASAP!
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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
#4
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Mine needed just a light hone. Did not have to break the caps or anything. It was cheap.
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#5
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face it, nothing like Rods even with today's CNC machining that are good ,and are mass produced for under 400 bucks are going to be dead spot on on every time !
I would much more prefer they be on the tight side and have to Honed on for 10 seconds each then to be too big and have to be split open again and then re- torqued up to get resized as that makes for one less of a torque up cycle before the bolts will need to get replaced.
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#6
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I've assembled a lot of engines with the generic "H" beam rods, basically a copy of the Eagle "H" beams. Butler used to supply them with their stroker kits and they came in that dark "shaggy" cardboard indicative of Chinese manufacture. Without exception every single set required a little work on the small end for better pin fit as mentioned above. I purchased a small ball hone for that purpose and had fit each pin during the build. Usually no more than 20-30 passes thru and they slid right in.
All have been flawless now and some are dating back nearly two decades, so no worries about breaking one. I have heard about others having issues on the big end of the rod, which is NOT an easy fix compared to opening up the small end just a tad. I've also read where some folks recommended upgrading to a better ARP fastener, but I never did that and all the ones we used held the recommended torque values just fine. I'd also mention that a few sets were in pretty big HP applications and making the grade. In recent years I noticed less and less being available, even KRE's Proline rods disappeared and they moved over to Eagle "H" beams. http://www.krepower.com/Pontiac%20Cr...and%20Rods.htm The last 4 or 5 spinning assemblies they did for us were supplied with Eagle or Crower "H" beams instead of the lesser expensive ones. My favorite rod for these engines are the Crower rods. I've got them out there in builds well over 700hp and some have a LOT of miles/track runs on them. Every single set we've used has been spot on for fit/finish and they are very strong rods and leaves the end user sleeping better at night as you aren't going to kill one for any reason related to strength, that's for sure. We actually had an ill fated 455 cave in the lifter bores at 6700rpm on the top end of the track. The only thing that survived that ordeal were some rocker arms, a few pistons and the Crower rods. We ended up getting them checked out and used them in another build. To this day I can't believe it didn't bend at last 2 or 3 of them into and "S" as hard as some of the pistons got hit during that ordeal.....Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
#7
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Thanks for all the responses. Seems like, for this particular build, they will be a reasonable choice. Fingers crossed on slight undersized vs oversized.
Small ends won't be an issue, since 0.984" Mopar wrist pins will be used. |
#8
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If I was going to use those rods, I would do the following: Remove the bolts and lube with ARP Ultralube and reinstall and torque to specs. Loosen and repeat 3 times to exercise those fasteners and burnish the threads in the rods. Then measure and hone the big ends to specs. They will be small 90% of the time as mentioned. Then size the small ends to your pins. In your case, a ball hone would not be my choice because you are talking about removing .004" from the small end which is hard to do with a ball hone and keep them straight and round. I would use a Sunnen rigid pin hone. Wash them up and your ready to go.
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#9
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Quote:
Stuart |
#10
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Having to remove .004" from the small end would be a LOT and if you need to remove that much for sure use a rigid hone.
All the sets I've opened up were just a few ten thousands not thousands. Actually the pins will usually just about slide thru them without any help, but I like to open them up if/as needed so they slip in easily but no wobble whatsoever. This will only require a few light passes with a hand drill and ball hone. If you end up having to remove more than about .001" you might want to take them to a competent machinist so they can be done to keep the holes uniform with the crank throws......Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
#11
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I would not make any attempt to do the machine work myself.
0.004 was Mike's estimate. I'll be using Mopar 0.984 pins, press fit. So maybe only 0.003" . In any case, a machinist with tools and skills will do the work. Stuart |
#12
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Lets make sure we are clear on this. I looked at your ebay link and those rods are full floating with bronze bushings. So you would want to run them that way. Stock Pontiac pin .980. " The Mopar pin you wanted to use .984." . That's where my nominal .004" material removal came from. No problem to hone the bushings ,004" if those are the pins you want to use. But you will need full floating pistons with some way to retain locks. I don't think you can use those rods in a press fit application unless they come without bushings. Sorry for the confusion but I assumed you were going to run them floating until I saw your last post. If there is no way to retain a lock in the old TRW pistons, I would go another direction, I think. There used to be a hand operated lock ring cutter for pistons but I haven't seen one in decades. Having 16 machine cut would probably cost too much for the project you are describing. Best of luck with the decisions.
Last edited by mgarblik; 11-12-2019 at 09:57 AM. |
#13
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I had the luxury of teaching machine shop and had access to adjustable reamers. I pin fit some Chevy pink rods by reaming them to about .001 or so then honing them with a brake hone. Those were the days.
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1979 Trans Am WS-6 .030 455 zero decked flat pistons 96 heads with SS valves 041 cam with Rhoads lifters 1.65 rockers RPM rods 800 Cliffs Q Jet on Holley Street Dominator ST-10 4 speed (3.42 first) w 2.73 rear gear __________________________________________________ _______________________________ 469th TFS Korat Thailand 1968-69 F-4E Muzzle 2 Last edited by track73; 11-13-2019 at 12:00 PM. Reason: Spelling |
#14
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Sorry, my bad! I should have seen that the rods were bushed, it is very obvious and in the write up. Let's call it brain damage on my part!
Looks like the $400 RPM 4340 rods are the logical choice then. Stuart |
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