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Discussion Starter #1
I have in the past utilized a lot of technoligies reconditioning all sorts of engine parts; shot-peening (Curtiss-Wright), cryogenic, abrasive flow porting, specialty coatings etc. Are 1600 AR rods worth the effort? Mine look sound but looking for sound advice regarding proven procedure. Just a hot street motor, not asking too much of this profound masterpiece of engineering.

Cheers S
 

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Discussion Starter #3
Very nice...what processes did you use for i.e. straightening balancing surface treatment etc?
 

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Depends on what you intend to do. I've had most of mine checked over the years by Norman Racing including magnafluxing and other than occasionally needing new pin bushes, have never had a problem with stock rods. They're relatively heavy compared to Carillo etc. But strong. Lighter pistons and rods will make the crank a lot happier.
Andrew
 

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Discussion Starter #5
Thanks Andrew. I think I have found the engine shop I will work with. In the past I have utilized aerospace tech, and I have a local Curtiss-Wright aircraft shot-peen facility that has done some jet/aero quality for a reasonable price. I have no problem with the stock rods. My Ducati has a Carillo rod, Ross piston, Total Seal rings, aerospace coatings, nikasil cylinders, etc, and will be rated at 9,500+ rpm. So I think if I can work with stock great. The issues I see as you say is magnaflux, straightness, stress relief and weight.
 

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Straight polishing is not advised, this was the words from the great Mike Sperry. Polishing is very good, it will remove micro cracks but then shot-peening is a necessity to re-harden the surface.
 

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Discussion Starter #7
classicalfas I agree. Polishing is a recipe for disaster especially in high stress parts. I think too many people think "pretty" is a good thing. First off I am a big believer in shot-peening and have a local provider of that. There are also new micro-peen, high speed (ultrasonic) treatments out of Japan and now in the US that provide incredible hardening/stress-relief and low friction surfaces. I have experience with this process and the results are both strong beyond belief and "pretty" with an incredibly low friction coefficient.

Cheers, S
 

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i am not worried.. the rods were checked before i had them frozen cyro treatment, and after.. then wen i polished them 120 grit on a sanding roll,( lots of them on a dremal tool ) then down to 400 grit rolls. 800 grit... then 1500 grit, hand sanding to wet 2000 grit,,,, for a very long time by hand * watched tv " then onto a polishing wheel,, then re tested for and cracks at machine shop.. rex hutchison racing engines here in sacramento.... oem rods ( the ones i am useing ) are powder forged ( g.m uses them on there diesel as does dodge and porsche) the oem rods as stock are good to 300 hp,' the 2.2 and 2.0 and the 2.4 rods" the engine builders use these rods found out just by a nice polish ( not like what i did ) the rods are good to 400 hp so i think my rods are in good shape, and i am not spinning my engine to 9500 rpm..i have a soft fuel cut off on my ecu starting at 7200 rpm.. remember these ' alfa romeo con rods were designed in the late 60's and early 70's... con rod making has come a long way sence then.. my engine was designed in the late 1990's and it was designed in all places..Germany.. the head it was a lotus design... so polishing the con rods that i am useing...i dont worry at all about them...update...just a thought.. the rod i am using had about 120000 miles on them.. so i called rex up and asked a question.. are used rods ' stress relived? he said yes.. an in a good way.. then i remembered that bmw used ' seasond 4 cly engine blocks in there F1 cars in the 70's and 80's and got over 1000 hp out of an ' old block '
 

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also my con rod arnt as heavy as the oem alfa rods..i think they weigh in at low 500 grames each.. and all are balance to each other. to .000 oz
 

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Discussion Starter #11
Regardless of treatment, stress relief i.e. shot-peening is always reasonably priced insurance, especially after polishing which creates potential micro-fractures. Cryogenic is a fantastic temperature treatment. Ideally, virtually any metal benefits from heat and cold treatments, actually changing the metals temper at the molecular level. You could literally dip your whole engine/trans in a cryogenic treatment and optimize the whole shooting match. In my opinion I want to preserve Alfa parts for the future beyond my lifetime as I do with any historic parts that deserve the best.

Cheers, S
 

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I'm a shot-peening fan too

Pete
 
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