MercRod????

[Chaz]

BTW .. that thrust face looks good .. in tarnished , burnt silver .. huh .. ???

[Dave S]

Chazz the mannn….good read......I like the 3.4 newer rods...….

[powerabout]

does anyone crack test rods?
what method do you use?

[Chaz]

Yes , cranks too ..

Mine is an older twin magnet , iron powder particulate spray model .. works good .

https://goodson.com/collections/magnaflux

If I ever have any doubts , about a scratch really being a crack . My friend's auto machine shop has a big cabinet model Zyglo (black light , green slime) tester ..

[H2OPERF]

Any one ever do roto-peen, kinda like a flap wheel with #330 shot bound to the flaps used in a die grinder. That's what we used at the round engine shop for small parts and to finish grind out/ weld repairs. No need to mask or cover anything if ur careful. I have done all my motors like this. yea i got lazy at the thread area.. Oh yea omc not merc and we can crack test at +9k foam mercry cant get there....

[Chaz]

Well Dave , they say if ya learn sumptin , it was a good day . I got mine in before 8:30 this morning .. thank you for that ..
Do you have a single flap on a mandrel , or the air motor / folded flap .. ?

Don't ya gotta have Yamaha ignition .. or aftermarket ECU to get an OMC there ..
The foam motors don't need to spin to 9K+ , cuz they gotz enough stroke to make the same power @ 6500 ..
Besides , at anything more ... the toothpick styro rods start sawin the block in half … "axe" me how I know …
G-man stuck his finger thru the "slot" an spun what was left of the big end. Said , cranks still good ..





https://www.ebay.com/i/333224790297?...6540a16dde7a42

[H2OPERF]

Now for the bad news the little flappers are super expensive 3m owns the technology but i have a source that can get them every time a big mil job comes around and every once in a while they pop up on ebay cheap. I use the little ones like in the top pic. There is a whole process to do it by the book...where you set the rpm on the grinder with a regulator and hit a test metal strip until you get full coverage with deformation of the strip, but we found as long as you set the die grinder speed down to a point where the strips last a descent amount of time and get the dings on top of the dings using a circular motion for full coverage its good...

[H2OPERF]

Hitting an area like the rod bolt hole at the wrong angle will shred one real quick like the one i trashed in the pic, its a learning curve. You can usually get one rod per flapper if your careful..

[Dave S]

Shimmazddo…. I did em by hand...…..HeeHee…..

[wolfgangb]

Chaz, impressive work and knowledge! Need to do a set of 141 rods myself. What shot-peening spec do I have to tell the specialist?
Rgds, Wolfgang (South Africa)

[FUJIMO]

[FUJIMO]

[Dave S]

Drrnn things have changed up...…..still thimgz go BOOM

[H2OPERF]

Yup, everything on that table prob cost more than my whole motor...

[Chaz]

Hitting an area like the rod bolt hole at the wrong angle will shred one real quick like the one i trashed in the pic, its a learning curve. You can usually get one rod per flapper if your careful..

A little too aggressive for my liking .. but even the cabinet will turn the shot into powder with too much air pressure .

wolfgangb

Chaz, impressive work and knowledge! Need to do a set of 141 rods myself. What shot-peening spec do I have to tell the specialist?
Rgds, Wolfgang (South Africa)

Thank you sir .. I have been using a mix of 170 and 230 . A good balance between getting a peened surface and beating up the blaster . Porcelin cups and cabinet glass go away at an alarming rate ..