Shot Peen Old Pistons

[XJoshua]

How much life can I expect to get out of perfectly fine 150,XXXmi pistons after being shot peened?

Using the old pistons will help save me some money, but Im woundering if itll be worth it in the long run? Which during the rebuild, will be slightly higher lift crankshaft, bigger intake, as far as things thatll cause more strain on the engine.

Thanks much,
Joshua

 

[5-90]

I wouldn't bother. Shot-peening will alter the surface of the pistons, and probably flake off the anti-heat coatings they have (and if you have moly skirts, I'd really not want to think about what will happen to those!)

I've seen RENIX pistons after 220Kmiles or so, and didn't have any trouble at all putting them back in, after taking a little Scotch-Brite to them (gently) and cleaning off the carbon.

5-90

 

[XJoshua]

My current '88 Renix is at 214,XXXmi, and its on it last stand, might last one or two more years. But Id rather get started on a rebuild so I have a new engine when it dies. So I have a renix with rod knock that I might pick up, to rebuild for the replacement.

 

[5-90]

214K? That's break-in mileage for a RENIX! I've got an 88 with 270K on the clock - it's been through five gearboxes (damn Peugeot...) but the engine is still strong, with good compression numbers and good leakdown tests every year (I don't recall the specific numbers, but I think the leakdown showed something like a 93% seal last time, with all pressure lost by the rings - which I'd expect.)

What symptoms make you think yours is on its last legs?

5-90

 

[XJoshua]

No its not really on its last leg. I just dont see it lasting much longer. Ive heard stories about them lasting up into the 350k, but Im just afraid that when in college itll break down, and I wont have a ride. Just rather be prepared for the unexcpected, and have a slightly more powerful 4.0.

 

[ChicksDigWagons]

For what its worth, if you want real peace of mind, spend the money and go through and replace all your sensors and clean up and fix all your electrical connections and upgrade the cooling system and maybe replace the timing chain and oil pump.

My Renix is at 180k and running pretty strong. 95% of Renix 4.0 failures I've seen are attributed to bad sensors, severe overheating, or running it completely out of oil. A lot of people spend money to rebuild their engine and then slap all the old sensors on it and wonder why its still not right.

 

[XJoshua]

No the rebuild in plan will be spiffy new sensors. New rocker arms, and pushrods. Oversized valves. Might shave the head a few. Port the intake exhaust. Higher lift camshaft. ARP studs, and bolts. High pressure/flow oil pump. new cooling system all high rate, high flow crap.

Just pistons were outrageous on my last rebuild, but they were high quality racing pistons. Just the pistons will really help on price reduction.

 

[jeepinwi]

You can pick up Sealed Power pistons for less than $30 a piece. That's only $150.

 

[streetpirate]

You can pick up Sealed Power pistons for less than $30 a piece. That's only $150.

X2!!!!!!!!!!!

go check out summitracing.com for pistons.

 

[old_man]

Are you talking about just a re-ring on the engine or are you going to bore the cylinders? If you bore, you will need new pistons anyway.

Tip for cleaning pistons: Get a gallon of Castrol SuperClean. Fill a can with the cleaner and dump the piston in for 15 minutes. All the crud will simply wash off.

 

[streetpirate]

Are you talking about just a re-ring on the engine or are you going to bore the cylinders? If you bore, you will need new pistons anyway.

Tip for cleaning pistons: Get a gallon of Castrol SuperClean. Fill a can with the cleaner and dump the piston in for 15 minutes. All the crud will simply wash off.

umm, that should work well, but you should also know that superclean will eat the flesh from your bone. so wear a rubber. glove.

 

[XJoshua]

Just a hone, and re-ring. Might up the compression by shaving the head, but I still have to look into the pros and cons on that.