Original rods with forged pistons on a xu9j4 mi16

[Tom Rallye 3 1 Cars]

Last year my mi16 was totally overhauled (new pistons, liners, valves, tappets, cams, oil pump, ...).

Unfotunately I decided that I wanted a nice red camcover, so it was sandblasted and painted.

I forgot to check the breather on top of the camcover for residu of the sandblasting grid.

When I started the engine everything seemed to be ok but when the oil got warm, oilpressure dropped. To cut a long story short: we dismantled the engine and it was full of sandblastinggrid.

After nearly a year we picked the project up again and we had all the engineparts cleaned with ultrasound. Everything is now being measured to check what is reusable. The pistons seem lost as they have very deep scars.

We would like to keep the original rods as they had quite a bit of machining done to them (so costed a lot).

New OEM spec pistons can't be found anymore, but I found some forged Wiseco pistons with the original dimensions: www.fineline-imports.nl/motorisch/motor-internals/wiseco-zuigers/wke226m83-wiseco-piston-set-peugeot-xu9j4-1-9l-16v-cr-10-4-1-83-00mm-309-p19422-112934.html?filter=k229:84514&filterc=19422

Is it possible to use these pistons with the original rods, or is that a no-go?

[petert 586]

Probably not what you want to hear, but Mi16 rods are centred by the piston, not the rod like 8V and later 16V XU engines. Most forged pistons have draft inside the piston. Thus unless you machine them flat and make thrust washers, the side loading from the rods will crack the piston pin bosses. Three choices:

 

1. buy the piston and make thrust washers

2. bush some 1.9 8V rods

3. find some good 2nd hand pistons

[wicked 103 3 Cars]

4. Buy forged xu10j4 rods. 

[petert 586]

How do you make a 152mm rod replace a 143mm rod? And 22mm vrs 23mm pin?

Edited May 16, 2018 by petert

[wicked 103 3 Cars]

My mistake:

Buy xu9j4 rods. Some have xu10j4 big end width, meaning they are crank centered. 

 

Maxspeedingrods

Small end diameter	22mm
Big end width	24.2mm
Small end width	22.45mm

Edited May 16, 2018 by wicked

[welshpug 1,657]

would rather buy pistons made to fit than those.

[Tom Rallye 3 1 Cars]

Why? Bad experiences?

[petert 586]

I think what Welshpug is saying, is that the standard Mi16 rod is a better choice than a cheap Chinese rod for what you're doing. I'd also prefer to buy a decent set of 83.50mm pistons, given you've already reco'd the rods.

 

Mi16 pistons usually wear well. I wouldn't be afraid to find a good 2nd hand set and fit new rings either.

[Tom Rallye 3 1 Cars]

We measured 4 sets of oem pistons and they all were out off tollerance, that's the reason we're looking for forged ones.

We can get a set of new oem pistons, but they're nameless and don't have any marks on them, so we're a bit in doubt about their quality...

[petert 586]

What do you mean by out of tolerance?

[Tom Rallye 3 1 Cars]

They are not totally round anymore, more oval. They were measured at a company that overhaules engines.

 

[petert 586]

Everyone on here has different thoughts on forged pistons. If you can find a set which is designed for an Mi16 rod, then they're the cheapest. Otherwise, I've found Iapel very good value for money.

[Andy 105 1 Cars]

Evening,

 Been down this route with my ongoing ( read paused) engine build. PEC rods for the XU9J4 are crank centred, so problem solved with aftermarket forged pistons. If you want to keep the o.e rods, then do as Peter suggests and machine and shim the Wiseco pistons . If you have already got and checked four sets of used o.e pistons and none are serviceable, you probably do not have any appetite for looking for another set