Wiseco Pistons and 90 rods.

[dsm1gturbotalon]

I was planning on rebuilding my motor after the timing jumped with Wiseco 8.3:1 pistons from slowboy, arp head studs, and stainless valves. Those are the only aftermarket parts I was going with. The car is at the Eagle service department in my home town so this info is relayed through my father. The technician said this about the pistons: "I would not recommend you go with the higher compression pistons. You'll have to reset your fuel/air controls and it will probably run rough. But more important is that in older engines the connecting rods actually lengthen and with a piston that is higher to increase compression could cause it to hit the valves. Unless your willing to change the connecting rods too! There is not allot of clearance between valve and piston." And now for the his opinion on the studs: "Head studs also not a good idea. I actually uses them in my racing engine and they are stronger then bolts. But they leak (coolant) all the time. So in my application it works because I'm all the time changing parts and don't really care if it leaks during a race. But for everyday use the bolts are better. Mitsu makes a high quality bolt and since you won't have the higher compression pistons anyway the bolts will work fine." I had never really heard of any of these problems, but then again I haven't had the time to really look into engine rebuilding in depth. My question is whether any of this makes sense? Is this guy just trying to make me purchase the stuff through him (remember he works at a dealership). Any help would be appreciated because I need to start ordering parts Monday. Thanks

 

[allwheelTSI]

your car will run just fine with 8.3:1 pistons,get your rods shot peened,see if you can get that done on the technicians head aswell....
the only reason he would be leaking coolant is because he's having sealing issues,it would'nt be due to the studs themselves.

 

[Groomz]

Take your car somewhere else. That monkey wrench has no idea what he is talking about. Rods don't stretch , especially on street cars. If it was an F1 car spinning 18K RPMs, then it might be a problem. I plan on running 9:1 and plenty of other people do also that are on the forum. Get a picture of that guy and send it to Webster, that way they can put it next to the definition of moron.