would i need rods

[thumper]

alright here's the story. I'm looking to get a 91' Talon Tsi i found one that had pushed a valve, the head was replaced, but now it isn't running right. supposidly the valve hit the pistonand gouged it. The guy had it checked for compression and cylinder one is dead. IF i buy this i'd have to replace pistons for sure. now, my goal is to make 300whp roughly. For this i think 95 pistons will work. now to fit those i found the specs u have to shave the rod to make the piston fit. I'm not looking to make 400hp so would the stock rods be strong enough. I want this to be reliable so if it's going to reduce stress on the rods and make it more reliable i'll get some eagle rods, they seem like the way to go if ineed rods. any and all help will be good.

 

[L2RTSiAWD]

Stock big rods would be fine for your application.

 

[out there]

that's the same thing i'm thinking about, getting different rods with better pistons... but i decided to save $400 and stick with the stock rods because they'll be fine until i get over 500hp. why not get evo pistons? 8.7 instead of 8.5 comp and they're a few grams lighter. www.turbotrix.com has some decent deals on pistons, they even machine your rods to fit the pistons for good price. i'm planning on asking if they'll machine evo or even forged (hmm...) to my rods for a few bucks extra

 

[thumper]

when you say stock big rods, do you mean the ones that are in there? or are the big rods out of a 2g. sorry for the newbie question, but i'm not an engine guy. I just want to be.

 

[BoostinAWD]

Big rods came in all the 6bolt motors, pre april 92

Since you have a 91 you have stock big rods.

Just get them machined to 95pistons, those evo pistons are overpriced in my opinion. Why would you want compression that is that high. That defeats the purpose of having a turbo.

You can get 95 pistons for $38 a piece. And a compete ring set for them for $110 or so. From www.partznet.com goto the club dsm page.

Oh btw, get your rods shotpeened magnafluxed and all that neat stuff while your at it. With good tuning they can handle some 500WHP

 

[out there]

i'm getting evo pistons because when i get a larger turbo, it will spool faster. i don't ever intend to attempt breaking 400whp with this car, and i don't want a vast amount of turbo lag because this will be driven almost solely on the street.

 

[thumper]

thanks for the info. i visited the site, another question what is the purpose of overboring. would that be if the walls were scared. To cure the scare u had to bore it out then u want overbore pistons? or is there a power gain or something from that. just curious thanks again for the help

 

[nutshot]

These are good questions, keep them coming. Boring an engine block will increase the displacement of the motor by increasing the cylinder size. The benefits include cleaner cylinder walls, no cone shape of the cylinder (most motors slowly develop a slightly larger bore at the bottom than the top) and improved fuel flow from the head. The draw back is you can't use stock pistons. I personally think all rebuilt motors should be bored over stock to gaurantee clean walls and to remove any of the slop that a cone shape causes. Plus, increased displacement= greater torque and horsepower.

 

[diefwd]

when you bore it out does that mean its not a 2.0 anymore? would it be a 2.1 or am i completely wrong?

 

[thumper]

so this means it's a good idea to bore the cylinder to be safe/add performance/prefect shape. just roughly a guess how much hp and torque are u gonna gain it's not gonna be that much is it? I mean if you bore it's less than a half inch total. so you don't gain a huge amount of displacement really do you?

 

[BoostinAWD]

The gains you will receive from boring out your cylinder walls will be the same as if you were to scape some bugs off of your bumper as weight reduction.

Were talking 1000's of an inch. If your cylinder walls are scratched up or scored badly get them overbored, if not just rehone and run standard bore pistons and rings.