2G I need help with piston info

[wicked98gsx]

Ok, so to make this simple. I'm trading a 6 bolt block and crank for new evo pistons/rods/bearings. I have been reading on some threads that just turn into a dead end thread with absolutely no help. I see people talon about how much better the evo pistons are over the stock 7 bolt pistons. Then I read that they aren't better and lower compression and I need a different head to bring the compression ration back to stock ratio. Then I read that they have to be installed backwards and ect. The machine shop I'm getting to do the work is not going to know this shit and I need to get my block finished. Please help me understand what I'm missing info wise cause this trade is for brand new parts for a used block. And I really want to trade for them

 

[BogusSVO]

The EVO head is 43cc, DSM Is 47cc

Yes your CR will be lower.
To get the CR back up, you need the old school Hyundai head from a 1.6 or 1.8l


The intake and exhaust valves are flipped from that of a DSM, so for the valve reliefs are backwards, so to get them to be on the correct side you install the backwards. So install then the evo way, and this can be done with small cams, and Std valves.

Personally, I suggest that you just get the stock NPR replacement pistons.

http://www.dsmtuners.com/threads/how-to-figure-compression-ratio.468895/

In this write up, I had a short block that had the evo pistons in it. They sat .060 below the deck.

 

[wicked98gsx]

http://m.ebay.com/itm/161232523457?nav=SEARCH


This? I have no idea here. I'm not assembling my engine, I'm just gathering parts. The machine shop told me I should only need rings. I just assumed evo pistons were better and would love to go that toute. There really isn't anything wrong with the pistons. Also, my car pulls really hard and no issues there. I know my rings went because of my tune (or no tune I should say) I have dsm link v2 but the local tuner shops to me don't do street tuning and there is no awd shop close to me. So I'm sure when in boost, my 10.2 afr's are not helping me out. Should I be ok with just new rings? All my bearing are fine according to the shop.

 

[BogusSVO]

Those are "Nippon Racing Pistons" NRP

NOT "Nippon Piston Rings" NPR, who is the OE supplier
http://www.ebay.com/itm/93-99-Mitsu...Parts_Accessories&hash=item4614228b8f&vxp=mtr

I do not have your parts or specs in front of me to be able to tell if you can get away with just rings.

Have you formed a build plan? set a goal? or a budget?

 

[wicked98gsx]

I want my car to stop blowing smoke out the exhaust every time I come out of boost. Brand new FP HTA68 with 20g billet wheel upgrade. FP manifold, tial 38 mm wastegate, 880cc injectors, gates timing and balance belts, 3g lifters, 3" turbo back exhaust ( cat delete ), 4" fmic with 2.5 piping. Was told evo 8 springs and retainers, can't verify that since i didn't do it. My goal would be 400 hp DD. My auto trans will remain stock. I'm upgrading to link v3 by the end of the year. Compression is 120psi on Cyl 1-3 and 90psi on Cyl 4. Compression goes to 155-158 psi on all cylinders if I put oil in them with throttle open and injectors not firing. Head gasket is fine but obviously I'm going to replace it again. Going to replace all the timing pull is and tensioner cause I think it's rattling. At ide or no throttle, engine sounds beautiful, any gas and something rattles... but only when moving, free rev and no noises.

 

[BogusSVO]

All good info,

Could be bad rings....

Could be worn cylinders

Could be both.

Pistons need mic'ed

Cylinders need mic'ed

The math done to see what PTW is