Once again who has the wiseco 13:1 pistons in there rx-1?

[JDMCRX]

I got a set of 13:1 pistons for my sled. Im gonna chuck them in along with possibly some mild head work what kind of difference will i be seeing?

Anyone

 

[SUPERTUNER]

Make sure you check piston to wall clearance. The Wiseco specs are too tight. Need .002" piston to wall clearance minimum. .003" with a turbo or supercharger,

Freddie

 

[JDMCRX]

OK coo will do. Im slapping these and the head porting and exhaust hope to pick up some more power.

Josh

 

[kinger]

What is stock CR 11:1? If memory serves I thought for every pt of CR you get around 10hp. What type of gas will this now require? I port and polish heads for certain cars and would love sometime to get a rx head and look it over. Good project!

 

[Red2003]

Stock comp ratio is 12.5:1, so you're not gonna get much there. Exhaust is good for a few HP on top. Head work I assume means porting. I'm thinking your gonna gain maybe 15HP altogether. I'm sure one of the engine guys like Freddie could give you a better idea, but I don't see huge improvements with these mods. If you put in better rods and ignition and turned it 12,500 or 13,000 with bigger cams you'd see much better improvements. Why not drop another $3000 while you're in there. Of course, you could have slapped on a turbo by then and gotten 220HP +. Tough call.

 

[ReX]

According to my Yamaha shop manual, stock compression is 11.8:1.

 

[JDMCRX]

I was gonna do a set of cams but we will see.

Main reason for changing the pistons. Change the rings and i want to verify the low connecting rod bolts are good. The head work ill flow bench it. Basicly a clean up of the casting flashes and polish up the exhaust side. and a valve job.

Next year ill make 300hp on this motor with pistons and a set of rods.

I just want a bit more power and 15hp would help me out. This year Im gonna do alot of trail riding and ill have the wideband in there to get my jetting perfect and ill run 91 octane.