I’ve been looking to refresh/build my engine in my evo 9, i have Saenz I beam rods already (150mm) and i was looking to do a 94mm crank based on research i did here but the one thing i wasnt sure on is what pistons i would need to achieve 10:1 comp. Car will be mostly on ethanol as its not a daily driver but i just dont know how to go about picking the pistons, any help would be great

 

I am not sure what size motor that comes out to be. Is that a 2.1? I know a 158 and a 94mm crank comes out to a 2.2 idk. Anyways to answer your question depending on what the engine displacement comes out to be you may have to order them custom. I know most piston manufactures shelve 10.1 so that shouldn't be the the issue. The issue would be what displacement does it come out to be. I have never heard of Saenz rods before but I guess the question is will they handle the power goals your looking to achieve?

 

oh yeah im sure, this is going to be an FPred uhf on an FP manifold, nothing crazy, mid 500hp at best. Saenz is big in the honda community, these rods are rated for 900+hp like a turbo tuff or most other I beam

 

It sounds like a fun little setup for sure. I would just make sure the math for the motor works out. I would hate to see you buy some bad *** rods only to not be able to use them cause of the choice of crank you would have to use ya know. Custom pistons are expensive to do as well. I know when I had my 12.5:1 done 10 years ago they were over a grand back then. So id suggest next step to make sure crank and rods will work to a proper size engine displacement that way you can choose easy rod size to go with them.

 

just from looking thru whats available it seems that CP has a 9.5:1 that should suffice. just still unsure about what the 150mm rod on the 94mm crank is worth it or just stay with the stock 88mm crank and get the compression that i want. which is 10:1

 

I get where your coming from and all but your missing one important thing. You cant just order piston with this setup. After doing some searching looks like what your trying to do is a 2.1 liter engine correct? With that said your going to have to call and see what pistons are available for a 2.1. After you find out what is available it isn't going to matter if you go 9.5 or 10:1 being there really isnt much difference in performance.

 

Manley has a 10.5:1 compression piston for 150mm rod and 94mm stroke x 85mm bore
https://stmtuned.com/products/618200...b3YMiaoJQfO1NL

 

on the CP catalog they distinguish pistons for all the stroke lengths, i think the only time u need custom is when u want a desired comp or if you have a custom rod. Otherwise they have a selection for 150mm and 156mm with 88, 94 and 100mm cranks

 

perfect, thank you for that

 

That may be so but that doesn't mean they're an off-the-shelf piston. That just means they're in the catalog I bet if you were to call them and ask them if those were available they would tell you they would have to be made. I could be wrong I don't know but in my experience that's what I have found. I like the manly Pistons I run those myself I have the Manly pros and they're a good piston I have nothing bad to say about them I like the cp pistons too but when I was building originally this last time the CP Pistons weren't enough to go with the goal I was going for. That is why I went with Manley