Background information:

I already have an EM1 with a stock b18b1 boosted making 298 wheel. So I thought I might as well drop in another motor when that one goes. I found this deal online for $400 that I couldn’t pass up.

It was a b18b1 block (stock sleeve) and a ported b18b1(Basically built) non vtec head that I picked up for super cheap, even came with new BC stage 2 cams, valve springs and a few other things.



I wanted to use this for a turbo build, which will get all the necessary ARP hardware but recently I have ran into a problem.

I was first going to run forged b18b1 rods and Nippon turbo pistons to net me around 9.5/9.8:1 compression… The problem is, is that I cannot find the b18 rods anymore, but I do have forged b16 rods on hand. I also haven’t purchased any pistons yet.



So here is my dilemma.



I can purchase the Nippon turbo pistons and then repurchase forged rods. I really don’t want to reorder rods that I bought brand new last year.

I can purchase used Wiseco pistons for $400 and use the forged b16 rods, which will net me a solid 9.0:1 compression. These pistons have a +8.30CC and are considered high compression, but due to the shorter rod, it drops down to 9:1.



I’m leaning more towards using the b16 rods as I have them on hand but I need some more input. Everything checks out on the Zeal compression calculator.

This is a B18b1 block and head with b16 rods and high comp pistons with +8.30 cc

 

I would expect issues with that set up. The hi-comp piston theory may work compression wise but understand that the hi comp piston is designed to ignite fuel under certain circumstances. In tighter clearances. I think first problem will be the "swirl" effect and not burn fuel properly. And I can see this going 2 or possibly more ways. The peak of the piston can retain heat under heavy cycling and cause premature detonation (as it poses the same threat in hi comp applications.) Or just have s*** for efficiency and cause flooding or even a miss unless under boost.



don't mind or listen to me I'm sure I don't know what I'm saying and I can be very wrong.

 

Will the piston skirt clear the crank at the bottom of the stroke with the shorter rod?

Also makes the rod to stroke ratio poor. And there will be zero quench area. Piston dwell time will also go down.

 

OP already got his answer in his duplicate thread he made in the FI section.

This topic should be locked and burned for being ultra-stupid.