Is it possible to combine H23a1 Pistons with H22a1 Crank and Rods and still have Head/Valve clearance? If so what would the compression ratio be considering this combination andthe lower stroke of the h22 crank? Current compression of h23a1 pistons is 9.8:1. With the lower stroke it should be reduced. This would be Good for Boost without having to payout the expense of resleeving for aftermarket pistons or using Mahle Gold series FRM compatible pistons. What are your thoughts?

 

sleeving and aftermarket pistons are always more durable and reliable

you dont need super low compression for boost if your setup is right

 

The material that stock pistons designed for FRM sleeves are created from is brittle... so lower compression or not, you are still going to be limited on how much power you can make by using stock type pistons.

 

resleeve your block and purchase correct pistons for your rod to crank. saves plenty of headaches and less worries about frm sleeves

 

This is the biggest deal with these engines and Boost/ Nitrous/ big power N/A. Most boost guys now are actually running 10+ compression with decent fuel and tuning, especially E85.

If you want to pull an engine apart, do it right the first time. Otherwise you are handicapping the engine so much that a well built N/A setup will be faster and more reliable.