[Joshinator99]

Originally Posted by Eldi Z

OK, but did someone actually check the LT4 ring gaps for tighness?
I ask this, because everyone is talking about the LT1s as this being the main weak spot. Maybe this is not it?
Could it be that 1.3 points higher compression by itself cause the LT1s to blow easier?

Has anyone actually compared the % of destroyed LT1s on boost, Vs. LT4s tuned to 900 WHP, while their stock 93 specs are ~ 560-570 WHP?

We know the LT1 rings are too tight for boost because multiple guys have chimed in after measuring them. I don’t remember the exact numbers off hand but I remember them being 75% tighter than the gaps on my forged pistons if memory serves…!

The ring gaps are not the only reason stock bottom end LT1s die. The higher compression, like you mentioned, does require more octane to prevent knock… so when guys push boost with pump gas or non-direct port meth they usually build heat in the chamber, exposing the tight ring gaps and breaking ring lands…or just general destruction from excessive knock. Take your pick. Either way the LT4 does not have those problems unless someone screws up their build.

TLDR; build your car depending on what you can get for fuel. If you’re stuck with pump gas, lower your compression ratio. And E85 is a godsend for boosting SBE LT1s since you get both high octane AND pulling heat out of the combustion chamber…oh, and E is great for all boosted engines for that matter.