Originally posted on Dec/06/00 said:There's a common misconception among Honda enthusiasts regarding cylinder breakage, what causes it and where it begins.
Truth be known, a properly tuned engine, running detonation limiting equipment will break the cylinders mid-way down the bore, where rod side thrust is the highest. Forces on the central portion of the cylinders on the primary and secondary thrust axis's cause the casting to break. The intake side is the major thrust axis, so the piston is really trying to shove itself through that wall when you're really cookin'. This is a primary reason we advocate longer rods.
Cylinder cracking will spread to the top of the cylinder, rather than starting at the top and traveling downward.
Blockguards seal the top of the cylinders from direct water contact and the additional aluminum mass acts to hold a lot of heat in that upper cylinder area, which in-turn, contributes to detonation.
We've only run sealed decks on engines that are drag racing only pieces...and most of those were combinations where we were extending the deck height to permit the installation of longer rods.
I do not recommend the use of Blockguard "type" devices in street applications, due to the issues I've pointed out.
I keep telling you folks that those things are one of the worst possible mods you can make...
You'll likely have to bore and hone the cylinders to make them round again (and pray that they don't "remember" the egg-shape).
If you want an engine to last and run properly with a more "correct" air fuel mixture, make sure you've taken necessary measures to limit detonation and don't do anything to compromise cooling.
We do "post" cylinders in engines we build. We'll have a feature up shortly showing just how it's done...and it'll also be in some magazine articles coming up.
"Posting" the cylinders gives them tremendous strength and it actually aids cylinder cooling, which is a pretty good deal in our book.
nicklk on Feb/03/04 said:Posting seems like it is a "mideval" way of putting support into our motors, just something about it makes me quiver??