Wicked Sol

Is it necessary to remove the pistons or hone the block when installing a block guard? How is the process done?

riceboy

dont do it

turbosol

I'll second that!!!

riceboy

they reduce chances of detonation huh? I believe its the exact opposite of that, where is a block guard placed? At the top of the cylinder walls. Where is the most heat in the combustion chamber? At the top of the cylinder walls. And with a block guard installed, there is now no coolant in the top of the cylinder walls, thus no cooling for the hottest part of the cylinder, so the cylinder walls stay hotter than they could taking in the benefit of an open deck design. And as for those so called "coolant holes" that are in those things, they are so small they might as well not be there. And as for cylinder flex, where is the maximum thrust angle? Midway in the stroke, there is nearly no side loading at TDC so why brace the cylinder there? The flex will still be persistant at the center of the stroke, they may not "wobble" as much now, but you are combating the problem the wrong way, with the side loading still persistant, now the cylinder dosent want to flex and it is even eassier to shove a rod through the cylinder wall. The actual way to solve both cylinder flex and decrease chance for detonation is to leave the open deck and reinforce the actual part of the cylinder that needs it (EG, the point of maximum side loading)

sushibug

i think its all about preference. i eblieve someone mentioned that the darton/payn closed deck blocks run fine, and there are people who run 12psi on nothing but a block guard (internal wise). some people consider them as ricey as altezzas. personally i would do it... myself.. anyway... he was asking how to install not why he should or shouldnt... so this wasnt very helpful

DSF

Necessary...err, not absolutley. However, I personally would never install one without at least honing. The thing should fit tight, tight enough to possibly cause shifting in the bore. Oh, and fyi, I'm using one in my LS/VTEC and will be using one in the next engine in my SOHC CRX. Good insurance if you ask me because I can't afford and don't "need" sleeves. I look at it this way, the guard is there to protect against mechanical stresses, NOT prevent detonation. If it does elevate combustion temps (which I have seen no hard data) then dump in more fuel

rtype11

no opinion here just your answer: freeze your blockguard for a few hours while you remove your head, once head is removed, take the blockguard from freezer noting its orientation drop it in, should go in flush on its own and remain about 1/8" below deck. thats it reinstall everything. if you have to force it in dont, try again without forcing, you will end up with core shift.

MIKES

Stoopidr has a stock bottom end with only a STR blockguard and he runs 20psi on stock internals. He has also had lots and lots of hard track passes and its still together. I know tuning is key, and his car is well tuned with the Hondata unit. Like the guy said earlier, I think its just personal perference. Some people swear against them and some people don't. I don't see the harm in it provided your not putting it in thinking its going to solve all tuning aspects of the motor. A well tuned motor is the key, the block guard with a well tuned motor is just added protection, just my 2 cents.

c_penson

I have the str blockgard and i dont have any problems with it i installed it 1/8 lower than the deck it self and i have hat 17psi and all is fine

1337 Si

Spend more money and get some Darton sleeves. WAAAAAAAAAAY stronger!

Wicked Sol

I would if I have the money but I don't. I'm just trying to find out if a block gaurd does any good or if I'm just throwing my money away. I want to be able to run 10 psi on the street with no problems. I can't afford to rebuild another motor.
Should I get a new over sized head gasket if the block was bored? Or is factory bore ok?

riceboy

you can run ten on stock sleeves no block guard, no problem, and yes, get an over sized head gasket to match the bore

DSF

According to the amount of bore. I am going to 81.5mm and using a stock headgasket.

filetofit

Pressurizing a cylinder in a block with an open deck puts the cylinder walls in tension. The maximum pressure is at about 20 degrees ATDC. IF you look at sleeves that have failed, the fractures are at the top near the head. Also the bottom of a cylinder is supported radially by the block. The top is a free edge = more stress. A block guard provides a radial load path for pressure stresses into the block rather than just stressing the sleeve. The point about cooling is well taken, a block guard may increase the chances of detonation by inhibiting cooling but then again the sleeve is more likely to survive detonation.