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View Full Version : why use a Block guard??



MRJDM
12-07-2004, 03:45 PM
http://goldeneaglemfg.com/miva/graphics/00000001/strpr_blockguard.jpg
what does a block guard do??

pornstar
12-07-2004, 04:13 PM
its for open deck honda blocks that have the water jacket around each cylinder. The radiator fluid flows in those jackets, but with high cylinder pressures, the sleeves can walk, or at worse u can see the block flex or be prone to flex. inserting the gaurd into the water jacket creates a rigidty in the block, and hence help with high pressure loads on it from combustion, this is especially the case with boost, but even at high cylinder pressures for an NA car, it would be good to have.

MRJDM
12-07-2004, 04:24 PM
so if you had a b20 running 12.5:1 CR, would you use a block guard?

pornstar
12-07-2004, 04:30 PM
mrJDM, it all depends on ur budgets. but firstly i wouldnt ever use a b20 as a high revving Na machine. secondly, i dont even know if the b20 is open block or closed block design, if it is open block, are the cylinder walls aluminiujm like the h22a? cos h22as need to be resleeved.
for NA, id use one as a peace of mind, but tahts just me. its all up to u man. if i ahd the money id resleeve. but if i was going na monster, my engine wouldnt be a b20.
hope that helps, otherwise PM me if u need any more info.

MRJDM
12-07-2004, 06:35 PM
the only reason im asking cos i seen a b20 monster on friday night at the cruise to meet James-Hondata. this thing was and animal. james built it apparently. i seen this thing take off, it was crazy.

MRJDM
12-07-2004, 06:35 PM
thanks for the info

Weq
12-07-2004, 09:08 PM
blockgaurds can also be a cause of overheating if not done preciesly. They are a cheap solution to re-sleeving..
also investigate block posting :)

poid
12-07-2004, 09:10 PM
not only overheating, but if they arent installed properly they can warp the top of the cylinders. Useful if done right though

pornstar
12-07-2004, 09:22 PM
the monster that ur talking about is 2tease Blue CRX mrJDM. It was built by Adrian from Razztech, to all razztech specs. Yes its a monster, id go a b20 in that circumstance where money isnt too much of a problem ;) actually Adrian is here on this forum, speak to him, his nick is razztech. great bloke, and he gives head too :P

SP0017
13-07-2004, 03:46 PM
I think if you resleeve a b20 block and use a girdle for the block, then the "weakness" of the b20 block for high revs is circumvented.

So its very possible to go for bigger NA power and higher revs with the b20 block.

There is a really interesting article on how to build a NA b20 block. They don't even resleeve the block here. they just do postings

http://www.theoldone.com/articles/badtothebone/

pornstar
13-07-2004, 04:36 PM
and if i were u, id also knife edge the crank, and balance it out, put i stronger piston to rod pins too, but then for that sort of money, id just start with a better balanced motor :)

blackdc2
14-07-2004, 08:43 AM
and if i were u, id also knife edge the crank,

does the crank sit in the oil, if it doesnt, then knife edging wont do much.

pornstar
14-07-2004, 09:18 AM
pretty sure it does, but id lighten it and balance it anyway if ur going to be revving high :)

blackdc2
14-07-2004, 09:22 AM
i know on my b18 it doesnt sit in the oil... if you lighten it you are going to weaken it..

balancing is a good idea

pornstar
14-07-2004, 09:40 AM
his talking about NA, dont tell me u wouldnt lighten the crank while its out?

blackdc2
14-07-2004, 09:46 AM
his talking about NA, dont tell me u wouldnt lighten the crank while its out?

nope, honda cranks are specialy hardened, any machining and you would have to re harden it to bring it back to its proper stregth.

correct me if i am wrong

pornstar
14-07-2004, 09:49 AM
hmmm next time i take my crank out ill confirm that for ya, but for now, i have always sent my crank out to be lightened. I mean look at the cost of taking the engine apart! gotta be done ;)

Psyklops
14-07-2004, 10:26 AM
hmmm next time i take my crank out ill confirm that for ya, but for now, i have always sent my crank out to be lightened. I mean look at the cost of taking the engine apart! gotta be done ;)

Not a bad idea considering that a lower reciprocating mass=higher RPM capability

SP0017
14-07-2004, 10:36 AM
I have been told not to lighten the crank too. just balance it. something to do with harmonics but again i'm not sure