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-   -   Block Guard Or Posting? (https://www.homemadeturbo.com/forced-induction-7/block-guard-posting-66008/)

93hatchy 08-02-2006 03:11 AM

Re: Block Guard Or Posting?
 
damn i dont think i convince myself of just letting them go like that, i kinda wanna post it just for extra peace of mind, i mean it woulda hurt ya know?

HMT-Admin 08-02-2006 03:24 AM

Re: Block Guard Or Posting?
 
Then do it, but it wont make much of a difference, I can show you a pic of a 350ish whp setup that was posted/pinned that cracked the sleeves right where the pin/post was set at. It's all in tuning


93hatchy 08-02-2006 11:45 AM

Re: Block Guard Or Posting?
 
alright, i think ill post just for a little extra security. i just really hope they will take 400whp.

Inquisition 08-02-2006 11:48 AM

Re: Block Guard Or Posting?
 
I've said this a number of times. Posting/block guards are a bad idea. Floating sleeves were designed to expand and contract. Its a characterist of metal, and in the design it was allowed for. Now by installing posts/block guard it keeps the sleeves from expanding/contracting. This will stress the metal because metal in general does what it feels like. So the end result will be stressed sleeves. The only benefit of posting/block guards seems to be, when the sleeves fail, they fail in a less dramatic way so that sometimes your pistons are not totally fucked. If you want to know the trick to keeping stock sleeves and making power its relatively simple. Good machine work, proper tolerance, and conservative tuning.

93hatchy 08-02-2006 12:26 PM

Re: Block Guard Or Posting?
 
what you are saying makes sense in a way, but as long as they dont expand they have less chance of cracking (with the help of posting). however, by not posting it allow room to expand thus cracking sleeves. i understand a small amount of expanding is ok, but how likely is it that itll only expand a small amount, thus needing something to help hold them more in place. to me, "stress" as you said, is in TOO MUCH expanding

i dont know much about this, so this is just how i see it, i could be totally off *shruggs*

Inquisition 08-02-2006 12:44 PM

Re: Block Guard Or Posting?
 
Thats not right at all. Metal expands by its nature. Some metals expand less than others. What happens in a stock engine right now is as temperature increases, the sleeves can expand with the pistons. Nothing stops them from expanding because hondas have a floating deck design. The material used in the engine block also expands more than other metals in the world but we aren't talking about inches, but very small amounts. Now when you put posts you are effectively not allowing the sleeve to expand, which it naturally does. It was engineered to do so. So now the sleeve is pushing against the post/guard yet can't move out. This causes unnecessary stress. Yes the sleeve doesn't want to expand much, but it still wants to, and you aren't letting it. I can't think of any reason not to let the sleeves expand that small amount, so its unnecessary stress. This can throw off piston to wall specs as well because the piston will keep expanding, while the sleeve is staying more or less stationary. Overall, I've yet to see a single reason to install a block guard or posting. I've asked people to explain it to me on a number of occassions, and no one has.

http://honda-tech.com/zerothread?id=1612855&page=1

I wrote some information in that thread that explains my point of view inregards to blockguards. Username: nowtype. Hopefully that clears things up as I don't feel like retyping everything. I apologize for the other idiots in the thread. Its honda-tech, you can't expect much.

93hatchy 08-02-2006 12:54 PM

Re: Block Guard Or Posting?
 
i completely understand what you are saying, im not saying that it doesnt make sense. but my question to you is, what causes sleeves to crack if its not the expanding of the sleeves when left untouched and unmodified?

90dx 08-02-2006 01:09 PM

Re: Block Guard Or Posting?
 
I put a GE blockguard in my ls vtec i just built.It was file fitted prior to boring.I felt it really couldnt hurt and if anything hopefully it will prevent ruining the pistons etc if i crack a sleeve due to my tuning :P

beerbongskickass 08-02-2006 01:12 PM

Re: Block Guard Or Posting?
 

Originally Posted by 93hatchy
i completely understand what you are saying, im not saying that it doesnt make sense. but my question to you is, what causes sleeves to crack if its not the expanding of the sleeves when left untouched and unmodified?

Read this if you want to know why sleeves crack. That website has a lot of very good info.

http://forums.evans-tuning.com/viewtopic.php?t=133

extensioncordy 08-02-2006 01:13 PM

Re: Block Guard Or Posting?
 
my buddy is now done building his gsr hatch with just pistons and rods and a blockguard and his tuner told him he would get him 500hp on the gt30. the tuner i guess has tuned multiple setup's without sleeves for 500hp


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