whar are the effects of a cracked sleeve? do b2o sleeves crack often?

 

no compression is the big thing besides the hole.....and I don't know if they crack often

 

well it doesnt really make a hole just a really small crack usually inbetween the cylinders. Burning oil, low compression, the car being totally gutless are signs that you have cracked your sleeves. Also b20 are more prone to cracking than any other honda motor, but I dont know if if you can say they crack often.

 

no...we actually built a 85x87 B20 stock sleeves 13.1 comp and held up all last years events. this year same block 85x95 and still going."knock on wood". so quiet strong.

 

It really depends on every motor. Some of the B20 castings were not as strong as the others (no real way to tell) I have heard of stock blocks pushing past 220whp and others cracking sleeves with less than 160whp. Your best bet is to inspect the sleeves, If you get it apart...and look in between the water jackets for any weak spots or inperfections.

If you crack a sleeve then it's game over. Not only will you lose compresion but your cylinders will feel with anti-freeze and...I don't know what the current octain rating of water is but you can do the math...

I hope that I don't want to discourage you because I myself am going to be running an oversized high comp B20 with stock sleeves...knock on wood...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rev master &raquo;</TD></TR><TR><TD CLASS="quote">no...we actually built a 85x87 B20 stock sleeves 13.1 comp and held up all last years events. this year same block 85x95 and still going."knock on wood". so quiet strong.</TD></TR></TABLE>

hmm did I say they were not strong? I have done 2 b20 builds now and I love em. All I said was that b20 sleeves are more prone to cracking than other Honda motors. Can you tell me another honda motor that has sleeve problems like the b20?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rev master &raquo;</TD></TR><TR><TD CLASS="quote">no...we actually built a 85x87 B20 stock sleeves 13.1 comp and held up all last years events. this year same block 85x95 and still going."knock on wood". so quiet strong.</TD></TR></TABLE>

85mm on stock sleeves with 13.1 comp

I am just oversized 84mm with 11.9 comp and have ran all year long on stock sleeves.
So far so good.

 

Using a block quard is cheap insurance for a 85m b20 setup. It adds strength to the top of your stock sleeves were they usually start to crack. I'm personally going to run one in my 85m b20 vtec setup and strongly recommend one for you're setup.

 

In some cases it shows up as overheating, similar to a HG issue. Combustion gasses leak out and displace coolant in the head. If you catch it before it over heats you may notice your over flow filling up and coolant level mysteriously dropping.

 

A block guard is not cheap insurance. It is counter productive and a waste of money. Why would you radial constrain the part of the sleeve that see's the highest loads. Also, you limit cooling to the hottest part of the cylinder.

 

Block guard will physically reinforce the top of the cylinder sleeve
In terms of strengthening = reduce moment at the sleeve

But the drawbacks of having block guard is blocking the coolant which will elevate the sleeve temperature = more fragile sleeve

I always wonder if someone has carry out an experiment of adding a block-guard to investigate the sleeve temperature and coolant variation

that's just my thoughts

 

you can always do block posting like endyn does...