Sleeves that moved.

[OConnor Racing]

A while back, Freak had a sleeve spin in a BB cylinder. This was about the same time I was building mine. I thought this was an isolated incident but didn't want to take the chance so I installed pins between my sleeve and cylinder. The pins are plugs made for repairing cracks in cylinder heads and exhaust manifolds. I got a CT and Vito's cylinder in last week and both of the sleeves have moved. Needless to say, I'm putting pins in both of them. I don't think this is a manufacturing defect but rather a heat issue. Sleeves need to be installed with a .004” interference fit. We get the sleeve to drop in by heating up the cylinder until it's larger than the sleeve. I did some testing last week and found that when the cylinder temperature was 450 degrees, the cylinder had expanded .010” larger than the sleeve. The test was done with a 1986 CR 250 cylinder. Granted, no one is running @ 450 but high 200's is probably enough to open up the clearances enough to let the sleeve shift if the counter bore is off. Here's a pic of the repair we did to the CT.

 

[theblasterboy]

o damn 15151515

 

[sicivicdude]

So a CT/La sleeve can spin as well huh?

I was looking at the picture thinking that kit was a nikasil'd liner until I saw how far out the steel extends (not like a factory sleeve huh?).

The pins look good... I've seen those used on cracked exhaust manifolds before, they seem to work well for that purpose (if used properly). Is this something that's going to be factored into the price of working on BBK's from now on?

 

[Awk08]

always finding solutions to hidden problems !!!!!!!!
again....great stuff from KOR

ps..... congrats on today being your first day, full time at the shop !!!!!!!!!!!!!!!!!

 

[sicivicdude]

See... I'm liking a ported stroker standard bore more and more (even with the "limited" amount of power it can make.

Maybe a big bore kit truly cannot pass off enough heat (steel to aluminum ratio is too low) for it's own good.

 

[super noober]

so those 2 light grey pins are the repair or failsafe? thats cool stuff, did ct do anything about the spun cylinder or is it just buyer beware? i would be piiiiiiiissed to finally get my dream cylinder then it craps out.. X(

 

[Awk08]

See... I'm liking a ported stroker standard bore more and more (even with the "limited" amount of power it can make.
QUOTE]

agreed 100%
thats all you'll ever see me do in the future, to hell with bbk's and piston availabilty problems, and now this, phhhhhhht

 

[sicivicdude]

The pins probably make the sleeve sliding a non-problem but when you throw all of the other problems together it sounds like the BBK's are trouble.

 

[super noober]

i dunno.. personally i would still get a LA kit at some time for a drag bike. mabey jet it a bit rich to keep it cooler or run it on alky? but civic is right, i am plenty happy with a ported stock jug and stroker for trail use.

 

[sicivicdude]

Well... for a drag bike, all bets are off. I would try running it on dynamite in order to win a drag race if that's what it took...

What I should have said is, for my uses (very light "fun" drag racing at busco and trail riding) the BBK sounds like more headache than I need.

 

[slickerthanyou]

Nice work Ken! Way to save a jug! I love my stroker ported powerhouse, if i could only get to ride it! Damn weather!

 

[Whitty21]

damn nice, innovation for sure!!

 

[Kgibson]

Always solvin somethin aint ya ;}

 

[darederek]

i think i would do a ported +3 or +4 before a bbk. just seems like less trouble

 

[OConnor Racing]

I talked to “Tim the Tech” at Wiseco today. I'm thinking about having a dozen or so pistons for the big bores run and also talking to a sleeve company about making custom sleeves for a big bore. No intake bridge. No triple exhaust and no boost ports. No room in a stock cylinder to put them in a big bore. I don't think LA is going to deliver and I think when Vito's sell out they're done. This is a pretty substantial investment. I will guarantee these cylinders for life. The sleeve won't move and all of the ports will be perfectly matched. Who's in?

 

[OConnor Racing]

I talked to “Tim the Tech” at Wiseco today. I'm thinking about having a dozen or so pistons for the big bores run and also talking to a sleeve company about making custom sleeves for a big bore. No intake bridge. No triple exhaust and no boost ports. No room in a stock cylinder to put them in a big bore. I don't think LA is going to deliver and I think when Vito's sell out they're done. This is a pretty substantial investment. I will guarantee these cylinders for life. The sleeve won't move and all of the ports will be perfectly matched. Who's in?

 

[Whitty21]

i would be in when i run out of bores on my cylinder lol

 

[92blasty]

When I bought my blaster it had a big bore sleeve in the stock cylinder and it had twisted, so I don't think the problem is isolated to actual big bore cylinders. Is it possible to install these pins in the sock cylinder, and if so, is it possible to get it back out if I need the jug re-sleeved someday? If I get my cylinder ported, it seems like a shame to have to buy a new cylinder and have it be re-ported when I run out of bores eventually.

 

[mayor west]

mine has done exacly the same, took he engine apart last week and the sleeve has twisted around 3-4mm, im tyring to find someone to fix it here in the uk.

 

[ricekiller1985]

I got my big bore at .050 being machined now but when it runs out I would be interested in a new one from you. granted it will hopefully be a long while before it is needed but a new supplier would be great