does a 62t cylinder still need a head girdle?

Mouthfulloflake

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
I read on the group K website where the sleeves are thicker, or the casting is thicker, or something is beefier on the T cylinder vs the X cylinder.

does this mean a 62t can get a high compression head without the need for a girdle?

Just curious.
 
Mouthfulloflake

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
I have heard that too SFL, that the pipes that mount to the head are detrimental too.

But ive also read that the increased compression and vibration cause the cracks.

so you are saying I could run 220 psi on a 61x cylinder with no girdle if the pipe doesnt mount there and be safe?
 
S

sflsurfrider

no. its not that the pipe is mounted to the head or otherwise. its that the weight of the pipe is on the left side of the cylinder, regardless of how it mounts. that forces the right side "up". the casting breaks because its supported by the cylinder bolts and it has so much weight at the top of the cylinder, that the vibration puts a lot of stress on it. a girdle setup "squeezes" the cylinder so the stress is taken off if it and placed on the girdle setup.

increased compression and porting will also weaken the cylinder.
 
Mouthfulloflake

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
ok, taking all of that into account.

is it logical to surmise that since the 62t cylinder is befeier, that it it less likely to crack than a 61x? ( without a girdle?)
 
Sanford

Sanford

ECF
Location
Freeride capital of the world
Look at it this way, its like buying a $75 insurance policy. Thats all the diff is in a new ADA (girly vs. no-girly).

Also, if you ever sell a billet head, girly head will bring more money.
 
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Sanford

Sanford

ECF
Location
Freeride capital of the world
FWIW: I've been running my semi-ported 61X cyl on my SJ for about 10 years using just a stock milled head (180psi). My motor vibrates more than a "pocket rocket" while hooked up to 3-phase 480V AC and I've never had any cylinder cracking!

I believe if I had a pipe that bolted to the top of the head or serious porting, my situation would be different. I've been running a FP B.

The only reason I haven't put a billet girly head on it is because it works and I don't screw around with what works (besides, it cuts into my 365/year ride time).
 
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Mouthfulloflake

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
that is GREAT info to know Sanford, thanks!

ive got a milled stock head, and an old Coffman pipe that doesnt mount to the head.. ( until I find that elusive cheap B pipe)

thanks for the info!



Sanford said:
FWIW: I've been running my semi-ported 61X cyl on my SJ for about 10 years using just a stock milled head (180psi). My motor vibrates more than a "pocket rocket" while hooked up to 3-phase 480V AC and I've never had any cylinder cracking!

I believe if I had a pipe that bolted to the top of the head or serious porting, my situation would be different. I've been running a FP B.

The only reason I haven't put a billet girly head on it is because it works and I don't screw around with what works (besides, it cuts into my 365/year ride time).
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