jett ls Q 500
 

I HAVE Q500 LS JETT

IS IT CORRECT PUT Cylinder Shim FOR MORE PERFORMANCE

HOW I NEED PUT

WHAT IS YOUR RECOMENDATION

RE: jett ls Q 500
 

Call Dub and ask him.

RE: jett ls Q 500
 

What engine do you have?
This is a good time to call Dubb as he has no electric. I am not sure he has phone service but you can try. Do you have a BSE or Cast case? What vintage?Where is your head and liner.and what prop are you using? Your question has many answers.
Tom

RE: jett ls Q 500
 

Email Dub, things are getting back to normal here in Houston.

RE: jett ls Q 500
 

adding a shime or shimes to the case liner will increase port durations which does equal more rpm,s but torque will suffer also you must remember if you raise the liner your also raising the distance between the cylinder head dome and the piston crown which results in a lower compression ratio. you can try this cylinder raise but you must make sure you re set the squish [ head clearance ] to specified clearance settings. if you do this just check your case exhaust port to liner to make sure none of the liner top section is being blocked off by the case top. i have seen some moded race engines where the guys have raised the piston liner forgetting about the top of the case exhaust port which was partically blocking exhaust flows.

RE: jett ls Q 500
 

Just remember where you started and what you added or subtracted so you can always go back.

Do you have a way of measuring the sleeve and head height?

I've had good luck over the years leaving my heads a little higher than most, using a big prop, launching a little rich, and hope for the big unload :) Doesn't always work, but experiment and find out what works for you. Not sure your elevation, but my guess is that its higher than what most of us in the US deal with, so that may change things also.

Is there anyone in your area that races these things that could work with you and help show what works?

Ignore the .001 shims and start with .003 or even .005 adjustments and fine tune from there.

RE: jett ls Q 500
 

HI TOM

Q500 LS BSE .005 IN THE HEAD DONT IN THE CYLINDER

AND Q40 CAST CASE LS IN THE HEAD 2 .005 DONT HAVE IN THE CYLINDER