Hey guy. Newbie here building a little drag bike with a predator 6.5 212cc. I milled the head .050 and add 18lbs springs and bored out the carb. I'm trying to set the lash on the valve and I read every post here and most people say .003 for exhust and .002 for intake. But after I set it and spin the motor back to top dead center they are wicked loose and fall off so I set it again and spin it and it does it every time. Are there any tips that would help me out?
Predator lash settings
- Thread starter Thirdfloor
- Start date
- Tags 18lbs lash? predator tips valve lash
my cam is stock but i just ordered a MOD 2 cam. ill try to set it after that and see what happens. what would you guys recommend i have 18lbs springs,milled head and boared carb and air kit and home made pipe and 140 emulsion and .36 jets. do you think i should get a billet rod or flywheel i can only afford 1 or the other right now
The Mod 2 I think is .003 for both intake and exhaust. I think you are off to a good start, Do you have your governor intact or did you remove it? If it is removed you MUST get the Billet Rod and Flywheel. (especially with heavier valve springs!) Ohh also make sure your pushrods are in their "place" so they don't fall and screw up your measurements.
Not until you decide to step up the RPM's. I suggest getting a thinner head gasket. then remember to reset the lash once you change the head gasket! Cranking up the compression is a great way to squeeze power out of these. Check out NRRacing.com and look at the hemi head predator kits they have with bigger valves. That would be very nice.
You have to be careful when moving from a dished piston. 1st if the tolerances are not set correctly a forged Wiseco piston will expand into a Seizeco piston. 2nd you will not be able to put a HUGE camshaft because it will hit the piston. I would stay with the stock piston. and get a large amount of lift and duration.
Is it a old style or newer "hemi" style engine? I ask because, the old one has a small venture carb. With your etube, the 36 may be to big for it. A mod 2 is a great cam. Get a billet rod and flywheel as suggested. I ran my hemi pred yesterday and turned 8000 for many laps with stock pushrods. I have also made 100's of laps with my older engines turning 7300+, and they all have stock pushrods and rockers. I did have 1 pushrod break in my best Hemi pred, but it makes 24hp on meth, and I turned it 8200+ on the dyno for over 200 pulls before it did. You will like the power of the pred, just be carefull and have fun!