Predator 6.5 tear down and build in 24 hrs (pics)

[Squisherton]

So I recently bought my 2nd 212cc and was mainly going to use it for spare parts and available cores. I had to go back to hf for something totally unrelated and while i was there a guy was returning his predator 6.5 because he needed a 1" shaft. I commented to the cashier that i had to but a 2nd one just for parts and she happened to be the manager and offered to let me grab a few tools and take whatever parts i wanted off the return. :devil2: I proceeded to grab almost everything i could and when i asked how much she wanted to charge all she wanted was for me to buy some $20 member club. Anyway now i had enough parts to have fun with a motor, have some spare stuff, and have the ability to get some parts machined, all while having a functioning motor. Bliss!:clap:

Enough of me rambling here's what i did monday afternoon and most of yesterday:

What i started with

The teardown process:

 

[Squisherton]

Measuring for cam clearance: (oddly enough, this block didn't need any additional clearance for the 265 cam i have. I did picture my other block which did.)

Make sure to not mess teeth up on your flywheel bolt. Really hard to find a die!

 

[Squisherton]

ARC rod and piston install:

Had to grind side of the lobe for rod clearance:

 

[Squisherton]

Hardware:

At this point i have 3 heads. 2 were stock and another is becoming a headache. I did a mild porting on one of the stockers and this is the comparison:

 

[Squisherton]

Cleaning some stuck gasket off:

 

[Squisherton]

Head and Valve train Assembly:

Sealing up the block:

 

[Squisherton]

Flywheel Key Filed for an additional 4degrees!

Flywheel Carb and Exhaust bolted on:

OH CRAP!! I lost my quick start guide. What to do now? hahahaha

Finished project:

Oh and if anyone needs any oem parts for these motor.... i might have a few.....

 

[ezeerider]

How much extra power did the cam & carb & timing & exhaust change get you?
Did you also put in stiffer valve springs?
What carb are you using and what jet sizes are you running?
Whats the new rpm limit?
Is there some place you can look up a list of mods for the Predator engines and the amount of power each group of mods will produce?

 

[Squisherton]

Whoa! Whoa! First and foremost I haven't even put oil in the thing. The frame this thing is going on is in pieces and probaby won't be together till next week. As far as the other questions:18lb springs are in the pics but I'm thinking about putting in 26 and 1.1 reinforced rockers. The pushrods are moly's the carb is the mikuni 22mm round and I have no clue which jets I'm running because I haven't tuned it yet. And no, to my knowledge there is no place that lists "if you do this you get this" as far as parts and power goes. My advice is if you don't know what a good set up will be, read around the forum and learn what others have done and what you shouldn't do. And if you can't figure it out from the posts on here than I'd recommend not trying to tackle a build by yourself.

 

[Squisherton]

And with 18lb springs rpm limit should be between 6200-6500 with the 26lb set up it should be around 7200. Again this is theoretical. I have,'t started this motor yet. What's a good weight oil for breaking in btw?

 

[ezeerider]

My advice is if you don't know what a good set up will be, read around the forum and learn what others have done and what you shouldn't do. And if you can't figure it out from the posts on here than I'd recommend not trying to tackle a build by yourself.

Thats why I asked.
I understand how an engine works. I have been a Harley mechanic for 30 years. I have rebuilt everything from 2 stroke weedeater engines to bored and stroked small block Chevys. I haven't screwed around with these Predator engines, and I have no idea whats available for them. I've been to the NR Racing website and see the packages they offer for the Predators... pretty basic stuff... stronger rods and flywheels, bigger carbs, free flowing exhausts, heavier springs, different ratio rockers. I know how to increase compression by milling heads, and clearancing for valves, stroker cranks and bigger cams. I have ported and polished, Sportsters, Panheads, Shovelheads, an Evo or two and even a Toyota 20R. I've timed breathers, drilled and tapped for dual plug heads, and set up single fire ignitions. I've done Dyno Tuning, built up stroker cranks, cc'ed heads, and just about everything you can do to a V-Twin engine to squeeze more power out of them.
I just thought that some of the guys here have already hotrodded these little engines and they might be able to clue me in on a setup that has worked for them in the past, and maybe save me a little trial and error testing. But nevermind....... you're right..... I'll figure it out for myself. Sorry to bother ya.

 

[Squisherton]

Wasn't trying to hate on ya man. just trying to make sure you weren't trying to get into something over your head. With that said. Go to nrracing.com. Or call Russel there. There's a stroker rod crank piston combo for these motors. Also if you were looking for more compression the 14cc head will work you just need to bore the dowel holes bigger to fit. And as far as a good set up, I've read around and asked around and it seems like tuning wise that each of the hf predator's are different from the next. What would work well as far as jetting ignition timing spring ratio blah blah for me might be horrible for you. Obviously you know the basics. More air more fuel better spark more compression more power! Go! Hahaha anything else I could help you out with man just ask.

 

[ezeerider]

Wasn't trying to hate on ya man. just trying to make sure you weren't trying to get into something over your head. With that said. Go to nrracing.com. Or call russel there. There's a stroker rod crank piston combo for these motors. Also if you were looking for mpore compression the 14cc head wiLl work you juat need to bore the dowel holes bigger to fit. And as far as a good set up, I've read around and asked around and it seems like tuning wise that each of the hf predator's are different from the next. What would work well as far as jetting ignition timing spring ratio blah blah for me might be horrible for you. Obviously you know the basics. More air more fuel better spark more compression more power! Go! Hahaha anything else I could help you out with man just ask.

Thats cool..... thanks.

 

[Squisherton]

My question again is does anyone have a suggestion for a good break in oil/method for the motor. The thing is brand new and never run.....?

 

[hemigremmy]

I dunno what to tell you on break in lube, maybe check over at http://karting.4cycle.com/
and see what some say to do over there. Seem to be a bunch of knowledgable people there as well that build clones for karts.

Worth a try. :shrug:

 

[Squisherton]

Thanks. I've checked there already. There's just a debate between synthetic or non and didn't know if anyone had any insight or opinions about either.

 

[Newoldstock]

Hardware:

At this point i have 3 heads. 2 were stock and another is becoming a headache. I did a mild porting on one of the stockers and this is the comparison:

Looks good.
How about the short radious, did you round that down and smooth it?

You've stopped right about the same point I stop in the bowl.
I tried more and then I tried less with epoxy but eventualy I ended up in about the same place you have.

I think you did a real fine job.
Those are stock valves and retainers though.
I never had a failure but I noticed a couple sets of valves were wearing and mashing up around the retainer.

Maybe try one of the break in oils like the amzoil, Brad pen or Lucas.

 

[Moedog07]

I've got a 383 roller motor for my '55 that I am building. I bought Comp Cams break in oil 10w-30 for it. 5-6 bucks a quart at Summit. On my Predators I have used standard motor oil 10w-30 Castrol, but mine are bone stock. (Right now) you have a considerable amount of time, effort & money in your Predators . Get some good oil.

I have not used the break in oil before but my machine shop highly recommend it.

 

[Squisherton]

I was kinda thinking the same thing i just didn't know if someone knew better. I'm always looking to learn.

 

[Squisherton]

AS far as the port work goes the valves that are in this head right now are stock's and yes the retainers are stock as well. I did round out the short radius on the exhaust side and intake side as well as tried to get the everything gasket matched. I do have some stainless (stock sized) valves, 26lb springs, and 1.1 reinforced rockers. I was very much considering putting those in here instead. I'm trying to have eventually 3 motors: 1) An EXTREMELY high output motor where anything and everything is pushed to the limits (and then some:devil2 2) A stout motor between 14-16hp that's durable and somewhat reliable. 3) A mildly built motor 9-10hp that will run all day everyday. I have a frame right now that's in the midst of some mod's to fit some goodies:grind::hammer:. But I also bought a lot of extra metal stock for the fabbing on that frame and have been thinking about building a frame up custom to put one of the other motors on. My wife wants to have something to play with as well so the #3 motor and 2nd frame might be her's.......

I'm on my way to having something around the #1 motor. I just need to get a few more internal things and work out some numbers as far as the spring ratio and cam duration stuff goes. I would like this motor to be my #2 and i have enough parts in the garage to at least start getting something close to #3. I must be insane to be going as far as i do with this stuff..... But god do i LOVE IT!!!!:evil_laughter: