Rod question

[Kbaker]

I'm wanting to build a 6.5 predator and know I will need a billet rod and fly wheel, I'm wanting something very dependable and that runs on pump gas so my question is what length rod do I run and will I need to upgrade my piston also. Any links will be appreciated and cheap is always good.
Thanks

 

[chancer]

Here is the most complete link and it contains every link you can imagine to do what you want to do.
http://www.diygokarts.com/vb/showthread.php?t=32385

 

[Hellion]

I concur. Make the N00B read... all 50+ pages worth.

Be careful how you word a statement like that. Predators come in "built" condition already. We think you're asking for more speed but that's just a wild guess. Just remove the governor and be on your merry way.

 

[chancer]

But really if someone read all that... and followed the links, (and the Missy pics)
There really are no more Questions.

 

[OzFab]

If you deviate from stock length on the conrod, you will need a new piston; as the new conrod is longer, the stock piston will push farther up into the combustion chamber; before you start thinking "that's a good thing because it will raise the compression ratio", it may also cause interference with the valve heads, which will end up costing you a lot more than a new piston; 0.020" may not seem like a lot but, it could mean the difference between a great engine & a pile of scrap metal...

By all means, try it but, triple check all measurements & clearances BEFORE attempting to start the engine...

 

[bob58o]

My hemi stock piston sat at 0.024" in the hole with the stock Rod.
You NEED to measure if contemplating a longer Rod.
I got a +0.020" Rod.
I am now at 0.004" in the hole with the stock hemi flat top piston in the hemi block.
I milled the Head 0.037"
I use a 0.027" gasket for 11:1 CR.
I use 100 octane.

---------- Post added at 10:32 PM ---------- Previous post was at 10:27 PM ----------

Just get the standard length Rod and use the stock piston.
Stock gasket.
Keeps you at 8.5 : 1 compression ratio.
87 octane.

---------- Post added at 10:49 PM ---------- Previous post was at 10:32 PM ----------

I think this is it.
http://www.arcracing.com/6254-arc-billet-rod-hf-predator-212cc-3-308-std/
Call ARC.
Ask for Jody.

800-521-3560

 

[Kbaker]

Thanks for the info. I planned on pulling the governor gear and knew that would turn to many r's for the stock bottom end. I always want to go faster but my main issue is weight. I weigh 175 and my boys are around 40 pounds but are to young to drive so I'm just looking for a little more power. The

 

[chancer]

Very Dependable and runs on pump gas.
Just remove the governor. You do not need to buy any parts. The valve springs will
Float at 5500 RPM keeping the bottom end safe.
and We do not care what OMB says, They are WRONG. You DO NOT need a Billet flywheel or Rod to do this mod.
100+ members here can't be wrong.

 

[Kbaker]

One other question on the rod, how many rpm is a stock rod and flywheel good for?
Thanks

 

[Bbqjoe]

One other question on the rod, how many rpm is a stock rod and flywheel good for?
Thanks

The rod, I can't say, but I'd do it for peace of mind.

After reading tons of stuff, this is what I believe, in my very OWN opinion.
You show me a blown up flywheel, and I'll show you someone who funded something up.

 

[Poboy kartman]

Chancer has already said the bottom end is good to 5500 rpm...I wouldn't turn a stock rod much faster...but completely removing the govenor and keeping the stock springs has been proven to be reliable here many times over.

 

[OzFab]

One other question on the rod, how many rpm is a stock rod and flywheel good for?
Thanks

Stock rod around 6000rpm IIRC; stock flywheel is still up for debate...

The main reason most change the flywheel is not for safety reasons (very few have ever seen a flywheel explode that wasn't already damaged), it's to reduce weight so the engine spins up to speed faster & for the advanced timing feature...