[paging motor builders] Question # 1 help with rods
Thread Starter
Race Director
Joined: Jul 2001
Posts: 14,604
Likes: 3
From: Glendale, AZ
[paging motor builders] Question # 1 help with rods
i have decided to buy a bare zz4 block, i am still deciding on the crank....forged and either 5140 or nitrided 4340 400 crank with 350 mains!
now, with the 3.75" stroke will i need 5.7" rods or 6.0" rods for this setup. would someone need to know the head and piston setup first?
:confused: this is getting hard! :crazy:
now, with the 3.75" stroke will i need 5.7" rods or 6.0" rods for this setup. would someone need to know the head and piston setup first?
:confused: this is getting hard! :crazy:
Drifting
Joined: Mar 1999
Posts: 1,931
Likes: 1
From: Norcross GA
Re: [paging motor builders] Question # 1 help with rods (85_togo)
You will need to do the math w/ the piston's you will be using. It all starts w/ what Comp Ratio do you want.
5.7 or 6.0 rods is an other decission. Choosing one or the other will spark more debate.
It is not that hard,.... just math.
5.7 or 6.0 rods is an other decission. Choosing one or the other will spark more debate.
It is not that hard,.... just math.
Drifting
Joined: Mar 2001
Posts: 1,636
Likes: 3
From: Lafayette IN
Re: [paging motor builders] Question # 1 help with rods (85_togo)
:confused: this is getting hard! :crazy:
Pistons are manufactured for either setup you want to go with. Due to the location of the pin through the piston, you need to decide if your engine is going to be NA or forced/N2O. Ring placement is critical to blown applications. Best off talking with the piston manufacturers on this and how they expect their pistons to work under such circumstances.
For rod length, keep in mind that changing the rod length will change the geometry of the rotating assembly. It will help if you know what RPM range you want the engine to be built for. I am sure there are a few good sites on the net dealing with rod/stoke relationship. Lingenfelter goes into a bit of discussion on it in his book "John Lingenfelter on Modifying Small-Block Chevy Engines".
Those are just the basics to help you get started. Good luck! -Matt-
