Planning 406, rookie questions...

Jack71 · 01-18-2003, 05:29 PM

I've read a ton of good info out here on 400 blocks. This is a great place to learn.

So, with a 400, I'd like to put longer rods in there. Is any additional machine work necessary to use 5.7 or 6 inch rods?

I'll probably just buy a complete rotating assembly from SCAT or something.

Also, I'd like to use a hyd roller cam. Besides the purchase cost of the cam and lifters, what other upgrades or machine work may be necessary?

Thanks in advance for any help.

--Jack

1979toy · 01-19-2003, 09:28 AM

Longer rods will give you less distance from the piston pin to the top of the piston. That is also the area where the piston rings live. For a street motor thicker rings are better. With 6 inch rods the piston pin is under the lower rings.
Longer rods will also give you more clearance issues with the camshaft. You may not hit with a 5.7 rod and a street cam but any more will require grinding. That is all dependant on what cam, rods and rod bolts you use.
If you are going to use a roller cam you will need to use valve springs designed for that. They are larger diameter than regular springs so you will have to have the valve spring seats machined, even on most aftermarket heads.

LD85 · 01-19-2003, 10:58 AM

Good info here http://www.eecis.udel.edu/~dzug/92z28/406project.html

0ski_dwn_it · 01-21-2003, 11:33 AM

You can see my setup going together in the C4 tech section.

Corky is having great sucess with the setup at 11.10@124mph.

The rods are Lunati 5.7" and needed to be clearanced just a hair to clear the cam.

Corky had built quite a few engines and warned against longer rods that intersect the oil ring lands. He said you will eventually have oil burning problems. :cheers:

Go check out the buildup.