Attn: 400SBC w/ 5.7 rods owners

[shupach]

how'd u get the rods to fit? mine wont fit and i just talked to summit and they said use the smaller rod or small base circle cam. I dont want to use either and was wondering if there was any other alternative. btw the my rods are internally threaded and the top of the threaded end is hitting the cam lobe.

phill

 

[89GMCSuburban]

Not really an option that I've heard of. I had a buddy do this to his 400, had to go with the smaller cam...if you're worried about breaking the cam, don't worry, my buddy REALLY abuses his...

 

[bigmack]

Did you get pistons that are for use with a 5.7 rod ? I have 400's in both of my trucks and both have 5.7 rods and I didn't have any problems when I built them. What are the specs on the cam ? You said your rod is internally threaded, is it like an H-beam rod ? One of my motors has Eagle I-beams and the other has stock GM rods with ARP bolts. Is the crank just a stock GM that you had turned or is it an aftermarket crank ?

 

[Longhorn4x4]

There are rods like the Eagle ESP 3D stroker rods that have one side shorter than the other for just this reason. If the rods you have are not made that way, you may be forced to used a reduced base circle cam, like it or not, unless you change rods.

As an example, when I build a 400 with 5.7 stock rods I grind the head on the inner bolt, or actually, sand it.

I use the Eagle ESP 3D strokers in most 400 crank engines.

When building full race engines with rods like Crowers or Olivers, I use reduced base circle cams.

 

[78shortbox]

The easiest way to fix this is to just grind a little off of the rods. You need to have about 0.060" clearance between the rods and the cam lobes. Unless you have a pretty big cam, or a really big rod, you shouldn't need to go with a reduced base circle.

Taking a little bit of metal off the rod in this area will not affect the strength, so you don't need to worry about that. I have a 383 with 6" h-beam rods and a .550" lift standard base circle cam in my car and everything clears without a problem.