409 rod question

[jm32409]

Hey Guys,

This may have been asked before but what is the solution for the 409's weak rod problem? Does anyone make a better rod for a stock 409? Or does anyone make a piston with a corrected pin heigth to accept the 6.135 BBC rod with a stock 409 crank? I would like to use an H beam style rod or is the stock rod with ARP bolts strong enough? Building a street rod but want a strong bottom end.

I have really learned a lot on here,

Thanks,

Jeff

 

[SteveD409]

I think Aubrey may have such an animal (pistons).

SteveD

 

[Fathead Racing]

Pistons.

Aubrey, http://www.bruneauperformance.ca/ will get you the correct pistons. You can use the BB rods or you can do a stroker with a 396,427 or 454 crank!

 

[jim_ss409]

I think you've got the right idea going to a longer rod. Good aftermarket rods aren't nearly as expensive as they used to be. When I was talking to Curt Harvey a while back he said that the stock rods were a weak point on these engines. Especially when used with heavy stock pistons. He said that if you wanted to re-use them you should be sure to get them checked for cracks (magnafluxing) and also check that the pin end hadn't been streched from over reving. I think he said that the hole the wrist pin goes through is sometimes streched oblong. At the convention Lamar Walden who mainly builds race engines pretty much said that you should never re-use the stock rods. The stroker engine Tony Shaffer built to give away at the convention made 574 streetable horspower. It had a set of Aubreys pistons in it so I think they'd be a good way to go.

 

[dq409]

One of the best ways to go is with the Eagle BBC H-beam rods and a set of Aubreys pistons.
Thats what I`m running in my engine.

I think you are smart to think about the bottom end.

Once you beef up the bottom end you should never have to worry and then later on ad more horse power without redoing the bottom end,,,dq

 

[CDNpontiac409guy]

Thank YOU, guys ....

Here's a link to a picture from another thread:

http://www.348-409.com/forum/attachment.php?attachmentid=1576

These are the stocker pistons and rods that are in my engine.

 

[jim_ss409]

I also used Eagle H-beams and Curt told me that I could run at 6.000 rpm without hurting anything and he said even at 7,000 the rods and pistons would be fine but bearing life would be affected. This is with a 476ci stroker so my guess is you could go even higher with a stock stroke. Most guys would never rev that high but it's nice to know you could. Having said that though I thought that a 6,000rpm chip in my rev limiter would be plenty, but when I got to the track with my new engine I wished I'd have brought a bigger chip. My factory tach wasn't very accurate and I kept bumping into the rev limiter because the engine was still pulling hard at that rpm. So I'm glad I built the bottom end strong enough to at least try going to 6,200 or so.

 

[MRHP]

7,000

Hey jim ss409, I wind my 474 up to 7,000. Give it a try sometime. It pulls like a monster! I too was told 7000 was safe on a balanced assy with h beams but rod bearing wear would be accelerated. If it was built right, it won't come apart.

 

[jim_ss409]

MRHP, I can't wait till spring. I've got a hydraulic roller cam so I'll probably run into valve float long before I get to 7,000rpm but it felt to be pulling harder than ever at 6,000 so I'm definitely going to test it's rpm limits next year. When I decided to go with a 4" stroke I thought I'd have a torquey low reving engine that died off above 5800 but this thing loves to rev, just like you said it would. Once again I'm glad I went with good pistons and rods. One less thing to worry about.

 

[jm32409]

Thanks for the info guys. I am not building a race car but I am building a hot rod (1934 ford) and it might see some 1320 passes. My motor is a 340hp 409 at the machine shop getting bored so I am needing to order pistons. Aubrey those pistons and rods looked great I will try to give you a call about ordering a set of those. By the way here are some pics of the frame with a 348 in it for build purposes.

Thanks guys,

Jeff

 

[jim_ss409]

Looking good Jeff! bang That 34's going to be a rocket with that 409 in it. :eek: And those W motor valve covers will really make it stand out from the crowd.

 

[dq409]

Yep Jeff, Thats going to be one fine ride !!

But don`t cut corners on the bottom end.
After all ,, once you have a bullit proof bottom end you will most likely won`t have to open it up for many happy years.
Later if you want more power you can always bolt on a set of the new aluminum heads without pulling the engine or doing a thing to the lower end !! ,,, dq

 

[CDNpontiac409guy]

Awe man, Jeff, isn't there just something about an old Ford 3 window !

looking very cool

You can find all my contact info in my Engine parts page.