Hey Guys I posted this in the forced induction forum figure I would try over here as well.Never can have to much info.Here is my plan to put together a 434 using a F1C procharger.I know I would need a tall deck block guy at gm say they make a tall deck block not a production block it has thicker walls which I would need to run 20 psi +shot of nos.My problem is selecting rod lenth.With a standard deck as explained to me I would not use say 6.00 rods because of ratio.Would that still apply with tall deck?Alot of this will be custom work pistons,cam etc.Any direction would be appreciated

 

They did a big inch build up on Horsepower TV last season. He's a similar engine: http://www.shafiroff.com/472_675_engine.asp

 

The rod ratio is not what is holding you back. You can do a 434 on a stock, production 400 block with a 6" rod and a piston with a 1" compression height. This would be fine n/a but I don't think it would live to long with 20psi and n2o. The only way to get a taller piston is to shorten the rod(most likely will not clear a 4" stroke) or raise the deck height. With a tall deck you can use a 6.125 inch rod with a 1.2" CH or a 6inch rod with a 1.325" CH.

 

You dont need a tall deck block to make a 434, tall deck gets you 472" if you feel like it.

You would likely need an aftermarket 350 block with wide pan rails to make it work easier, I think you can do it on a factory width rail A/M block though. Just pick up either a dart or world 350 main (or honda main) block with 4.125 bores, bore it .030 and a 4.00" crank tada!

 

Thanks for the replys guys.The block was not really the problem I all ready have a Dart eagle block tall deck.Got it at a super chevy show.Guy had three or four he wanted to get rid of needless to say we took them all.Since I had the block just sitting in the corner wanted to do something with it.I started to do the normal 383 but suddenly change my mind.Think I have that disorder when people change their mind all of a sudden My main concern was the rod lenth and wanted to see if anyone tried this setup yet.

 

Shoot...if you have a talldeck why bother with a 434? Get a 4.25" crank, 6.125 rods and 4.155 pistons and have the biggest SBC you can build?

 

470 is big yeah but there have been 528 cube SBC's, Mindgame even had a old Sonny Lenoard 504 cube SBC.

Not Cheap!

Bret

 

Bret, I was under the impression 472 was the biggest? Maybe its the biggest with OTS parts, or biggest relatively easily built?

 

As Bret said not cheap.Price has alot to with this project.Even though I can get some things at jobbers price there are many that can get very expensive.Will need custom cam,pistons etc etc.This is going to be a street(not everyday)strip setup just didn't want to get in over my head.Anyone have experiance with a buildup like this?Thanks again

 

Almost forgot Hey Bret I heard you are a cam wizard when it comes to designing a cam.Maybe when I get all my components together you can design one for me.

 

You're right Jon, although you're kinda thinking in the box.

If you use a custom machined billet crankshaft, you can do all kinds of neat stuff with the counterweights.

Now consider this... if I take my custom 4.437" stroke billet crank, use a tall deck rocket block, move the bores a little, stuff 4.25" slugs in it... what have I got?

Yeah, one big 504 cid small block.

Of course there's a little more to it than that, like the moving spark plugs and stuff but that's the mechanics of it.

-Mindgame

 

"Move the bores a little"....this is possible on an existing block, not making one from scratch?

I wouldve thought the major problem with such a huge stroke is the rod bolts cranking the block by the rail and bores, not the counterweights? I guess the counterweights might cause a problem with the bottom of pistons maybe?

 

Yes, possible although I don't know all the dirty details. Of course, we go back to a custom billet crankshaft making this possible.

The rods clear fine. Notching is about the size of a nickle (maybe a tad bigger) and you'd probably get the nickle about centerline deep in the notch. Lots of meat on the rocket block though.

For the real deep down dirt, you'll have to give Sonny a call. He'll tell you everything for a price.

-Mindgame

 

lol.....

I kinda wondered about that.....

Any chance that you had some small rod journals in this puppy?

How long ago did you run that thing?

The best part is the Makes me wonder how far you are offsetting the bores....

Bret

 

I'm still wondering about the offset bores here....

On a standard bore spacing that's not enough material between the cylinders. Now say you offset the bores from the center a 1/16" and sleeve it you now have issues with the lifter bores and combustion chambers..... You gotta give us some details on this... I can't wait till the EM contest in October to ask Sonny abou this.

Bret