409 sbc build

[chevyking72]

well I'm building a sbc 409 and would like some input on what to expect with my build. I started with a 400 cid block bored it .40 over and used the stock crank and purchased keith blck floating hyp pistons along with scats 3.75 rods also floating, Im using the Edelbrock rpm air gap intake along with the edelbrock 60999 aluminum heads. I plan on using the holley 750 mechanicle carb. every bolt was replaced with arp bolts etc. what can i expect to make as far as torq and hp.

[CivRacer95]

Not exactly my expertise here, so I'll move it to the Chevy section and let those gearheads give you a hand with your questions

*Edit: Moved to this section because I had no idea where to put it exactly. Sorry to the Chevy mods, figured you would be able to take it from here!

[534BC]

Welcome to AF forums.

HP is directly calc with VE and rpm since you have already listed the displacement.
VE can be estimated maybe 70-80% and then calc at whatever rpm you desire.

It mostly determined by your camshaft and heads selection. sorry I can't be specific. 400-500 HP maybe? I'm sure there are online calcs that'll help more.

[777stickman]

SummitRacing.com has a bunch of calculator sites. You might also take a look at the carb sizing calculator as that 750 may be a bit too much for your application.

[chevyking72]

Originally Posted by 777stickman

SummitRacing.com has a bunch of calculator sites. You might also take a look at the carb sizing calculator as that 750 may be a bit too much for your application.

I'm using the comp cam magnum 292h cam and lifter kit sorry I left that out. Also using summits online calculator kinda confused me and I'm not sure I put in the correct info

[MrPbody]

Well, without a cam spec, we're gonna be "lost" for power.

Avoid the KB hyper-eutectic pistons. They've been "problematic" since their introduction in the mid '90s. Setting them "up" to work AND live is not trivial. Speed Pro are good forgings and reasonably priced. The Icon (fka Kieth Black) forgings are also very good and reasonable.

I would also suggest Eagle rods versus the Scat. We've seen metalurgical issues with the Scats. What is a 3.75 rod? For the "safest" 400 build, a 6" rod is called for.

The factory crank is fine. In fact, better than ANY of the aftermarket castings. Just be sure the grind is done by a good crank shop.

I hope that block is a "2-bolt". 4-bolt 400s are very weak in the bulkheads, where they removed material in the WRONG places for the outboard bolt holes. Unlike 350, a 2-bolt is a better block. If power levels reach the point where 4-bolt is needed, "splayed bolt" caps are called for. Once you go past about 550 HP, I would highly recommend an aftermarket block, like "Little M". Unlike 350, with 400, the block is the "weak link".

FWIW

Jim

[chevyking72]

Good information! The only thing is the machine work and assembly of motor is complete. So I'm just wanting to know should I sale this and rebuild or for street cruising I'm fine.

[techinspector1]

Originally Posted by chevyking72

I'm using the comp cam magnum 292h cam and lifter kit sorry I left that out. Also using summits online calculator kinda confused me and I'm not sure I put in the correct info

I would never use this much cam for a street cruiser. What's the static compression ratio of the motor. You cannot intelligently choose a camshaft for a motor until you know the exact static compression ratio.
http://www.cranecams.com/faqview.php?s_id=9

[maxwedge]

Originally Posted by techinspector1

I would never use this much cam for a street cruiser. What's the static compression ratio of the motor. You cannot intelligently choose a camshaft for a motor until you know the exact static compression ratio.
http://www.cranecams.com/faqview.php?s_id=9

Agreed, that cam would need a big convertor and gear to work and at least 10:1 with the alloy heads, I believe the 3.75 rods refers to the stroke? Forget vacuum for the p/brakes also.

[oldblu65]

Anyone wanting advice on a Chevy 409 build should contact Lamar or Rob Walden @ http://www.worldcastings.com/ or by calling 770-449-0315 . They are the premier builders of 409's in the country and can get you going in the right direction with your build . I am not connected in any way with this company - just know it by their reputation ! They are located in Doraville , Ga. !

[maxwedge]

Originally Posted by oldblu65

Anyone wanting advice on a Chevy 409 build should contact Lamar or Rob Walden @ http://www.worldcastings.com/ or by calling 770-449-0315 . They are the premier builders of 409's in the country and can get you going in the right direction with your build . I am not connected in any way with this company - just know it by their reputation ! They are located in Doraville , Ga. !

"Old", he is referring to a 409 cu. in. small block not the W engine 409.

[oldblu65]

Originally Posted by maxwedge

"Old", he is referring to a 409 cu. in. small block not the W engine 409.

I apparently missed the " SBC " part of the thread ? Sorry , guys !