Chevy Nova Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
1,899 Posts
Discussion Starter #1
http://v8s10.org/forum/album_page.php?pic_id=1498&sid=cb059102245a72518b10c735fe9601e7

http://v8s10.org/forum/album_page.php?pic_id=1499&sid=55d877aface5cef2f051bf6efa509846

It's a 400 sbc casting code 330817. Suffix code is CSU. It's out of a '74 Caprice. It's a virgin core in need of a rebuild. The bottom end is complete and it also came with a pair of heavy casting 333882 heads.

I'm getting ready to put it on the engine stand and tear it down and send the block off to the machine shop to be cleaned, magged and sonic checked. If all goes well it'll be bored .030 and anything else that needs done.

Right now I'm tossing around ideas on how I want to build this engine. I know alot of people go all out when building these engines. I'm thinking since these were torque monsters from the get-go, why not keep it that way?

I was planning on reusing the stock rods and crank but I have been advised to ditch the 5.650 rods and instead go with either 5.7's or 6's. Why is this?

To help get the compression up I plan on replacing the stock pistons with flat tops, though I'm not sure if I should go with the 2 valve relief flat tops or the 4 valve reliefs. I'm wanting to keep it pump gas friendly.....any suggestions?

For the heads.....I know the 882's aren't all that great, but atleast I have the heavy castings which are less prone to cracking. I have considered reusing the 882's.

However I've been also tossing sround the idea of Vortecs. And then I have considered a set of 186 casting heads with 2.02/1.60 valves. Yes I know even these aren't the best head but I figure if I could get a set cheap enough that were good then atleast they'd flow better/give more compression than the 882's, plus the intakes are relatively cheap. I'm sure the Vortecs would still be better?

As for the cam.....I'm still undecided, but I'm considering a roller cam. I'm debating on using the new Voo Doo cam since it has the latest greatest cam technology but I'm not sure if they make any roller cams.

I don't plan on running this engine any higher than 6k, and I don't plan to use nitrous. I want to build this so it has good street manners, good vacuum and when I press the pedal it just pulls hard....very hard. Twisted Evil

I'm considering going carbed but then again I wonder if anyone makes a fuel injection kit for this size engine?

This will be primarly a street engine that will see some time at the track. If anything I'd love to build this engine so it can hang with, if not outrun the LS1 F bodies. I've been told I can make this push 425-450 hp n/a and still have a ton of torque down below....is this so?

Your thoughts/suggestions are welcome.
 

·
Registered
Joined
·
576 Posts
I just completed my 406 and I’m working on getting it dialed in. I learned a lot off this web and doing research, but I’m no expert. I went with 6” rods because it lowers the Dynamic Compression ratio a tad more than 5.7 rods. If you stay with “I” beam rods you more than likely won’t need to clearance the block, like you would with heavier “H” beam rods.
Flat tops raise the CR kind of high on a 406 you may want to consider 15cc or 22cc dish pistons.
Here’s an article on a 406, there are quite a few out there if you look around.
http://www.chevyhiperformance.com/techarticles/6113/
Have fun
 

·
Registered
Joined
·
1,899 Posts
Discussion Starter #4
Yeah Dan actually a friend of mine and I picked it up out of the bed of my truck when unloading from the bed :D ....of course for safety reasons we had the engine stand bolted to it first.

Still open to ideas for a nice streetable engine to keep the LS1 boys at bay. :)
 

·
Registered
Joined
·
1,040 Posts
I would run 5.7 oem chevy rods with arp bolts,and dished forged pistons like the last post says! with the vortecs or 186 heads you will be around 10.1
If you run flattops and the 882 heads you will also be around 10.1
The engine will fall on its face at 5000 rpm with the 882 or 186 stock heads!!!
the vortecs would see more like 5800 rpm ,thats with like a 230 @ .050 camshaft.
 

·
Registered
Joined
·
57 Posts
I had a 406 in a 74 i owned years ago. It had the stock heads, mildly ported 9.5-1 comp. and i think about a 450 lift 280 or 290 duration cam. 750 quadrajet on a 327/365 intake. Looked completely stock. The car ran 12.0's through the muf's on 245/60/14 radial street tires. It's not hard to get a lot of power out of a 400. If you want to go FI check this out. It will handle that much motor.http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?storeId=10001&catalogId=10002&catalogIdentifier=Jegs_Direct&categoryId=14295&parentCategoryId=10299
 

·
Registered
Joined
·
1,899 Posts
Discussion Starter #7
Jason thanx for the tip. I'm rather suprised to hear the 186 heads would be out of breath by 5k....wern't these the very same heads used on the 302 DZ engines in the '68 and '69 Z28's? We all know how those things didn't start making power until like 5k....

I can believe the 882's being out of breath by them since they were low performance anyways.

I'll definitley go with the 5.7 rods. In fact a neighbor said he'd sell me his for $35...I'm guessing that's probably not a bad deal?

I just need to find a piston to work with the 5.7 rods that would give a 10:1 c.r. when used with a 64 cc head. Even if I don't plan to spray would you still recommend forged pistons?

Also when is it necessary to run splayed main caps? This thing still has the stocker 2 bolt mains.

I figure most of the $$ will go towards heads and then some towards engine machining/balance work. But I won't sacrifice dirability where needed.
 

·
Registered
Joined
·
7,257 Posts
If you looked at my budget 350 thread, the 186's and the like don't flow over 200 cfm. They have smallish ports as well. This leads to low rpm on a big motor like a 400. There's a big difference with 98 more cubic inches to feed!

Kev
 

·
Registered
Joined
·
1,899 Posts
Discussion Starter #9
No actually I haven't been following...I haven't been on here much lately....I see that topic is now up to 56 pages long. :eek:
 
1 - 9 of 9 Posts
Top