If it was your engine

[phxraptor]

Going to build a 406 from bare block up. If it were your engine how would you build it? What 400 engine would you look for in the bone yard as a base block? I plan on a 700r4 trans, any thoughts there? What diff? Going in my 81,looking for around 450hp and a like amount of torque. Thanks !

 

[Jacko]

Are there still 400 blocks laying around in the boneyards?
I haven't seen one in quite some time here in upstate NY.
What kind of money do you expect to pay to pick one up?
How complete do you expect this motor to be?
Curious as I have a couple in my garage, wondering what todays market value might be.

 

[phxraptor]

Are there still 400 blocks laying around in the boneyards?
I haven't seen one in quite some time here in upstate NY.
What kind of money do you expect to pay to pick one up?
How complete do you expect this motor to be?
Curious as I have a couple in my garage, wondering what todays market value might be.

Don't know what they are worth,there must be some around out of the millions produced. Would'nt think they are worth more than a hundred bucks if that.

 

[cruisin-davey-g]

RE: 400 Small Block.

Hi: Reguarding your 400 small block build up. If you do manage to find a bone-yard block (or whole engine), just make sure that you take it to a reputable shop to have it hot tanked & checked for cracks (stress) & to make sure you've got a good block to begine with. Also, look for a 2 bolt main, rather than a 4 bolter, 'cause GM had a problem with the 4 bolt block's webbing stress cracking. If you want added strenght to the mains, take a 2 bolt & have it "splayed" for a 4 bolt. From there, it just a matter of how many ponies you want & how much money money you're willing to spend. And, don't forget to remember how much you plan to "Pound On" this engine. Building it right the first time will save you headaches in the long run. On your pick of "trannies". I would opt for the 200-4R rather than the 700R-4 as a chioce of trans. And, you should definately look into a much stronger rear-end set up than the stock vette rear, if you're planning to get up to around the 500 horse mark IMHO. Take care & good luck on your project

Dave

 

[FlyingFinn]

Heavy Metal Mouse

There's a recent article in Chevy Hi Perf magazine about "7 Hot Engine Combos". The article includes details on a "Heavy Metal Mouse" 406 ci configuration putting out 520 hp and 480 ft-lbs torque. You can check it out at http://www.chevyhiperformance.com/techarticles/71298/

Regards,
Arto

 

[AKRAY4PLAY]

PHX,
Dave hit on some very good points. a two bolt block with ARP main studs will hold up to 500hp with a top notch balance job and staying under 6000rpm. going higher in hp or rpm i would most deffinately go splayed. 400's are hard to find in good shape and usually run about $300. you can only go .030" overbore with a good performance motor. sonic checking a block is always a good idea, it will identify any thin spots in the casting if they exist. also look for signs of core shift, it can lead to stress cracks and major block failure. if you are looking at the best reliabilty, splayed mains are the way to go. if you want splayed, the cost of machine work and caps of prepping an old block are about the same as a new rocket block availible from GM performance. the new block will allow you to stroke the 400 up to a 454. you can easily go to a 426 with no major machine work, just finish honing. the rocket block has priority main oiling, factory splayed mains, spread oil pan rails and a raised cam location, in other words it was made to be built for big power. cost is about $2300. i have some other info on 406's if you are interested. mine is 606hp and 588ft/lbs on pump gas, but not very street friendly. hope this helps, Brian

 

[MaineShark]

Mmmm... 400-block...

I've been looking at a 406 (though I've been very tempted to wait a few years, save up some more money, and do a 427 or 454).

Here's some of what I came up with for a budget 406:

Start with a 400-block and stock 350 rods (5.7"). Clean, test, machine, bore 0.030 over.

Add a Scat 9000-series cast crank (9-104000). $200

Add Keith Black 18cc pistons (KB147, ordered for 0.030 overbore). $260

Deck the block to put the pistons 0.005 or 0.010 in the hole. With 64cc heads and a 0.040" head gasket, that gives you 10.04:1 or 9.93:1 compression.

Heads are a little iffy. I was looking at Trickflow (under $850), but I've also been told to look at Dart Pro1 heads (a bit more expensive).

I think that roller-tip rockers should be used, at the very least. If you can get a good deal (eBay, swap meet, or somesuch) on full roller rockers, I'd go that route.

I think that the Edelbrock Performer Air-Gap or Performer RPM Air-Gap would both make good intakes. I think the regular Performer Air-Gap might fit under the stock hood, but the RPM Air-Gap would probably be happier with a taller hood, to allow a decent-sized air cleaner.

Cam choice is going to be based on your particular needs. I'd suggest choosing the rest, first, then talking to the cam anufacturer, and following their recommendations. Roller or regular - depends on how much you feel like spending.

The rest is pretty much just odds and ends. Oil pump, fuel pump, balancer & flexplate (both need to be designed for the 400 engine, not the 350, unless you want to shell out for an internally-balanced crank), valve covers, oil pan, bearings, gaskets, piston rings, pushrods, timing chain and cover, etc. etc. etc.

Joe