Small block 400

[hirschdalechevy]

I dunno I guess some peoples breaking the bank is not the same as mine lol.

As soon as you mention aluminum heads. I think the bank is broken!

Well thats why I added in vortec heads if you want to save some $$$.

But if you compare , vortec's new , about 630.00 , afr's 1600.00 , blueprint's 1000.00 , trickflow's 1200.00

So you have to save up another 500 to 1000 dollar's for good heads and then you can run higher cylinder pressure = more power at any rpm and you dont have to worry about cam lift.

just my 2 cents on it.

 

[350runner]

[quote name="MadOgre" post=272130]I dunno I guess some peoples breaking the bank is not the same as mine lol.





As soon as you mention aluminum heads. I think the bank is broken!

Well thats why I added in vortec heads if you want to save some $$$.





But if you compare , vortec's new , about 630.00 , afr's 1600.00 , blueprint's 1000.00 , trickflow's 1200.00





So you have to save up another 500 to 1000 dollar's for good heads and then you can run higher cylinder pressure = more power at any rpm and you dont have to worry about cam lift.





just my 2 cents on it.[/quote]

Man your making me think of ditching the L.A. idea and going 400sb. can you provide any other info on that build?

Sent from the dust in front of you!

 

[MikeB]

Thanks for the replies guys. Yea I don't plan on this thing to do 150 mph but low end torque is what I want/need. I don't know much about aftermarket cams. What's a good lift? Duration?

The cam mentioned above (comp xe268h cam 224/230 dur at 0.050, 477/480 lift 110 lsa) is great for that particular build, but it's not anything you would consider for an otherwise stock engine with stock heads & valve springs. Check out the specs on the Edelbrock 2103 cam I mentioned above. http://www.summitracing.com/parts/edl-2103

And for making lots of torque, erring on the smaller side is better. Even the old standby Summit K-1102 cam & lifter kit would work fine. http://www.summitracing.com/parts/sum-k1102

 

[MikeB]

Vortec's work well but they dont stack up to aftermarket heads , imo.

Well, that's true for high lift cams, but NOTHING builds torque at low-mid RPM like stock Vortecs with a cam up to .470" lift or so. And it's not just the CFM rating -- it's the velocity created by the intake runners.

But, then again, I'm prejudiced.

My 355 with GM Voretc heads and roller cam used in HT383 and RamJet 350

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[DoubleDingo]

Well, that's true for high lift cams, but NOTHING builds torque at low-mid RPM like stock Vortecs with a cam up to .470" lift or so. And it's not just the CFM rating -- it's the velocity created by the intake runners.

But, then again, I'm prejudiced.

My 355 with GM Voretc heads and roller cam used in HT383 and RamJet 350

Even a stock 350 with stock vortec's, a mild cam that doesn't exceed the maximum lift , a good dual plane intake, stock quadrajet, and stock single exhaust can generate some good low end torque. I too am biased

Although a sbc400 would be a nice upgrade.

 

[MadOgre]

IMO the 383 is the best of both worlds and if that much money was thrown at a 383 it would be just as capable of roasting tires!

 

[Don5]

I ran a 406 in my lifted 1/2 ton for several years. I drag raced a lot of Ford pickups and 1 dodge. If you want a torque motor than the 406 is the one. I have no experience with the stroker motors.

I stayed away from those due to longevity issues with them. It seemed that everyone that had one back then could not keep them together for any length of time. Maybe that is not the case now. I have no idea.

Here is what I do know. Back in the day, early to middle 80's. I ran a 400 with the following specs.

Cast crank, Forged pistons, double roller timing chain, Edelbrock Performer intake, Hi volume oil pump, Blackjack headers, Q-jet carb, stock 194 heads and a Crane Fireball cam 290 duration with 454 lift.

This motor ran extremely well. It would pull well past 5000 rpm. I had several guys convinced I had a big block. I ran with some big block Fords and the one 440 Dodge, and occasionally caught one napping and beat it. In any event several guys were stunned that I had a small block instead of a big block. Now this was my experience here in a small to medium sized city back during a time when you could get away with it. This is not true now.

There were no Vortec heads back then either. You had to buy aluminum or 202,205 iron heads to get more performance.

I like the specs on the Performer Rpm 2103 cam that Mike posted the link to. That is close to what I had on mine back then. I also say that if you can afford the aluminum heads, then go for it. Or go with the Vortec. Whatever you can afford that gets the job done.

If I have to choose between a 355,383 or 400, I won't hesitate. Give me the 400. No substitute for cubic inches. That is a torque motor plain and simple...

 

[Linville33]

http://m.summitracing.com/parts/cca-cl12-231-2 this one looks good to me. When it comes to the lift and duration I don't know much. This would be my first chevy build

 

[MikeB]

If I have to choose between a 355,383 or 400, I won't hesitate. Give me the 400. No substitute for cubic inches. That is a torque motor plain and simple...

Me, too. I wish GMPP would start selling crate 400s, short blocks, or at least bare blocks. I'd bet they wouldn't be able to make them fast enough to meet demand. Unfortunately, the least expensive option is a Dart SHP bare block for around $1680.

http://m.summitracing.com/parts/cca-cl12-231-2
This one looks good to me.

I agree.

 

[MadOgre]

So I was thinking about this 400 SB thing and I think its relevant to incorporate all the details of 400 vs 383. SO.

400:

Bore 4.125"
stroke 3.75"
Rod 5.565"
Main journal 2.65
rod journal 2.10

350:

Bore 4.00"
Stroke 3.48"
Rod 5.7
Main journal 2.30-2.45"
Rod journal 2.00-2.10"


383:

Bore 4.060"
Stroke 3.75"
Rod 5.7"
Main Journal 2.30-2.45"
Rod journal 2.00-2.10"

So the 400 SB has shorter connecting rods, larger main journals, Siamesed cylinders that can create cooling issues however the design is stronger than non siamesed blocks. This does limit the choice of cylinder heads to be used.

The advantage of stroking a 350 is that you have the benefit of smaller main journals, no cooling issues, the same stroke as the 400 which is key to torque, longer connecting rods which is again key to power production and the use of any head design for SB 350s

Another way to think of this is that you can utilize any SB 350 components that you can dream of with the added benefit of an extra 33 cubic inches and the extra 0.27 inches of stroke.

Or you can look at it as a 400 with better components that is a whopping 17 cubic inches smaller

The better components make up for the loss of 17 inches

A lot of stock 400s with poor head designs are very difficult to distinguish from a 350 based purely on performance.

When a well built 355 can come very close to producing power like a 400 you have to think that when adding the stroke and 33 inches to a 350 that the gap in performance would be nill if not lopsided in favor of the 383.

Sure you can argue that the 400 makes better torque but this is primarily due to the 3.75" stroke which is retained in the 383 stroker.

When you take that stroke coupled with better heads and longer rods you actually make better power than a 400

For durability issues use a 2 bolt main block and have it splayed.


Sure when it comes to finding junkyard motors to run off road I would put in a 400SB over a 350 but......when it comes to throwing money at a motor I would opt for the stroked 350 AKA 383 any day of the week!

 

[MadOgre]

You also may wonder why GM has a crate 383 HP motor and not a 400 ?

Its because the 383 is a better motor

 

[MadOgre]

Also most reliability issues associated to the 383 were due to poor milling quality of the crank and inexperienced guys forgetting to clearance the block or taking so much that it weakened the casting.

 

[MadOgre]

The New GM 383 crate motor will blow the socks off any old 400 SB

 

[morrow07]

Dude, relax. They don't produce 400 crate motors because they haven't produced the blocks in over 30 years.

I have a 406, with Sportman 2 heads, and 5.7 rods. I'm upgrading to AFR's this summer. In 10 years the motor never ran any hotter then my 355 with the stock cooling system. I have a Griffin aluminum radiator, weiand high flow pump, and dual fans. The fans hardly run.

Part for part, dollar for dollar, the 400/406 will always make more power everywhere then a 383. High, low, doesn't matter.

Sent from my C771 using Tapatalk 2

 

[HotRodPC]

Different Strokes.... Bottom Line. Although Ogre, I get what your saying because I'm semi old school too. You're partially right and partially wrong. Those #'s you're talking in that long post while true back then, it's different now days. Notice the kit IIRC, Morrow mentioned, and I want to make sure the OP KNOWS THIS, He suggested the Scat crank for a reason. YES, the OEM 400 does use a shorter rod. The only small block that used a rod different from the 5.7 rod. This was done to be able to pull the longer stroke back in the day. NOW days... There are kits out there where you use the matching crank and pistons with the correct compression height and you can indeed use 5.7 rods with a SBC 400.
The 383 came about long long ago by turning down a SBC 400 crank on the main journals, using the SBC 400 shorter rods and special ordered pistons with the correct compression height in a 350 block, and also had to use the SBC 400 flexplate and balancer for the external balanced motor where all the other small blocks were internally balanced. (IIRC, there are both Int and Ext balanced 305's, I didn't care to learn much about those and avoided the boat anchors, so I could wrong when it comes to the Wee O Fives). So that was the making of the original 383 back then now known as Old School. Now days, there are 383 kits that are made as ready to bolt in stroker kits and using 5.7 rods, as well as internally balanced using more common balancers and flexplates. Most of the added performance from a 400 is going to be the longer stoke which is where the added torque comes from.

Having the SBC 400 already does offer the OP other options to consider of the several he'll have. IMO, if wanted to run the 400/406, I'd just be going with the old school OEM way of doing it, otherwise it's going to be expensive. Just have the same block bored .030, same crank turned and trued, same con rods, cleaned, shot peened, magnafluxed checked for twist and big end resized. The Vortec heads may very well offer to much compression. Maybe not, being the OEM 400 pistons had a hell of a dish on them to lower compression since emissions were in full force when the 400 came about, so even with the Vortec heads and small combustion chambers, good chance compression will be just fine. Especially if running a bit bigger cam with a little valve overlap and lope to it that will bleed off some compression. Building the same OEM 400 with Vortec heads with steam holes drilled, is probably going to be cheapest way to build since the block, crank and rods can be reused.

Buying a new crank kit to build the SBC 400, IMO, that's going to be the most expensive option. I think we all know and agree, anything for a 350 block is going to be the least expensive, even if it's a 383 stroker kit, but then OP has to acquire or purchase a good 350 block.