how much nitrous??

[atxcobra]

how much nitrous can a 400 small block take? also where can i find a cheap setup?

[VileZambonie]

How much? how fast do you want to blow it up?  Personally I would never N20 a 400 unless I did some serious engine work but if you're gung ho on it what pistons do you have and what's your compression ratio to start with?

[Leadfoot]

I'm with Vile,unless it's got aftermarket crank,rods and good pistons,I wouldn't even think about nitrous on a 400..

[Lt.Del]

I say open that valve all the way and let er rip!  Have someone videotape it and put it on Youtube--i wanna see that.

[Big78Chevy]

I'm with Sgtdel, Open it up and let it loose. But seriously to put NOS on a 400 is like a match to a $100 bill.. you just don't do it, (unless your completely filthy rich). The 400 blocks are great in the hp/torque dept. to begin with but run hot as it is without having to ad a NOS charge. But if you don't care about the engine by all means break out the video camera.........LOL 

[cjtimp]

NONE..............don't like NOS.....the risk is not worth the ride.

[SUX2BU99]

How come all the comment about the 400s being fragile? What is their weakness? Too much taken out of the block to get 400 cubes from it, causing thin walls? Overheating (why)?  Must be something wrong with them because 350s are still way way more popular as a perf. motor than a 400.

[Leadfoot]

they have siamesed bores,cast together instead of seperate like a 350..personally never had one run hot,but if you use anything but stock 400 heads on them,the heads must have the steam holes drilled in them to match the 400 head gasket,no big deal to do,but MUST be done.. their connecting rods are shorter than a 350,cast only and basically junk,crankshaft is cast only also,no factory steel cranks available..and the 4 bolt main blocks tend to crack on the webs where the main caps bolt down.. ideally,you take a 2 bolt block and have it machined to accept 4 bolt caps,throw in a good aftermarket crank and H-beam rods,with some good heads and you got a -_- motor..they are very popular among the racers,I rarely see them for sale,the fact that they only made them for 3 years doesn't help either..  they never even offered a 400 sbc with a 4 barrel carb from the factory,all 2 barrels with the highest hp rating of 165hp   there ya go,everything you probably never wanted to know about a 400 in one paragraph   I had an all forged 406 with sportsmanII heads in an 84 silverado longbed that showed many mustangs,corvettes and camaros it's taillights..


Tim

[VileZambonie]

the fact that they only made them for 3 years doesn't help either..  they never even offered a 400 sbc with a 4 barrel carb from the factory,all 2 barrels with the highest hp rating of 165hp 

Where did you get that information from? 

[VileZambonie]

The 400 was a great engine for stock and mild applications. If you want Nitrous I would go with something that has a shorter stroke. My 1st truck was a 1980 c10 with a 400 4bbl and I loved that truck!

I found an image with some 400 data

[Leadfoot]

the fact that they only made them for 3 years doesn't help either..  they never even offered a 400 sbc with a 4 barrel carb from the factory,all 2 barrels with the highest hp rating of 165hp 

Where did you get that information from?  that I couldn't tell ya.. I read it somewhere,several years ago.. guess the 3 years I was thinking of was the 4 bolt blocks..my mistake

[Captkaos]

4 bolt mains were 3 year only (as image indicates), the 400 was made until 1980 as indicated, just 2 bolt.