SlowZ28/SS

iTrader: (14)

Hey guys. I'm curious as to what the largest stroke crank i can run in a 400 sbc is? I know i'll have to clearance the block for it. I'm wanting to run a 4.125 stroke crank and a 4.155 bore. The engine wont be anything crazy, just a small roller cam turning around 7k or so. I plan on spraying a 200 shot on it also. I just dont know if i'm goin to have problems gettin into the water jackets when i go to clearance the block and if i did would it be ok to put block filler in it?

JTM

4" is really pushing it in a factory block, 4.155 Bore, 4.000” would be a 434. It can be done, do I think it would last very long? No. If your planning on throwing that much stroke at it plus a 200 shot you should really look into an aftermarket dart or motown block.

SlowZ28/SS

iTrader: (14)

Thanks for the input JTM. Just curious as to what people thought. I think the 200 hit would be optional depending on E.T. on all motor. Engines goin in a 89 s-10. I already have one s-10 with a 412 in it running 10's on motor. I'm just wanting to get 9's out of this one and keep it pretty streetable.

LS1 Coupe

Although the 400 motors back in the day where quite over looked do to overheating (mostly peoples own fault) 400 blocks had some bad core shift issues, also check to make sure there are no cracks, these blocks are quite old these days. 4" is about max you want to put in a 400 Block, you can also go to a 3.850" and a 4.165 bore that puts you at 427" but the block will pretty much be toast after that for any reboring, If you can even get it to bore that far, Good idea would be to have the block and cylinders sonic tested. If your really wanting to go big stroke in a small block and keep some deffinate longevity look at a Dart or Motown block. There is also an offset crank 3.823" that with a .030 bore will get you 415". Best bet in my opinion is to use the stock stroke crank and do a basic hipo rebuild and build a whole seperate big inch sbc with a quality block.

ZONES89RS

iTrader: (25)

Yea, i been down that road, as LS1 coupe said, use stock stroke and build with aftermarket block. I wanted to do the same badly but found there are too many dead ends.

Shawn @ VA Speed

iTrader: (3)

even thought i have built some 434's using stock blocks,i would recommend staying with the stock stroke as well.Anything over that should have a tall deck block and anything over 4" stroke needs a raised cam and spread pan rails.Those extra cubes wont help that much,406's run thier asses off when built correctly.I went 9.70's n/a on street tires with one several years ago.

racer7088

4 inch stroke is really getting there and 4.125 is pretty hard. It totally depends on what crank, rods and cam you use and such and you are NA only at 4.125 stroke for the most part. Everything hits everything in the SBC unfortunately so there's a lot of clearancing.

bluebeast

iTrader: (1)

max stroke on a 400 is somewhere close to 470ish cubes...... may want to get a dart block to do this but you did ask MAX stroke not max safest stroke on stock block.....

kenSS

iTrader: (1)

get a dart iron eagle block with the .391 raised cam and wider oil pan rails and call it a day.

racer7088

That's cheating but it would sure be a lot easier! Now if only there was a DART LT1 block like that we'd all be happy!

SlowZ28/SS

iTrader: (14)

Thanks for all the input. I guess I should have stated that I was wanting to know the "safest stroke" I think i'm just going to run a 3.875" stroke since I have the crank already from a previous build. So let me ask you this. Putting this 3.875 stroke crank in a 400 will have have to run a cam with no backside one it..????

ZONES89RS

iTrader: (25)

As in a small base circle cam? It is allways best to do so in a stroker application anyways but usually a set of aftermarket rods are clearances for stroker applications anyways.