Oil Support Rails and Drag Racing

[72DMag]

Getting my 400 block back from machine shop soon or when this quarantine is over.

Originally planning to do a 451 but with my down time I have been looking at stroker kits. Eagle, Scat, and 440 Source all make a 500 ci stroker kit for the 400 block but all 3 companies use a piston that has an oil support rail.

With drag racing are oil support rails something to avoid and another thing to worry about going wrong? Sounds like they can turn on the piston (Some have the dimple where the pin hole is but does that really do anything??) and or collapse with the oil ring causing issues or serious damage.

The 500 stroker is same price at 440 source no matter which one you get but not sure about the support rail.

 

[hemi446]

We have used them a lot in the stroker motors we have built and don't see any problems with them. Just a side note Chevy guys have been using them for so long if they don't have a piston that needs them the think something is wrong. But that a Chevy thing they have to put 40 lbs of in a 10 lb bag to make it work

 

[72DMag]

@hemi446 Do the chevy pistons have the cut out for the pin to go through? or do they run the support rails with pistons that are solid just to do it? Wasn't sure what you meant by your statement.

What's better to run with a button or the support rail having a dimple in it. Both eagle and scat kits that are offered do not have the button only the dimple support rail. I find it hard to believe that little dimple will keep it from spinning.

Thanks

 

[AndyF]

I wouldn't use them when there are plenty of kits that don't require it. Use a 4.25 stroke crank with the 2.200 rod journals and then use a 2.200/0.990 rod and get a piston with the 0.990 pin. That is what I have in my Duster and it doesn't have the support rails. The 0.990 pin is smaller and stays out of the oil groove.

 

[72DMag]

@AndyF I am pretty sure the kit that you are describing is for the 512ci stroker. I wouldn't mind going with that but I am not a fan of the distance below deck height being 0". I looked at those kits and could not find one that didn't have that.

 

[hemi446]

@hemi446 Do the chevy pistons have the cut out for the pin to go through? or do they run the support rails with pistons that are solid just to do it? Wasn't sure what you meant by your statement.

What's better to run with a button or the support rail having a dimple in it. Both eagle and scat kits that are offered do not have the button only the dimple support rail. I find it hard to believe that little dimple will keep it from spinning.

Thanks

The pistons have a cut out for the pin to go through. The dimple works just find. I can’t remember having to take any pistons out because of a oil problem. We just did a 426 small block that used a 340 block as its base and those pistons have a dimple to lock the support ring in place.

 

[AndyF]

@AndyF I am pretty sure the kit that you are describing is for the 512ci stroker. I wouldn't mind going with that but I am not a fan of the distance below deck height being 0". I looked at those kits and could not find one that didn't have that.

If you're going to build a serious engine then take the time and research all of the available pistons. It shouldn't take more an an hour or two and then you'll know. The kits only make up a fraction of what is available. Here is the research I did on my last 505 engine.