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400 Stroker Piston question

Posted By: tact1

400 Stroker Piston question - 10/01/16 03:13 AM

Trying to find a 400 stroker kit but I need a .060 over piston. Everybody says what we list is all we have. Been trying to find a piston listed by someone that I could buy off the shelf to replace the kit pistons but no luck so far. Was going to use a 440 Source kit with 3.91 crank. Suggestions?
Posted By: 451Mopar

Re: 400 Stroker Piston question - 10/01/16 03:37 AM

Most kit pistons are 0.055" over for a 4.375" bore.
If you need a full 0.060" 4.380" bore piston, there is still a good selection of piston rings in that size too, but I'm not sure about off the shelf stroker pistons?
I looked on Summit and ICON (KB) makes twos 4.382" bore stroker piston for the 3.91" stroke crank? IC825-40 flat top, and IC839-40 dish, 1.480" compression height? These are also 0.990" pin.
Stock rod would have that pretty far down the bore at TDC, almost need a 6.5" (6.535"? lists on summits site?) rod to near zero deck height?

ROSS had a large selection of these type of stroker pistons too, but I haven't checked in many years?
Posted By: GTS340

Re: 400 Stroker Piston question - 10/01/16 04:14 AM

.060 over 400 would be 4.402 bore, which is a size that I have never seen a shelf piston offered in, however AutoTec does bore changes to shelf pistons at no cost
Posted By: tact1

Re: 400 Stroker Piston question - 10/01/16 04:43 AM

Have seen 2 different rods used, 6.535" (440 Source)with a 1.485 comp. hgt. piston and a 6.7" rod with a 1.320 comp.hgt. piston (Muscle Motors) Would the longer rod be better than the short rod?
Posted By: AndyF

Re: 400 Stroker Piston question - 10/01/16 05:32 AM

I'd use the longer rod but it probably doesn't matter much for most builds. ICON has 0.060 over 400 stroker pistons but 440Source doesn't stock them. So you have to buy the crank and rods from one vendor and the pistons from another vendor.

You can save some money by using a 440Source crank, SCAT I beam rods, and ICON pistons. You can get the rods and pistons from Summit.
Posted By: AndyF

Re: 400 Stroker Piston question - 10/01/16 05:34 AM

For my 470 I used a SCAT crank, SCAT I beam rods and a Diamond shelf piston. This engine was 4.375 bore size but you can go 0.060 over if you want. Pistons and rings shouldn't be a problem.

Attached picture DSC_9003 (Large).JPG
Posted By: tact1

Re: 400 Stroker Piston question - 10/02/16 05:32 AM

Thanks for the info. I have been trying to piece a kit together and with all the manufacturers having parts to sort through it is almost overwhelming. I'll call them Monday.
Posted By: AndyF

Re: 400 Stroker Piston question - 10/02/16 04:39 PM

Did you look in the tech archives? I documented a lot of this stuff a while back:

http://www.moparts.org/Tech/Archive/bb/BBM_Stroker_Pistons.html
Posted By: tact1

Re: 400 Stroker Piston question - 10/03/16 05:16 PM

It has been a while since I looked, I will go there now.
Posted By: AndyF

Re: 400 Stroker Piston question - 10/03/16 07:13 PM

I have a customer who is building a 0.060 over 470 (actually is a 476). I told him to use a Molnar crank, SCAT I beam rods (6.700 long) and the ICON 837-060 pistons. That will give you around 10:1 compression with an Edelbrock head or 10.5 with a Trick Flow head.

Only issue with this is that the block needs to be full height. If it has been decked before then the pistons might stick out of the bore a tiny amount. Not really a big problem, just order a thick head gasket from Cometic.

The SCAT rods are $370 from Summit, the crank is around $700 and the pistons are about $600. By the time you add bearings and rings you'll be at $2000 for the rotating assembly. If you are going to really beat on the engine then step up to an H beam rod for another $100 and switch over to a JE or Diamond piston for a few hundred more. Then you'll have a bracket engine that can handle 700 hp all day long.
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