Does anyone make 4.040 X 3.875 X 6 in rod pistons?

I am looking for some 4.040 or 4.060 bore 3.875 stroke with 6 inch rod flst top pistons off the shelf. I can only find SRP's 4.030 and others that only offer the 4.030 size. The bores on mine are needing .040 to clean up.
Thanks

All of the major players can make one up for you. A bit more expensive than an off-the-shelf piece, but not outrageous by any means. I will say that a 60 over stock small block is pushing it.

Rich

What Rich said. :)

If you're looking for lower cost, high quality, then the SRP is a good choice. I'd also check with Diamond as they list this piston (PN:09024040) in their 2006 catalog as a "non-stocking item".

Good luck.

-Mindgame

That is the piston I'm currently running...I got them from Diamond. There are about the same cost as a "better" (i.e., good, better, best) off the shelf piston. I'm running 14 psi boost and speedpro rings with no problems. They actually have more material above the first ring (comparison between JE -28cc 383 6" rod -vs- Diamond -12cc 396 6" rod) and longer skirts.

I bought the SRP's and had the block bored .030. It didn't clean up adequately in 2 cylinders. The shop says that .040 over should get me there. RSKRAUSE, you are right, .060 is not where I want to go. I did have the block acid dipped, and have a half fill of rock block for strength, and water jacket/oil pan rail problems with clearancing. I was hoping SRP made .040 ones off the shelf so I could just trade them up. I guess I'm in the custom made area now. Suppose I could just get a new block to work with or sleeve this one.

sleeving = leaking ;)

I bought the SRP's and had the block bored .030. It didn't clean up adequately in 2 cylinders.

I would not be a happy camper. What are they checking bore wear/taper with, an old Folgers can?

Get the shop to pay for the pistons. I'd let them have the .030's for another build if they'd pay.

-Mindgame

Thats why I always hone on the bad cylinders before getting pistons! I've not seen many LTx engine not clean up at 4.030 though!!!

they all make any pistons but get the walle tout.i just bought mine for my 427 stroker,660 for the set

I've seen em not get put into the right spot relative to the crank at .030" but not clean up... WTF happened to that core?

I've seen em not get put into the right spot relative to the crank at .030" but not clean up... WTF happened to that core?

I never bore a good standard bore block usually since I can hone .030 in no time plus I immediately know what is going on with the block then. With modern hone jobs and moly rings and EFI we usually don't see much ring groove wear in modern blocks though anymore compared to the old days with the carb stuff. Those would be eaten up and they all had better rod ratios and taller pistons! Shows you how much that matters.

It was a small piece of sand or something that apparently got into the cast. Just bad luck. I'm looking at a set of Wiseco's for a 5.85 rod right now. Just need to get the rods to use them. It's just money man right!:(

Depending on what you are going to do with the motor 5.85 might be a blessing anyway. With that stroke and a 6" rod the pin ends up awefully high crowding the ringpack, 5.85s give them a little more room.

We use Diamond pistons on the last one. they had 4.040 and 4.060. We Were using 5.85 rods. there were more options for the 6.00 rod BTW.

I never bore a good standard bore block usually since I can hone .030 in no time plus I immediately know what is going on with the block then. With modern hone jobs and moly rings and EFI we usually don't see much ring groove wear in modern blocks though anymore compared to the old days with the carb stuff. Those would be eaten up and they all had better rod ratios and taller pistons! Shows you how much that matters.


Eric,

I was talking about the placement of the bore relative to where it should be in terms of the crank centerline. A lot of the time the V will not be exactly at 90° or each bank might be shifted to or away from the thrust side of the block.... last one I had done was shifted .008-.009 on one side and .012-.014 on the other, that means you gotta run them where they are on a .030 overbore or go to a .040 and fix the placement. (Guys if the bore centerline is moved .014 that means that it's not going to clean up with a .030 bore because you cut .015 off each side of the centerline) Can't do that with a hone... maybe I would do that on a CNC Bowtie since the bores are in the right spots.

I know the hones today can take material out quick but don't you get some ****ty stone life doing so?

Bret

You can always run a 5.75" rod, then you can run 383 6" rod pistons... 1.125" CH.

Lunati has some shelf Pro Mod Rods that are that length, or get some Carrillos!

Bret

I know the hones today can take material out quick but don't you get some ****ty stone life doing so?

Bret

You use the appropriate stones which are made for roughing or fast stock removal. They look like gravel almost (70 grit)! I do this to get out to about .005 away and then go back to finer grits.

Thanks, Just interesting to see how different people do it.

Bret

I can take that initial .020 out about as fast as boring anyway considering that I do not have to change machines between operations. If I'm taking a lot out or it's a hard block like a Bowtie, SVO or Dart etc. I will bore it then of course or if it's a block I know, or think, might have crooked cylinders. Like everything it depends. Also many true race shops like honing a lot of material out when you have a real hone as the bores get rounder and rounder the longer they are honed. With the right measuring equipment you will see it but few people have anything other than a dial bore gauge so they can only see points at a time. If you have anything other than a Sunnen hone it might NEED to be honed at least .020 to get really round anyway.

JE makes a piston that is .012 shorter on the C.H. I think the part number is 181909. The piston is for a 3.5 stroke 6.250 rod and comes close to what you need. I was in the same situation a couple months ago and ran across these. Just be careful to not cut too much off the deck so your intake will still fit right.

Tim

I looked into that...The skirts will hit the counterweights. I've already surrendered and found a new block. I thank everyone for their help/recommendations.