Check out the glory that is my custom pistons

[Nightmare302]

My own custom pistons. Important specs are .280 top down, .200 skirt thickness. These are some super beefy pistons. 436 grams of pure CP/Real Street Performance epicness. Going into my new setup, shooting for 1krwhp through a th400.

 

[oldmodman]

I couldn't tell from the picture. Do you have to run a support rail for the oil ring?

And what (and whose) rings did you decide to go with?

Have you weighed them? Last set of CP pistons I worked with were absolutely dead on from piston to piston with weight. No adjustments needed.

 

[Nightmare302]

I couldn't tell from the picture. Do you have to run a support rail for the oil ring?

And what (and whose) rings did you decide to go with?

Have you weighed them? Last set of CP pistons I worked with were absolutely dead on from piston to piston with weight. No adjustments needed.

I do not. I went with Total Seal Steel rings with a custom napier cut second ring. These are custom bore pistons at 3.560 so it will make for a nice and high oil tension as well. I went with Trend H13 tool steel .200 wall wrist pins as well. With the Manley billet rods this thing should not even break a sweat at 1000rwhp.

 

[Oiljunkie]

The most beautiful part of a built engine that you never get to see again. High end slugs are a thing of beauty

 

[MTBSully]

Very nice. Who is building the engine? You? Make a build thread!

 

[Nightmare302]

Very nice. Who is building the engine? You? Make a build thread!

Siebert performance is doing the machine work. I'm putting it together.

 

[JP0814GT]

Beefy Nice pistons! CP's are good stuff.

 

[Arrickh]

You only need to upgrade pistons for around 1k rwhp anyway right? kinda new to having a termi!

 

[Nightmare302]

You only need to upgrade pistons for around 1k rwhp anyway right? kinda new to having a termi!

I would never run factory pistons and expect them to survive at that kind of horsepower. Even off the shelf mod motor pistons I would not trust at the hp level.

 

[Nightmare302]

Got out the caliper today, measured at .201 skirt thickness and .280 top down. Ring package is 1.5 1.5 3.0. After much discussion I had Real Street Performance make a SKU for these pistons. We are working on getting the custom napier cut ring package as well. This puts the bore at 3.560 meaning almost any stock bore car can use this and not go all the way out to .20 over bore leaving a lot more material in the block while still being able to remove almost any imperfections in a bore. Secondly the skirt on these is almost twice as thick as a probe piston and 1/3 thicker than a diamond piston. They also come with a double pin oiler. These pistons are significantly stronger than ANY off the shelf combo you can find. With the total seal rings you will also get a solid ~13lbs of oil tension, perfect for boosted vehicles. Put a solid wrist pin in here (I used Trend H13 tool steel .200 wall) and you have a serious serious setup. I can put anyone in touch with the man if they would like to order these.

 

[Nolimit]

Now for the big ? Price?

 

[Nightmare302]

Now for the big ? Price?

We are waiting to hear back from total seal for the custom ring package price. To be honest the rings killed me when I had them setup, but if Real Street can work something out it will be extremely affordable.

 

[MalcolmV8]

What ring gap are you going with?

 

[SlowSVT]

436 grams is getting a bit on the heafty side. The .200 wall wristpin will add even more. That will put more loading on the rods.

When I bought my pistons from CP all I told them was I wanted a 23cc "blower" piston for a Boss block this is what they sent me. .300 top down ring, .165 skirts, .180 wall wrist pins. They all weighed 399 grams.

Modmax pistons weighed a whopping 455 grams

CP's are very nice pistons.

 

[SID297]

beefy

 

[Nightmare302]

436 grams is getting a bit on the heafty side. The .200 wall wristpin will add even more. That will put more loading on the rods.

When I bought my pistons from CP all I told them was I wanted a 23cc "blower" piston for a Boss block this is what they sent me. .300 top down ring, .165 skirts, .180 wall wrist pins. They all weighed 399 grams.

Modmax pistons weighed a whopping 455 grams

CP's are very nice pistons.

A billet manley rod will have zero issues with the extra weight. I'd MUCH prefer a thick skirt and wrist pin over some "weight savings". If this was an all out NA car I would agree. .180 Tool steel will also work on a blower combo as they typically don't have the same RPM stress associated with turbo cars I however would want a much thicker skirt.

 

[MalcolmV8]

My new Diamond pistons are 402 ~ 403 grams. They are also complete circles at the bottom, I'd never seen that before.

 

[SlowSVT]

A billet manley rod will have zero issues with the extra weight. I'd MUCH prefer a thick skirt and wrist pin over some "weight savings". If this was an all out NA car I would agree. .180 Tool steel will also work on a blower combo as they typically don't have the same RPM stress associated with turbo cars I however would want a much thicker skirt.

A thick walled piston is great for heat transfer and strength. If the engine is going to see huge boost #'s I would lean toward a heavier (walled) piston. The problem is adding mass to the reciprocation assembly results in higher loading on the rods, wrist pins, bearings and will impose more parasitic loss accelerating and decelerating the pistons as they go "up" & "down". An engine with lighter pistons will rev quicker, higher and should register a few more ponies at the rear wheels as the motor climes the scale. Chances are you won't blow your engine running heavier piston but the bottom end will be more stressed than with lighter slugs I would be more reluctant spinning them for any period of time at high rpm. Bottom end failures in a mod motor are almost "non-existant" anyhow I have never seen one throw a rod but at some point the benefit of the added mass starts to diminish. It's a "give & take" situation, you add beef at the expense of added weight.

I bought my CP's through Modmax of all places. Originally I was going to buy Manely's which were at a great price, spec'd out well and were "off-the-shelf". I had second thoughts after ordering the Manley's and decided to get a set of custom piston from either Diamond or CP. Modmax carries just about every major mfg so they were OK with changing the order. The tech at Modmax was very knowledgeable about pistons as he's dealt with so many brands and what was successful and what wasn't. Both the CP's and Diamond had a feature or two that the other lacked and I had some difficulty deciding which set to buy. The tech explained both were very good piston with the nod going to CP for finish. I knew how I wanted the piston spec'd regarding ring location, dome thickness as well as some of the other options CP offers and was explaining to the tech what I was looking for and how they would be used. His recommendation was just to specify the engine config, how the car was to be used and let them build the piston. At one point he stated: "CP takes great pride in their work and it shows! It is dangerous telling people who make pistons for a living how to make pistons!". That made a lot of sense, my response was " I need a blower piston for a 3.700 bore 5.0 Boss block running 16 lbs on pump swill for a street car with a 23cc dish" and the piston pictured above is what they sent me

CP does (or didn't) offer any kind of coating what so ever which was fine by me, just pain Jane bare aluminum, no anodizing, no Teflon coating, no ceramic crowns (which you should never do in an FI engine). Bare aluminum skirts will maximize the heat transfer to the wall, anodize or a layer of polymer won't.

My engine will be equipped with Oliver rods and PAC springs and should spin comfortably to 8K. I think the pistons in this engine are at a pretty good "happy point" with regard the piston config. No matter how you slice it CP makes a very nice piston but they are expensive.

Are there valve relief in the crowns? What are you setting the PWC at?

 

[Nightmare302]

I plan to push 25+ lbs of boost. The piston is set to handle 1krwhp and well beyond thus the reason for the large wrist pins as well. I'll be running Brian Tooley springs. They have intake reliefs, and that's still being discussed. Most people suggest bore x .007

 

[SlowSVT]

I plan to push 25+ lbs of boost. The piston is set to handle 1krwhp and well beyond thus the reason for the large wrist pins as well. I'll be running Brian Tooley springs. They have intake reliefs, and that's still being discussed. Most people suggest bore x .007

That's going to be a pretty steep engine. Sounds like you go the right slugs for the job. I try to avoid reliefs but that limits your choice of cams. The reliefs are the first place the pistons will fail if they are inclined to do so. .007 is pretty loose, is that what they are subscribing for your engine? CP recommended .0045 I am going to hone for .0035. My engine will be running on pump gas and won't be anywhere near what your building but .007 seems a little excessive.