SRP piston question.

[gn69z28]

SRP 212136 is listed as a small dome -23.00 cc dome. Does anyone know the actual height of the dome? I'm trying to find a replacement for a piston with a .095 dome. Don't want compression to change when assembled. Thanks

[BillK]

SRP 212136 is listed as a small dome -23.00 cc dome. Does anyone know the actual height of the dome? I'm trying to find a replacement for a piston with a .095 dome. Don't want compression to change when assembled. Thanks

The height of the dome really does not tell you much about the compression. Too many other variables. Mainly the valve reliefs but also compression hgt. Are you only replacing one piston or a complete set ? If only one do you know the cc of the dome of the present piston ? You really need to know that if you want to make sure that the replacement will be the same compression.

Also dont forget weight of the piston and pin need to be pretty close if you dont want to have balance issues.

[ProPower engines]

So what piston brand and part number are you trying to replace???
If you had that detail this would be simple. BBC pistons are very common but we need the current dome volume.
As Bill mentioned the height has little to do with it between the V/relief volume off setting the dome volume the height has not much to do with anything.

[gn69z28]

What I have now are forged pistons from a marine engine that the owner is putting in a truck. There are no numbers on the current pistons. Measuring the dome with a depth mic I have a .095 dome height. These are the pistons that came in the engine from Chevrolet. The owner wants to bore block and get new pistons that will give him the same compression ratio he had with old pistons. I do not know the cc's of the old pistons. I'm sorry but that's all the info I have.

[bobmc]

SRP 306725 looks like a similar fit for your pistons

[Lillibridge]

Is there a way of knowing for certain without actually trying them on?

[BillK]

Have you cleaned the pistons real good ? I have never seen a GM or Mercruiser Marine 454 without a number on the pistons. It might be on the underside or on the pin boss. If not can you post a picture of the existing piston ?

[pdq67]

Isn't a .095" domed BBC piston usually a 9 to 9.5 to 1 CR?

And I do know that way more info is needed too!

Engine size;
Bore;
Stroke;
Compression height;
Valve notch CC;
Open or closed chamber;
Head gasket thickness;

pdq67

[DCal]

Nowhere did I see you say if its a BBC or SBC, if its around 4.468 bore it is a CPC502 . JE probably made a million of them , the overbore replacement is pt# 281919. Check the bore first so that we know what engine we're dealing with. I think the dome is only 8cc and it looks like a closed chamber dome not an open.

[gn69z28]

Piston has been cleaned and no stampings anywhere. Sealed power number L2399AF is the same as this piston but customer is looking at SRP and Wiesco online so I was just trying to find one of those close to what he has. I forgot how to post a picture on this site.

[piston guy]

The dome height is about .250 tall on that part number. 212136 is a 4.310 bore +23 dome for a stock rod and 4" stroke crankshaft. CR is 10-1 with a 118cc head at zero deck.

[BillK]

Piston has been cleaned and no stampings anywhere. Sealed power number L2399AF is the same as this piston

If what you have is an L2399 then it is a 13.8 cc dome so the SRP will be quite a bit more compression if it is 23cc

[ProPower engines]

Piston has been cleaned and no stampings anywhere. Sealed power number L2399AF is the same as this piston but customer is looking at SRP and Wiesco online so I was just trying to find one of those close to what he has. I forgot how to post a picture on this site.

From the description it must be an LS-6 piston for 454 BBC as I thought.
This must be a job your are not real familiar with so here ya go some things you will need to get before you can get pistons.
1st is what is the chamber volume of the head your going to use??? Or a casting number will get a close place to start.
2nd what rod length is being used??? Stock rod 6.135"??? the compression height of the pistons that were in the block will need to be confirmed to get a piston with a close enough compression height so the block does not need a ton cut from the decks to get back to where it started from. If you pick up the phone and call the tech line with the part number of the original piston they will be able to tell you all this info 800 325 8886 ext. 2 on the voice prompts tell them the part number.

After you get the details above then it will be easier to move forward with a choice if he don't want to just use the same style piston.
If this is a marine engine he would be better off going back to what he had to start with.
If its only about cost there is a hypereutectic duplicate also available from Speed Pro/ Sealed Power as well that uses a standard run of the mill 5/56 5/65 3/16 moly ring set.

[pdq67]

So this is what we are talking about. Right!

"Brand: Sportsman Racing Products
Manufacturer's Part Number: 212136
Part Type: Pistons
Product Line: SRP Big Block Chevy Small Dome Profile Pistons
Summit Racing Part Number: SRP-212136-8
Piston Rings Included: No
Bore (in): 4.310 in.
Bore (mm): 109.474mm
Stroke: 4.000 in.
Engine Stroke Type: Stock/Stroked
Rod Length: 6.135 in.
Piston Style: Dome, with two valve reliefs
Piston Material: Forged aluminum
Compression Height (in): 1.645 in.
Piston Head Volume (cc): -23.00cc
Wrist Pin Style: Press-fit or floating
Wrist Pin Retainers Included: No
Wrist Pin Included: Yes
Pin Diameter (in): 0.990 in.
Piston Ring Thickness: 1/16 in. x 1/16 in. x 3/16 in.
File Fit: No
Gapless: No
Quantity: Sold as a set of 8.
In-Store Pickup: Choose In-store pick-up (OH, NV, GA, TX) on our web site.
Calculator Compression Calculator
Tool Stroker Combinations

SRP big block Chevy small dome profile pistons are designed to fit Edelbrock 110cc and GM Signature series heads. They're 4032 low-expansion, high-silicon aluminum alloy that's heat-treated to SRP specifications. CNC-machined domes with radiused valve reliefs provide optimum flame travel. They include a pin fitting, double Spiro locks, and a wall wrist pin. Their CNC-machined ring grooves accept 1/16, 1/16, 3/16 rings and their closed chamber accepts 5/64, 5/64, 3/16 rings. Pin upgrades are available. "

pdq67

[ProPower engines]

So this is what we are talking about. Right!

"Brand: Sportsman Racing Products
Manufacturer's Part Number: 212136
Part Type: Pistons
Product Line: SRP Big Block Chevy Small Dome Profile Pistons
Summit Racing Part Number: SRP-212136-8
Piston Rings Included: No
Bore (in): 4.310 in.
Bore (mm): 109.474mm
Stroke: 4.000 in.
Engine Stroke Type: Stock/Stroked
Rod Length: 6.135 in.
Piston Style: Dome, with two valve reliefs
Piston Material: Forged aluminum
Compression Height (in): 1.645 in.
Piston Head Volume (cc): -23.00cc
Wrist Pin Style: Press-fit or floating
Wrist Pin Retainers Included: No
Wrist Pin Included: Yes
Pin Diameter (in): 0.990 in.
Piston Ring Thickness: 1/16 in. x 1/16 in. x 3/16 in.
File Fit: No
Gapless: No
Quantity: Sold as a set of 8.
In-Store Pickup: Choose In-store pick-up (OH, NV, GA, TX) on our web site.
Calculator Compression Calculator
Tool Stroker Combinations

SRP big block Chevy small dome profile pistons are designed to fit Edelbrock 110cc and GM Signature series heads. They're 4032 low-expansion, high-silicon aluminum alloy that's heat-treated to SRP specifications. CNC-machined domes with radiused valve reliefs provide optimum flame travel. They include a pin fitting, double Spiro locks, and a wall wrist pin. Their CNC-machined ring grooves accept 1/16, 1/16, 3/16 rings and their closed chamber accepts 5/64, 5/64, 3/16 rings. Pin upgrades are available. "

pdq67

Thats what he was asking about but its wrong as a direct replacement for what is currently in the engine.
OP stated his customer wants to go with JE/SRP or Wiseco but does not have the same dome volume option as the OE.

He still needs to answer the other questions like what head is being used or chamber volume to get a piston to suit and still be between 9-9.5 to 1 comp. that said he has more home work to do before he can choose a piston.

He has some basic engine math problems to look at so he can select a piston with suitable dome volume to keep things the same as before.