Pistons for 406
Thread Starter
Racer
Joined: Oct 2006
Posts: 269
Likes: 7
Pistons for 406
I am purchasing a 406 rotating assembly and I am having trouble finding forged pistons that will give me over a 10:1 CR. I am using cast iron heads and an OEM block that has not been zero decked. The bore size is 4.155 and I will be using 6" rods.
I want to be at least 10.5 but not over 11.0. So far I have looked at SRP, Federal Mogul and Wiseco. Any suggestions would be greatly appreciated.
I want to be at least 10.5 but not over 11.0. So far I have looked at SRP, Federal Mogul and Wiseco. Any suggestions would be greatly appreciated.
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
For the money, Probe forged pistons are great. They'll have the pison you want. Check them out:
http://www.probeindustries.com/Pistons/pistons.htm
http://www.probeindustries.com/Pistons/pistons.htm
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
I am purchasing a 406 rotating assembly and I am having trouble finding forged pistons that will give me over a 10:1 CR. I am using cast iron heads and an OEM block that has not been zero decked. The bore size is 4.155 and I will be using 6" rods.
I want to be at least 10.5 but not over 11.0. So far I have looked at SRP, Federal Mogul and Wiseco. Any suggestions would be greatly appreciated.
I want to be at least 10.5 but not over 11.0. So far I have looked at SRP, Federal Mogul and Wiseco. Any suggestions would be greatly appreciated.
- How many cc is the combustion chamber of your Iron head?
- Why do you want at least 10.5:1 scr w/ Iron head 406?
- What octane fuel will you routinely use?
- What's this motor's primary purpose? Street, Drag? etc
- What cam profile?
- Carb of FI?
Thread Starter
Racer
Joined: Oct 2006
Posts: 269
Likes: 7
I want to go as high as possible with the scr because I intend to upgrade to aluminum heads in the future
I will use 94 octane or if necessary I have access to race fuel
It will be primarily a street motor, may go to track once or twice
Cam is a Lunati 60103 - duration 227 in 233 ex lift 495 in 510 ex
Will be using a reworked Qjet hopefully a Lars rebuild
Race Director
Joined: Jul 2004
Posts: 12,696
Likes: 329
From: Scottsdale Arizona
The combustion chamber is 64cc pocket ported 3927186 camel hump w/ 2.02 - 1.60 valves
I want to go as high as possible with the scr because I intend to upgrade to aluminum heads in the future
I will use 94 octane or if necessary I have access to race fuel
It will be primarily a street motor, may go to track once or twice
Cam is a Lunati 60103 - duration 227 in 233 ex lift 495 in 510 ex
Will be using a reworked Qjet hopefully a Lars rebuild
I want to go as high as possible with the scr because I intend to upgrade to aluminum heads in the future
I will use 94 octane or if necessary I have access to race fuel
It will be primarily a street motor, may go to track once or twice
Cam is a Lunati 60103 - duration 227 in 233 ex lift 495 in 510 ex
Will be using a reworked Qjet hopefully a Lars rebuild
This is VERY similar to an engine that I just finished building (installing this weekend hopefully).
Here's the post where I chose the same cam:
http://forums.corvetteforum.com/show....php?t=1654716
The pistons that I had were stock replacements with a 12.5 cc dish. Based on my calculations, the SCR was 10.1 to 1. With the aluminumb heads, I'm hoping this beast will run on pump gas.
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Safety Car
Joined: Mar 2000
Posts: 4,077
Likes: 27
From: Northeast South Dakota
I found that finding a piston for my 406 with a lower compression ratio (lower being under 10:1) and any longer than stock rod is a very expensive proposition. I ended up going with a 5.7 rod and using a federal mogul powerforged piston but then had to use a 72 cc chamber head to keep the compression down. I am running around 10.25:1 CR on pump gas. My cam specs aren't coming to me right now. (My cam card is in my desk at work)
-Justin
-Justin
Thread Starter
Racer
Joined: Oct 2006
Posts: 269
Likes: 7
I finally found a Wiseco flat top forged piston# PT020H3 that they have listed as 11.4. Their c/r is based on .010 deck height and a .038 gasket. If I then calculate compression using a Felpro 1044 .051 gasket, assume a stock .025 deck height and -5.4 dome volume I get a 10.6 c/r with the Wiseco piston.
That is as high as I want to go.
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
I went with Diamond on my 406 build. They will allow one modification to piston design without a "custom" fee. In my case, I modified the compression height.
http://www.diamondracing.net/products.asp
http://www.diamondracing.net/products.asp
