Do what?!

 

what thickness gasket are you running?

 

Thats a suprise you cant get a custom piston to your specs from JE. Wonder if they are trying to shoehorn an existing blank to do the job.

I had a 427 with 4.00 stroke and 6.125 rods

I have since built a 6.0 litre block with the same crank and rods and deck hieght with a CR of less than 8.5:1.

We had a custom dish piston built for this motor, also using SCE Titan series copper gaskets 61 thou thick and the chambers are 72 cc.

They cost me a bomb but it can be done.

 

Nitrorocket, this response is not directed at you, but in a general resonse, by the way..Phone tag, your it.

When I called JE, the salesman, did his basic math, and said they did not make a off the shelf piston for my particular application, that it would have to be custom made. He also stated that the piston would have to go to engineering for final spec.

I am not an engineer by any sort of the imagination, but my feeling here....the same conversation came up with the diamond pistsons that are currently in the car, when I ordered those, Chris @ diamond did not want me to use a 6.125" rod but a 6.100" rod, because with a blown application and the long stroke, he said he wanted a thicker surface for the piston, and to get that the rod had to be shorted so that he did not have to move the wrist pin up into the bottom of the piston. He said it was important to have a certain amount of clearence between the bottom of the piston and the top of the wrist pin. Doing so would have caused the piston surface to be thinner, and my guess is that is a bad deal for a blown application.

When I was talking to JE, the exact same converstation came up, was it a blown app(yes), and was I going to use NOS(no, at least not for power). JE engineering came back and said that the maximum allowable safe CR with my setup which was a 4.00" stroke and 6.125" rod was 9.5:1.

I will try to call again tomorrow.

 

.045 Cometic

 

Forgive me, would not a shorter stroke would allow you to use the same length rod, and have more clearence between te bottom of the pistons deck, and the top of the wrist pin given the same application?

 

Bryan, here is the same physical piston you need. Give JE this job #. This exact piston made 1200 hp on pumpgas and could make alot more. See what they say about that!

JE Custom Forged, SBC400, 18 degree V8
Part Number: 195653
Custom Job Number: 294520
Material: Forged Aluminum 518 D
Bore: 4.125"
Stroke: 4.000"
Rod Length: 6.125"
Dish Depth: .255"
Compression Distance: 1.175"
Compression Ratio: 8.5:1
Valve Pocket Depth: .250", Measured From Deck
Top Ring Groove: .064"
Top Ring Land: .310"
2nd Ring Groove: .064"
2nd Ring Land: .180"
Oil Ring Groove: .218"
Oil Ring Land: .090"
Pin Nomenclature: JE Pro Max Pin
Pin Part Number: JE 92727501793S
Pin Material: Steel Alloy
Pin Diameter: .927"
Pin Length: 2.750"
Pin Retention: Double Spiro Locks
Piston to Cylinder Wall Clearance: .0055"
Measure Clearance: .500" from Bottom of Piston Skirt
Weight (grams) 468

 

I will call them on Monday, and see what they say, left you a message on your answering machine.
Bryan

 

I'm just curious about the 3.00" stroke?!

 

I was generalizing, about the stroke of the stock motor.

 

I apparently made a mistake,

In reading the order form they sent me it says the following
Displacement 428
Piston Type Dish
Bore 4.127
Stroke 4.00
Rod Length 6.125
Dish Depth .160
Compr Dist 1.109
Comp Ratio 9.3 to 1
Acutal Weight 465.

I am satisfied with 9.3 to 1. I am not sure why I kept thinking it was 9.5
However, the new heads will be able to be opened up to 76cc, so that will get me closer to 9.0.

 

Oh, ok...I thought you were saying it was three inches even.