Engine

[Slyclone]

So i finally got a chance to rip down the block last night. I discovered that cyl # 3 piston cracked.

Can anyone tell me anything about stock pistons? are they forged. if so the forging had cracked right off. Indicating low compression. injector problems.. ( all from prior owner)

I had block and put it on stand and had examined it before i send it to my machinist.

what i discovered. I called a friend and hes telling me to put forged steel pistons in the thing. not sure if he was smoking crack but if i am wrong, let me know. most of the engines i have taken apart all have had machined alum.

 

[Don W.]

Re: Engine

What do you mean by "forging had cracked right off?"

Pistons are either cast or forged. They are ALL "machined."

Your friend is mistaken. No such thing as a "steel" piston. At least not in the automotive world. Cast alum. Forged alum. And, many years ago, cast iron.

I have a set of stock rods and pistons for sale if you're interested. Won't sell just one though. Pistons are stock bore and in good shape but they are take-outs.

 

[Slyclone]

Re: Engine

I know what you mean i wasnt about to get into a big discussion with him i have never seen one either. He has a ford motor now he built and insisted forged steel.


Top part of piston cracked between compression rings. a few small fragments i noticed at first than i realised there was more to it.


Im not a piston specialist i been looking into a few diffrent Low comression options all are on thr upward of 350-400 for the items.

 

[Sportmachines]

Re: Engine

I believe you are talking about the ring lands. The edges of the pistons will "mushroom' and or crack if there is extreme detonation.

A good set of forged pistons start in the $400-500 range. And if you're going to do the pistons, and machine work, might as well do the rods, etc. You can also go with a replacement stock bottom end using another good stock motor.

HTH

 

[dgoodhue]

Re: Engine

Stock pistons are hypereutectic.

I would not assume it was injector issue that ruined the motor, 3 and 4 are the lean cylinders detonation killed it. It was more likely a tune issue such as leaking vacuum lines, too much boost or the improper fueling/timing. Many of SyTY engine failure could have been prevented by regularly looking at a scan tool, When you repair/replace the motor you will want to monitor the engine with a scan tool to see why detonation killed the last motor.

 

[Slyclone]

Re: Engine

Looking at pistons on Race proven motors, Seem that the ones i need are like 425 w/o rings.

Can anyone direct me to a good piston reasonable price. maby a few other places to look. Need some options here. Im looking to do the .30 over.

 

[dgoodhue]

Re: Engine

Srp are little cheaper than Je pistons. Trw used to make good budget forged piston but they are discontinued. You can search around SBC piston for dished forged piston (5.7 rod) to see if anything has changed. I was surprised to see years ago the selection was pretty limited.

 

[muddbane]

Re: Engine

What do you mean by "forging had cracked right off?"

Pistons are either cast or forged. They are ALL "machined."

Your friend is mistaken. No such thing as a "steel" piston. At least not in the automotive world. Cast alum. Forged alum. And, many years ago, cast iron.

I have a set of stock rods and pistons for sale if you're interested. Won't sell just one though. Pistons are stock bore and in good shape but they are take-outs.

I'm looking for stock std pistons, how much you sell them for?

 

[Don W.]

Re: Engine

I'm looking for stock std pistons, how much you sell them for?

PM sent...

 

[Slyclone]

Re: Engine

So i got a call that my crank checks out, and all that.cylinder walls are good. just looking to do pistons and a rehone. going to probably go with SRP pistons from SYTY performance if my options are that limited.

My thought was whats the deal with the pricing i see there is a variance from 4.00 to 4.20 why is one more can anyone give any imput?

going to start with standard main bearings the pistons, and looking for some connecting rod hardware, Do we know if ARP supplys anything? new rod hardware

Also just looking for some imput on anything before i pull the trigger on my build Thanks