Ford Muscle Cars Tech Forum banner

1 - 20 of 23 Posts

·
Banned
Joined
·
6,355 Posts
Discussion Starter · #1 ·
how many can't tell the difference between a cast and forged piston ?

stop by the cleveland forum once in awhile . the book/net know it members still can't tell .
the part number even has a code to tell the difference for TRW?SpeedPro pistons
 

·
Registered
Joined
·
10,327 Posts
Which Cleve forum Dan? The Network54 one?

David
 

·
Banned
Joined
·
6,355 Posts
Discussion Starter · #3 ·
Which Cleve forum Dan? The Network54 one?

David
yes , the 54 0ne .

where are the other Cleveland forums ? I didn't know of any other C forums
 

·
Premium Member
Joined
·
1,060 Posts
Well for instance, I can tell on you! I can tell when black cat is not an orange cat. I can tell when my fishin bait is gone, I can tell when I'm going to get a run in my paint yet I put more on anyway..... You see? I can tell anything. LOL

Just FE being FE.
 

·
Premium Member
Joined
·
1,060 Posts
From that I know :rolleyes: a cast piston is rougher on the inside and you can see the sharp edges of the castings. A forged piston is smoother and looks more finished. A cast piston is better for low horsepower and forged will take more abuse (detonation etc.) and horsepower. Forged pistons should be used with nitrous, they also expand more with heat so they are looser in the bore. Now maybe PSIG or one of the smart guys on the forum will chime in :).
 

·
Registered
Joined
·
1,786 Posts
What is the PERFORMANCE difference between Cast and Forged pistons?

Sense it seems you are being ignored...... :frown: The forged piston will take more abuse than a cast piston. There is no 'written in stone" hp cutoffs. Its all in the pressures involve. (ie N2O levels, boost levels heat, detonation handling etc)
Why do we have Hyper eutectic, forged and cast pistons? Why not one type????
To confuse the easily confusable folk like you an me ;) think the order of strength is cast is the weakest, then the Hyper then the full blown forged... Altho the hypers are recommended in certain apps.... Now its clear as mud, not to discount the TBC styles avail, in any of the three kinds of pistons.


The pistons in my clev are forged flattops, as it was originally built for a 'heavy' car and LOTS of N2O shots. I bought the whole car just for the engine when the windsor decided to let alot of innards out instead of keeping them in place... And ill say at first start up its a little noisy for the first few minutes of running but not a big deal...

MRO.....
 

·
Registered
Joined
·
10,327 Posts
Without taking a stand on any position, let my describe it this way. There are different ways to design and manufacture pistons, and different materials with various properties to make them with. Each has pros and cons that can be balanced to the application. There are many pros and cons that can be considered. Much like bolts that are non-grade, Grade 2, 5, 8, NAS, AN, SPS, etc. - they each have 'best' applications, as well as cross-over applications. They also have unacceptable applications. So, while you could use an expensive Grade 8 bolt to hold your mailbox up, you should never use one to hold a propeller on an aircraft engine, due to it's physical properties and likelihood of failure in that application.

Pistons are a similar dilemma. Most applications are mundane, any standard design and material will work, and cost is the primary factor. That indicates cast pistons. An analogy would be a glass drinking mug.

Some applications can benefit from reduced slop and greater stability when cold, or greater hot-strength, or greater hardness to resist pressure. These are some of the attributes of higher-cost hypereutectic pistons. The analogy would be a ceramic drinking mug.

Other applications can benefit from custom sizing, ductile resistance to detonation or abusive pre-ignition. Those are some attributes of expensive forged pistons. The analogy would be a drinking mug made of soft lead.

So, while I cannot take the space to list all of the attributes of each type (and various sub-types) here and the 'gray areas' where properties overlap; the selection of piston design and material is very similar to selecting the best bolt for a specific purpose, and the considerations that would accompany that. Hope that helps.

David
 

·
Registered
Joined
·
576 Posts
So for the most part, a run of the mill V8 with a cam and under 400 HP for instance, it wouldn't matter at all what style piston was used?

Am I eating this pie correctly?

(ThanksMOF2U)
My GENERAL rule of thumb is...
STOCK rebuild, cast is no problem...Unless it needs new slugs or bored. In that case Hypers aren't that much higher , so why not spring for them.

Performance build with NO power adders up to the 400ishHP range gets Hypers.

Race build over an expected 400+ gets forged, altho in some applications, Hypers may still be correct.

In any case the machine shop needs to know what you're going to use beforehand for correct clearances and wall finish.
 

·
Premium Member
Joined
·
1,025 Posts
Lets say I want a 300 hp engine but also want a 25-100hp burst of NOS once in awhile, then forged pistons are the way to go?
 
1 - 20 of 23 Posts
Top