Why are forged pistons so bloody expensive?

[Dom]

I really don't understand why?

 

Someone must know

[Conor]

Because creating forged stuff isn't cheap.

 

To forge something you make a mold out of very good steel. You put a plate of the metal you want to forge between the two halves of a mold, and squeeze the mold very hard, as in many tens (and for large things, hundreds) of tons, from a press that may outweigh your house. (The moveable half of the mold is called a "tool"; the stationary half is called a "die.")

 

The metal flows like toothpaste, and when you open the mold, you have your part. A little finishing, and its ready to use. Its an expensive process to set up - the molds are very expensive to make, and the press, while quite simple, is huge, and costs accordingly.

[Fishtailparka]

All the forged stuff down our market is well cheap.

[sambo]

^^^

 

 

LOL!

[BIGKEV]

Lmao

[Dom]

Lol, I asked my bro where the best place to get a set of forged pistons from cos he used to be an engine builder, he just said it's not worth it i'd be better off with a real set.

 

Joker

[Streetfighter]

What are the actual real world benefits of Forged pistons over Cast?

[bmxdave]

They can take more abuse. I always thought it was because of the denser material and the fact it isnt as brittle as anything thats cast.

[Vista]

They can take more abuse. I always thought it was because of the denser material and the fact it isnt as brittle as anything thats cast.

 

What he said.

 

They are much stronger and can withstand much higher compression ratios (high compression = more power). They are also less susceptible to damage from knocking that can be caused by running HC performance engines on the crap pump fuel that we have to put up with.

[Streetfighter]

But ar they really worth £700 on a 120BHP etc road engine?

[Vista]

The question to ask isn't whether they're worth £700 on a 120bhp road engine, it's whether you need them on an engine of that spec.

 

If you're getting 120bhp from an 1100cc high revving motor with high compression and all the bells and whistles then yes definitely! But if it's a warm X -flow or pinto then no you don't.

[Fiesta Steve]

Don't forget they are a shit load lighter than cast

 

I used cast pistons in my Crossflow for over 150 bhp/8500 rpm.

[Toby]

Don't forget they are a shit load lighter than cast

 

 

I always thought cast were lighter as they're less dense and can be cored out more as the forging process can't produce undercuts due to the process.

 

Also I think a cast piston is better in an engine that doesn't NEED forged pistons, they are usually made of a material that expands less so you can get a better bore to piston clearance. Certain designs of cast pistons are better than others though. You want drilled oil ways in them not slots.

 

HC and rev's won't do cast pistons any good, but a well thought out set up a Vista said means cast pistons can be used for quite a high spec engine - like Steve's

[mk1super]

What gets me is that in the states you can get 8 forged pistons, rods and steel crank for like half of what you would pay over here for say the same for a pinto One reason i heard for this is greater demand in the states for such stuff so more mass production = lower prices

[Dom]

Less is more so they say

[Streetfighter]

Shame they've bumped up the importing taxes etc.. Could do with a tonne of Pre Crossflow bits.. Ah well.

[Fiesta Steve]

Don't forget they are a shit load lighter than cast

 

 

I always thought cast were lighter as they're less dense and can be cored out more as the forging process can't produce undercuts due to the process.

 

Also I think a cast piston is better in an engine that doesn't NEED forged pistons, they are usually made of a material that expands less so you can get a better bore to piston clearance. Certain designs of cast pistons are better than others though. You want drilled oil ways in them not slots.

 

HC and rev's won't do cast pistons any good, but a well thought out set up a Vista said means cast pistons can be used for quite a high spec engine - like Steve's

 

They are certainly lighter in the Crossflow but perhaps not in others, probably depends on the original design and crossflow pistons are fookin heavy !