Cracked Forgies??? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

UCNTRY · 11-17-2004, 03:21

hey guys just want to know if anyone has ever heard of cracking forgies i just got my new motor it is a 351 with 4mab crank arp rod bolts standard shot peened rods some sought of forgies its .30 over and has been decked to some height with 2v closed chambers that have been polished single valve springs with collets and retainers can you tell me whether you reckon it is possible the pistons are cracked as previous owner has said they are and can you also tell me what sought of block it is JG41ML26734K thanks guys any answers would be appreciated

TTNOS8 · 11-17-2004, 04:11

Yes they can crack.

brenx · 11-17-2004, 05:03

Detonation can crack anything.

Brenden

azza · 11-17-2004, 14:56

do you need forgies in your engine? if you need to pull it down i'd recomend not to put them back in i am using kb signature series hypers in my new engine but many other good brands out there acl race series are quite good from what i here. how noisy is the engine on start up as?
AZZA

TTNOS8 · 11-17-2004, 15:14

Isn't the engine boosted?

Forgies probably aren't bad insurance

brenx · 11-17-2004, 15:24

Quote:

Originally Posted by azza

do you need forgies in your engine? if you need to pull it down i'd recomend not to put them back in i am using kb signature series hypers in my new engine but many other good brands out there acl race series are quite good from what i here. how noisy is the engine on start up as?
AZZA

If forgies were noisey on startup? So would have hypers. It's called piston slap. More common with LS1's. It's not unheard of with a clevo but it's not a good practise to rev a clevo with piston slap. Piston slap is cause by bad clearancing (too much clearance).

I run forged pistons without any issues. I run them due to my 11.2:1 compression. Hypers supposedly aren't made to take more than 10.5:1 punishment? I honestly can't see why but I am not an mechanical engineer.

Brenden

TTNOS8 · 11-17-2004, 20:53

Brenden,

Agreed. But forged do require slightly more clearnace due to their tiny bit more expansion. Depending on what type. We're not talking much here, but hey.

I had always been told that forged require more warm up time/ or gentler warm up.

Hopefully hypers can take more than 10.5:1 punishment as I'm around 10.4:1 with gas?

Time will tell I suppose. But at this stage I'm on your side saying why not??

Back to the original post, why did the previous owner think the pistons were cracked?

brenx · 11-17-2004, 21:25

These days with machining equipment etc there is no excuse for piston slap.

I let mine hit 60deg C from there on in it has hell to pay. ROFL.

Brenden

UCNTRY · 11-17-2004, 23:45

hey guys the previous owner bought the engine ioff another fella who said they were cracked neither me or the previous owner have heard the engine started only been told so i am speculating to pull it down but yeah i dont no much about the state of the pistons at the moment and have got a set of hyper's lined up if needed they are a set of sterling high performance pistons model number h555p if anyone knows anything about these pistons could they please share it and also can someone tell me what sought of block i have

UCNTRY · 11-18-2004, 02:21

some comments guys