vettenuts

iTrader: (4)

Clean off the carbon (I used a chopstick so it didn't scratch the piston and a scotchbrite pad with a little denatured alcohol) then use some dye penetrant. That's about all you can do.

PREDATOR-Z

Shrt of dissasembling, no.
You can check compression after you put it back together. If you're doing the work yourself, you'll loose mostly labor time and some fluids/sealant. Cometics are reusable, your heads would be fixed.

Just clean the pistons with mineral spirit and use a magnifier with UV light to see if anything is visible from the top at TDC.

hammertime

iTrader: (1)

That would be tough with the head off. Even after you assemble it, a compression leakdown test would help, but you ideally want to run it on a hot engine.

On another note, is ETP sending you new springs, or are you sending the heads to them? Perhaps they can check the guide and replace the valve for you. Either way, props to them for volunteering to replace the springs.

PREDATOR-Z

IMO they should take the heads back and fix everything, including shipping back and forth.

Detroitmuscle

iTrader: (16)

I completely agree seeing as they told me they had many problems with these springs breaking. I actually live about 45 minutes away from them so I was planning on taking the heads to them myself. I'm gonna clean off the piston best I can and try to see if there is a crack also probably do a leakdown test as well when its back together, hopefully it won't be all that work for nothing.

Proud2bSS

iTrader: (2)

I don't know whether you say that half seriously and/or half jokingly, but I have seen more damage from the breaking of a single spring setup. He could very easily be replacing a lot more than just a valve and spring.

When it comes to fixing this, leave no stone unturned. As others have said, check the cam, lifter, piston. There are more than a few people who have "assumed" that the rest "should be okay", only to discover that they are now having to rebuild because something let go that was not checked. Realistically, I "doubt" you have "hidden", but I am pretty **** about checking stuff as "insurance". me----> <----me

ShevrolayZ28

iTrader: (4)

I see some of the sring broke off. Try to locate that piece and remove it from the engine.

Proud2B, I'm pretty sure it was said faceciously. This failure indicates that the dual spring most likely prevented a catastrophic failure, the dropping of the valve.

Detroitmuscle

iTrader: (16)

I will be sure to examine everything thanks for the great information guys I really appreciate it all. Just out of curiosity how much would you figure a forged 347 (nitrous motor) would run me if I handed the short block off to a local shop?

Proud2bSS

iTrader: (2)

Depends a lot on the parts themselves. Are you talking "forged" as in just pistons, or forged as in "crank, rods, pistons"? I like the thrill of the hunt. It would be better to ask some local shops what they would charge for the build (machine work, assembly) and then price the parts (pistons, rings...and if applicable...rods, crank, etc.) It's just me, but that's my style for building a motor, cuz I'm an old school 50+ year old who loves to maximize his $$s. Plus I would rather spend $500-$1000 on the tools (ie hoist, engine stand, etc) to do it myself than pay the shop for them to have fun. But I'm weird that way.

Detroitmuscle

iTrader: (16)

Can I build a reliable forged motor with rods and pistons (stock crank)? The most I would ever run would be a 200 shot but probably just 150 for a while.

PREDATOR-Z

Yeap, you can.
3.903 bore
6.125 rods
3.622 crank (micropolished), you could even nitrate the crank and shoot 400 on it if you want.

Detroitmuscle

iTrader: (16)

Any ideas of prices on the whole thing? Can it be done for under 2K?

david vericker

iTrader: (1)

yes parts only - machining and assembly will run you considerably more. 5.5K total if your lucky.

erikthegoalie

iTrader: (29)

hell that actuall looks cool, now you have a guide to flycut with , we should all BE so lucky hahah

Beast96Z

iTrader: (21)

For a 347? $2500-3k tops......$5.5 will get you a bad *** stroker motor.

DONAIMIAN

iTrader: (18)

Are you kidding, you can get a forged 347 for under 3k without a core.

Detroitmuscle

iTrader: (16)

Thats more of what I wanted to hear how much does assembly usually run? I figure I can do pretty much everything myself to save some coin aside from the machine work but I really wouldn't wanna risk this kind of cash learning how to build my first motor. Machine work should run no more than $400 and the rods and pistons are about $1000 so if I could find a shop to do the assembly under $1000 I'd be very happy.

Specialized

iTrader: (15)

Damn, if it's that cheap, I might be just getting some forged pistons and getting my block overbored this summer.


Hello direct port. I even have a spare intake manifold to start designing plumbings on.

slowassta

iTrader: (12)

i built my forged 347 bottom end for about $1425

forged h-beam rods and mahle pistons... $750
machining the block and crank.... $350 (included cam bearings and install)
balancing the rotating assembly... $175
rod and crank bearings... $150


i saved a few $$$ assembling it myself and file fitting my rings

slowassta

iTrader: (12)

blueprinted and assembled i was quoted $400 at a very reputable engine builder