rspears9

my car is a 95 z28,it dropped a valve today,i heard a real bad sound and car shut down.i took the driverside valve cover off and the spring was broke and the valve was gone down the head,is this bad,and how hard is the driver side head to take off.

SpeedDensityZ

iTrader: (5)

Yes, real bad. It isn't that bad if you have the right tools.

rspears9

my engine just has 2800 miles on fresh forged internals,it also has a comp cam with 500 lift,but it was already installed,but apparently the guy didnt switch the springs out,i had alreay changed to 2 and had the rest to finish another day,but this happened,i hop it didnt bust my probe forged piston.

Formula350

iTrader: (3)

It's less a point of not switching out springs (he would've had to for that cam), but more of did he install them right or use quality locks? A spring can collapse and that I think is generally what happens when they get old, but I suppose it can cause enough slack for the locks to fall out. Now, if the builder didn't install them correctly and it wasn't seated all the way in the retainer, it could've wore into either the valve or retainer and then finally created enough room to come out :\

I would say that you're going to need a new head (that's a lot of metal inside the combustion chamber), a new piston, possibly a new rod and if you're very very lucky your block will be salvageable. As to you 'hope' of not damaging the piston, even if it doesn't have a hole in it, it's definitely damaged heh Damaged enough that it can create a hot spot and melt it later on.

I'd be on the horn with your builder tomorrow and chewing him out. Hopefully you have a receipt of all that went into the motor, and if he didn't put in new springs, ream him hard and tell him you're informing everyone to stay clear of his shop. Then again I might be misunderstanding you and you bought the car/motor as it is. :\

Good luck man, sorry to hear of your misfortune :\

Camaro Jearmy

Yea, most likely you ruined the piston, i've had it happen in two instances and both times the piston expanded enough it cracked the cylinder, so either sleeve it or find another block, it will most likely bent the rod to. Even being forged. like ^ said, probably ruined the head to. Sucks!

rspears9

it wasnt nothing the builder done,all of that was good,the boy that i bought car from said he put new springs with the roller rock lifters,and cam.but all of a sudden few of the springs broke,we replaced them today,and i told my friend i would change the rest out this weekend,all of those were on the passenger side,but the dropped valve and broke spring was on the driver side this time.

marc97taws6

iTrader: (6)

That officially sucks!

Look for some major downtime and engine work.. sorry!

ElkySS

iTrader: (6)

if it only has that many miles on it id be calling my engine builder and bitching him the hell out

shbox

Your probably looking at replacement of several major items, including the block. It would be unusual for the block to escape damage from a dropped valve.

rspears9

im going to go ahead and look for heads,what casting# would the the 95z28 have

Puck

iTrader: (17)

Did you examine the block and tear everything down?

Sorry to say, but that engine is probably toast. Dropping a valve usually equals catastrophic failure beyond the point of being feasable to repair. I would look for another shortblock then swap everything that is inspected and found to be good from your engine into it.

rusty2198

call your builder and make him fix it

Formula350

iTrader: (3)

Doesn't matter, just make sure you get aluminum ones You don't HAVE to, they can be the cast iron ones as they flow more, but the heat soak will probably negate the performance gain from better flow.

And as Puck said, might as well not buy anything until you find out how extensive the damage is. If it's block, heads, and rod, well you might as well find a used short block. You'll get the heads and block you'd need, and then you can have it punched out to what you need for the 7 remaining good rods/pistons, which will mean you only need to buy another rod and piston to finish it off. I'd totally ditch every spring, lock and retainer from that blown motor, just to be sure.

When you do the springs on the new head/s, after you installed the locks and they're in, hit them with a rubber mallet to make sure they're seated (with decent force, but not overboard!). Trick my shop teacher taught us. (old school guy and knew his **** so hush lol)

Camaro Jearmy

sleeving that cylinder is always an option. Save the price of buying another block, cost about the same as getting a new block you buy bored.

rspears9

the blocked was bored 30 over before.can i have that cylinder sleeved and rebored to 30 0ver,what kind of cost would that be.

Formula350

iTrader: (3)

It may be cheaper to just find a new block and have it punched, but I don't know.

Camaro Jearmy

you can have only that cylinder sleeved. probably looking at under 200$, a sleeve is about 70-80$, so depends what a shop charges you to put it in. Shouldn't be more then $100 to put it in. Make sure they loc tite it. Then buy a piston, rod, rings, bearings, and install.

ss.slp.ls1

iTrader: (36)

Listen to Formula350 and Puck. Pick yourself up a new block (you can find blocks for dirt cheap now), have it machined and bored 30 over. You can reuse your undamaged internals, pick up a rod and a piston. Get ALL NEW springs , seats, retainers, & locks. Smack them with a mallet for good measure. '643' and '374' are supposed to be the desirable aluminum castings because they have more meat on them for porting.

rspears9

my friend just called,they hand turn the engine and got valve back up,put new spring,they had to get another pushrod,and roller rocker,installed those parts and car runs like a charm.i prayed all night to god,and so far looks like it helped.

Puck

iTrader: (17)

Are you serious? I would NOT trust an engine that dropped a valve while running.

Think about what was going on inside that cylinder as the piston was traveling hundreds of feet per second with a valve inside it.