tmonttt

iTrader: (10)

To make a short story even shorter, on Tuesday afternoon the valve spring on cylinder 1 intake valve broke. The valve then sheared about 1/4" up the stem above the head of the valve leaving a nice size chunk of metal in the cylinder for the last couple seconds of its life...

When I pulled the driver side valve cover, I found that the outer spring of the PRC .650 duals had split at two different places as well as a the inner spring on cylinder 3 intake valve. After pulling the driver side head off, the damage was obviously quite significant. The heads suffered some mild gouging, and one chuck was taken out of the chamber but will be alleviated by using a tig and heat treating process. The block has absolutely no gouges on the cylinder wall.

I will be re using my PRC LS6 2.5 heads with the torquer V3 cam as well as the LS6 block and going with the following parts that I ordered from Texas Speed today;

TSP 383ci Rotating Assembly
-TSP Forged Crankshaft
-TSP 6.125 H Beams - ARP 2000 bolts
-Wiseco 3.903" -15cc dish Pistons
-Clevite Main & Rod Bearings
-Clevite Cam Bearings
-New LS7 lifters
-OEM GM MLS Headgaskets
-16 x PRC .650 Dual Valve Springs
-16 x PRC Valve Seals
-PRC 2.02" Intake Valve
-PRC 1.57" Exhaust Valve
-Clutch master
-Clutch slave
-Waterpump


Everything will be here Monday, and the motor will be out the car by then as well so that everything can be taken to the machine shop.

If anyone has any recommendations or suggestions of things to do while the motor is out, let me know.

itsslow98

iTrader: (18)

Two things, why -15cc dished pistons on a 383? And now would be a good time to have the trans gone through and freshened up at that mileage. Might be able to justify it as preventative maintenance so its all fresh with the new engine and no chance of putting the car down again for a catastrophic failure.

tmonttt

iTrader: (10)

The reasoning behind the -15cc dished pistons is that it will put me at a 10:1 compression ratio, and I plan on throwing a decent amount of boost at it within the next year or so. If I never had intentions to throw some boost at it, I would of went with a higher compression.

Going through the trans is something I'll add to the list. What's the best deals for something like that? Sending it to Tick or just letting a local transmission shop go through it?

itsslow98

iTrader: (18)

Well it depends who is local. I know Tick and TDP are top notch but if you have someone local I wouldnt fault you for not dealing with shipping.

Good call on the 10:1 if you plan to boost it. Should leave you with a fair amount of options with whatever power adder you decide on.

D.K

iTrader: (1)

Wow! That really sucks! How many miles did you have on those PRCs?

NIKDSC5

iTrader: (10)

This ^ I want to know how long those springs lasted. Also, did you do any investigative work as to what was causing you to burn oil?

punishmentcycle

iTrader: (6)

id say that spring has been broken for a little while...or the guide was worn and let the valve walk around a bit causing the seal to leak

BudRacing

iTrader: (3)

Yeah, this probably could have been avoided if a valve cover would have been pulled to investigate the smoking. Oh well, newly built engine to come!

tmonttt

iTrader: (10)

The valve covers had been off the car multiple times without any signs of what was leading to the smoking. The valve seals had all been inspected as well as the springs, rockers, and pushrods but could never pinpoint where the smoking was coming from.

The spring definitely was not broke prior to this incident. Once the spring broke a very predominate misfire began occurring instantaneously. The car ran for about 45 seconds after the spring broke and that's when the major catastrophe happened. The PRC 2.5 Heads had right at 30k miles on them, which was probably longer than I should of ran the springs before I changed them. I had actually ordered a set of new PRC .650 springs earlier in the week, but I guess time wasn't on my side.

I had been on the fence of going with a forged motor for the car anyways so this incident just pushed me to the other side. I can't say that I'm mad about the situation because this is what I had been wanting to do anyways.

DarkCharisma

Wow, you lucked out that the block survived all that ... Looking forward to following this one. Should be pretty cool.

Ballpark for me the kind of power a 383 stroker has, coming from an LS6? Are there any inherent reliability problems as a result of stroking it?

Steve01SS

iTrader: (43)

Replace the lifter trays. With that mileage im sure they are a lil loose. Gen 4 trays are a better design and are drop in.

New motor = new oil pump. Didnt see one in the list.

Im very surprised theres no cyl damage...lucked out there. Inspect the cam lobes for damage or markings as well.

tmonttt

iTrader: (10)

I was nearly sure that I would need to buy a new block for the build, but was pleasantly surprised when I saw that the cylinder wall still appeared as new, even after all the damage that occurred.

I'm not one to bench race off of numbers, but I would hope the setup puts down at a minimum 450-460 rwhp with the PRC heads and the Torquer V3 cam. Lifter trays were definitely a good call, something I would of missed. As far as the oil pump, I had just put a ported Melling pump in there less than 3000 miles ago, do y'all still suggest that a new one is a must?

The cam will be pulled tonight once the shortblock is out of the car and inspected for any visible damage. I plan on pulling the shortblock out of the car with the trans still attached to it since I want to go through it anyways.

The damaged PRC head was dropped off today to my buddy at the welding shop to repair the bits of damage that occurred. Once the old short block is dissembled and the head is done being repaired, they will both be taken to the machine shop for their portion of the work. Hoping to have the car back up and running within the next couple weeks.

DMM

What type of FI are you contemplating? How much boost? 10:1 is still a bit much for boost, unless you're looking at a max of 5-8 lbs of boost.

How much is having the shortblock built going to cost you compared to getting a mail order one?

tmonttt

iTrader: (10)

I had planned on a single front or rear mounted turbo setup since I have a 76mm Precision turbo that has been sitting around, waiting for me to do something with it. I don't ever really plan to take it further than 10-12 lbs max. I'm really only looking for ~550-600 rwhp and that's down the road. It's a car I daily drive, so I'm not looking for a ***** out build.

If I was to order the same shortblock with the options I had chosen from Texas Speed, it would be $4,074.99 + shipping. Instead, I'm only into the balanced rotating assembly with bearings, rings, steel top rings, etc. for $2,250 shipped + $450 for the machine shop work. Grand total of the short block assembly for $2,700, and that's using my LS6 block opposed to the 5.3 Aluminum block they use.



So here's where I stand as I finished up on the car tonight;

The motor and transmission is out of the car. When I separated the trans from the motor, I did confirm that the car had a Spec clutch in it like the seller had told me. The only downside to this is that he mounted this new clutch to the OEM dual mass flywheel...

Now my question is, can someone shed some light if I can get rid of this dual mass flywheel while still retaining the Spec clutch setup? I realize that it would require a different slave than the OEM one, but which flywheel/slave combo could I use with the Spec clutch? This is one of my top priorities because I damn sure don't want to put the car back together with the dual mass flywheel still in it.

The motor and trans came out surprisingly easy, so that was a nice surprise. Lets just hope it goes back together as easy as it came apart.

01_SuperSlow

iTrader: (7)

Pretty much any single flywheel with a single clutch combo will work with a LS7 slave.
It's best to measure to make sure though.

tmonttt

iTrader: (10)

Could someone link to me a couple single flywheels for the V that would work with the Spec clutch that is already in the car? Could I use an LS7 flywheel with the Spec clutch and Ls7 slave?

FuzzyLog1c

iTrader: (4)

I think so. The Spec clutch is just a powdercoated OEM LS7 clutch. If you're looking for a steel flywheel, F1 Racing sells a 20.4 lb chromoly steel (hardened 4140 alloy steel) flywheel that I beat on for 18,000 miles with no apparent wear.

http://www.ebay.com/itm/F1-FORGED-RACE-LIGHT-FLYWHEEL-CAMARO-SS-CORVETTE-6-0L-LS2-6-2L-LS3-Z06-7-0L-LS7-/161028401060?pt=Motors_Car_Truck_Parts_Accessories&hash=item257e0a67a4&vxp=mtr
Another option would be a 13 lb Fidanza, but they're about $450.

http://www.ebay.com/itm/FIDANZA-FLYWHEEL-05-10-CORVETTE-6-0L-LS2-6-2L-LS3-C6-Z06-7-0L-LS7-2010-CAMARO-SS-/400490237230?pt=Motors_Car_Truck_Parts_Accessories&hash=item5d3f140d2e&vxp=mtr
In both cases, you'll need a 26 spline tool, a PowerTorque CS2529 LS7 slave, a remote bleeder (if you don't already have one), and a pack of ARP 330-2802 flywheel bolts (you can't reuse the OEM ones, which are torque-to-yield). It's a good idea to replace the pilot bearing while you're at it.

The thing is, I really don't see the point in keeping that old clutch around. That Spec looks battered, and you're likely to need to refresh the friction disc soon. Once you add up the cost for all of the above, you might as well buy the whole LS7 clutch assembly for around $550:

http://www.ebay.com/itm/EXEDY-CLUTCH-KIT-SLAVE-RACE-FLYWHEEL-CORVETTE-C6-6-0L-LS2-6-2L-LS3-Z06-7-0L-LS7-/151059134652?pt=Motors_Car_Truck_Parts_Accessories&hash=item232bd378bc&vxp=mtr
You'll still needs flywheel bolts and the bleeder with it. By the way, if you hit eBay and search "F1 Racing LS7," you can also find several, slightly improved F1 Racing designs, such as their Stage 2 kit:

http://www.ebay.com/itm/F1-STAGE-2-CLUTCH-KIT-SLAVE-FLYWHEEL-CORVETTE-C6-6-0L-LS2-6-2L-LS3-Z06-7-0L-LS7-/151059134647?pt=Motors_Car_Truck_Parts_Accessories&hash=item232bd378b7&vxp=mtr

05CTSV

iTrader: (16)

What type of valve guides were in the heads, bronze or powdered steel? I noticed in the one picture it looked like factory style rockers. If they were bronze guides, that may have helped the valve stem become compromised. There's a good bit of push out with the factory style rockers at higher rpm, the softer bronze will eventually elongate. Once that happens, the valve stem is ridding in a slight oval and the rocker continues to push, eventually...snap.

54inches

iTrader: (4)

in for the build.......good luck brother....

liqidvenom

iTrader: (2)

Man its like you get ontop of something and another thing pops up