Bad day on the dyno...

[carbuff]

Time for an update...

It's not been a good week, but at least I have more data to make decisions about moving forward. Things I've found this week:

• The crank needs to be turned (think I already mentioned this). Turnaround time is 3-weeks, but cost is a little less than I was previously told. So it's on the way to ShafTech to turn and re-harden.
  
• The clutch I have is an immitation of the Monster Clutch product, made in Mexico. In talking to Monster, the pressure plate I have is problematic, and looking at the disc, I probably need to replace it. So I'm headed down the path of a full clutch and flywheel replacement.
  
• Today I learned that the heads are toast. The first phone call I received about them told me that the valve tips seemed to have excessive wear, to the point the shop didn't want to reuse them (which may mean my rockers are toast as well). However, it seemed like they could repair the damage from the shrapnel by welding and milling the heads. About 30m later he called back to tell me the heads had been milled down to 59cc's, which is way too small for what I want to do (deck too thin). So, I have a couple of heavy paperweights now.

I've been shopping the LS forums for options on parts that I might use for the rebuild. One thing Tim educated me on last weekend was that I could use an LS7 block with a wet sump, so I've been looking for one of those. While I was traveling last week, I just missed one for sale in my backyard (30m away) that sold the day before I got back.

Then, in preparation for the possibility of the heads needing to be replaced, I was searching for aftermarket sets of those. I found a great set for sale that I was emailing with the seller about. Danged if he didn't sell those last night, so again, just missed them...

On the positive side... Eric shipped my leaking radiator back to PRC who originally manufactured it, and they agreed to repair the pinhole leak at no cost, other than shipping. So that's one little problem solved.

Also, while everything is apart, I called AGR who made the steering rack I put in the car last year. My PS pump has been making some strange noises. I got an education on pumps and racks, and I have a new pump on the way from them. Hopefully that will take care of that problem!

At this stage, I have a half-formed plan in place. With the additional problems that I've found, I've decided to get my crank fixed by ShafTech and Callies which will allow me to reuse it and my rods. Unless I stumble onto an LS7 block before the crank returns, I will go ahead and reuse my block and build it back as a 405 (4.010" bore / 4.000" stroke). I am continuing my search for a set of heads, but at a minimum I'll buy a set of CNC ported L92's. I could either get the GM CNC version, or have one of the many different shops that do the CNC work do them for me. I am going to call a few of those tomorrow to discuss pricing and lead times...

I'm probably going to get the new LT1-S twin-disc clutch setups to ensure that I don't run into a clutch issue in the near term:

http://monsterclutches.com/2004-2006...eet-gto-clutch

Steve just installed this in his LS / T56 build and seems to like it.

That's it for now. More to come soon...

[carbuff]

One more thing that I learned today...

The likely cause of the valve spring failure was the engine sitting for so long after being assembled. The motor was originally built back in 2007 if I remember correctly. I didn't fire it up until 2013. So there's a good chance that a few valve springs were compressed for 5+ years. It seems that can cause springs to weaken and ultimately fail. Makes complete sense, but not something I would have thought of...

[glassman]

Hey Bryan, what heads you doing? I didn't see it on the clutch site, but is that aluminum or steel flywheel?

Hang in there bud, she'll be back in no time. Remember what you named her, and that there high maintenance haha.

Mines still hurt from Texas, suspensions back, interiors back together, but still got electrical gremlins. Josh (my local LS guru) thinks i lost my MAF, i think that may be the case (i hope) as when i drove to Texas in the GG tour, i/we drove thru that super knarley storm and i believe i got water up in the MAF.....dunno....but sucs not driving it....

[carbuff]

I'd love to step up to some All Pro, TFS/TEA, or other similar aftermarket castings. The consensus seems mixed as to what the gains from those are over a good CNC port on the L92's though, so I'm trying to decide the best path...

On the clutch, it can be done either way. In talking to Monster, the LT1 twin has a lower moment of inertia than a normal single disc pressure plate. Given that, the clutch will have a feel (in terms of momentum to launch the car) that falls between a steel and aluminum single-disc setup. So the lightweight twin would feel really light in that sense. Given that TOW is a pretty heavy car with me in her, I don't think the lightweight setup is the way to go...

Sorry to hear that yours is still having trouble! Electrical gremlins are the worst, so I'm glad I haven't really had any of those with TOW. Hopefully you can get everything sorted before the season starts out there for you west coast guys!

[71RS/SS396]

Originally Posted by carbuff

I'd love to step up to some All Pro, TFS/TEA, or other similar aftermarket castings. The consensus seems mixed as to what the gains from those are over a good CNC port on the L92's though, so I'm trying to decide the best path...

On the clutch, it can be done either way. In talking to Monster, the LT1 twin has a lower moment of inertia than a normal single disc pressure plate. Given that, the clutch will have a feel (in terms of momentum to launch the car) that falls between a steel and aluminum single-disc setup. So the lightweight twin would feel really light in that sense. Given that TOW is a pretty heavy car with me in her, I don't think the lightweight setup is the way to go...

Sorry to hear that yours is still having trouble! Electrical gremlins are the worst, so I'm glad I haven't really had any of those with TOW. Hopefully you can get everything sorted before the season starts out there for you west coast guys!

You don't need to buy any fancy aftermarket head for your goals, ported LS3's will easily support 650+ hp.

[Solid LT1]

Do yourself a big favor.....talk to the machine shop and have them port and smooth the oil passages in the engine block where the oil pump mounts to the block and the front 90 degree drilling that intersects the rear oil galley going to the rear passages to the oil filter ports. Check the oil pan and filter passages and port and smooth these passages too. The oiling system on the LS motor flat out SUCKS! for extended high RPM operation. The 2.00" rod journals are fine....that is the size of the original Small Block Chevy......worked well for many years with a good multistage dry sump system.....rod/main journal sizes can be further reduced as NASCAR has done to minimize oiling system power losses by reducing oiling system demands but, you had better have a good engineer helping with system design. NASCAR made 900HP 9000+RPM motors last for 500+ hard miles of racing with small Honda/IRL rods.....typically 1.88" journals. Frankenstein cylinder heads has one of the better LS3 CNC programs at this time but, don't know how backed up they are for deliveries.....if going aftermarket it's hard to beat the TFS head or MAST LS offerings.

[Sieg]

Just have Tim send you a Finch motor.

[intocarss]

Talk to West Coast Cylinder heads in Reseda Ca

[carbuff]

Originally Posted by Sieg

Just have Tim send you a Finch motor.