The best Christmas present

[tirebird]

It was time to rebuild my LS6(a quart every 400 miles) so, it was not without a lot of trepidation, that I took the beast to Victory Automotive in San Jose for a tear down.

Friday we got some great news. The bottom end was still perfect. No significant wear on the crank, cylinders, and bearings. The top end was another matter. We're getting new valves, hardware, etc.(A 14 72, casting#: 3964291) because, most of the oil consumption was due to valve guides and seals. We're polishing the crank and boring the cylinders :30 over and buying the best new forged pistons but keeping the rods which, we know, are pretty stout on the LS6.

We're also going with flat top pistons and hydraulic lifters with roller rockers to lessen valve train wear and make the engine much more pump gas friendly.

The big question, which we'll find out tomorrow, is if we have to deck the block and by how much. I don't want to lose the (T0417CRR) marking and if we can possibly take only .010 off the top then the stamping will probably stay.

But, because it's more important to do the job correctly, we may have to take more off which means that we'll lose the stamping. We're taking every possible picture of the rebuild, including the stamping, so that we can document what was done and when. That should be enough to quell any questions.

By the way, we did solve one mystery. I couldn't get a good look at the engine date stamping until the engine was pulled. It's "C 27 72" on a four bolt main #3999289 block. Some of you may remember that this was a "warranty replacement" LS6 bought from Berger in 1972 and installed the following year in the "Tirebird" by Tom Senter.The cross drilled crank looks perfect and I'm really looking forward to getting back driving the beast.

Happy New Year everyone. http://www.yenko.net/ubbthreads/images/graemlins/beers.gif

[indyjps]

your shop should be able to deck it without losing the stamping

[Charley Lillard]

If you can't rebuild that engine without touching that pad you need to go somewhere else. Or just do the heads and leave it alone. Taking anything at all off thet pad is not needed and shouldn't be done. There are great head gaskets out there that seal very well.

"The bottom end was still perfect. No significant wear on the crank, cylinders, and bearings." Why change pistons or bore it ? Do you drive it enough that you need to run on pump gas ? If I were in the market for your car I would have alot less interest in it if you do what you are planning. Orig pistons, bore ,high compression etc is what makes it cool. Especially that untouched pad.

[tirebird]

Yes, Charley, I do. I'm driving to L.A. next June for the POCI convention and I hit a lot of car shows in the Central Valley and Northern California, about 10-15k a year.

I agree, I would like to find some high quality stock flat top piston's for the 454 but there are not a lot of great choices compared to :30 over. After all, everyone who rebuilds their engine usually goes one size larger and the market reflects that.

I think you're comment about using a good set of gaskets has merit. But, good engine builders don't like to go halfway and would like the straightest surface possible to mate with the heads.

This car is a keeper and I don't plan on selling it. So, I'm not concerned about the value for the next owner. It's a driver that is a lot of fun.

However, you're absolutely correct that there has to be a way to deck the block while protecting the pad numbers and will do everything possible to reach that end.

John

[BUIZILLA]

flat tops in a big block????

no wayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

you looking for 7.0 comp ratio??

JH

[tirebird]

With closed chamber LS6 109c.c. heads,..about 9.5:1.

[Kurt S]

The factory built the LS6 and the ZL1 and the L88 and the xxx, all with broached (not decked) blocks. Seems like they all ran fine like that, including your block.
Decking is kinda like a 4 bolt main. Makes you feel good, but really doesn't do much. In this case, I agree it is a big negative.

[JRSully]

you can resurface the deck and save the stamp by using a special bridgeport machine, your shop should know about it. Basically it swirl cuts up until you get to the stamping area and then flat/straight cuts it from there. They did it on my 70 L78 and it came out perfect. Good luck

[tirebird]

Thanks everyone. The builder is back in the shop this morning and I'll give him a call to discuss your suggestions. He agrees with me about leaving the stamping on the block. Thanks again.