368...should I, could I, would I

[-=Jeff=-]

Originally Posted by Hib Halverson

I do put some faith in what Marc tells me. I've known him for a long time.

I also have know Marc for at least 12 years.. I have known Pete for over 15 years..

I would trust my car with either of them. Both have incredible knowledge on the LT5 and both do amazing work

Good luck with whatever you decide..

[Hib Halverson]

I've made no decisions yet. A freshening/upgrading of the engine is on my "wish list" but, as yet, is not on my "do" list.

To be honest, the 350 in the car still runs pretty good. What I don't like--never have liked since I bought a C5 in 2004--is the car's weight.

When the engine was done back in the day, the car made 413 at the wheels (I don't have headers and do have cats) which, considering the 18% loss of C4s, had me at a hair over 500-hp.

My 04 Z06 (430-hp LS6) was just about as quick or maybe a tick quicker, depending on the air and if my driving is on the mark, and I attribute that to the weight difference between a 95 ZR1 and the 04 Z06. I'm not going to gut my ZR1 into a Snake Skinner so the only other choice is to bump the power up another notch.

That's where I come up with the 368.

I was thinking of budgeting 10 grand for the engine upgrade and the R&R.

While I dream about more power, I've got the '95 out in the shop, upgrading the sound system. Easy and cheap jobs first, you see.

[sammy]

dont mean to hijack this thread. pete if you were doing an AES block what would you build if you were using the stk crank? also would you offset grind the crank ?

[Hib Halverson]

Originally Posted by Pete

(snip)
Because someone disagrees with you does this mean they have an attitude.

Re-read the post. You'll note I never disagreed, but I did ask some questions and stated I felt you have an "attitude".

If you think you won't like the answers i suggest don't post questions on a puplic forum.

It is unnecessary to lecture me about public forums on web, I've been around them a long time. Folks need to try harder if they're expecting that I..."won't like answers."

Question right back at ya, has any other tuner done durability tests?

Silly question and you know it.
It's possible operations like Katech or LPE may have done some sort of "durability" testing on their engine packages but the rest of the "tuners" either lack the resources, the time, the money or the smarts to durability test aftermarket engine enhancement packages.

Well if five 1000 mile trips,racing her hard,driving in Chicago traffic is not good testing,what is?

I never said 5000 road miles and several dozen drag strip passes was "...not good testing." What I asked you was if your road miles and drag racing were...

Originally Posted by Hib Halverson

"...demonstrative of good durability and oil control superior to that of "20-year old stuff"?

Originally Posted by Pete

I will need documents from GM on the durability of the 368.

Sheesh you're a smart-***.
Obviously, GM never ran a 368 for durability as it was not production...although it should have been as the four-oh bore would have unshrouded the valves offering a useful power gain out of proportion to the 18 cuin increase in displacement. We owe the 3.9 bore to some GM executives' moronic insistence that the bore centers on the LT5 be 4.440-in. Had Lotus done what they wanted and used a 4-in. bore and a larger distance between bore CLs, the first gen. (two-bolt) engine would have come in at 400-horses and ZF wouldn't have had to make a special version of the S6-40 for ZR-1s, but, I digress...

I suspect that given stock or RB cams and a reasonable rev limit, a properly assembled 368 is going to approach the durability of a stock 350. It's possible the only place it might get weak is oil use after very high mileage, say over 125,000-mi. I say that only because my belief is the steel liners' walls might not be quite as durable as the nikasil-plated aluminum liners in stockers.

Jerry tested his head gaskets did he spend millions and thousands of hours...

unlikely

... i don't know,i was satisfied with his testing and i'm using his head gaskets will they hold up 200k miles.

Jerry Downey sells mighty fine head gaskets. I suspect they'll last "forever" as long as they're not abused. But, your comparison is weak. To get head gaskets with outstanding durability for modified engines ain't rocket science. You go to a high-end head gasket maker like Cometic or SCE, and have them make some killer MLS piece for the LT5. No problem as long as you have the money. Durability testing a highly-modified engine is another story all together.

Man if you use 1 qrt every 8k miles that is one killer motor i would not touch the short block,there i go again disagreeing with you.lol

The engine was assembled by one of those guys who does 20-year old stuff.

LS7 pushrods been around since caveman.:

Actually DOHC engines predate pushrod engines by about five years. Both showed up long after cavemen but pushrod engines are a more contemporary development.

And now, some more questions...
It was said earlier that a 380 is only about $300 more expensive than doing a 368.
Ok.
How does one get the additional 12 cid to 380 and how much additional torque does that get me?

Lastly...ya know, I just noticed all these flag waving smilies.

Indeed I am!!

[Paul Workman]

Hib...

I believe you've got the wrong idea somewhere about Pete, in particular, but other purveyors of the LT5 in general. And, it is clear too that you've been out of touch with developments taken place with that engine over the past 20 years.

Of course you're absolutely correct that we wouldn't even be having this discussion were it not for those pioneers of 20 years ago - and we're forever greatful to them too!

Case in point, here is some modding based on Lingenfelter's work that is being applied to this head. Wanna talk about un-shrouding the intake valves? That is only a beginning.



I'm sure you can appreciate that truth is where you find it. It matters not if truth came from talented professional automotive engineers with an alphabet of credentials following their names, or some dedicated experimenter in his garage that makes a profound discovery...or two...or...

The misunderstanding may have come from your initial post: "Would I..." It seemed to me and others too, including Pete, that you were genuinely asking for comment on your 368 plan. I can't imagine you would have received the outpouring of information about other options if it was clear from the start that your question was a rhetorical one (or so it seems).

So, here's my point: It would be a mistake to think the sun rises and sets on the LSx (pushrod) platform as "state of the art". Taking nothing away from the LSx platform, much of the hub-bub it garners comes from cubic inches and supercharging and (in no small part) modern computer controls (not to mention the incessant exuberance pouring out of some automotive "tech writer's" articles these days). To say pushrod technology eclipses the DOHC architecture as "state of the art" completely dismisses the efficiency and dynamic versitility and flexibility afforded by DOHC. (You might like to witness the comparison to the NA LS7 and a 7.0L LT5 and see if it doesn't leave you scratching your head!)

Much is being done now with DOHC platforms, e.g., cam phasing and even 5 valves/cylinder. There in lies an opportunity for one such as yourself to shed some light on these latest inovations and compare them and some innovations to the LT5. It would be of immense interest to members of the Registry and be an opportunity to really put a spotlight on those efforts of 20 years ago, and what may have ultimately been the result if GM (Corvette) had gone another path!

Perhaps a visit to the digs known as the "FBI" would be a chance to meet Pete, make some new friends, meet some of the "behind the scenes" talent residing here. It would be a chance to see firsthand what is being done, has been done, and hear some of the technical discussions over one of the famous (infamous?) FBI pizza nights. Just a thought. I expect you'd come away with a new perspective and appreciation for what Pete and others were sharing with regard to alternatives to the 368 option.

There are "doers" and those that only write about it (present company excepted). For the latter to take on the former is like the preverbal "bringing a knife to a gunfight!"

Peace be with you and good luck on whatever path you decide. And, even if it is just 368, let me plant a seed: Marc recently revisited a 368 (done by another well known tuner) that was putting down about what you said yours does now. After Marc "laid hands" on it he ended up with 450 hp to the rear wheels on stock cams. Q: How many 6.0L LSx motors put down those numbers with a smooth 750 rpm idle? Are we sure the LSx isn't at or near it's pinnacle, whereas the really impressive performance numbers are now being made by "that other" (non-pushrod) platform? How 'bout a stock bottom end LT5, NA with street manners that is making 474 hp to the rear wheels? I'm sure the pioneers would be proud!

Look forward to your thoughts, and even more the chance for you to meet some of this infamous gang of carbide cowboys of the "FBI", break bread and smoke some rubber. Butcha better hurry... Up here in da nawth cuntree snow will be a flying soon enough!

P.

[Blue Flame Restorations]

If I were writing the check, the 368 would not be a consideration since there are more cost effective $$$/per HP options available these days, thanks to guys like Pete and Marc.

The old saying, "you get what you pay for" seems to resonate with me.

[scottfab]

Hib
You should step up the the bigger cubes the FBI offers.
Maybe not the top cubes but North of 400.
What's a few bucks? And the write-up you could do
would help the ZR-1 and Corvettes in general not
to mention yourself.