Rodbolt

Anybody ever build a tall deck motor LS 502 or similar size stroker motor for use on road courses with a C5
I'm curious how you like it, what block, rotating assembly, heads & cam you used.

0Anthony @ LGMotorsports

We did one in a C6Z a number of years ago. It was a Dart Products Warhawk block. Callies crank/rods/Mahle pistons. Ported LS7 heads...and at the time still a stock LS7 intake.

Car made solid power....682rwhp and 630 rwtq if I remember correctly on Sunoco 100 octane as for final numbers.



Couple of things when doing these. Nothing is off the shelf so building one is not cheap. Cranks are special done, rods the same thing...after you already purchase the block. A few things have to be 'adapted' like the intake as the tall decks move the cylinder head location. Same goes for exhaust.

If you are going to be road racing this kind of engine, you need to look into doing a dedicated dry sump, not the LS7 style, but a true dry sump.

If you want me to put something together I can, just let me know any and all questions you have.

briannutter1

ERL, SAM and Wiseco participated in the first one with LS7 heads and intake. Made power past 7000 with mild ls7 heads and about 725 crank horsepower with a medium sized cam and fast 102 intake and small header primaries. Katech did the 2nd and more publicized one. Warhawks, Dart Billet, RHS out there as well. As LG stated, these are not for the faint of heart or people that don't measure every.single.thing. Sleeve length is key to getting the piston to ride nicely. 10.200 is a little taller deck height than necessary in retrospect. A raised cam block would be nice as well. Lots of other things to consider, but they're hard earned for the engine builders and I don't want to disclose them.

Rodbolt

I started participating in HPDE's about 1 1/2 years ago, and boy, it's one of the most exhilarating things I've ever done. The first thing I did was buy a lift so I could work on this thing in my boat repair shop, I started with a stock C5Z and some good pads, rotors, brake fluid, braided lines and some sticky tires. I spent most of the first year trying to make the car safe, and handle better. Next I put on a thicker tunnel plate, oil cooler, headers and a tune.
It seems like I'm never satisfied, so over the last couple of months I put on some C6Z brakes, different braided lines, different shocks, and 18 inchers in the front to clear those big calipers. I've got some Hoosier scrubs being installed this week then a track alignment & oh yea I've got some T1 bars on the way. Probably gonna be like learning how to drive a whole new car but I cant wait to try it.
I need to pause and thank all the forum members and vendors that I have purchased stuff from, this is a great place to hang out with this crazy addictive hobby that has grabbed me by the nads. I'm not sure whether to blame my cousin or thank him for getting me started. I could blame him because he is a Honda driver and probably does not peruse this forum.
I'm sure I cant drive the car to its potential and I dont need more power but I want more power anyway!!! I wake up at night thinking of how fun it would be to have a lumpy idling, loud tork-a-saurus of a beast. When & if I ever make this dream a reality I think I'll give her that name. Tork-a-Saurus!

FASTFATBOY

Buy brake pads and rotors in bulk........

A well driven head/cam C5 Zo6 is damn fast...DAMN FAST.

RC000E

Can you estimate what a complete shortblock might cost? Has anyone attempted doing some welded deck risers and sleeves, versus a whole custom block? We did this in the import world with engines that a custom block wasn't possible, shy of having LG Corvette guy money...lol.

0Anthony @ LGMotorsports

ERL made what was called their SuperDeck II, that had a billet plate and used longer sleeves in the block to do a modified tall deck. We did one of those before they stopped production a number of years ago. This, in some ways, was a bit cheaper to do than the aftermarket blocks and "fit better" as far as the accessories go, but still has some fitment issues in the car.

That being said, an assembled short block less pan and cam typically would run $14-17.5k depending on options on the crank/rods/pistons.

Rodbolt

RHS makes a tall deck which I believe is .51 taller than a standard block. With there intake spacers and a FAST 102 intake do you think a stock C5 hood would shut without hitting?
What other type of fitment issues might there be. It looks like the headers have a small amount of room to move up and over slightly

0Anthony @ LGMotorsports

Typically it doesn't throw off most of the headers out there....hood clearance is generally ok as well. Biggest issue is the intake hitting the cowl.

RC000E

Hmmm...very interesting. What kind of power do you think is possible on pump gas with one of these? I'm considering removing my supercharged/LS6 setup. I had a built LS7, but sold it to fund my restaurant build-out . I've been thinking 8 liter is what I need though...lol.

In the end though, it's street car/hpde/optima battery challenge type ride...wanna keep it that way.

0Anthony @ LGMotorsports

ERL is not doing the Super Deck II builds anymore so you are pretty much stuck with a tall deck RHS, Warhawk, or LSX block that I know of to start with. LSX of course is going to be heavy, the Warhawk probably had the best finish, and the RHS needed the most machine work.

Now that you have better intakes than a stock LS7 that we had on the above engine in the video and bigger TB's...I see no reason why you could not duplicate that power on pump gas, if not more depending on overall setup.

Screamin Z

Have a RHS tall deck in our car with RHS heads and 102 intake. Had to notch the cowling to make it fit and some of the fiberglass firewall for fuel fittings.

C6Z

Werks

had to notch my cowling too to make the tall deck RHS fit.

mesospeedy

I gotta agree. A C5 Z is a fast car to begin with, add suspension, brakes, shed a little weight, heads & cam and there ain't many street cars out there that will out run it if driven to it's potential. Going from a 400ish hp LS6 straight to a 700-800hp 502 is a hellacious jump, especially after just 1.5 years in hpde. Don't mean to sound like a d**k, or be insulting, just saying it may be better to take baby steps. Just my 2 cents, take it for what it's worth (probably not even worth 2 cents, haha)

Bill Dearborn

I agree. $15K would get you a lot of track days where you could learn to drive your car faster than if you spent the money on a motor and spent less time on the track. To get really good you need to spend a minimum of 20 days/year on the track. At $500 avg entry fee for two day events that means you can get 60 days of experience over 3 years.

Bill

0Anthony @ LGMotorsports

Many different ways to skin the cat so to speak.

Tires, suspension, aero, and brakes can do wonders......as can just seat time.

Some electronic aids like a good race traction control system can knock seconds off too.


I have seen some pretty big HP cars on track with our GT2 Corvette when we go out testing....and not come close to the lap times it does (at only 500 rwhp and 3100lb race weight)....so yes there are other ways to drop times.

600 ftlbs at 2000 RPM is pretty cool too though if you do the big engine.

Rodbolt

I have talked to a couple of people that think a LS 502 tall deck motor may only last a year. Is there a reliable stroker formula?
What about a LS 454 build?

briannutter1

I'm a stickler for weight over the front end and I'm thinking about going with a 4.155 bore 4.250 stroke 461CI aftermarket sleeved block myself because the rotating assemblies cost the same no matter which way you go. There is a technical issue though. The ls7 blocks barely have enough cylinder sleeve length to support *a properly designed* piston properly at bdc with 4.250 stroke. *Some* of the aftermarket sleeved blocks have addressed this, but not all. The piston manufacturer Must know what they're doing otherwise you'll wipe out the piston skirts in 1000 miles. There are also specially designed stroker rods to help clear the cam lobes etc.

The Dart LSNext has an optional 9.450 deck height and the RHS tall deck is 9.750. Dart Billet could be wide open deck and cam location though at extra cost.

With the LSnext, a 4.375 with a 6.25 rod and 1.012 compression height could be achieved, but it would be a tough balance job and the reluctor ring clearance is going be close and may need modded. Rod to lobe clearance also likely an issue. Reduced base circle cams can be used, but then lifters ride lower in the bores. Lifter oiling bands and holes may need corrected to maintain full lift with a hydraulic roller....etc. etc. You can see where I'm going with this. 4.250 is still the safer choice without raised cam for a guy equipped with nothing but feeler gauges and a dream.

The RHS optional tall deck has .388" raised cam (2 extra links in the timing chain) and 9.750 deck height. 4.375 with a 6.450 rod and thicker ring-land 1.110 compression height piston would be an easier build in terms of critical clearances. 4.5 with a 6.350 rod and 1.110 piston is optional (or possible 1" tall piston with 6.450 rod) but you're getting into shorter rods again (nothing to do with power....just piston to counterweight (heavy metal balancing) and sleeve length considerations).

You would need intake manifold spacers either way and you'd have 475CI with a 4.155 bore and 4.375 stroke. The engine could be lowered a bit to offset the .360 taller engine (9.750 deck).

Optional reading: http://www.chevyhardcore.com/tech-st...ket-ls-blocks/ http://www.racingheadservice.com/doc...ns/54900IS.pdf

454-461ci starts looking a little more attractive doesn't it.

el es tu

what about the Katech 8L?

Block should be 3500...

briannutter1

http://katechengines.com/performance...gine-packages/

Their first 500 was a Dart Billet with Nicasil sleeves. Pretty trick. Their latest are RHS tall deck based.

As LG mentioned, ERL isn't doing their tall deck any longer, but these are both interesting.

http://www.erlperformance.com/images...imensioins.pdf

http://www.erlperformance.com/images...eve_Design.pdf