extremecorvette

I called Larry at the Corvette Shop last night. He has done two cars both for him self, costing around 20k to get the motor in the car and working perfect. He got all the electronics to work with the motor and has had no problems for the last 2 years. He said there was detailed pictures in a Vett Magazine about a year ago, does any one have that or know what issue it was in? He said he’s getting ready to do another car and looking to make 560 RWHP and a lot of Tq. The car he has know is 400 RWHP and took him about 6 months to get the motor in the car. He used some stock LS1 brackets and notified a few or just had to make his own. He pointed out when driving a LS1 or LS6 car and your on the Interstate in 5th or 6th and if you want to pass some one fast you have to get the RPM’s high and with the big block you can leave it in 5th or 6th can the car moves. The motor is 3” longer than stock LS1 so the power steering had to be moves along with the rack, drive shaft had to be shortened, custom flywheel, and the list goes on. I don’t think it’s worth it my self. I’m looking into buying the C5R block and see what the biggest size I could bore it, does any one know? How has the best pricing on a block or does some one have a used one for sale? Thanks

kromberg

I have heard that the C5R block can be overbored to 4.155", but GM recommends a max overbore of 4.125". If you go with the 4.155" bore and a 4.25" stroke crank, you would get a 461 CID motor.

Keith

extremecorvette

Are they coming out with a C6R block when the C6's come out? What are the main diffrences in the LS6 Block vs the C5R What is the max bore on both and is Lunati the only one that makes a crankshaft the has a 4.125"
4.125" bore x 4.00" stroke = 427ci

What is there any diffrence in using the LS6 that has been sleeved to make a 4.125" bore



[Modified by extremecorvette, 9:01 AM 7/9/2003]

kromberg

The LS6 block has a bore of 3.9" and can be overbored to 3.91". The C5R block has a bore 4.125" and can in theory be overbored to 4.155". I believe that Scat also make a 4.125" stroke crank. I know they make a 4.0" stroke crank since I have one :)

Keith

NEPTUNEBILL

With the 4.155 bore and 4.125 stroke you would have a 447ci motor, my stroker has a 4.1 bore and 4.125 stroke and is a 436ci. Callies also makes a very good stroker crank that is in my motor and a number of friends--If the c5r block is already at a 4.125 bore I would simply use the 4.125 stroke for a 441ci motor, the c5r block is superior in it is not a resleave and built for the extra cubes and I think it has other advantages for cooling ducts etc, the blocks (bare) were about 5500 bucks--you can resleave for half that and the rest would be the same expense---I have not heard of anyone using the 4.250 crank successfully at this point a lot of clearance problems etc and probably too much stroke anyway---

marco383

The idea of a big block motor in a C5 just won't die the natural death it deserves. As has been stated before, the added weight in the front of the car will destroy what is close to 50/50 weight distribution with the LS1/LS/6/C5R engines.

If you can't live without a big block, build a 40 ****** coupe. They're neat too, and no one expects them to handle.

Godspeed

We've had some of our smaller 418 CID motors break 500 rwhp & rwtq. I tuned a C5R motor this weekend that did 530RWHP without much trouble. Your limiting factor at this point will be the intake manifold.

At this point I'm not sure if it would worth the hassle to install a 496 in a C5, do the weight and other customizations necessary. As soon as we see some aftermarket intake manifold hit the market, big CID LSx motors will be making 550-600 rwhp naturally aspirated.

extremecorvette

The big block just adds 200lbs and makes the car 49/51

extremecorvette

I was thinking of using a LS6 block set up to 427, and I can get CR5 heads but would it just be better to stick with LS6 heads?

Godspeed

The C5R heads to flow better than the LS6 heads, but keep in mind you can not use the LS6 intake with the C5R heads. You will have to use a custom job such as the one on this C5R motor below:

Big Casino

I don't have any trouble passing on the interstate, except when I am in my Truck. :)

I would go with one of LG's kits for half the money and a lot less time and trouble. Unless you want to put the C5R block in just to say you did it. Which I understand too. Good Luck with whatever you choose. :cheers:

flynbludream

What you guys are missing is the POTENTIAL involved with a big block. It might be a good idea to ask the guy if there is a huge difference in handling or not. People swore up and down that those who are using iron blocks for N20 would have crappy handling and for normal use most everyone I have seen don't really notice a difference.

Sure you can get a stroked LSx engine to 500 maybe 530 rwhp, but right now that is about as high as you can go N/A. With a big block you can drop in a mean cam and pull easy 750+ rwhp on pump gas.

Throw a 500 rwhp big block dyno graph up next to a stroked small block 500 rwhp dyno graph and you will see where the difference in cubes will help you out. I think I remember that 502 C5 running mid 10's with severe traction problems. Might not be the best setup for roadracing, but around town look out baby. :party:

runamuk

:confused: I thought the C5R block has the same outer dimensions as the LS-xx blocks and as far as shortening the "drive shaft" thats actually a 2 piece unit and another forum member was looking for info on how to do that for a street rod project and found it was going to be next to impossible.

J-Rod

Why don't you compare the numbers of most Big Block heads to the flow numbers on an LS6. I think you might be suprised. As for whatever potential might be there, unless you are using an aluminum block and heads I only see you messing up a C5 doing this sort of swap. Also, once you do a swap like that, what are you going to do for induction? Are you going to put a big high-rise hood on it? IF you are talking about a big cam, etc... in the car, are you going to make it a race car only and not force it to meet emission standards?

For the cost and fabrication standpoint, I would look at any number of much cooler options. Twin turbo c5r engine with c5R heads and a sheetmetal manifold for instance. The cost of a base 502 is more than equal to the cost of a stoker. Once you figure in the cost of injection, a computer swap, etc.... You are looking at a sizeable investment. If you did it right.


[Modified by J-Rod, 9:28 AM 7/10/2003]

extremecorvette

Larry used the stock computer in the corvette with the LS1 and the electronics on the 496 motor work with the LS1 computer just fine with out any mods.

Heretic

The thought of a 496 in a vette reminds me of the ad for pioneer stereos that came out a few years ago. There was a picture of a 450lb dude in a speedo, and the caption was "Just because it fits, it does not mean it looks right"

flynbludream

:confused: Where are you getting your numbers from? You can pick up a 502 crate engine in any hot rod magazine for like 5-6k complete. According to extremecorvette this guy can do the whole conversion for $20k. Where can you pick up a C5R based engine with twin turbos for under 50k? As for emissions I doubt that anyone who was serious about putting a big block into any newer car would really be concerned about emissions. Big block+emissions= :lolg:

J-Rod

A 502 base motor un-assembled, and no intake $5,899.80 Horsepower: 502 @ 5200 RPM Torque: 567 @ 4200 RPM
A fully assembled ZZ502 Price: $7,298.80 Horsepower: 502 @ 5200 RPM Torque: 567 @ 4200 RPM
A Ramjet 502 which already is set up for F.I. $8,999.95 Horsepower: 510 @ 5500 RPM Torque: 550 @ 4500 RPM

OK, so now you have your 502, which F.I unit are you going to use, are you going to fab a pan to clear the cross member and ensure decent gorund clearnqace, are you going to fab all the custom parts you outlined (driveshaft, etc...). For a motor that makes 500 HP at the crank, which once you have it installed in the car is about 450HP . If you look at a 422 in motor, you can make more HP and about the same torque, with much less in terms of fabrication costs. Oh, and you can pass emissions if you go with a bit smaller cam.

Now if you want to make more HP with a big block, you are going to need a big nasty cam, and/or a lot more cubes. I can buy a Scott Shafiroff 532 shortblock for around $3800-$3900, once I have that, I need a decent set of heads, then I have to go buy a F.I. setup. Keep in mind a really good set of CNC ported BB Chevy heads will probably run me about $3000-$3500. Ok, now for complete FI kit you are looking at around $3500. Now comes the cost of getting it into the car, etc.... Again if you look at the costs involved I don't see the improvement being worth the money.

I know what kind of power you can make with a Big Block, I also know what it costs. You think that 400HP with 500+ lbft of Tq is the hot ticket for $20K? Here let me offer you another idea. If you want to spend $20K buy one of the TTi twin turbo kits for $8995. If you want to get completely crazy, buy a stroker crank it at the same time. You'll make more HP and more Tq. and you'll pass any sniffer test in the U.S.

As for an emissions test not being an issue, is their no visual or tailpipe test where you are at? In many places this would be an real concern.

I've seen a guy put a BB in a Geo Metro. Sure, you can do it, the question is why would you? Not saying that a BB is a bad motor, but if I wanted to put a BB in somthing, I think I'd find something easier. Like a early model Corvette, Camaro, pickup truck, etc....


As for a C5R with twins,

A base 422 engine short block is going to run you about $9000
Add a C5R block $6295
C5R heads - $2550 ($1,275.00each)
Ti Valves $1200
Spring retainers, etc... $500
Porting $3000
Sheetmetal manifold $3000-$4000
TTi Twin Turbo Kit - $8995
Halltech TT ~$14000-$15000

If you want to skip the C5R heads and the custom intake, you could save some money, I posted it becasue of the trick factor. All in all, thats quite bit less than $50K. And, it would pass emissions...

Look at the recent numbers for a 387 stroker from 21CMC 620rwhp and 647rwtq. All in all, if you want stump pulling torque there are better more cost effective ways to get there for the money.

[Modified by J-Rod, 9:14 AM 7/11/2003]


[Modified by J-Rod, 9:15 AM 7/11/2003]

flynbludream

I see what you are trying to say, but in the real world the TTi kit has proven itself incapable of supporting more than stock displacement engines. Just look in the FI section for Shinobi's thread. As for the Halltech TT's, there is potential there, but until to date there is only one car on this forum with that setup and they are still working out the issues so until that happens, there are no other options besides LPE and that is minimum $50k for a 427TT.

I also disagree that you have to go with a big nasty cam to get a lot of HP out of a 502. I had an issue of Chevy high performance magazine a few months ago that did a medium cam swap and some very minor porting to the heads and got 68x hp out of it on pump gas. The costs that you give also don't include labor which depending on who you go with will add a good chunk of money to your estimates.

J-Rod

The TTi kit is based on the same turbo used in lots of import platforms (16g). This turbo is basically infinitely upgradable. I was simply pointing out there are plenty of ways to make ridiculous ammounts of HP without having to gut the car and put a big block into it, for about the same (or less) money.