Demon Of Dreams

iTrader: (3)

I know everyone is usually on the bigger is better trip...

but it made me wonder... especially for the guys who are doing turbo setups.

anyone here really do it?

slt200mph

iTrader: (42)

Making small LSx engines has been discussed adnausiam on here many time over. Unless you are limited by displacment size in a particular class in competition why would you need to do it. You do not have to work a larger engine as hard to make reliable horse power..

KHShapiro

iTrader: (10)

the old saying... there is no replacement for displacement

jeffstar

iTrader: (6)

Wow I remember all the "327" LT1 posts or something a while back on cz28.com. To have the "ability" to spin the motor up to 8-9k. Again...if you have the cubes, you don't need the RPM. Further more you can spend a lot less on cylinder head with more displacement.

Reckless

iTrader: (9)

Well let me see, we might have tried that once (destroked 6.0L block):

http://www.w2wpowertrain.com/t-Casper-2.aspx

Demon Of Dreams

iTrader: (3)

again, I said it more leaning towards the turbo guys...

you can make power with ease but are limited to lower RPM's, and a higher revving engine with a turbo or two is probably going to not only hold together better if its built to take it, but make just as much power.

of course I Don't know how streetable it'd be.

I was just curious

sprayjunkie

Look at the Daytona prototype cars, I believe they are limited to 5.0 liters, and those LSX's whoop some ***!
Its awesome seeing DESTROKED LSX motors running toe to toe with UPSTROKED Ford Mod Motors.
To hell with the rules of displacement, all else being equal, the LSX's are truly superior engines.

slt200mph

iTrader: (42)

I am of the bigger is better school of thought. The C5R and C6R 427 cu in engines have shown to be extremely reliable and make plenty of horse power. They have been regulated in the amount of horse power that they can make by restrictions in their ability to breath. Much like what nascar has done with restrictor plates. They have dominated their class for the past 6 seasons in ALMS racing. This year they were hit with reductions in fuel capicity and additional weight penalities during the season. They still managed to win the championship again. These engines red line at 6200-6300 rpms. They are torque monsters to say the least. I can only remember one engine failure in the last 3 or 4 years. (petit le mans 2005) Reliability is paramount in endurance racing. The short races are 3 hours. The long ones are 10 hours, 12 hours and 24 hours. All the cars that the C5R and C6R have competed against over the years have sounded like weed eaters. When the Corvettes go past you they sound like they could eat the world. The sound of a big inch American V8 makes a big grin appear on my face.
No need to make a small highly stressed engine (rpms are what kill them) when you can make reliabel horse power without stressing the engine to the max to produce it. I still love the sound of a high winding small block Chevy. I used to run a 301 cu in D\Gasser. We would buzz them up over 8000 rpms. But we were limited on engine displacement by class rules.

Demon Of Dreams

iTrader: (3)

why would it be stressing the engine if it were built to handle it?

just curious agai

Nate_Taufer

iTrader: (1)

Because RPM kills parts. Think about it. Instead of making the same amount of power with a 5.7L motor that is starting and stopping a piston moving at 500 feet per second 6000 times, you're effectively stopping and starting that same piston in a 5L motor moving at roughly the same speed 2000 more times per minute for a high rpm motor.

Plus a well setup motor will make roughly 1.25 rwtq per cubic inch. That's 377 rwtq for a 5L whereas the 5.7L will make 432 rwtq.

Makes sense now doesn't it?

Nate

dug

iTrader: (10)

Its pointless to destroke motors. The rpm limit is tha valvetrain

calongo_SS

iTrader: (7)

It's not pointless to destroke the motor. But for a street car, probably not many benefits. The valvetrain does put a pretty low limit on rpm's in a hydraulic motor, but a solid roller w/ machined heads and big springs can be revved pretty damn high.

For a turbo all out race car destroking can be a good thing if set up properly.

I don't know if none of you have clicked the link that W2W posted above or not. I think the fact that the fastest lsx powered car (high 6 @ 205 mph) is running a destroked motor pretty well disputes all you guys saying destroking is useless.

Nate_Taufer

iTrader: (1)

That's because they were displacement limited When will you guys realize that the only time destroking is a benefit is when your class is limited in displacement. Then you run the biggest bore possible and pick a stroke to match. There is no benefit to reducing the size of your motor, unless you consider making less power a benefit.

KHShapiro

iTrader: (10)

Think of what it could have made with a big bore big stroke

ram09

iTrader: (1)

If I ever get the money I want to build a 69 Z28 with a LS7 type motor. That would be 4.125 Inch Bore on a 3.00 Inch Stroke. Thats 320 Inches if you cant do the math. Using the LS7 head or a similiar type head. I figure it wont be very streetable but it should wind up to at least 7 or 8k (or more) with out a problem! I would love to see the hp numbers that it could make either NA or with a turbo

Cop Car

iTrader: (14)

id like to get a 4.124 bore block and use a 4.8 L truck crank, comes out to be a 5.7

a more practical way would be to use the 5.7 crank, put forged connecting rods on it and pistons, top it off with some LS7 heads and GMPP intake and you would have one sick high reving motor..

slt200mph

iTrader: (42)

Well said..some folks just don't "get it"... going small has no bennefit and just limits the HP produced..that is why they have class rules..

racer7088

You certainly couldn't use that car as a comparison to anything really as that's not a car that has to run against any real competition in a class where they can run bigger engines at the same weight or it wouldn't be winning anything. Most all of the fast cars with small blocks in Outlaw racing with turbos use 400-450 inch motors and still spin 8500+ rpm. Destroking engines just makes them slower in any heads up environment unless you have no traction in which case the engine is already less important than the chassis anyway.

427

iTrader: (3)

We do build slightly bigger engines for most of our racecars (402 mostly). The 352 of mine was built for racing in the Tech series with a 360ci limit. It would be very competetive in its current form in many local races running against open competition turbo cars. It still is the fastest/quickest LS based engine in a quarter mile, although I can't believe it still is.

Kurt

Asmodeus

With a good valvetrain you can spin a 427 LS7 to 8k pretty easy, no need to destroke and make more power.