EZ GOIN

Well the end of last year I was thinking of putting a new motor in my car. I was thinking a 427 would be perfect, well a few things changed and I was unable to do it but now things seem to be back to normal(or atleast closer to it) so I started doing some research again and ran across this puppy471ci LS2 but I can't seem to find much on any forums about it, nor can I find a LS2 with this many cubic inches from any other vender.
This seems to be pushing the LS2 block too its limits, I would think.

Sooo, how dependable, reliable do you think this set-up would/could be?
I'm thinking mild cam(don't know exactly what size yet) and keep my 100 shot on it. Wouldn't race it but maybe 5-6 times a year (1/4 mile) with maybe one autocross in there.
I'm thinking if it can be done reliably, this could be one heck of a street car.
So what do you guys think?

mikey

iTrader: (6)

If it's a street car, don't do it. This one is on the edge of what is possible with the LS2 blocks. Stay with a 427 (4.125 x 4.00) as they are more reliable on a daily driver. I have a 471 in process for the drag car but we don't mind a re-build once a year. I don't recommend any stroke over 4.000" on a street car. Call me if you want to chat about options. Some recent developments will allow reliable larger cubes.

JAvenger007

iTrader: (9)

i wouldnt autocross with a 471 either. Too much power can hurt your times, and with torque like that on tap itll be difficult to control throttle and balance the tail through turns. Sounds like not that big of a deal for you if your only going once or twice, but youll likely find it more of a struggle with a setup like that.

Depending on what route you take, which sounds like you want some motor with a shot on top. You can make good power with a 402 ls2.

DavidNJ

Is that the World block that will allow a 471? I thought it wouldn't support a big enough bore.

Question: In your current 471, you spec a hydraulic cam, even though the engine is pretty extreme, must have Jesel rockers, and must need a pretty big cam to breath.

93LS1RX7

iTrader: (8)

So thats what you are bringing to the Ram Raciong fight.....Yikes I will have to check it out next week when I come up to dyno.

Mike

mikey

iTrader: (6)

LOL, I wish. I'll be happy if the old 441 is back together. It's been really busy and my stuff always gets pushed back. See you next week

Beast96Z

iTrader: (21)

What does it matter as long as the bore/stroke ratio is kept within tolerance? If you had a 4.150 bore x 4.125 stroke, it would seem to me like it would last a very long time in a street app. I'm running a 4.150x4.185, which nets a better bore/stroke ratio than a "all stroke" 382. One would think that the bigger motor would last longer due to less loading. Really just wondering, thanks.

DavidNJ

I think its a matter of supporting the piston at the bottom of the stroke.

Steve - Race Eng

iTrader: (1)

Upcoming Darton MID sleeves will be .125" longer to accomodate 4.25" stroke cranks. 4.200" bore x 4.25" stroke will yield 472 cubic inches.

Darton will also have 4.190" capable extra length dry sleeves for the LS2 on the shelf in short order (468 cubic inches). This Using the repair sleeve for the LS7 block. Will work fine normally aspirated or with mild power adders at max. bore. The MID should be used for max. effort (high boost or nitrous) engines.

As Mikey pointed out, strokes greater than 4" will reduce engine life. This because of the available space for rod length (side thrust) and piston skirt length (area).

Nonetheless, if you want a killer big inch motor, I will soon be able to supply sleeved blocks to do the job. Mikey, Allan Futral, and Horsepower Engineering will be able to supply short blocks and complete engines using my sleeved blocks.

Steve

EZ GOIN

Thanks for all the feed back guys. I figured the 471 might be too radical for my needs but had to ask. I've only been looking at engines option for a few days but LS2 402 seems to be EXTREMELY popular and a great bang for the buck engine. Don't see any sense in resleeveing an LS1 anymore.

So is a 427 as big as I can go and still keep it to a 4.00" stroke?

VINCE

iTrader: (1)

You can go with a 4.200" x 4.00" and it will yield a 447ci if I remember correctly.

squealingtires

iTrader: (14)

How in the heck can you have a 4.2" bore. I thought the cylinders were 4.4" on center...Yikes! zero cylinder wall. Ok, I'm wrong, what are the bore center distances

Steve - Race Eng

iTrader: (1)

At 4.200" bore size there is .200" of gasket seating area left between the bores. This is more than sufficient. Cometic has gaskets to work at this bore size with the MID blocks.

The BMW M5 engine has 4 mm between the aluminum nikasil bores as does the aluminum nikasil bore 4.6 Ford race block. That is only .157" between the cylinders.

Steve

cantdrv65

iTrader: (3)

Wow! If engine longevity is harmed by such a long stroke Id never want one BUT.....I cant wait to see some numbers from something like a 471!!!