ChevyChad

iTrader: (50)

Up until now, my plan for my engine build has been a 383 with an Eagle crank, compstar rods, and custom diamond pistons. Well now after digging very deep, I am not so sure about the Eagle brand crank. I talked to a very knowledgeable race engine builder at a local machine shop. He said all the SBC Eagle cranks he’s seen, he has had to turn down .010 to get them to be true on the main journals. (This is for standard SBC chevy engines- he has not done to many LS1’s.) Apparently Eagle has a machine that polishes their journals, and it is inaccurate and applies not enough/ too much pressure randomly. Add to that, it is made out of a lesser quality steel from China. So I am at a bit of a standstill here. I’d really like a Lunati crank, but they are out of my price range ($1900). The next step up is the Callies at $1460. Now keep in mind- even that is almost twice what I had planned on paying for the Eagle ($780). So now, that stock crank I have just sitting there is not really looking so bad. No one has ever broken a stock crank to my knowledge- and there are plenty of people using them making more power than I plan on making (I think). Mahle makes an off the shelf piston that would get me to the same SCR and DCR as what I was planning on going the 383 route, so pistons would be cheaper since I wouldn’t have to get custom ones made, and I’d get the brand I originally wanted (Mahle). Also, I wouldn’t have to clearance the block for the longer stroke = cheaper machining/ or less time screwing around with the block. So I’ll ask you guys, what do you think I should do? 383 or 347? My criteria and goals are as follows:

I want a reliable and strong engine that can handle 8~10psi of boost without worry of getting on it whenever I want. 600rwhp (+/- 50 is fine), 10.99 at the track. Power is not a huge concern since I will be making what I consider “enough” either way. It must be daily driveable, and not require ‘race car’ maintenance. I don’t want to have to tear this engine apart again for a very long time. Money is not a huge factor, but the less the better (of coarse) however, I will not skimp and buy cheap parts- I am not going to sacrifice quality. That being said, the savings of a 347 over a callies crank 383 is roughly $1725.

What do you guys think? What would you do?

brad8266

iTrader: (23)

If you wanna spend the extra $$ for a stroker then get the callies crack. If you dont want to fork out the $$ for a crank stay with the stocker, it wont break either.

My vote is 383 callies. Bigger CI motors are badass.

ChevyChad

iTrader: (50)

I'm not sure that the extra displacement would help me that much since it is an FI... Just something to keep in mind.

Steve Burger

iTrader: (33)

If you have a 10.99 goal for the track build a 347. It will handle the boost and save some cash at the same time. I'm running 10s NA on a 347.

Vertigo

iTrader: (1)

Have you considered a Cola crank?

ChevyChad

iTrader: (50)

never heard of that... got anymore info?

Gannet

I'd use a stock crank and rods with upgraded bolts. That's $1,500-$2,000 in your pocket. With your FI setup you will be making plenty of power for your goals.

Let's say you make 1.5 rwhp/ci. The 383 nets you 54 extra rwhp. At $2000 that would be $37/rwhp, which ain't bad at all.

So I guess it depends on whether you need that 54 hp. Sounds like you really don't.

One other plus for the stroker is that it will make more power and torque all the time, even off-boost. This can be nice for street SOTP feel. OTOH is will get a little less mileage, all else equal.

Me, I think for *real* street cars, which is what it sounds like you want, there is such a thing as "enough" power. A good 10psi LS1 will make that much, and more.

ChevyChad

iTrader: (50)

Very good points Gannet. Thanks for the input

Hawk108

iTrader: (1)

personally i would just stick with the 347......but if you REALLY want a 383 then do it cuz youll prolly wish you would have if you dont.

GR33N GoblinM6

iTrader: (14)

383 383 383 383 383.. thats all i ever hear.. kind of tired of it.. 347 for the win

99blancoSS

iTrader: (115)

Its a money issue really. If you have the money to throw on the callies crank then you'll always have peice of mind. BUT the stock crank is fine as well as the Eagle. They dont break and yes the tolerances are what people have issues with on the Eagles but none have had breakage issues that I've read about.

darrensls1

Between the two I say just stay with the 347 for cost effectiveness. If you really want to up the cubes then I would go 408 since most builders will build them for the same price they charge to build a 383.

TheLS1Kid

iTrader: (12)

get a 427 and call it a day

Pimpium57

iTrader: (104)

FOR YOUR GOALS, I voted 346/347. A decent set of rods, pistons, rod bolts, and good rings w stock block n crank will be just fine for the power/driveability/longevity you want.

If you've got some extra money to burn and you feel you might go more radical in the future, I agree with darrensls1 on the 408 (or even an iron 370).

david vericker

iTrader: (1)

.3905 bore is as large as a stock LS1 block can go (.3905 bore x .400 stroke = 383). So you know motor builders that will do the additional cylinder head work and supply the sleeves at no extra cost? Please give me the names of those builders!! And don't tell me their going to do it all (408)with the stroke either.

david vericker

iTrader: (1)

Oops - 3.905 x 4.00 = 383

Kraest

iTrader: (3)

Forged 347 w/stock crank, then pulley down the blower until you get as much boost as you want.

JPH

iTrader: (2)

try that TSP 370 motor, and blow as much air thru it as possible, u won't be disappointed. eagle cranks are fine, and will hold tremndous power. i voted 383 w/eagle crank, been there done that with no problems what so ever. car will make plenty of power, i wouldn't worry so much about the crank, but be more concerned with cam/cylinder head combo and getting it tuned properly. good luck

billc5

iTrader: (1)

More displacement = more FUN

The benefit of more displacement is that you start with more NA Power, Therefor the Manifold pressure is less for the same power and hence lower IAT's and less detonation.

No centrifugal blower is ever going to give you the driving pleasure of more Displacement, On the street displacement makes you smile, on the track it's a Blower that wins.

If you have the choice, go 383 or more.

raymond mckinney

iTrader: (4)

I might get some feed back on this but i really never see 383 ls1 cars run better than 347 cars on a budget.