I am going to rebuild my engine starting next winter. I am wanting to use my stock block. I was wondering if I should keep the stock crank and throw forged rod and pistons or should I put in a 4.00 crank and go with a stroked 383.

My car is going to be mostly street use and will see the track a few times a year. I plan on running my boost to at least over 10 PS1 if possible. Current mods are full bolt ons and d1sc.

What are your guys opinions on the matter.

 

i would stick with the 347 and use the money you'd spend on the 4" Crank somewhere else. Sure the 383 would make more power on the same boost but considering your going to be built no matter what, just up the boost a little more on the 347 to achieve the same goal. Then you will have an extra $1200 or whatever a crank is to spend else on a clutch or to put towards a rear end or beef up the fuel system more. Just my 0.02

 

I have debated the same thing and I believe I will try the 383 route even though you will spend $879 on a Compstar crank I feel the out of boost drive ability will be better and making more power on a lesser boost setting sounds great especially around where I live as the highest octane we have is 91. I know that I could add a meth kit but I would like to try and reach my current goal without it as I just don’t like the idea of my car being dependent on two fuels to make the power I want. Later yes I will put a meth kit on to try and make the bigger numbers when I get a boost controller and up the boost. But for my street driving I wanted to be able to make the most power I can without meth and still have great off boost fun that works with my octane.

Also less boost even on a forged motor is going to be less stressful to it and make sure octane isn’t an issue as we have a local guy with a twin turbo 402 corvette that I believe has a high 9 to 1 very close to 10 to 1 compression ration and he still had to run meth because 91 just wasn’t enough. So going bigger doesn’t always work especially if your compression isn’t low enough to accommodate your local octane. I plan to go with a flat 9 to 1 compression or maybe even 8.9 to 1 in hopes to use the larger cubes and boost to work with the 91 octane and still make my power goals without the meth.

Either way you won’t go wrong but more cubes are normally a good thing for making more power. Although I don’t know what kit you are running so turbo sizing if you are going to be running turbos has some to do with the size of motor you want. I am going to be running a stage 1 APS kit and I felt 383 was a good in between as some feel 402 is too big and I don’t want to get a new block that is heavier so 370 iron was out and a LS2 is just an added cost that I didn’t want either as I wanted to use my stock block to, so that is when I decided that if APS says a 6.0 liter is the perfect size and 402 is too big even though many are running 402’s. A 383 would be just the perfect balance for me in bigger cubes and cost. Don’t know for sure so I guess I will just have to find out. Food for thought and I hope this helps some but in the end it is money and what you want. I now have to pay off my wedding so either my cars engine will have to be put off for 6 more months to a year or I may just go with pistons and rods if I can afford that even.

Good Luck
Travis

 

why change heads and everything... i guess it matters what all you want to spend.. Me, personally, i would forge the bottem end, and use money else where.. Goodluck n post progress!

 

My vote is to sell the stock engine if it is in fairly good shape and just buy a fully forged 346/347 from a sponsor such as Texas-Speed, Livernois Motorsports, etc. You can usually get a very well built shortblock with good forged parts for around $3K and it is fully assembled and balanced so you wouldnt need to find a shop to rehone your cylinders, balance the rotating assembly, etc. Plus youd have a warranty if anything went wrong or failed that wasnt due to install or driver error. Then get some Patriot 6.0 heads, a decent FI cam (if you dont already have one), and a good tune and you should be good to go. Of course drivetrain and rear end will eventually go but thats the route I would take if I were doing the build. Either way goodluck and let us know what you choose!

 

Go with the stroker motor and you will never be sorry.

 

I'm interested in this topic as well.

Lets say you have a 550rwhp 346 and a 550rwhp 383, both Procharged. Would there be a noticeable difference in SOTP fun factor driving around the street? What about track times?

Is the increase in cost to go 383 justified, especially when there are alot of 346's putting down some stout numbers, both at the track and dyno?

Gary

 

If I was gonna spend the money to go 383... I'de just go 402.

 

One more question for you guys, what is the typical machining cost associated with rebuilding and engine?

 

I paid ~$570 to have a shop clean the block, polish the crank, hone for the new pistons, install the cam bearings and balance it all. They also rekeyed my crank for the superdampner.

 

Thanks man...

 

I would do the 347 .

 

Ok next question for you guys. How much boost could the stock block handle assuming I went with a 383 and a 3.905 cylinder bore after it is honed out.

BTW thanks to everyone for you input so far.

 

Boost is irrelevant.

Ive run my best times on a 382, stock LS6 block. Ive been using this same block, for about 3 years now, since I first fitted an LS motor to my car. Its been built, and rebuilt in various guises, from 346, 382, back to 346, and now 383, with varying pistons, heads, cam etc.

Its now a 383, and holding up fine so far.

my only complaint, is that the ****** still hasnt given me a 9 !!!!!

 

Im pretty sure people have pushed the stock block at or exceeding 20 psi, so a 383 with 10 psi shouldnt even be a concern whatsoever as long as you have all the supporting mods.

 

Why not go 427.....or hell if your gonna spend the money on a 427 might as well go 454.

It has to stop somewhere. a 402 can make 800 RWHP and a 346 can make 800 RWHp. Go 346, make a but load of power and ge descent gas mileage. Dont go too low in compression. 10:1 will be fine. Great throttle response and driveability out of boost. There is no reason to run a super low compression and boost to the moon. Run higher compression and less boost and still make the same power. A good boosted engine starts with a good N/A motor.

 

 

You can build a 383 for just the added cost of the 4.0 stroker crank. To build a 402 you will need to start with a 6.0L iron block or an LS2 alum block, or have your 346 block bored and Dartin sleeves (very expensive) installed. The 383 ends up being less money unless you already have an iron block or an LS2, or you sell your block and buy one. Bob

 

KP's T/A ran great with the 'lil 346.
http://www.exoticperformanceplus.com...html?item=1109

This 346 makes 740 rwhp through stock cats.
http://www.exoticperformanceplus.com...Car.php?car=40

The 383 would indeed give you more torque, it is a tough call.

Here is our price for bringing a car in, removing the engine and rebuilding it, then reinstalling the engine and tuning it in. http://www.exoticperformanceplus.com...php?service=83 Bob

 

Thanks Bob for your reply, but I have spent to much money with you already.....LOL
Only kidding will more than likely be spending more soon.

Thanks for everyone else that has replied as well.