Hey as you guys know I have a SBC350 and i was told the stock cam and rods couldn't hold up my nos spray. What is crankshaft (14088526) rated up too. I have stock rods. They all came out of this motor ( 10243880). I will be pushing 400-500hp without spray.

 

Doesn't matter. I don't even know if there are any "ratings" for that sort of thing. It's a bunch of STOCK parts: I can about 100.0000000% guarantee you that the people who designed them, DID NOT sit around and figure out how much nitrous you could put on there without voiding the warranty. They were thinking about whatever the published warranty for THAT motor, in its STOCK condition, needed to be. That's IT.

A cast crank won't stand up to that. Stock rods, and above all stock rod BOLTS, won't either. Put a motor together like that, and it's not a question of whether it will grenade, rather it'll be a sure thing it will turn to shrapnel on the 1st pass, it's just a question of whether it will be at the line or farther down the track. In that light, what difference does a bunch of "ratings" make, when YOU'RE the one paying the cleanup bill at the track?

 

It's a typical cast iron crank, should live indefinitely at the 400-500 HP level, if that's what you actually end up with. Any appreciable amount of spray on top of that should get a forged crank just to be sure.

 

well i was just asking a question cause some people said it will be ok and other said it will be ok but after a few times it will go to ****. So i figured i ask but there is always one *** hole out there like sofakingdom who like to talk **** on someone who is just trying to square things away, and learn from other peoples mistakes. So why don't you try to be a help to someone who not afraid to ask question and stop trying to act like some bad ***. Cause you are the type of person who mess up this kind of stuff. By thinking its ok to just make someone feel stupid. I am sorry I don't have all the knowledge. I am a young kid trying to have fun. So ******* make more people feel like an ***. I hope i see you on the street one day so i can blow your f***ing doors off your car. Than we will see who feels like an ***.

 

I was thinking about a 150 spray. Apeiron what do you think about this crankshaft(http://store.summitracing.com/partde...L&autoview=sku) and connecting rods(http://store.summitracing.com/partde...&autoview=sku), I have already bought ARP bolts for it.

 

A stock crank and rods WILL NOT stand up to 400+ HP N/A, and 150 HP of nitrous on top of that.

I'm not like you, and I don't need to use words that the message board won't allow, to tell you that.

Get some real parts, IF that's more than abunch of empty talk and you intend to actually put it into effect, or resign yourself to breaking LOTS of bottom ends.

Let me let you in on a secret learned from several decades in this hobby: it quits being fun IN A BIG HURRY, when you have to keep replacing big expensive things that keep breaking. I can tell you've never had that experience yet (your first motor!!), which is OK, we all started out SOMEWHERE. But that's OK, if you want to learn that for yourself the hard way, I look forward to being in the other lane when it happens to you.

 

The 4340 forged crank would be ok, but if you're already replacing the rotating assembly, why not pay the same money to build a 383 and get almost 10% more cubes for free? I wouldn't trust the rods. There wasn't a lot of point to buying ARP bolts first, any rods you buy will either come with bolts, or might not take the same bolts you bought.

I hope you've got some deep pockets, you're starting an expensive project.

 

I got the bolts in a package. It was the whole bolt ***. kit from ARP and Main Bolts ARP as a package deal. I was thinking about going 383 but i just change my mind want to stick with I had in mind. Which Connecting rods would you recommand.

 

Something at least as good as an Eagle ESP series H beam with a 7/16" rod bolt, or better. A good set of rods will cost at least as much as the crank, sometimes more.

If this is your first engine, you might want to set your sights a little lower. Sofa may be a little abrupt, but he's worth listening to. He's probably built more fast engines than 90% of the people here have built slow ones combined.

 

what u mean by you might want to set your sights a little lower? They are pretty low already i think atleast. tell me what you had in mind

 

I have personally used a stock gm crank (one piece rear main seal too), and rods (ground and shot peened) with a 12.5 comp ratio, and made that much hp and more, It made almost 500 hp on engine alone, and with a 150 shot 644 I also ran a 225 shot on it for awhile, but didnt go to the track with times to see what it did I est about 700. the rods did have arp bolts in them though.
so properly prepped stock parts will hold up, the bottom end of this car was together for about 10 years , long before I had it. in fact, it was built for the magazine article it was in, I changed pistons but not even bearings. The only reason it was taken apart was excessive leakdown, due to a ring that got stuck in one oil ring, I found signs of damage from lack of oil, but that was a pickup tube that had broken. when i put it back together I made it a 383, now its around 900 hp, with a stock block...I dont know how much that will take though lol

 

Thanks so all you did was get the rods ground and shot peened and did nothing to the crank?

 

the crank was cut with a larger radius on the journals it was cut .010 on the mains and .020 on the rods. the rods are going in another engine, and the crank is probably a building in china by now lol

 

The rpm at which you produce the hp is the big factor on whether the stock crank will survive. GM cast cranks have proven to be superior to aftermarket castings. Keep the rpm under 6000 (that pretty much says you'll be closer to 400 than 500 NA fwhp), run a good damper, balanced rotating assembly, spray a 150 or 200 shot, and the stock crank is the least of your worries.
I'm not sure what "stock" rods you're working with. The later GM PM rods are up to the task of taking 600 hp at 6000 rpm, even with stock bolts.
Of the dozens of LT1's I personally know of making between 500 and 700 hp on the bone-stock rotating assembly, the only failures have been bearing failures and piston failures. Bad tunes and fuel supply problems were responsible for the piston failures.
I think I understand your motive here. Since any aftermarket balanced rotating assembly that includes a cast crank is gonna be inferior to the stock one, and decent forged rotating assemblies are pricey, you're thinking of just replacing pistons (.030 over and forged for the nitrous?), rebalancing, and put it together? That's understandable, and hopefully the pistons are close enough to the stock weights that rebalancing is not a big issue. If it is, then the forged rotating assembly starts to look more attractive and removes all worries.

From my experience, it's been most cost-effective to either:

1. stay with bone stock GM shortblocks .....believe it or not, a junkyard motor with new bearings and oil pump is more reliable than half of the rebuilds out there!......., spray that 150 shot at the track with a safe tune (conservative timing and plenty rich), and have fun for a long time, ...or

2. go all the way with a quality forged assembly rebuild

 

well i just scraped them today going 383

 

doh hate it when that happens lol, and those hp numbers, 500 at 6000 rpm, that is...been there done that, sprayed it with a 150 shot @ 650 trapping at 6200 thank you, if it wasnt for the oil pump pickup I would still be running it too lol

 

I have 10243880 bare block. I'm looking to build a 383 monster. I've already have gotten a Howards cam #180245-12,.501/509 valve 280/292 duration 112 lobe. 1.5 roller rockers. Huge Dart heads. But my ?? is rod size. Do I have clearance for a 6 inch rod, without doing machine work to the block, other then boring for pistons. And if so, what crank stroke do i go with? Is the gain worth it going with the 6in rod compared to 5.7 rods.