shaggy56

I have a 4-bolt block that has cast internals that Im going to run for a little while. Im running the superram intake and everything is pretty much running. I want to step up to a centrifugal supercharger but my budget for now is to build the shortblock to work. I dont plan on spinning it any more than 5500-6000 rpm and I want it to hold together. My budget for the shortblock is $2000-$3000 range but Im being told I will have trouble with the stock block and need an aftermarket block which will blow my budget fast since I will need all forged internals. Does anyone think this would be doable without killing my budget?

AC

iTrader: (3)

shaggy, there are PLENTY of people running blowers on stock engines. I was one of them in the past. I only had a stock 2 bolt L98 and was pushing 6-8lbs of boost up to 5500 reliably. What failed was my 700r4...not the engine.

shaggy56

Have any suggestions on a reliable rotating assembly? Do you know of any good assemblies that come from balancer to flexplate that come pre-balanced that will hold the power reliably for under $3000. I have a 2 piece 4 bolt main block if that helps. So many guys running this setup in stock block corvettes and Im getting alot of its going to be difficult. Im running a refreshed 1991 700r4 but I think it has the stock sunshell and drum. Im thinking if I baby it till I upgrade the transmission it may last a little bit. Im going to run 76 cc heads and hope to have my compression around 8.3:1 which will hopefully allow me to run pump gas,

Blownz28man

iTrader: (2)

When i built my first 355 that went in my 92Z28 w/p600b charger it was great at first. Was running stock crank, PM rods and KB pistons. Boy i beat the Heck out of it..FAST! But one day I was just crusing and it just died. Spent a few hours Diag..No fuel, no spark.. Than I noticed accessorys not turning. Yep sure enough.. Broke the crank right behind the timing gear..LOL I was told it was because that much stress was not to be on a stock crank.. Also was told it was a defective crank..Also told your not suppose to balance with a fluid damper. Also did it to a 383 cast crank. At that point I was PISSED! I say if your gonna run a charger at least run a strong crank. Learn from my mistakes and $$$. Also don't balance with a fluid damper (from what i've heard) Hope that helps a lil.

AC

iTrader: (3)

I bought and am running a fully forged, balanced, rotating assembly from Eagle. Thats the only thing at this point that I could recommend or speak about intelligently. I think I paid a little over 1800 from Summit
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BTW, my stock 700r4 with 31000 miles GRENADED 3&4th on the highway with my procharger setup. I was suprised. This was after only 6k-8k miles. BE CAREFUL with a stock slushbox....your gambling when putting anything stout in front of it.

shaggy56

BlownZ28,
I definately am going with a fully forged rotating assembly and I have a $3000 budget to do so. The issue I was facing is I was getting mixed opinions about the stock block handling the power.

AC

iTrader: (3)

Another tidbit on stock internals. I have a friend (fellow TGO member) who puts out 380 rwhp with his stock crank, 305 and 12+ psi D1SC....for over 2 years now. No problems yet that I know of on his setup.

shaggy56

That may be fine for a 305 but Im going to build a 383 and I will most likely be over 500-550+ hp and I doubt stock internals will last long.

Batass

I had my shortblock built for about $3k. Used Scat forged crank and rods. The guys said he liked them better than Eagle.

Actually if you keep your rpms down under 6k, the stock internals should have no problem with 600hp. But do you plan on staying at that power level?

Also if your building a new engine, you might as well go forged. I think my rods were only like 250-300 bucks and the crank was the same. Pistons were kinda steep because of the 6" rod and compression ratio I wanted with the 72cc heads.

Stock block is fine for 800hp. (4 bolt) 2 bolt will be only slightly less. The lifter valley seems to crack first. The older non roller blocks are stronger, and the ones from late 60's to early 70's are stronger yet, more nickel. My builder tried talkin me into using a non roller block but a retro fit roller cam kit is $$$$$ and I thought I would be fine. Now I'm looking to push 800-850hp, and kicking myself in the a$$.

shaggy56

Someone just offered me a set of brand new in the box 6 inch oliver rods for $300. He says they check out perfect and weigh 751 grams each. He said they have 7/16" oliver capscrews and are for a large jouranl small block. Any opinons do you think these would be ok?

AC

iTrader: (3)

Correct me if I'm wrong but won't 6" rods leave you with a real short skirt piston?? Those I were told (short skirted pistons) weren't that street friendly. I'm just remembering this but who knows, I'm no engine builder (I paid a race shop to assembly my shortblock).

Batass

You do have to use shorter pistons, never heard anything about that being a prolem though. The 6 inch rods are supposed to add durability over the shorter 5.7 with the longer throw of the crank.

shaggy56

Ive heard the same thing Im running 5.7 inch rods now. I wasnt sure if this was going to be ok. I may end up passing on it. Maybe go with some Lunati rods or something.

AC

iTrader: (3)

I don't want to start getting this off track but I don't understand how 300 thousands of an inch (.300") longer throw (using a 6.0 rod) would be more durable? Your throwing mass that much farther away from center putting that much more stress on the bearing surfaces. Again, we're only talking .300 so maybe its no big issue. I just remember when I ordered my 383 kit from Summit / Eagle they accidentally sent me the 6.0 rods with my kit and my engine builder called me to come in and see. When I got there he said those short skirt pistons weren't going to be that street friendly compared to the 5.7 rods because of oiling and ring life. I don't know. Get some opinions from local engine builders (performance ones) to get some more insight.

shaggy56

Definately not getting off track. I already know that the crank and pistons will be readily available and plenty to choose from. Im almost positive Im going with the Callies crank and SRP or JE pistons should do the job. I really dont want to skimp on the rods since this seems the top failure I see. Im trying to get away from the China imported parts though because thats what im running now and they give me butterflys in my stomach.

MYBLUZ

Correct me if Im wrong here, but I thought a Callies crank was a couple grand? Would kind of blow the budget. For whats its worth I got a forged set-up from Scat for $1875. I should have looked around for a dealer and saved a few bucks. I tried to buy my Procharger from the factory. They sent me to a dealer online and I saved like $1100 or more. And I DID save money on my car insurance by swithing to Gieco.

Batass

I think it has to do with the side force on the piston. Think about how the force is applied to the piston from the crank. The shorter the rod, the more side force to the cylinder wall, the longer the rod, the less side force and more up force.

Ive even heard the 6.0 can make more power, never heard anything bad about them. I'm sure someone on here with a lot of experience will chime in. Or maybe you should start a new thread......

shaggy56

Callies Dragonslayer 3.75 with 350 mains is $899. Compstar cranks are a bit cheaper but imported from Japan but Im trying to stay away from import stuff. Callies hardening process exceeds most of any other brand crank. I would be interested in the dealer who sold you your procharger.

joeblue83

iTrader: (8)

If you have the L98 block with the 2 bolt mains, I would suggest splaying the main before putting that much power to it. Its a little sense of security that the bottom end will hold together.

MrBrooks

Longer rod length does not change the length of "throw", that is all in the crank stroke. A longer rod corrects the geometry of the rod as it enters the cylinder, allowing it to go up rather than through the side of the wall. the wrist pin is thus moved up in the piston to make up for that extra length. When you order pistons you will state the rod length to get the proper wrist pin position. You're engine man was correct. I wouldn't worry about all that unless it's a daily driver rather than a weekend play toy.

WIll36

iTrader: (12)

Mr Brooks and Batass are correct by going with the longer rod you reduce the side load on the piston and thus the bores. I'm building a 408 and through a local builder i bought a forged scat crank, billet rods and forged SRP pistons for just of 1600 including shipping. I would recommend splayed 4 bolt caps on the center 3 journals, because they bear the majority of the load. I would also go with scat or eagle, because from the research I did before I bought my stuff eagles parts are machined overseas while scats cranks are cast overseas and machined in the states. Just my 2 cents but if your worried about fill the bottom third of the block to improve stability and it won't effect coolant and is relatively cheap

Batass

You meant to say Scat OVER Eagle right?

IIRC, Chinese steel isnt as good as ours, but I cant say Ive ever heard anyone complain about Eagle (besides the slightly sub-par machining) or Scat's stuff.

I dont think you'll make over 700hp with that superram. Might top out around 6500 rpms. Forged Scat crank and I-beam rods will easily handle that. Rpms are the roughest on engine parts and 6500 is still safe. You'd save yourself some good cash.

Splayed is a good idea but I dont think a necessity. Probably dont need a short block fill either.

How many lbs of boost do you plan on running? You could run 10psi on a completely stock shortblock and if you kept it under 6k and a little fat on the tune, it would last a very long time.

planey13

Better safe than sorry, build it once and build it right (says the man who blew up 3 engines!) Now I have a 4 bolt main block with Scat Forged internals H-beam rods and SRP pistons. Runs great! oh yeah I had studs intalled in the main caps, I guess this takes the potential for the short block from 450hp to 750hp capability its a 70s 010 block.