How old was the crank and was it a stroker crank? older stuff worked OK as was already stated it was maybe 5-7 years ago the Eagle cast cranks went to hell.

If a real racer is using a modern one maybe the reason the modern cranks are cracking is bad weight placement or something and they corrected it with machining before using it, or maybe the class requires it and he had it treated like cryo or nitrided or something to help it live.

Either way there is more too it, the Eagle cast cranks in recent years are breaking very often in modest power applications, usually strokers making less power than a decent stock shortblock with heads and cam, because if someone builds a stroker with a cast crank usually the rest of the decisions are terrible too.

 

These are serious questions. This is important info for us to help you. Part numbers would be nice too.

Call your machinist and ask what he used specifically for the crank. Brand of Crank? Cast or Forged Crank? This is important info for us to help you.

Over 10:1 means nothing here. How much over? Stock LT1's are 10.4:1 Changing nothing else except a .040" over bore and a 3.75" Stroke makes this 11.3:1. Thinner head gaskets, any block decking or head milling at it goes up from there. This limits your cam selection on 93 octane fuel. This is pertinent information we need to know to help recommend a cam.

Did he deck the block? If so how much.

KB pistons have a good reputation, are they forged also?

Are your control rods forged also? What length?

Have the heads been worked at all? Valve job? Guides? Port work (doesn't look like it)? New springs and retainers?

Given the little info you provided you cant run the hot cam in that motor, you will need a tune, you will not hit 400hp at the wheels and most likely will not hit that at the flywheel either.

$1200 left to finish this project sucks man. I just spent $4500 to rebuild my engine and I did all the work my self minus machine work. Machine shop ran me $1K.

Honestly in your scenario what I would do personally, I'd MAKE SURE the rotating assembly is fully forged. If it isn't already, get one and get a refund on the cast one from the machinist. I'm assuming the engine has never run? If you need this running for daily transportation the hit up craigslist for a used running LT1 and drop it in (that'll run less than the $1200 you have left) until you finish this build properly. You will need at least another $2000 to finish this build and hit 400+hp in just the engine.

Once you know for a fact the rotating assembly will stand the test of time and power (400rwhp is closer to 460-480 at the engine), then move on to the cam selection.

NOTE: The Cast SCAT crank isn't bad. The Eagle cast crank is crap though. Eagle forged is good, but all forged stroker cranks are a good bet. Better to forged than not. However, if he used a SCAT cast crank you should be fine.

Let us know!!!

BTW here's the monetary break down of my recently completed 400rwhp build (please note, I scored some pretty good deals on some of this stuff so your could be higher, but could be lower): I linked in what I bought.

Connecting Rods: $260.97
Rebuild Kit: $609.97
Heads (LE2): $1,100.00
Cam (Lunati 230/238); $ 235.00
Machine Shop*: $1,046.00
Harland Sharp 1.6 RR: $ 249.00
36# Injectors: $ 90.94
260LPH Fuel Pump: $ 49.98
Head Bolts: $ 46.00
3/4"-3" LT Headers: $ 200.00
3" ORY: $ 146.00
Oil Pressure Switch: $ 27.90
Knock Sensor: $ 40.94
O2 Sensor: $ 43.00
Spark Plugs: $ 17.39
Lubes, Sealants, Misc: $ 250.00
Total: $4,413.09

*Machine Shop work: Oven Bake, Bore and Hone, 0 Deck, Line Hone, Install Cam Bearings, Grind Crank, Balance Rotating Assembly, Assemble Pistons to Rods

This isn't cheap. As you can see I got a discount on an LE2 set up and with everything else added in it adds up quick.

 

Do you have a part number for the pistons?

 

I don't know about the age of the crank he is using. I'm willing to bet that he spent a lot of money on machine work if it spins 8k RPM's and there were many hours spent on the crank.

 

Hey guys here is an update on my engine. The engine is done, just waiting on the cam to be put in. I talked to a guy at JEGS that has over 7 93-02 Camaro's and has built them all. He got me a cam.

The duration at lash point in degrees (intake/exhaust) is 279/287; duration at .050" tappet lift (intake/exhaust) is 218/228; and maximum lift with 1.6 rocker ratio (intake/exhaust) is 525/525. Valve lash is zero/zero and lobe centerline is 112 degrees.

I have a kit coming with new 1.6 rockers, valve springs,valve caps,valve keys, etc. I have been fighting with my machinist about this. He bored my LT1 .040 over and stroked it 383 with a 400 crank. New crankshaft was put in. He told me stock compression is 9:5 and he is running in my engine atm 10:1. He told me if i go over 10.1 I have to run more octane fuel, but when I look up specs stock LT1 are running 10:4.1 so now I don't where to go from here.

I have spent 2900 in machine work, and I hate to of spent that much and leave horsepower on the table when I should be running 11.3-11.6 compression.

 

So you went with the hot cam? I'm interested to see how he got the compression down to 10:1. It sounds like you need a new machinist that actually knows LT1's. Good luck with your build and let us know how it all turns out.

 

Listening to the idiots of tech would have gotten you a better performing motor.

But, at least it will last and be reliable, the hot cam certainly won't be doing much for you.

 

OP

sounds like your builder is using gen 1 sbc formula and is not as familiar with the Gen 3 LT1. ask him how far in the hole your pistons are....or did he "zero" deck the block

ask him if he removed the oil galley check ball when hot tanking/cleaning the block...and did he put it back in. If he stutters....confirm it is in fact back in and was not "lost". It is located rear mail oil gallery adjacent to oil filter boss.

what thickness head gasket did he spec (assume he had to spec something to figure CR). if it was the .050 F-body one, run the .029 "iron head" one which will help bump up your compression

I see the stamped rockers...so going with a RR will be better

what brand, part # is this cam you got from JEGS?

 

Where is the picture of the star treck guy doing a facepalm? That fits here.

Shownomercy, it won't be reliable if it has a cast eagle crank.

 

375-cs9966

 

Jesus dude..... I sincerely feel sorry for you wasting your money on something that will be lucky to see 350 HP. That machinist is definitely not up to date on anything past a GEN I SBC. An LT1 can run almost 12:1 compression safely on pump gas, stock is 10.4:1 so he doesn't know what he's talkign about. That cam is the Hotcam and is too small etc etc. It's too bad really.

 

That's a p/n for a FelPro gasket set. Maybe I missed it but do you have a Eagle cast crank?

 

With a what, 6000rpm peak, and a baby small CR, I am sure that crank will last.

Least I hope so.

 

809-12480002 sorry was wrong part number.

 

....ah that is a part # for a gasket set. not the cam JEGS advised, whatever that is

Op

I, and others, have offered advice to your ?'s albeit some responses were harsher than others, we are all saying that the build is just absolutely backwards. You have dug a hole in terms of what has already been done to the motor. Suggestions have been offered to salvage some increase in performance (like NOT using the hot cam). The Lloyd Elliott cams for stock heads would be way better...although with such low compression and what are most likely very heavy pistons you will be hard pressed to even match HP of a stock LT1. Because you have more cubes now you may see some increase in TQ but the lower compression is not helping

Good luck

 

If the machinist was as dumb as it seems what are the chances much else was done right.

 

OP, stop taking advice from people who are after your money (JEGS and your machinist) and start listening to those who have nothing to gain from your success or failure, like those on this board. We've offered advice and asked questions to try to help you and you keep disregarding it. Please go back and read this thread and go to your machinist and show it to him.

Stock gen II lt1s have 10.4:1 stock, LT4s have 10.8 and run pump gas. Stock rings are thin low drag 1.5/1.5/3mm not big *** old school rings. Cast eagle cranks break constantly and are weaker than stock. A hotcam is too small to get anywhere near 420 flywheel hp on a stock lightweight low resistance 350, never mind a low compression heavy piston big ring 383. Cubes don't add power, heads and cam do.

 

If anything, it'll be a torquey stump puller. Power band will be from about 300rpm to 4000rpm before the power curve will ski jump its way down into oblivion, kind of like the old L98 power curve.
You are going to starve that engine until you get some decent ported heads and a good cam in it. Once you do that, and run a thinner gasket you should make some decent power. I wouldn't dismiss the short block being a hindrance as of yet...

 

What about the forged eagle cranks? do you all think they are junk?
noticed there are several for sale on fleebay.

 

Durability wise they are fine. However the machinist should check the tolerances before putting it together to ensure it is within spec. Mine balanced nicely, didn't have to put any metal on it, but the crank snout is a tad undersized and the pilot hole and flywheel/flex plate flange are a tad oversized.