I agree with almost everything Dave and CJDave said, especially about, "In God we trust, everything else gets checked with a micrometer'! That is an absolute fact in engine building. Take no person or company word for anything, check all measurements at least twice, and that includes fastener torques. A complete mock up assembly is an absolute requirement before final cleaning and final assembly also. Don't wait until you put it together to find out something is wrong.
As I understand it, forged steel crank shafts are a little more scarce on the west coast than they are here. Still, all in all, almost every pick up truck to heavy truck chevy made in this country, with a 350 in it, had a forged steel crank, (so did most station wagons).
Forged steel crankshafts are not needed unless you plan to make more than 375 to 400 honest horse power.
The most important thing to note here is, unless you are making 400 honest horse power on a daily basis, you DO NOT need a 4 bolt main cap block.
Factory four bolt main caps start to fail about 550 horse power. (the material in the arch just starts to give way under the stress)
Head gasket, piston, connecting rod and main cap failures are 99.99% DETONATION INDUCED, not defective part failures. Detonation simply hammers the weakest link apart, and is hard as hell on every thing else.
If I remember right, most of the four bolt main blocks have a 010 cast into the bell housing flange on the drivers side top. The 020 were the two blot main, the 030 were the so called 'pressure castings' (don't worry about the 030 castings, none of them should have survived to this day), and the 040 castings were the high nickel 'industrial' engines. You will also find this number cast into the front of the block in the timing chain housing, and sometimes in the bell housing. Not to say that all 010 castings are 4 bolt mains, because if chevy was out of the 020 castings, they would use the 010 castings and only machine it for the two bolt main caps. Some were cast with both 010 & 020 in some places, and I never figured that out or could find anyone that could tell me...
Four bolt main cap 350 blocks grow on trees around the midwest. So many heavy half ton pickups (towing package), 4X4 anything, and 3/4 ton pickups, not to mention all of the station wagons and large farm trucks that had the heavy duty engines in them.
There are still a few of the 040 casting in the salvage yards around here. Nothing like a casting with 5 times the nickel content of the normal production cylinder case. It was used in combines of all things, and we have farm fields full of used and abandoned farm equipment!
(Anyone remember the forged steel crank, high nickel four bolt main 327 engines released as 'Industrial' engines in the 60's and early 70's? They can still be found on stuff like irrigation pumps, large generators, and in combines.)
Everyone overlooks the chevy SB 400 engine. Never released with a forged steel crank, all of the 400's had nodular iron cranks. The cylinder cases released in '70 & '71 had 4 bolt mains.
These 400 CID engine blocks were easy to identify, because they had a third freeze plug boss cast in the middle of the side of the block. The 4 bolt main versions (70 & 71) actually had the extra freeze plug, while the two bolt main versions (72 & Up) only had the boss, and no actual freeze plug.
It should be noted, that with the 400 you get 50 extra cubic inches, but the engine was externally balanced SBC and must have a 400 ballancer and flywheel or flex plate, use the only oddball connecting rod in the SBC family, only offers a cast crank, and the biggest draw back, had 'siamesed' cylinder walls. (Meaning the cylinders were so big, and so close to each other, that the cylinder walls actually connected to each other.
This made for a thermodynamic nightmare as the block expanded and contracted, and also trapped 'steam' at the top of the cylinders. Chevy solved this problem by drilling 'steam holes' in the block and head to bleed the trapped air off, but re builders rarely reuse the horrible 400 heads, and just as rarely drill the steam holes in the new heads, causing hot spots and heat distortions in the top of the cylinder.
All chevy's since 1958 have had forged steel rods, and I agree that the stock rod bolts are sadly lacking. I recommend SPS or ARP.
We hear so much about the 'Pink Stripe' connecting rod. The 'Pink Stripe' rod is nothing more than a pick up truck rod that has been shot peened twice. We successfully use stock production rods every day for up to 700 horse power engines.
(All we do is X-ray, magnaflux, resize the big end, bore the small end for floating rods, sometimes bush the small end, polish rod beams, stress relieve, double shot peen, buy & change the rod bolts, and balance..... By the time we find 8 good rods, throw tons of labor into them, and have them ready to use, the customer would have been better off buying aftermarket rods that were stronger, and ready to use out of the box...)
The hot ticket in chevy heads right now is the introduction of the Vortec V-8 heads! These are the best iron heads chevy has ever produced! You will need a new intake though, because these heads are nothing like the regular small block heads on the intake side.
They feature straighter intake passages, air flow guides in the intake pocket, no EGR passages, spark plug relocation and a host of other improvement that chevy has been dragging their feet on for 30 years. I only hope that an aluminum set isn't far off!!!
The valve rotators on chevy heads that CJDave spoke of are not really necessary anymore with the advent of hardened valves and valve seats. In the days of cast iron valve seats, and soft steel valves, rotators were an absolute must! If you choose to install rotators, don't forget to take the height of the rotate into account while measuring your spring install height. We get 3 or 4 cases a year in the shop here with a 'Mistery' problem, and missing rotators, or rotators installed with full size springs will be the problem.
I saw cam break in mentioned in one of the preceding posts, and that IS a problem in all engines, now more than ever.
Cam profiles are getting stiffer every day, and the ramp angles, ramp velocities, and spring pressures are really on the verge of insanity.
(Why 'Detroit' hasn't gone to electronically controlled valves before now is beyond me.
Just think about that for a minute, change your cam profile with a credit card swiped through a reader under the hood... How cool!
How about a switch on the dash that lets you go from a 400 HP cam to milage cam for highway driving...?)
Every cam manufacturer is different, but most want you to start the engine and keep it at 2,000 to 2,500 for 20 to 30 minutes now to break the cam in.
How many small time builders do you know that are ready to fire the engine and go straight to 2,500 RPM for 30 minutes? How many do you know that can static time the engine, static tune the carb, and have all of the connections and hoses correct at first firing?
We are lucky, we can break them in on the dyno, but most shops don't even have a test fixture to hold the engine for break in.
I have been thinking about a test fixture just for breaking in the cam. Some sort of engine cradle, an electric motor drive for oil pressure, and mock spring pressure on the lifters, and an electric motor on the cam at the required 2,000 or 2,500 RPM...
No timing drive, just drive the loaded cam until the required break in is done.
What do you guys think?
Later folks, Aaron.
So many cats, so few recipes...
