It does look pretty good internally. I never saw anything bigger than a 12" clutch on a Chevy truck, looks like I need to get out more.
I got everything removed from the block today (except camshaft bearings). Looks like the rod bearings for #5 cylinder failed which was causing the rod knock that the previous owner had mentioned. The main journals measured 2.3 inches and the rod journals measured 2 inches. The pistons/cylinders measured 4 inches. Upper main bearings were stamped: 57653 GMM420 293G5 (2x) 57653 GMM420 293J5 (2x) GMMA 57868 287HH5 Lower main bearings were stamped: 57653 GMM420 258N5 (4x) GMMA 57868 180A5 (the A was upside down) Rod bearings were stamped: 57734 GMM500 280N5 (4x) 57734 GMM500 280J5 (3x) 57734 GMM500 280J3 (1x) 57734 GMM500 288A5 (1x) 57734 GMM500 280B5 (1x) 57734 GMM500 253E5 (1x) 57734 GMM500 287X5(1x) 57734 GMM500 280A5 (1x) (the A was upside down) 57734 GMM500 280L5 (1x) unknown trashed bearings (2x) Crankshaft was stamped: 4577 (I didn't notice another number anywhere) Camshaft was stamped: K1 GM84 2798 Pistons were stamped: 3796494 bad rod bearings (#5) crankshaft wear from bad bearings (#5) rod wear from bad bearings (#5) #2 cylinder #4 cylinder #6 cylinder #8 cylinder #1 cylinder #3 cylinder #5 cylinder #7 cylinder
I take it that my first step would be to take the block, crank, rods, and heads to a machine shop to get inspected & machined? Also, how can I confirm if my heads are 60cc vs 70cc? Everything I come up with on searches of the stamp numbers point to 60cc.
Looks like i'm a bit late too the party here butt... I've been going some checking online and here's what i've found thus far. Block 3858174......................................................................'64-'67 327 Crankshaft 4577.................................................................... '62-'67 327 Forged Heads 3774684 (Pass. side)............................................................. '62-'64 283-327 75cc 3795896 (Driver side)........................................................... '63-'67 283-327 60cc Intake 3877652...................................................................... '65 283-327 2 Bolt main The flywheel, Cam, And pistions i didn't find because they didn't come in a z-28 Comaro so nastyz28.com doesn't list them. The head info. i got from Mortec.com so you know it's good.
Can that crank be saved? When I worked in a machine shop in the late 60's, we never went past .020 on a crank. But then there a lot of small block cranks around....The rest of the engine looks nice! Not to hi-jack here, maybe this will come up later, I saw pics not too long ago of a re- assembly in progress and the head bolts looked as if they had been wrapped with teflon tape?
Long overdue update for everyone! I'm just about ready to begin my build. Block was bored 0.040 over and decked 0.025. Crank main journals were turned 0.010 and the rod journals turned 0.040.
If you look at the front of the right side deck surface of the block you will see a water passage your new heads may not have it. If you drill the head using the gasket as a guide you will not have to use a circulation hose. It only needs to be done on the passenger side head.
What is that juice can sized canister just above the lifters/under the intake towards the back of the engine? I don't think that I've ever seen one of those before. Is that something that will go back in or can it be eliminated? Thanks—
It It's a oil separator for the pcv system. Definitely should go back in if your going to use the rest of the pcv system.
Just found this thread, great that you saved one! Realized it was old when I saw a post from George. Good news the crank could be saved, they aren't too easy to find.
Centre bolt [Vortec] heads with 8 bolt intake pattern, no heat crossover and raised intake ports. Here's an article on modifying the heads and another. A few more tricks here. Check you piston to valve clearance when doing things. Not sure if there will be issues with 327 bore and valves, hopefully someone more knowable will chime in with some up to date advice.?
I painted the block and installed the main bearings, main studs, crank, and rear main seal. Plastigauge on the mains was right at 0.002.
I installed the new oil pump (re-used the old pickup tube/screen), oil filter adapter, two piece dipstick tube & dipstick, timing chain cover, Vortec heads (.500 lift springs, machined valve guides, and .530 seals), hydraulic flat tappet lifters, pushrods, and rocker arms.
Before you get to far along with your build I would double check that the timing marks on the balancer your going to use and the timing indicator line up correctly with TDC on # 1 piston. It could save you a lot of grief later on.
Whatever you do, don't run that truck flywheel any faster than the governed rpm, which is probably 3,800 or 4,000 rpm. They WILL explode!!
Isn't that just like any other garden variety 168T 'wheel, only drilled for the larger clutch? If it is just a regular gray iron 30 pound flywheel then plenty of them have exceeded 6000 + RPM over the years. The factory, L-88 style nodular iron 15 pound 'wheel is safer but not good in a heavy vehicle.
FYI..I have read that you should not change the main bolts to studs, screws up the line bore..If going to studs the block should be line bored with the studs in use..Unless ARP says its ok..
Well I believe that truck engines that use that big adapter plate seen in the original pics on this thread, used a starter mounted to the adapter plate with 3 bolts and a 197 tooth flywheel...that is the flywheel that is limited on RPM.
You are absolutely right, and the 197 T flywheel is one I never knew existed. Had I taken a good look at that adapter I would have seen that the hole for the starter drive is offset to the outside, as compared to the offset for the smaller flywheel that is to the inside. Thanks for setting me right, xlr8.
That "juice can" was in all SBC from the begining long before there was a PCV top screwed to the block at the back. It was for the road draft tube then used as a PCV feeder. When the block was changed that device was redesigned and went in the valve cover. Great job by every one identifying all the strange parts not normally seen. I'm glad you changed the heads..
What cam are you using and what kind of induction system? This is a great thread, you do very nice work! Sent from my iPhone using H.A.M.B.
As you may have noticed, I plugged off the port for the old draft tube canister and will be using a PCV and breather on the valve covers. I checked and everything lines up exactly with the stock timing plate on the timing chain cover. I won't be re-using that flywheel & clutch. TEASER: it will be bolted to a BOP TH350. I am using a Speed Pro CS-1171R camshaft. It will have a Professional Products Cyclone intake manifold (#52007) paired with the Holley Sniper EFI system.
327s and 283s both could be had with power pac heads from the factory. Nuthin wrong with the heads at all, maybe not as in vogue as fuelie heads but they work and can be made to breath really well with a little elbow grease and a dremmel.
Wow, big turn in the road there-at least for me. Your engine your way. You've changed to newer cylinder heads, you're loosing the 327 breather system for side to side I guess because the intake you chose doesn't allow front to rear. You're putting an electronic fuel injection system on it and a slush box too. Why didn't you just use a 350 and leave the 327 for a more traditional type build?
As you will see, this entire build will be very non-traditional. I am doing this mostly for the learning experience and for fun. I stuck with this engine because it was free and you don't really hear of 327s.