2 Bent Pushrods in 350 SBC

[Decline]

I prbly should have tested the compression before I tore it apart. I was expecting to see piston to valve contact. There was none. How can I inspect the cam? Pull it out or just remove the #8 lifters?
The rest of the push rods on the even bank seemed straight by the roll method. The rockers on the other bank seemed pretty loose. Those push rods also seemed straight.
I would to get this engine back up and running while I decide on the future. Could it be as easy as 2 push rods and a valve and maybe a new flat tappet cam?
Also I need to figure out a better way to post pics. Should read that sticky about it posted somewhere.

[GregWeld]

Originally Posted by Decline

I prbly should have tested the compression before I tore it apart. I was expecting to see piston to valve contact. There was none. How can I inspect the cam? Pull it out or just remove the #8 lifters?
The rest of the push rods on the even bank seemed straight by the roll method. The rockers on the other bank seemed pretty loose. Those push rods also seemed straight.
I would to get this engine back up and running while I decide on the future. Could it be as easy as 2 push rods and a valve and maybe a new flat tappet cam?
Also I need to figure out a better way to post pics. Should read that sticky about it posted somewhere.

You should be able to see the cam thru the valley in the center of the block - looking down from where you removed the intake.... There's plenty of room to just look straight down there... and yes - pull the lifters out -- but keep them so that you know exactly which lifter bore they came out of. If they're okay -- and the cam is okay - then they need to go back to the bore to which they came. DO NOT mix them up. What you want to do is to feel how the lifters came out -- they should come out with zero effort - and be smooth... and not "sticky".

You can rotate the motor by using the crank bolt (after pulling ALL the spark plugs).... at the crank pulley (the lowest one). You can put a socket on it and a half inch ratchet or breaker bar and slowly rotate it. As you do this - look at the lobes on the cam. There should be NOTHING on the cam lobe that looks weird or ugly or scored or anything other than wonderful.
Make sure all the plugs are pulled -- and the car is in neutral.... if it doesn't rotate pretty easily theres something not right -- you're in gear -- or all the plugs aren't out - or?? There's no compression with the plugs pulled... What I'm trying to say - is don't force it if it doesn't rotate fairly easily. You don't want to break off the crank bolt!

[GregWeld]

I don't see any guide plates on this motor --- and that might have been the issue -- when you started to run the auto cross etc - you're revving the motor... and maybe the rocker started to wobble -- and the pushrod got caught up in the whole mess and bent - starting the motor to run rough.... and then spiraled from there.

I've never run a SBC without guide plates!

[Decline]

It's possible I may have over rev'd it at Del Mar. I put the TH350 in 1 and ran the course without shifting.
The lifters are solid. I will attempt to pull them out tomorrow. I need to check the springs for binding or a stuck valve. I'm also going to drain the oil to check for metal and try to rotate the crank and see if it moves freely.
I might as well pull the other head off now too..seems like good practice

[GregWeld]

Welcome to hot rodding..... LOL

[Vince@Meanstreets]

Originally Posted by Decline

It's possible I may have over rev'd it at Del Mar. I put the TH350 in 1 and ran the course without shifting.
The lifters are solid. I will attempt to pull them out tomorrow. I need to check the springs for binding or a stuck valve. I'm also going to drain the oil to check for metal and try to rotate the crank and see if it moves freely.
I might as well pull the other head off now too..seems like good practice

them oil deflector springs don't like high RPM. I agree on the guide plates.

[Che70velle]

Agreed. Guide plates are necessary for high rpm's. If your going to keep what you have here, meaning the small block chevy, I'd invest in a set, and have a quality minded machine shop set the heads up for them. As Vince stated, lose the cups on the springs...they are heavy.
You stated that the rockers were loose on the opposite bank. You also stated that this is a solid camshaft, and not a hydraulic. That tells me that you have an issue, as the rockers should not seem loose, unless you are referring to side to side movement from the lack of guide plates. A solid cam will hold its end play, so you shouldn't see any noticeable movement at the rocker. .010 to .012 is an average number for rocker to valve clearance, which moves very little with your hands. The rockers that you have are self aligning, and aren't a bad piece, you simply need your valve train to operate as a complete package, and a set of guide plates will compliment the valve train.
If your happy with your camshaft, and it isn't hurt, have your machinist set up your heads correctly. They will set the spring heights up according to your camshaft specs, and help you make sure that when this all goes back together, it will be correct. If you end up with a new camshaft, have them set up your heads to the new cam's specs. Pushrod length, spring installed height, rocker to retainer clearance, coil bind at full lift, are all important issues with a performance oriented valve train, so pick your machinist wisely. Triple check your settings after your all back together, and pull your valve covers every now and then, to go back through them with a feeler gauge to find problems early, before this happens twice. Solid lifter camshafts are fun, but are high maintenance.

[Decline]

More investigation of the crime scene commenced this evening.. I removed my crappy old leaky water pump to gain easier access to the crank bolt. The only accesories left connected to the block right now are the power steering and the starter. I attempted to rotate the bottom end and it spun fairly easily. I applied some shell rotella i had laying around to the cylinder walls and faces of the pistons and mating surface of the block so it wasnt dry. Then i pulled the #8 lifters out with a magnet. They slide out pretty smoothly(and dropped back in well also) All the lifters cycled smoothly as well. The one area of concern is I think the #8 exhaust lobe had like a small nick on it? Might have been oil but I tried to get a couple good pics of it. I dunno. Its a mystery.

My uncle thought it was weird that both push rods go in one cylinder at the same time. He thought the wrist pins let go. I only spoke with him on the phone and he hasnt seen the engine. I feel like the bottom end is fine
Other theories are that I floated a valve and screwed up the valve train but it took a couple weeks/drives for it to manifest itself in the bent PRs

Option 1..My friend at work knows a cylinder head shop that does good work but I'm torn spending like $2-400 fixing 1 old iron head. I need to call for an official estimate. This would be the fastest cheapest option. Maybe add another $150 for a new flat tappet cam that matches the existing springs

Option 2. I'm also conflicted on spending money on aluminum heads and guide plates and roller rockers and push rods ands a new cam. My engine leaks from the front and the rear and maybe the trans also? Not alot of fluid but enough to make a mess of my fancy suspension and annoy me in general
I guess $1500 isnt terrible to be back up and running and with like 75 more hp..

option 3
Get another engine. Definitly the long road and most exspensive. The LH6 i found on craigslist sold..Dammit. I would of had to refresh it anyway but the long block sold for $750. An aluminum 5.3 with 243(LS6)heads would have been sweet.. The GMPP carb intake manifold and MSD LS controller are about another $700. I need a flex plate to adapt the trans to an LS. Headers that work with an Art morrison front sub $800ish, the AME engine mounts. Anything else Im missing?

Ive got some decisons to make. In the mean time I put the passenger side head back on with 2 bolts and put the valve covers and manifold back on to kind of seal the motor up.