Hey everyone I have a potential olds 455 lined up for my 73 cutlass S complete motor for $400. It's making a knocking sound which from what I've read sounds like a thrown rod bearing or crank (main bearing) I don't mind getting my hands dirty and taking the engine apart and fixing it. My question is with this knocking sound what are the chances the engine block its self is damaged? If it's a main bearing I wouldn't mind installing a new crank shaft if needed or if damage was minor replacing the bearing. I just don't want to end up with a fucked off block. I will copy and paste the YouTube link so you can see and hear for your self.

 

Sounds like an exhaust leak to me.

 

I hate listening to videos, can never make out specific noises. It sounds like a combination of noises from exhaust leaks, to valve train, and lower end.

 

My main question is would it be worth while to buy this 455 and repair it ? Or am I taking a big risk?

 

If its cheap enough, rebuilding these old engines is always a crap shoot until you get it apart and inspect it.

 

Could be a rod, but it could be the flex plate as well. Won't know until you get it apart.
I bought a 455 25 years ago that ran just fine...for a month then it spun a rod bearing.
I would say rip it apart and go from there. For $400 you have a good start, but you'll have to open it up to see what's going on in there.

 

I'd offer him $200, I'm sure there is not a line of people to buy it.

 

Could cut open the oil filter...

 

Cutting up the oil filter could show me if there is internal block damage from what ever is banging around in there. As if there were any metal shavings in the oil filter? That's my big concern block damage. Worst case senario i disassemble the engine and find irreversible block damage.

 

I would chance it for the right price. The chances that the block is trashed from that noise, to me at least, are negligible.

 

Ok thanks from what everyone I've showed this video says about the same "you don't know until you open her up" lol but most people believe it's a rod and that isn't to bad of a fix. He's asking $400 for complete motor -exhaust manifold. I believe I could get it for a little less, so I think I'm going to go for it.

 

Let us know how it works out.

 

Yeah I'll keep people posted looks like in two weeks I'll be grabbing this 455 and we will hope for the best!

 

Update on Olds BIG BLUE. she came home with me yesterday engine + transmission $500. Motor complete -exhaust manifold. This weekend I'll be disconnecting the trans bagging it and storing it. Then mounting the engine on my engine stand to take apart and inspect. My mechanic really seems to think it's just a thrown rod. We will hope for the best. Keep you all posted .

 

If it "threw" a Rod it would most likely be hanging out somewhere.
Do yourself a favor, if you plan on making ANY hp at all, put a set of Eagle H beams in it along with a decent piston. You'll be glad you did.

 

Update. I found one of the pushrods with play in between the lifter. It's on my engine stand and I have pulled the cam which looks good. Tomorrow I'm pulling the heads, valves, and crank. Where I stand now I'm going ahead with a rebuild. Why not? The engine is already naked. I ordered new. Harmonic balancer, timing set, pushrods, valves. Hydraulic lifters, all new gaskets & water pump. After I pull the crank and pistons I will inspect then get the block re-honed and as long as the parts pass inspection I'm putting her back together. After I have the crank dialed in at the shop with the block. Just thought I would throw an update on here

 

Good luck with the build. Keep us updated.

 

If you bought the Comp rocker kit then the pushrods will most likely be wrong.
And now that you have it apart, I'd rebalance it since you're replacing the balancer.

 

Oh btw that brings up a good point the rocker arms haven't been purchased as of yet. Which manufacturer do you recommend buying them from. I was having a hard time finding them through summit.

 

Before you put in all those expensive parts, make sure you check the cylinders for taper and out of round. Do you know how many miles were on this build before the knocking started? Or if it was built right to begin with? Might want to have a machinist look it over and take some measurements.
What heads did you get with it?

 

I have no idea how many miles were on the engine previous to me purchasing the engine. I'm putting together the money needed to send the block out to have dipped, inspected, painted, and they are going to dial in the crank as well as a valve job. Once I get it back I will continue the build. The engine is a Fa block with the z bar taps and it came with C heads.

 

C heads are a plus. Sounds like you're on the right track. My 455 build is going pretty slow but sure. If you're having the rods reconditioned with ARP bolts, make sure the machinist separates the caps for you. Mine are stuck on pretty good. I think the knurls on the ARP bolts are a little grabbier.

 

Thanks macadoo, I have also noticed I have low compression pistons. Which at this point I plan on replacing as well. Max out compression while I have the block naked. It's slow going.But nonetheless will get there. Can you clarify what ARP bolts are. This is my first go around here and I'm learning as I go. Haven't quite learned all the basics... yet

 

ARP is a brand of high performance bolts and studs. They're supposed to make things more rigid and are stronger. I have both connecting rod bolts (that bolt the caps to the rods) and main cap studs.





https://www.ebay.com/itm/ARP-185-600...1VhaWQ&vxp=mtr

I finally got one of the rod caps off today using an expensive tool. They are insanely tight!
I'm learning as I go myself. So don't take my experience as normal, lol.

 

That's really not the real reason. Main reason is because big block Olds rods will spring apart once you unbolt them, just like Ford FE rods. That's one of the many reasons why I don't use them. Just an FYI.

 

So, the stock bolts are just so loose that they don't give us the same problem?

 

Yes they can be.