Rusty bores

[Joe R.]

Here's the scoop. This is a L72 (427/425) car. I am restoring the engine because a shattered pushrod caused a wiped camshaft lobe. I had the short block done by a local machinist. But I let it sit for three years due to moving plus family and work commitments. Of course, I was 99 % done with the old garage when it was time to move. But, I digress. Now I have rusty bores.

Does that mean that at a minimum, the rotating assembly has to come out so that the cylinders can be re-honed? I am also interested in making more power, as long is it won't have judging consequences on down the road. For now, I plan to drive and enjoy it with my kids.

Anyhow, would it make sense to convert to a 454 rotating assy while I'm at it? Would a 454 perform the same as a 427 as far as ops or PV judging go? Would it make the same amount of vacuum at idle? I understand the 454 crank is usually externally balanced, although the crank can be internally balanced. Would there be any external clues? Did I forget anything? If a 454 is the way to go, what do you all recommend as far as which parts to use?

Joe

[Timothy B.]

Re: Rusty bores

Joe,

Why not try some navel jelly to see if that cleans the surface rust then look carefully at the cylinder finish, it may be fine after you clean it up.

If it's a 425hp engine with the solid lifter cam I don't see how a 454 and more $$ is going to run better and be more fun. My friend had a 425 1966 car and I believe it's the fastest thing I ever drove.

[Joe R.]

Re: Rusty bores

Joe,

Why not try some navel jelly to see if that cleans the surface rust then look carefully at the cylinder finish, it may be fine after you clean it up.

If it's a 425hp engine with the solid lifter cam I don't see how a 454 and more $$ is going to run better and be more fun. My friend had a 425 1966 car and I believe it's the fastest thing I ever drove.

Tim,

Is navel jelly the same as petroleum jelly? Maybe I'll give that a shot.

Well, you're right, it was a rocket when it was running. But, if fast is good, ain't stupid fast even better?

Joe

[Terry M.]

Re: Rusty bores

Tim,

Is navel jelly the same as petroleum jelly? Maybe I'll give that a shot.

Well, you're right, it was a rocket when it was running. But, if fast is good, ain't stupid fast even better?

Joe

Then there is navel lint. Please do not use navel jelly in place of petroleum jelly. Just the thought hakes me shiver.

If you want stupid fast go buy a C6, and hurt yourself real good.

[Joe R.]

Re: Rusty bores

Then there is navel lint. Please do not use navel jelly in place of petroleum jelly. Just the thought hakes me shiver.

If you want stupid fast go buy a C6, and hurt yourself real good.

Terry,

I guess I should have done a Google search before opening my mouth. At least I didn't say something really dumb.

http://www.amazon.com/Permatex-82138.../dp/B000GKW2Q4

Well, a new ZR1 sounds real good. But I can more easily afford a 454 rotating assy.

Joe

[Terry M.]

Re: Rusty bores

Well, a new ZR1 sounds real good. But I can more easily afford a 454 rotating assy.

Joe

You just said "stupid fast." A Z06 will do that. Now if you want REALLY stupid fast you have to go to the ZR1 -- I guess. I really don't know, but there are several guys who post here regularly who can attest to really stupid fast. Even at the deals one can get on a new Z06, or a slightly used one, they can't compare to the cost of a 454 rotating assembly. But then they (454) are not all aluminum 427 either. Oh well, it is all in fun Joe. So long as we are having fun the degree of fun is less important.

[Michael H.]

Re: Rusty bores

Joe,

If it was my motor Joe I would dis-assemble it and have it hot tank and cleaned up, all it would take is some rust to get into the bearings and you'll liable to be out a lot more time and money again.

Bring those pictures to the meeting tonight and get Jim A. opinion. As far 454 vs 425HP you'll have more that enough power with the 425HP motor, I would stay with the stock set up myself.

Just my .02

Mike

[Joe R.]

Re: Rusty bores

Joe,

If it was my motor Joe I would dis-assemble it and have it hot tank and cleaned up, all it would take is some rust to get into the bearings and you'll liable to be out a lot more time and money again.

Bring those pictures to the meeting tonight and get Jim A. opinion. As far 454 vs 425HP you'll have more that enough power with the 425HP motor, I would stay with the stock set up myself.

Just my .02

Mike

Mike,

Thanks for the input. I'll email the photos to Jim.

Joe

[Joel F.]

Re: Rusty bores

Joe,

Of course you can use or ignore this advice at your discretion but I had the same issue for the same reason. I asked an engine builder what to do and he said to simply use a green scotch brite pad and some soapy water and clean up the surface rust, followed by a thorough cleaning, light oiling, and assembly. Use extra caution however that you do not leave any of the green lint from the scotch brite as it will not degrade in oil in the same way a paper towel lint might.

I guess it might also depend on how bad the rust really is.

Joel

[Joe R.]

Re: Rusty bores

Joe,

Of course you can use or ignore this advice at your discretion but I had the same issue for the same reason. I asked an engine builder what to do and he said to simply use a green scotch brite pad and some soapy water and clean up the surface rust, followed by a thorough cleaning, light oiling, and assembly. Use extra caution however that you do not leave any of the green lint from the scotch brite as it will not degrade in oil in the same way a paper towel lint might.

I guess it might also depend on how bad the rust really is.

Joel

Joel,

Thanks for your help. That is very interesting. Did you try it? How well did it work?

Joe

[Joel F.]

Re: Rusty bores

Hi Joe,

Sorry, I did not notice the pictures the first time around. At a minimum you will want to disassemble the rotating assembly to perform that clean up to ensure that you can thoroughly clean it when done.

It worked fine for me, no issues whatsoever.

[Joe L.]

Re: Rusty bores

Joe,

Of course you can use or ignore this advice at your discretion but I had the same issue for the same reason. I asked an engine builder what to do and he said to simply use a green scotch brite pad and some soapy water and clean up the surface rust, followed by a thorough cleaning, light oiling, and assembly. Use extra caution however that you do not leave any of the green lint from the scotch brite as it will not degrade in oil in the same way a paper towel lint might.

I guess it might also depend on how bad the rust really is.

Joel

Joel and Joe-----


After viewing the photos, I totally agree with this approach. If the cylinders or deck surface were more heavily rusted or more extensively rusted I'd probably say this was not the way to go. However, based upon what I see, I think this will work fine. I don't think you need to disassemble the engine, at all.

As far as converting to a 454 goes, it can be done with very little in the way of external "cues" that it's been done. The only external evidence of it would be the rear configuration of the harmonic balancer ring. Even that could be eliminated by having the crankshaft internally balanced using mallory metal.

However, the conversion would be expensive for you at this point and you would not gain enough to make it worthwhile. If you were building an engine from "scratch", that would be a different story. Also, 454 steel cranks are expensive and, if you were to have one internally balanced that would add a great deal more expense.

[Joe R.]

Re: Rusty bores

Joel and Joe-----


After viewing the photos, I totally agree with this approach. If the cylinders or deck surface were more heavily rusted or more extensively rusted I'd probably say this was not the way to go. However, based upon what I see, I think this will work fine. I don't think you need to disassemble the engine, at all.

As far as converting to a 454 goes, it can be done with very little in the way of external "cues" that it's been done. The only external evidence of it would be the rear configuration of the harmonic balancer ring. Even that could be eliminated by having the crankshaft internally balanced using mallory metal.

However, the conversion would be expensive for you at this point and you would not gain enough to make it worthwhile. If you were building an engine from "scratch", that would be a different story. Also, 454 steel cranks are expensive and, if you were to have one internally balanced that would add a great deal more expense.

Joe,

Interesting, I thought for sure you would vote 454! Just for grins, roughly how much do you think it would cost to go the 454 route, including internally balancing the crank?

If I was to stay with what I have, how would I clean up the rusty bores without removing the pistons, rods, etc?

Joe

[Patrick H.]

Re: Rusty bores

A guy local to me thought it'd be cheaper to put 454 parts in his 67 427 than to buy the right stuff and bring it back to a 427/390. The original engine had been removed in 73 with the first gas crisis.

After all, they made a lot of 454s, right?

The short answer is, he was wrong. He spent enough on that engine that he could have easily purchased a correctly dated restamped motor and dropped it right in. We told him that ahead of time, but nooooo....

[Joe L.]

Re: Rusty bores

Joe,

Interesting, I thought for sure you would vote 454! Just for grins, roughly how much do you think it would cost to go the 454 route, including internally balancing the crank?

If I was to stay with what I have, how would I clean up the rusty bores without removing the pistons, rods, etc?

Joe

Joe------


A new GM 454 steel crank GM lists for about $900. Aftermarket steel are more. Finding a good used 454 steel crank can be difficult and will still be relatively expensive. If you were to have it internally balanced, it would probably run at least $400-500 more and you'll also need to completely rebalance the reciprocating parts of th engine. You will also require new pistons. If you don't have the crank internally balanced, you'll need a new flywheel and harmonic balancer.

I don't see any corrosion in the bores below the first 1/2", or so. If there is more corrosion, then you will need to disassemble the engine for thorough corrosion removal.