Shot peening engine block question

[SS427]

The engine out of our Yenko is just too crusty with surface rust and 50 year old paint that thermal cleaning will not do it justice. Our local machine shop (Tim Wilkerson FC owner/driver) owns the shop. Their tech suggested I use their Ampro shot peening machine to clean the engine. I will admit that all the blocks they had in house looked great though none were Chevy blocks. I was concerned about loosing the stamps of the front pad as well as broach marks though they insisted this would not be an issue. The pad on this engine is not in the best of shape and I would like to try and bring it back best I can. Before I make a $20k error has anyone here used this or a similar system to clean their blocks and what were your pros and cons. It has also been suggested that I make a steel bracket that protects the pad area so I will likely be doing that anyway but before I ruin anything I wanted to check. From all that I have talked to there is no issues with cylinders, bearing saddles or anything such as those areas.

[MosportGreen66]

Hi Rick, while I've never used such a proposed service, I do echo the sentiment that the engine pad surface (stamp + broach marks), cast date, and cast # need complete protection. Is shot peening like media blasting? You also want to ensure the residual media is not inside the block post cleaning process and reassembly.

Good luck.

Dan

[k92]

I have has great success using glass beading on blocks and heads like this.If you want to be safe, cover it up, but I really dont think the glass beads would damage the stamping or broach marks.

[L78steve]

It looks like the broach marks are already gone. I would glass bead the stamp area then plate it before its cleaned. Are you shot peening or shot vibrating?

[bugsy]

just took a block to get shot peened and magved. we use silicone or a magnet that covers the deck ares for vin and letters. hope this helps.

[Billohio]

The engine shop I use has what I would assume is the same machine. It rotates cylinder heads or whatever they put in it in the top and then there's some device in the bottom that throws shot up and cleans the block or heads. I've had heads done in it and they come out looking like new. This guy does mostly race engines and seems to like the machine real well

[marxjunk]

shot peening and shot blasting are 2 diff procedures..

shot peening changes the surface and adds strength and promotes stress relieving..they shot peen Z28 rods for strength and stress relief..makes the rods perform better..you can actually see what shot peening does on a pink rod..its dramatic

shot blasting removes debris and surface scale....it doesnt change it deeply on a molecular level like shot peen..

shot peen gets a a specific media and air pressure changes the characteristics of how the "grain" aligns in the structure..its actually calibrated, by shooting beads at a metal gauge, and the distortion is measured and that determines what it does..it really changes the surface look and texture....the ole.."lemme roll it around in the shot peen thing" does not work as intended..theres science to it..metallurgy

thermal cleaning goes a long long way to restore the surface to original...the beads are pretty soft...it breaks the bond scale has to the metal..it also boils all the grease out of the pores..so its nice and clean and can oxidize immediately

the ampro machine does not peen it, if thats what you are afraid of...its the best system ive ever seen or used..i recommend it...i would think youd notice a 50-75% improvement over whats there right now..i use it on pulleys and things like that, it doesnt distort or change the machine marks, etc..i really like it for resto stuff...BUT..ive never had a Yenko block either..i understand the worry..ive seen it bring broach marks up better...with out it changing the readability..if that makes sense

find the worst block you have..send it thru..judge yourself..thats exactly what i would do...

[SS427]

Thanks all for the input and yes Mark, I misworded that as it is NOT shot peening but rather shot blasting. HUGE difference!

I can see broach marks on some of the deck but not in the area that the stamping was done as it was just too pitted. I am hoping that it shows up better once blasted. I am not as concerned about the broach marks as I am the VIN stamping but will likely put a plate on it regardless just to make sure. I was also told by someone else that the rocker studs should be removed as the blasting tends to round the threads.

[olredalert]

----Just spitballing here but how about soda blasting?.......Bill S

[SS427]

I live in the capital of Illinois, population 170,000 people (and no it is not Chicago :) ). I am lucky to find a hardware store let alone someone who does soda blasting. Ditto for plastic media as I have to go to Decatur for that. Good suggestion however.

[L_e_e]

I built a couple 392 Hemi's a few years ago and had the blocks shot blasted and they came out looking like new, the factory number stamps remained unaffected.
The lifter valley looks a little shiny as it was slightly smoothed before blasting.

[marxjunk]

Rick..Im getting ready to send off a batch to be thermal cleaned..i will take before and after pics for ya...

i have some 2.02 69 heads etc...it will not remove pitting, but it will not touch striations and extrusion marks...i have some steel and some alum going tomorrow...i will get some pics..it takes my guy a week..but i am never in a real hurry..he has an ampro system like your pics...i use it on everything like clutch pedals, brackets, pullies..i have a good asst going in..so it will give a good idea

the whole secret is new media...it makes a diff..a big diff..he called me last week and said he changed the media...so its really nice on alum..i run the separate...alum first then steel..

if you have really rusty steel..the alum will have a brown haze...if you do the steel first

i want to do a steel wheel this time...ive wanted to for some time..and am running one thru..i have concerns because it will burn the paint out of the joints..i wonder what that wull do..i want to experiment on a couple..im afraid rust will bleed out of the cracks etc...

[bbbentley]

I have a block (bbc) that has had the lifter valley that appears to have been shot peened. I can only assume it was to aid in oil drain back? The texture is smoother than the rest of the cast surfaces. If it had not been for my penchant to test fit everything before assembly, I would not have caught that the peening had distorted the tops of each lifter hole preventing lifter installing. Deburring corrected this. But be aware that distortions are possible.
On another bb I have that was rusty, the shop put it in a blast cabinet with a caustic soda rinse. Now, you have to use a magnifying glass to read the pad. Guess the shop screwed that one up? So, be careful. I like the magnet idea On the pad mentioned

[resto4u]

I would by a 55 gallon drum of safest rust remover and drop it in.

[Lynn]

I was going to suggest evaporust. I think it is comparable to safest. Might be expensive, but it does a great job of removing rust and leaving everything else.

[CamarosRus]

Rick, In another thread you, I and others were discussing cleaning parts in general.

Ive had all kinds of the other chassis parts, eng brkts etc etc....run through a local
shot blasting machine. What with all the massive shop time you charge customers
to stand in front of your slow glass beading machine, you need to take most of your other steel parts to the shot blaster assuming the cost is acceptable.
My shot blast guy also has a enclosed basket that I place fasteners into and then
shot blast. Ready to replate or you could quickly run thru your glass beader


Ive also bought a used MrDeBur shaker/vibrator which is another option to clean
restore metal finishes.

[SS427]

What with all the massive shop time you charge customers to stand in front of your slow glass beading machine

Chuck, glad to see you have analyzed how I run my business and seem to know how and what I charge our customers.

I currently use several forms of blasting for our customers; plastic, aluminum oxide, sand and shot. However, we normally do these in large quantities to keep the costs down low not to mention the drive time, fuel and labor costs to deliver and pick up. The glass beading cabinet is used primarily for small trinket parts and ones that will be dipped in paint as I do not want them to be etched. Also when we need to have something blasted immediately and cannot wait to take them to the commercial blaster.

I get your point though about wasting peoples time and money. Had it done to me a time or two.....

[bbbentley]

I was going to suggest evaporust. I think it is comparable to safest. Might be expensive, but it does a great job of removing rust and leaving everything else.
Just as effective and cost a LOT less is white vinegar. I can get a gallon at the dollar store for a buck. I would think a 55 gal. drum could be bought through Costco, GFS, Aldi, Sams?

[SS427]

I actually bought a tub, sprayer, hose and several gallons of Evapo-Rust (which I use lots of anyway) and just decided this block was just too crusty to go that route when for considerably less time and money I could have it shot blasted. I use Evapo-Rust on brake pedal assemblies, e-brake assemblies and many other components that were bare steel when assembled and it works quite well.

[CamarosRus]

Rick....You had earlier stated " We spend hours a day at the glass bead cabinet for things like spindles, steering arms, brackets, clips, etc and it is a complete waste of time when I could be having a machine do it automatically for me while we do something more constructive. The expense does not really bother me as that could be paid for in less than a week in saved production time alone."

I certainly didnt mean to imply you were overcharging anybody. I was suggesting that shot blasting and vibratory tumbling/shaking would cut down on your labor hours and increase your shop productivity.

My best regards,
__________________

[SS427]

Understood Chuck. My bad.

[TopRat]

Thanks all for the input and yes Mark, I misworded that as it is NOT shot peening but rather shot blasting. HUGE difference!

I can see broach marks on some of the deck but not in the area that the stamping was done as it was just too pitted. I am hoping that it shows up better once blasted. I am not as concerned about the broach marks as I am the VIN stamping but will likely put a plate on it regardless just to make sure. I was also told by someone else that the rocker studs should be removed as the blasting tends to round the threads.

I’ve had many of my blocks done Rick and it doesn’t hurt the stamping 👍🏻

[SS427]

I decided to have mine done and to be safe, made a plate to cover the VIN. The block turned out great and no damage anywhere. Based on what I saw of the block it likely would not have harmed the stamping or broach marks but decided to leave it virgin instead.

[NorCam]

My engine builder has a shot peen cabinet and a tumbler. On all of his higher end engine builds, they are hot washed, shot peen'd and then tumbled clean. I must say that the blocks turn out great. I was so impressed I asked him if he could do my 610 intake for my 68 and ho obliged.

It turned out great as well. I'll see if I can find a picture of my block when it was cleaned. Here's the intake before I added the correct M intake bolts.

https://preview.ibb.co/j5q3JT/IMG_8669.jpg (https://ibb.co/ifxTk8)

[Niblet]

shot peening and shot blasting are 2 diff procedures..

shot peening changes the surface and adds strength and promotes stress relieving..they shot peen Z28 rods for strength and stress relief..makes the rods perform better..you can actually see what shot peening does on a pink rod..its dramatic

shot blasting removes debris and surface scale....it doesnt change it deeply on a molecular level like shot peen..

shot peen gets a a specific media and air pressure changes the characteristics of how the "grain" aligns in the structure..its actually calibrated, by shooting beads at a metal gauge, and the distortion is measured and that determines what it does..it really changes the surface look and texture....the ole.."lemme roll it around in the shot peen thing" does not work as intended..theres science to it..metallurgy






Yes there's specific media and pressure, but it is NOT rocket science, its just hitting the surface with shot and making sure you get 100% coverage,, nothing really scientific at all,, we shot peen transport catagory aircraft parts all the time,,,its just selecting the right size shot and hitting it with the flapper wheel at a certain speed and verifying you get coverage
lets not overthink this,,thats what engineers do

[Justoldchevys]

The biggest problem I have found with the process seems to be time in the machine
It will cause problems with the broach and stamps but moreover that too moch of a good thing will alter lifter bores and put shot in every hole that is hard and time consuming to remove . I worked in aachine shop and we used hot tank
We had a. Freinf who used.ampro and I did not like the extra work it caused. Since it has been baked I would finish with a wire brush
Nothing worse than building your engine and then to find out the lifter. Bores areessed up
Good luck

[njsteve]

I would buy many gallons of the evaporust and find a plactic bin just big enough for the block. Line the bin with heavy plastic sheeting to reduce the amount of volume you need to fill with the fluid. Find a outdoor pool heater and put that in to get it up to around 85 degrees. Let it soak.

Remember the rusted 455 crankshaft I found for the Gramma car engine build?

https://www.yenko.net/forum/showthread.php?t=113621&highlight=evaporust&page=7

[SS427]

85* wine coolers, yuck! j/k ;)

[Xplantdad]

85* wine coolers, yuck! J/k ;)


lol!

[HawkX66]

For future rust issues... I've used the higher percentage acidity vinegar on quite a few things and it does better than Evaporust in my opinion. This gas tank was completely crusty and full of rust scale. It was a serious candidate for a new tank, but someone suggested the vinegar trick. I filled it, let it sit for a few days while giving it a good shake now and then. I did that three more times and this is how it came out. Not a spec of rust left. I've done it on several of my 69 parts and the results were just as amazing.

https://farm1.staticflickr.com/905/41461185164_6475dde521_z.jpg (https://flic.kr/p/26aMpS5)

[SS427]

I have tried Vinegar with varying degrees of success. Maybe I was not using it correctly as I was not that impressed with the results.

[HawkX66]

I have tried Vinegar with varying degrees of success. Maybe I was not using it correctly as I was not that impressed with the results.
Interesting. I didn't do anything special. Highest acidity I could get my hands on and fill the tank. Slosh it around real well, let it sit. Empty and repeat until clean then rinse. When I say the tank was rusty, I've never seen one as bad as that one was.
Glad your block ended up coming out nice regardless of the process!

[SS427]

I just wish the deck with the stampings had been in better shape but I guess I will take it over not having it at all.

[HawkX66]

I just wish the deck with the stampings had been in better shape but I guess I will take it over not having it at all.
Exactly. That's the best way to look at it. I know a lot of guys wish they had that for a problem.

[Hawkeye]

Did the shot blasting have any effect on the broach marks? If you had to do it over again would you have still covered the front pad?

Thanks,
Marty

[frankk]

Hawkeye where do you find the higher acidity vinegar? Have you used just the food store vinegar?

[marxjunk]

feed stores carry higher acidity..

grainger has 30%

walmart, tractor supply, amazon target etc list it as high acid, but like 10%

this place has it at 30%
https://www.factorydirectvinegar.com/products/vinegar-30-acedic-acid-pure-300-grain-white-distilled-vinegar?variant=1846487555

i use it alot to do bolts and hardware in my tumbler with the green pyramid product

95% vinegar..5% dawn dish soap..+/-......(specifically dawn) and it does amazing things

[frankk]

Thank you sir

[Hawkeye]

Thank you for the vinegar information.