Aluminum LS Block DESTROYED By Scotch Brite Wheels! Can It Be Fixed??
ฝัง
- เผยแพร่เมื่อ 7 ก.พ. 2025
- Thank you for watching! Please LIKE the Video and Subscribe for the next video!
If you would like to work with me, please email BrandRacingEnginesYT@gmail.com
It seems that the GM problem is far worse than the scotchbright problem. I also would note that if 2 different blocks cut way more on one side of a bank, I might check my machine
It could be how he set it up... He didn't show his clamping technique.. so we don't really know how reliable his methods are. It should still work fine though.
Yup if you want the same compression and volume cc's in each cylinder the deck height needs to be the same from the crank centerline.
⁵⁵⁶@@calholli
I used the bhj block fixture the squares off of the mains and the Cam bore.
@@BrandRacingEngines...I'm pretty sure that nobody was criticizing...
Ive used scothbright wheels on aluminum, but I am very cautious and dont generally use the brown discs. Ive reused my cometic head gaskets 5 times & just clea-up good with brake clean, and spray copper high-tack on both sides of the gasket . You want a smoothe, flat, clean surface as most know.
Does my heart good when I see Gerald come out with a new video!❤ always educating! Ronnie East Tennessee
I don't waste my time with aluminum blocks , they are to finicky and for the few pounds you save it isn't worth the hassle . Most street builds you will never have to worry about the extra weight .
Been using scotch brights for years to brush the surface never had a problem. The biggest key to it is your just cleaning it not digging into it. Most newbies need not do it.
Same here. One trick most don't do is use worn disks and if they soak them in motor oil they will clean and not bite in the metal.
Use the right one for the job, we have 3 different ones, and never had a problem in 30+ yrs of using them
I use 3m "roloc discs"
Same, except i tend to avoid it on aluminum…
@@hithereperson8137 bingo. White on aluminum and you're good to go unless you're a hamfisted ape.
Nice job Gerald.
That block was bad.
I really do not like the pads.
I always clean and prep by hand.
No power tools for sanding.
Thanks for sharing. 👍
Gerald and Ruby, y'all rock! Lo e the channel and content. Peace ❤
Thanks ,Jackie
Nice to see that GM still hasn’t changed the mill cutting head that they decked that block with since the 70’s ! Seen that wave ( minus the scotch bright bandit) on many of small blocks chevys .
During the iron block era, heads and blocks had _broached_ surfaces!
the liners are hard to cut with scotchbite wheel, but they're inline with block surface.
that makes me believe the block surface is out-of-flat due to massive overheating, not the scotchbritig (altough partial damage may take place on peripheral areas).
I learned this fixing a "polished" bike frame.
They took down the casted bumps with scotchbrite, and mad nasty deep swirls.
Took forever to correct.
so satisfying to watch , plus this man knows what a finish is ;) unlike many uploads here on youtube
Thanks
That looked like a perfect 92.5 degree GM V8 block to me...
Still 35 degrees better than a Furd one!
LOL
These guys are easy to locate in a shop because they are the same ones that use 1/2 tube of silicon on a timing cover. Just find the ones who request the most silicon, and you have the perp.
As a GM master tech there is multiple red "notes" in our service information engine repair stating NOT to use anything mechanical or abrasive to clean cylinder heads or the block deck.
We use CRC gasket remover and a razor blade or scraper to clean aluminum blocks and heads!
THAT IS IT!
When im done my heads look almost like factory
They also make a note that the surface doesn't have to be perfectly clean either. If it can't catch a fingernail I'd say send it
Those scotch brites are no joke. I used to use them at the bike shop for removing stubborn gasket leftovers but I'd turn the air down to the right angle grinder and go way slow and easy. Sometimes you can just pass it back and forth by hand/no grinder and get the job done.
Make good work for the shop LOL
Never underestimate the power of fools with power tools. It keeps guys like Brand racing working through, so it can't be all bad. 🤣
Was the second cylinder bank perpendicular to the cutter? It seems that the cutter did not even touch the deck at all towards the outside of the block for several passes of the cutter. (Maybe GM cut the deck at an angle!)
That was the same impression I got. It was wither done like that at the factory or another machine shop screwed the pooch.
It could be that the deck was not perpendicular to the crankshaft.
The swirl marks are too symmetrical and uniform to be done with a Scotch Brite wheel and like you say the block is either cut wrong and with the cutting marks from the factory or the block is not set up plumb and level in the surfacing machine.
Drinking you off my mind by Thyra great song
and excellent machine work my man
Master at work fixing another shade tree mechanics repair
lol this guy is a hack.
I’m sure many of you know already but mentioning for general consumption for those that don’t know. There are different rolocs/scotchbrights for different materials. 3m (parent company for many of these) has a 40+ page catalog for 100’s of applications. Everything from heavy rust removal to bristle brush try cleaners.
Another great video. That explains the disparity in performance between identical vehicles. I had no idea scotch-brite could do that kind of damage. OEM lack of quality is unbelievable.
OEM quality has zero to do with it, a moron with tools and lack of skills did the damage. They mass produce engines with tolerance stack in mind, their goal is never maximum power. Fact is for any serious performance build you'd mock up a piston at all four corners and deck to the spec you want, and the ra number finish the gaskets you are using call for. Guaranteed none of them call for a scotch Brite pad. The owner should have dropped it off and has it checked/decked. Not went crazy with scotch Brite pads on the end of a power tool.
Scotch brite isn't the problem here. The machinist is the problem.
It only took me 10 minutes to clean it with Scotchbrite and 6 hours for Mr. Gerald to make it right again.
What kind of a piece of shit does that with scotchbrite wheels to aluminum
@@lollipop84858 He just showed you how it wasn't any worse than the flaws that came from the factory.
@@lollipop84858Be nice. It's just simply ignorance, not malicious.
I mean they must have been sitting there a while to take that amount of material, I use the all the time and haven’t had any issues but I just remove the old gasket pieces I don’t polish the deck surface with it 😂
Don't ever use scotch Brite pads or whizz wheels on anything engine related. The ceramic dust coming off can wreck engine bearings if it gets into the oiling system
I worked with a mechanic who would "clean up" flywheels with an angle grinder and 3M pad whenever he did clutch jobs.
Sometimes I am glad I have a healthy dose of fear of messing something costly up so thread very lightly when I work on my projects because something like this can happen. Great video Gerald👍👍👍👍
No fear go for it. LOL
@@BrandRacingEngines 👍👍👍
I use the plastic discs for prepping aluminum surfaces. Also a plastic razor blade type tool for srapping off material.
I am a bodyman by trade and I can watch your videos all day long I really like how you explain everything as you do the work
Thanks
seen alot of things destroyed from cleaning with scratchbrite... Keep on Keeping on my friend
I used to work in machine shops for 40+ years.Some of the blocks and heads back in the 80s
looked like they were threaded .
3.8 ford v-6,2.3and 2.5 Taurus were the worst
Love all the comments telling Gerald hes doing it wrong. Keyboard warriors telling a guy with decades of experience.
You may say that but my personal experiences have been different. A mechanic with 30 years of experience who retired from the GM technical center told me the fins on your radiator had to be able to move some to cool the water inside. Another told me that a drum of solvent was bulging because of the “combustion inside”. I believe he was referring to Vapor Pressure.
well I'm not a keyboard Warrior I'm an experienced 40+ year machinist boring Mills Machining centers, Lathe's Blanchard Grinders centerless Grinders vtl's you name it I've run it and I know he's doing it wrong.
Gerald. Good job mate. Your channel is always top shelf. Do you have someone editing? I personally used to watch the techs at the dealership use scotch brite on the surfaces to speed up the cleaning process. Know wonder people go elsewhere once the warranty runs out. Too much pressure because of book time. Independents crush the ever-growing maintenance/rebuilt demand in the automotive market place.
Jackie does the editing.
What i learnd from this is let the shop clean it up. This insures the minimum of material is removed.
Several years ago at the shop I work at, a customer brought in a Subaru with head gasket issues. The customer said they had the head gaskets done at another shop a year or two ago. After removing the head, we discovered the other shop had done this exact same thing, cleaned up the aluminum block surface with a Scotch-Brite wheel. This was supposedly a "Subaru specialist" too. The customer didn't want to pay us to remove and resurface the block so we ended up just resurfacing the heads, spraying the gaskets with copper spray, and slapping it together with a note that we would not be offering a warranty on that repair. The customer ended up getting rid of the car before the gaskets started to leak again. Why somebody would take a Scotch-Brite wheel to an aluminum block surface is beyond me.
Subaru's ....... the lesbos deserve them.
I have a Subaru with a leaking camshaft cover. It's going to cost me $1100 just to take the cover off and find out why it's leaking.
That's why I'm also going to get rid of the car before I have to deal with it. Never getting another Subaru again!
Chisel gasket removal spray . Razor blade scraper , brake clean ,or a buddy with a wash or dunk tank is all you need and yea ls blocks are that bad straight from GM , cash iron or aluminum, anything mass produced can always use refinement, excellent work gentlemen.
Yep, I still have an old wood chisel from 1970's that's about half the length it was new as it's been sharpened so often with oilstone (never been on a grinder) That's a lot of engines. 😎
Yes, I'm fond of the sprays as well, can do a LOT of the grunt work for you with no risk of surface damage. Have had a chisel in my toolbox for 45 years for those tough spots and a proper razor scraper for almost as long.
About 2004, at a Chrysler dealer, one of the techs cleaned up the decks on a 3.3 with Scotch Brite wheels and the customer sued us when it started knocking. He took it somewhere else and they found the bearings wiped out. In court, the CUSTOMER shows US a Technical Service Bulletin that says "Never use Scotch Brite wheels on internal engine parts"! Turns out, Chrysler sent the TSB out but, the service manager never gave ANY bulletins to the techs! Nice. The previous manager made sure we saw every bit of info possible and we made 5Star. Lost it with the new manager. One question; can you measure a BBC 454 to see if it's ever been decked? I've got an LS6 that was cast in '72 and, is stamped as a '70 Chevelle but, looks like the correct broach milling.
BEAUTIFUUUUUULLLLL!!!
Yeah I'm sure few a spot was caused by scotch bright but a big majority of it was a factory surface angle cut versus your surface angle cut, as yours's could have been more square versus the factory cut, something you forget to factor in was they may have gotten the engine a little too hot so the aluminum did not shrink back into its original position.
I use to have a machine shop and did work for multiple dealers, I've had to take a cut on a head, then take them back to the dealers to show them what they were doing to the heads with those pads, great tool but they will fuck up both aluminum and iron heads and blocks fast !!
I just found your channel, I love watching machine work! When you see a block this much off on the 1 side of the block, do you ever question your setup being off a little? or is this just from many years experience and knowing that factory machine work is subpar?
That's just how factory block seem to be. I do go back and double-check myself.
I once had an older mechanic bring in a pair of heads that he used a body grinder on to clean every surface. It had the edges so rounded the heads were scrap.
I get excited every time I see you have a video
Great video. What is your recommended method of cleaning the deck surface?
A scraper and whetstone with mineral spirits on it.
Thank you for posting every interesting videos. Although it may be ok for daily use, but now I know the quality of the block isn't good enough for high performance vehicle.
Just wondering, do you match the depth dimension of both banks deck to crank center line? Great video! Thanks for sharing with us.
Yes
How off that block was reminded me of an episode of Roadkill Garage. Steve Dulcich had a shop zero deck a 360 - well, it wasn't making the power he expected on the dyno. Pulled it apart and found (If I remember correctly) #2 piston was like .020 downhole - and #8 was .010 down. You can bet he never took another engine to that shop.
i use scotchbright to smooth cylinders, get it half a thou off tolerance and wrap a pad around my honing stones makes them super smooth
Scotchbrite and graphite go together like peas and carrots 😊
GM.....mark of excellence.....righhhhhhht
Yep I used to hate that lazy mechanics would used. But then they would smear form a gasket on it with the gasket and the gasket would turn the mush 6 months later.
I've always felt that power tools were not meant for gasket removal. Scraper or single edge razor blade?
In the seventies and eighties, in our Japanese motorcycle shops (we had all four brands spread over eight stores) we used high-quality wood chisels, kept razor sharp. They will remove just about anything cleanly.
We loved it welding, scotch brite grain in stainless steel elevator doors, and such
You cleaned them up nicely, but you didn't seem to match the deck height, one side to the other.
YES I SQUARD THE DECKS
Scotchbrite pads on a die grinder=The WhizzyWheel of Death for precision machinery.
How much did you take off?
What about piston in hole dimension?
About .012 total. Custom had to check deck height.
@@BrandRacingEngineswhat if you ever had to take off twice that much, what then?
Great Video. You don't know how much these videos help this rookie machinist.
How much are you cutting per pass? I just got my BHJ Blok-Tru all set up and ready to use. Hopefully deck my first block today.
.002
I had to take .007-.008 off a set of 706s that someone went over with a cookie on a wizz wheel just to get them flat again... -_- (fyi, those low spots were between cylinders) I cant believe people still do that and expect it to work well.
Looks like the mill is not perpendicular to the surfaces of your blocks? Both blocks were immediately showing material removed on one side only...
Nice! I think El Grande Hefe's pick-up motor needs this same treatment after the cam job..
LOL
id be interested in seeing the process of setting up the block in the machine and zeroing it.
I have a video that has it on it.
This may be a dumb question, but here goes. Do you have to do the same process on the cylinder heads?
yes
That's why I like cast iron.
I might be wrong but I think put the coolant on the side that has no paint left on it since it is the side that is actually being cut.
How much do you normally remove on each pass normally?
How much did you remove from this block and was it equal for both sides(may be a dumb question, but I had to ask.. I would expect it to be equal).
The LS block.
.001 to .002 per pass.And I square deck it off the mains.
According to what I've read, GM does not recommend using Scotchbrite products on blocks or any internal engine parts when rebuilding an engine!
Good job; but I don't anything destroyed unless it's NOT savagable.
I use a 2 inch wood chisel to remove the stuff off the surface then put em in the washer cabinet before I throw em on the surfacer, I had an old boy bring me a iron duke head to surface, I put a straight edge on it and you could of thrown a cat under it, Had to cut .021 to fix it, he must of worn out out a whole box of wheels
Interesting to see what scotch brite does to a deck of a block. Just wondering how much did you end cutting off the deck??
Love the content and the information Gerald.
Cut .012 off one side and .017 off the other to square the block.
@@BrandRacingEnginesthank you for the answer I was wondering the same thing did Ruby lose her toy that's why she was sitting there looking at you
@@chief3378 yep she lost her toy
How many thousandths were removed? Will it change compression much?
you should narrate documentaries!
I have used Scotch Brite pads to grind broken screw drivers. Usually into some special tool.
That's what it's good for
Could the scotch brute damage be pre-existing, from a dealer warranty head gasket replacement, butchered, for warranty flat rate?
Thinking I’d want to take a close look at the head bolt threads, in case the fix was to overtorque the heads.
In this case of this video, he was square decking a block that wasn't square. And that's completely normal when doing a factory block.
All the ''look at what the scotch-brite did'' stuff was just garbage. There was even a couple instances where he pointed out ''scotch-brite'' gouges on clean spots. And clean spots are high spots that got machined down. Gouges make low spots that stay red.
Enjoy your videos!!!
How much did you take off each side????
Having learned machining in the ariospace industry I'm always amazed at how badly automotive factory parts are made. Their tolerance are just all over the place, amazing that some of the factory stuff will even hold a gasket at all. In aerospace when you start seeing you are a thousands out you start looking for why, you'd never see deck angles anywhere near that far off.
I agree but (Japanese) motorcycle and Toyota parts are far more accurate than most.
John doc has actually done a video awhile back where he took a wiz wheel or scotch bright wheel to a block and then had tkm see how bad it Jack's them up its crazy how fast u can blow thousands of dollars with a 40 dollar tool and not even realize your doin it till its too late lol
I decked a set of aluminum Jeep 4.7 heads in my garage using some wet sand paper and a travertine marble tile. Got it to within 20 thousandths.
you mean .002
So would you use thicker head gaskets after this to not mess up the compression as well? Slowly learning about machining video by video.
May be.? Change the sweet volume by 2 cc
Some people are pretty stupid when it comes to abrasives and soft metal. People are applying techniques that used to use on cast iron blocks to aluminum and that's a big no-no
2 questions. One what is the depth of cut? Two did you run an indicator down the bores to make sure you are square? Those passes all looked heavy to the back of the machine.
.001 to .002 per cut. The block squared to the mains and the cam tunnel.
What do you suggest we (home budget DIY) use for cleaning up a deck?
razor blade works well. I us a whetstone in the shop.
@@BrandRacingEngines A whetstone... excellent. Thanks!
That’s a great example of people not knowing what they are doing, and what tool is correct for the job. Over the years I’ve seen many a precision parts ruined by these. I think the worst was a rare flywheel that someone “scotchbrited” completely ruining the part!
I just slowly shake my head and roll my eyes when I walk into a "professional" shop and see workers cleaning off gasket surfaces with a 20k die grinder with a scotchbrite pad zinging away and knowing they are not going to be resurfacing that area. I see diesel shops doing that all the time.
how do you "touch off" and not even clean up your touch off line on first pass? i think the setup is off or the touch off was hasty
On an LS engine you literally pretty much only ever need brand new razor blades and brake cleaner it’s that easy brake cleaner will lift up the black parts of the gasket and the razor blade was scrape it smooth without digging gouges into the surface, if somebody uses a buffing wheel on any machined surfaces in my shop they get a big talking to!
I don't see any lube coming out of that nozzle... is it just so clear that it's hard to see?
Yes
Flamespray welding is a solution
There is a big difference between using a Scotch brite wheel and a Scotch brite pad by hand.
In my thirty plus years of engineering building, I’ve done many engines with just a clean up of the block. I don’t care what anyone says, not the guys commenting on the internet not your machinist or your buddies, ALWAYS get the deck surfaced! Not only does it help with sealing, it squares and evens the banks from side to side. I’m not an expert just a hobbyist. YMMV
Deff have to be careful. Have used red pads by hand to clean up blocks when a composite gasket is being used after without issue. Also have seen people royally screw up deck surface, Same deal people buy metal layer gaskets and not have the surface finish to correct RA then wonder why they keep having issues.
Too many think "oh I know what I'm doing" those are dangerous. I had a Mazda head on a B2200 back in the 90's. He had taken it to all the pro's and they kept tossing headgaskets at it. When I got it the block looked ok but the head looked funny. Took it to my machine shop guy who I learned my tiny bit if machining and his old ass spotted it right away. He told me to use it as a door prop. They had gouged the head then took it to a bad machine shop who ground the head at an angle. Since the headbolts didn't make full contact (yes it was that bad. Full run-out on one side hardly ground on the opposite) they loosened up which I caught and said they didn't torque it fully then saw the wonky head deck job. Lucky he was the parts counter guy so he ordered another head and sent that junk in for core. My machinist had to deck the one he ordered but nobody had to do another headgasket on that pickup lol.
I suspect the block was not mounted flat before machining when one corner is untouched and the opposite diagonal corner is machined smooth
I really enjoyed that hillbilly music. Lot better than listening to noisy shop machining, or informative dialogue.
As an engine builder, I hate seeing either scotch brite or wire wheels used on ANY gasket surface of any material. I have seen several cast iron diesel and gas blocks ruined by either process, usually because the holes in the block are "shadowed" Most people do not realize that many types of head gaskets rely on those machine marks to hold properly. Belt sander surfacing machines can destroy heads also even if properly maintained (usually not the case) because the surface scratches run across the cylinders, not between them like a milling machine does. If you have to use anything on non critical areas (oil pan rails etc) use a soft wire wheel going with the grain of the original marks being sure not to remove them.
Just curious how many thousands each pass is .
.001 to .002
Nice Job Sir.
Dare you go to deck true next?
;)...........
06:38.....might wanna consider replacing that air line brother.😉
That hissing is the cutting oil system that I use.😀
I have a question. I have an ls2 aluminum block that was stroked out to a 403 forged setup. A meth valve was ingested and created a hairline crack in one of the cylinders. Can i simply have that cylinder resleeved and install another weight matched piston?
yes
@@BrandRacingEngines next question....if I weight match the piston (weisco) would I need to have everything rebalanced? Common sense says no but I think the machine shops are trying to run the bill up. They want to clean and deck as well and I don't see why unless I really need to.
@@johngatsby1473 If the weight is match it is ok . It a good idle to deck the block.
Looks like a flap wheel and angle grinder job 😮
This damage was not caused by Scotch-Brite wheels.
This pattern is very typical to LS Alloy blocks
If you listen to about 3 and 1/2 minutes into the video
I am inclined to agree with you. The pattern is way too regular and even to be someone with a hand grinder.
How much are you taking off per pass?
.001 to .002
@@BrandRacingEnginesoh wow, that’s less than I thought. I figured .003 to .005, to be fair I’ve never machined an engine block.
Loving the videos. Could you please turn the machines off when you’re trying to explain stuff. And could you please tell us how much you’re cutting off each pass. The DICOM helps
.002 each pass.