We turn $200 junk LS7 heads into $5000 Ported Race Heads, Corvette 7.0 Engine Rehab Episode 3
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- Опубликовано: 19 авг 2023
- These heads were a disaster, ABANDONED by two different machine shops. Now watch part two of the rehab process and see how they're given a second lease on life, by a home machinist who know exactly what needed to be done to save them. Thanks for joining me in episode three of Engine Rehab.
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Watching this makes me appreciate you that much even more when you worked on my LS7 heads. I’m the one with the ls7 swapped Gto lol. Before bolting the heads to the engine, I had seen all the attention to detail you did, and just wondered how you did it and now I see and it’s truly a work of art. Thank you josh again so much 🙏🏽
DUDE that means a lot. Comment of the year!
Not trying to be negative just wondering
@@stevecobratei8538 the chamber volumes need to match. One head had a much larger chamber volume than the other so i had to cut it to match.
How can I get ahold of you and where are you located???
I'm digging the stones.
I use them too. No lapping needed.
I test with the Sioux vacuum gun.
No springs needed either. Good job.
Perfect job, nice to see a professional, who takes the time to makes this part perfecte 🎉 Greetings from the Netherlands
I’m glad you enjoyed it! I’m getting better at being engaging with each new video.
nice work. btw, those chamber bumps are locating pads so they can fixture the raw casting to be machined. The other pad in under the second port so it has five points of contact.
Amazing job. Really nice burr finish. 👏
Thanks! It was a boatload of work. I suppose the cores wouldn’t have been so cheap if they weren’t abused 😊
Hey kid: terrific video. Great commentary with a sense of humor. Awesome level of skill.
Not many people take the time to keep shit clean,
Great work
You are an artist. Extraordinary!!!
Thank you for sharing that piece of art🔥🔥🔥
love watching yourI have 50 years of experience as for all the naysayers this man knows what he is doing hopefully you can continue to feed off the negative energy I could not I no longer build engines people ask me everyday and I say no.
Super nice work.
Those heads look great!!!
Thanks to you, my knowledge of porting can no longer be written on the head of a pin. I can be trusted now for very simple things: way better.
Back in the day I remember when people would home port their heads to a slick finish and me and a friend were discussing that the slick finish would hurt the performance more than it would help. And seeing the burr finish that you did not only does it look awesome but but it creates turbulence in the ports and in the combustion chamber which helps the atomization of fuel and air mixing. I’m not sure if I am right on this correct me please if I’m wrong. But overall those are a awesome set of heads. I like what I see here.
In a nutshell the texture will make a port act smaller than it is. It also helps keep fuel homogeneous you’re on the right track
@@greatestevar polishing to a mirror polish is a total waste of time. old people and kids think it’s cool. The smoothest I’d personally take an exhaust is 80 grit. Shape is everything.
@@EngineRehabI'm in my 60's and I've only ever known to 'rough sand the ports'. I think the polished finish stops the gases from adhering to the walls of the port and thereby narrows the flow. Polishing is a lot of time and money and form what I've ever seen, costs power and performance.
The issue I now have is. What about that dimpling they put on the ports? My Alfa Romeo has the latest dimpling effect and I'm concerned about even touching it!
@@doraexplora9046polishing actually promotes air adhesion to the port wall. The little golf ball dimples actually create tiny vortices/turbulence in each dimple creating a protective layer/pocket of air making all the other air moving over it have essentially zero friction/drag. As he said earlier it makes the chamber act smaller in a sense because of those tiny pockets of air
@@smnkm4ehfer My Alfa 156 has this effect as standard all through the intake. I don't think there is anything that can be done to the head as the factory did it all already!
Looks nice!
I just found this channel and I love it. I want to send you my old 460 so you can rage-fix my custom porting job, and fix my horribly wonky valves,
4:46 IMO mirroring the combustion chamber and "golf balling" the barrel and port MIGHT be the best of both worlds. The combustion chamber is almost as much about reflection as much as air flow. More surface absorbs more heat, mirror has the least heat soak. Also "golf balling" is mostly about fuel suspension in the air flow, and the makes little difference IN the chamber. Heat however does physically push, walk out from the AC on a hot day and feel that wall, now I'm suggesting that "heat wall" does more then the "golf ball" method in the chamber.
Good job
can you make a video about valve angles ? your channel is really great!
About 45 years ago I was doing motorcycle heads. I used abrasive impregnated rubber wheels to finish the polish. I don't know if they're still available, but I never found anything to beat them.
I find it funny how the "experts" all seem to get other people to do their car work.
After 16 years in the automotive industry, I don't deal with customers because I just want to punch some out.
If a customer ever tries to start talking to me I just walk off and look busy, if they want to talk to me while I'm working on their car I stop go and have a coffee sit down until they get the message.
I love the "it's a quick job so why is it taking this long"
Steam starts coming out of my ears, because if it's so quick and easy and the customer knows what's involved, then why am I working on their car.
I have to be honest with you...I'm a bit excited ! My inguinal region is a bit....
Simi Valley is pronounced as “see-me” Valley.
Good looking stuff. I always hated the port and polish… you don’t polish the intake for a reason. People who don’t know how polish the work to make it look trick but it’s mainly waste of time.
Such a work of art.
Thank you! They’re nicer than I deserve!
Nice!
How much do you charge for something like that? Looks great man, attention to detail is top of the line! Keep up the great work!
Back when I was doing this for people this would have been close to $5000 including the parts. I’d say that’s about $2000 in parts i have sitting here. I own all the heads I’ll be posting.
Can you link to the valve seat cutting tools you use for a bridgeport?
Great video Josh. Did you buy the fly cutter for the mill or did you make it?
I bought it, and it’s no longer available. Big flycutter is a good alternative.
6:00 the dimples might help with velocity like a golf ball
I munched Ellio's Pizza whilst watching this great content
A night fit for a king
Amazong stuff so much to learn here. Do You cut Your valves seats all to the same height?
Yes everything gets cut to the same height as best as possible. It’s hard when something has been messed with.
Having worked on ferrari engines they are ported from factory, and are smoother then that. Combustion chambers where always mirror finish to minimise carbon deposits and maintain Combustion efficiency
I have a ferrari sitting that’s covered in deposits in the ports and chambers.
Lovely work!
When heads have gunk or gasket bits on all surfaces, or just look worn or wonky, how do you mount them up on the mill for fly cutting? I saw you chamfering and laying a file over the surface you were going to put on the table - is that about enough?
Gasket surfaces are pretty easy to scrape most of the time. I’ll use a carbide scraper then a flat file to make sure it doesn’t have any raised edges. I do that to all flat surfaces. If something isn’t flat I’ll remachine it so that it is.
I’m sure it takes you an hour to do your seat work on a knee mill.
How much guide to valve stem clearance are you setting up off of when you do this?
Where are you referencing seat depth from?
Is that a “magic marker” you’re using? I wonder if the tool and die world knows about using that bit of magic instead of the finite lapping processes they’re using?
I’m still bewildered at how I got away with lapping all those titanium valves in the multiple national title holding engines I’ve worked on? Damn….now I wished that I had not done that. No telling what that lapping compound did to those beryllium copper and moldstar90 valve seats. Particularly odd that most of them never required any seats or valves to be machined when they were freshened up annually or biannually.
A few thoughts and suggestions. One is that I’d be willing to bet money you’re better at doing this work than the day you started doing it. It is evident that you’ve learned a few things and this didn’t start yesterday. Just don’t give up on the idea that you can and should learn better and know it. There are holes in everything we do. There was only one perfect person. They nailed him to a cross for it.
That’s nice “looking” work you have going there especially with what you have available to work with. You’re working towards craftsmanship for sure and I’ll applaud you for working with your own two hands and not thumping buttons to do it. It forces many details to be known and minded. Wear and tear occurs over time. Conditions change and can grow out of control with what you’re working with. You’ll hopefully find the flaws and errors of your ways before someone else has to offer you up the missed self discipline. Remember it’s not a screw up unless it leaves the shop and you can fix it yourself.
Lose that “magic marker” it is lying to you. While the world you live in may be fine and well with the current. The work you’re showing the world will garner more detailed situations that will not be best served with it. They do not show the entire truth behind what is actually taking place. Especially when you can not afford .002” stem clearance on the parts when machining them.
I’ll quit busting your chops and hope you take the positive side over the trolling side of this comment. Machine shops are shops of trolls by virtue anyway.
Take care. Much better care. lol!
💯 👍👌👏👏
Enjoing your content, How much of clearance do you recommend for ls7 titanium 8mm valve stem to CHE bronze guide?
.001-.0012”
@@EngineRehab thx
Why would you remove so much from chamber. Looks like you added about 5cc
Youll have to excuse my ignorance as im a machinist but not an engine guy, won't decking 12 thou off to correct the chamber volume discrepancy end up changing the location/alignment of something else?
Yes it will contribute to intake misalignment, and affect pushrod length slightly as well, the best you can do is get both sides close within reason in this situation. .012” isn’t a terrible amount, but if the chambers weren’t so small already I’d have probably left the discrepancy alone.
Why will lapping ruin a titanium valve?
So what happened with these heads originally? Dropped a seat?
Dropped a valve
"In any system of energy, Control is what consumes energy the most.
No energy store holds enough energy to extract an amount of energy equal to the total energy it stores.
No system of energy can deliver sum useful energy in excess of the total energy put into constructing it.
This universal truth applies to all systems.
Energy, like time, flows from past to future" (2017).
Who’s the villain in this story?
Capitalism
Plot twist: it's jesus.
Well if you want to argue about it
I think it was a terrible movie and it wasn't even scary
Engines are air pumps. Anything that impedes airflow reduces power. Rough surfaces impede airflow.
Yes and no. They are air pumps but also fuel as well as needing to mix both ingredients. Some turbulence is necessary to create power thru proper mix.
True, but rough surfaces impede fuel flow as well. Less fuel and air in the cylinder is less power. Turbulence was traditionally created on the compression stroke through piston and combustion chamber design after cramming as much air and fuel in as possible. That why intakes and heads are ported AND polished.
Rough surface creates a boundary layer that can improve flow.
@@justinmiller1191 You could be right, but I bet the flow bench would say otherwise.
Far from 5k heads. Lol. Get your facts straight