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Just Some Dude in Jersey
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Discussion Starter · #1 ·
Today I removed my 2.2 FI intake manifold for the main purpose of substituting a spongier manifold gasket to stop a vacuum leak. I also wanted to inspect for "chroming ridges". I wasn't expecting to find what I saw.

Most of you would NEVER encounter what I found, unless you also decided to chrome everything in your engine compartment, like me. I have been sending stuff out to get chromed for 10 years and I never saw the problem of "chroming ridges". The first time I noticed it was a few months ago when I chromed the oem FI thermo housing. HUGE stalagtites of surplus chroming stuff had built up at the sharp corners of things. It was extremely hard to grind and file them down while trying to preserve overall flatness in a single plane. I guessed the reason, but I called the chromers to verify it. Yes, the chroming process tends to let the zinc/copper/chrome, when chroming aluminum, build up excessively at sharp corners. They told me that they normally grind/sand/file off a little bit of the aluminum near sharp corner before chroming to offset the chroming ridges problem. I can still see the patination marks from when the manifold was originally made, so it looks like they forgot to do that "relief sanding" before they chromed my manifold.

I put the manifold on my workbench after removing it, pressed a flat piece of metal against the ports, and shined a light to see if I could see light leakage. Yup, LOTS of light leakage!!!! Oh schit. How the hell am I going to do an accurate job of sanding/filing both pairs of intake ports. I tried filing. Forget it. A file won't file chrome, it's too hard. Schit! I'm going to have to use my bench top belt sander with metal grade sandpaper. Luckily it has a nice long flat surface that was just long enough to sand both pairs of intake ports simultaneously. But it wasn't easy holding a big, clunky, heavy, fully assembled, FI manifold evenly against the sand paper. Some areas had more build up than others and you have to change the orientation 180* now and then because the leading edge of what you're sanding tends to get over-sanded. But I managed to do a half-decent job.......I hope. Here's the before and after pics:

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Super Moderator
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6,068 Posts
How do the other mating surfaces look, such as the injector plates surfaces and carb mounts? Are you confident that you have sanded the head mating surfaces flat and PARALLEL? You would need a large pane of glass (or a good cast iron saw table table top) and a large sheet of sandpaper to do that properly. Ideally, you should take the manifold to a machine shop and have them mill the mating surfaces flat and parallel. Otherwise you have more vacuum leaks in your future. JM2CW
 

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Just Some Dude in Jersey
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Discussion Starter · #3 ·
None of my other chromed stuff showed this flaw. The chroming shop in Tennessee that I send my stuff to is swamped with work because many of the chroming shops around the country have gone out of business. I had to wait 3 months for them to do my recent main batch of FI stuff. Maybe a new guy did my stuff this time around. Yes, Keith, the perfect remediation of this issue would be to send it to a machine shop. I don't have one locally that I have used and can trust. I would have to send it to Virginia or Tennessee. I'm also leery of them milling too much off and giving me a thickness disparity with the exhaust manifold. I wasn't going to check the flatness of where the injector plates attached, but now that I have seen how bad the head mounting surface was, I'm going to remove the injector plates also and check. If there are ridges there it's going to REALLY suck to make them flat. The manifold cylinder is in the way and those areas will require me to try to hand file them flat. Oh well, that's the life of an Opel owner: Nothing but trouble. At least I now have a good explanation for my vacuum leaks. 😠
 

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Opeler
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3,153 Posts
As Keith suggested, use flat pane of glass.
Use emery cloth instead of (silicon-carbide) sandpaper.
Home Depot and Harbor Freight has it in stock.
Do you feel the pain (Humor)?

Sandpaper is just that - paper with an abrasive such as garnet, aluminum oxide or silicon carbide bonded to it. .
Emery cloth often contains aluminum oxide or iron oxide abrasives. Used mostly for metalworking, it is good at removing rust, corrosion, paint and polishing metals.
 

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Just Some Dude in Jersey
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Discussion Starter · #6 ·
CHROMING RIDGES!! Part Two

In my last video I detected that I still may have had a leak in the injector plate/holder on cylinders 3+4. After flattening the ports of the runners, I removed the injector plates and didn't really see much if any ridges, just a lot of casting pits in the metal. But might as well sand them anyway and see if any high spots revealed themselves. Their location made it impossible to use my belt sander, so I used a flat metal block and emery cloth. You can see in the pics that after the sanding you can see horizontal scratches going mostly unbroken across the whole surface. You can see that the pits in the metal on the right and left sides of the port pairs have been sanded away. My conclusion: They were pretty flat with only minor build up of chroming material at the edges. They're even flatter now. I'll copper spray the gaskets and maybe put a very thin buttering of high temp gasket/sealer on those pits in the manifold, then reassemble.

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Your Noble Friend ;-)
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The same thing happens when painting on corners or tight radii. A painter calls it a "Fatty Edge" or "Fat Edge".

Dieter
 
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Opel Rallier since 1977
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2,368 Posts
Have done the belt sander deal on Mopar 225 slant-6 exhasut manifolds. They want to twist and warp with heat and age and the manifolds hook to the heads like on these CIH engines. Have had success with keeping things parallel being careful and frequently checking on a machinist's flat. Hope you got it done, Gordo.
 

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Pedal Smasher
1973 Opel GT
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2,882 Posts
Gordo, have you port matched these parts? You might want to do some more sanding / grinding to match the ports of these parts to the intake ports on the head.
 

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Just Some Dude in Jersey
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Discussion Starter · #11 ·
I've done port matching, it doesn't do schit. I've even had a RallyBob intake that was ported to match and it wasn't even close. We had a discussion years ago where it was revealed that matching ports perfectly doesn't necessarily lead to more power. In fact, some inexactness in port matching can help "steer" the air going into the engine towards better flowing areas of the head. I noticed on the intake he did for me that he had done just that. All that porting and flowing only affects high rpm performance. I don't drive at high rpms. I just want a normal engine that runs normally like from the factory.
 

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Oh well, that's the life of an Opel owner: Nothing but trouble. At least I now have a good explanation for my vacuum leaks. 😠
Half the battle is just trying to figure out the problem and then the other half is fixing the problem.
Good luck Gordo, I'm sure you will fix the problem.
 

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Just Some Dude in Jersey
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Discussion Starter · #13 ·
I'm pretty confident that rectifying the ridges issue will have me up and running. I probably won't reinstall things until next weekend.

I'm tempted to make a list of all the hoops I've jumped through this past year to get my car running again.

I probably won't. Too depressing.

:ROFLMAO:
 

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I've done port matching, it doesn't do schit. I've even had a RallyBob intake that was ported to match and it wasn't even close. We had a discussion years ago where it was revealed that matching ports perfectly doesn't necessarily lead to more power. In fact, some inexactness in port matching can help "steer" the air going into the engine towards better flowing areas of the head. I noticed on the intake he did for me that he had done just that. All that porting and flowing only affects high rpm performance. I don't drive at high rpms. I just want a normal engine that runs normally like from the factory.
As long as it is the port in the head that is bigger than the one in the intake runner. And the opposite for the exhaust port.
 

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I'm tempted to make a list of all the hoops I've jumped through this past year to get my car running again. I probably won't. Too depressing
What's depressing about it? It's the stuff you've already done.

The depressing stuff are all the obstacles still in your way :p

When you use sandpaper you are going to create a rocking chair almost no matter what you do.

I'd suggest trying plate glass (window glass, not tempered, it's poured on a bed of molton tin) and lapping it smooth as others have suggested.
 

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Just Some Dude in Jersey
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Discussion Starter · #16 ·
Ha! It was all the misfires trying to figure out what was wrong with the previous engine and the money wasted. The depressing part was finding that all the work I myself did was perfect and it was the work done by other people that caused all my grief(My "builder", the machine shop, my builder, the chromers, and my builder). My only mistake was loosening and then not tightening a pipe plug blocking off the old oil pressure sensor location. :)
 
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