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2025 c3 ('68-'73) of the Year Finalist - Unmodified
2024 C3 of the Year Finalist - Unmodified
Intake manifold gasket replacement
So my question is how clean is clean? I can get a little bit more off the head mating surface but some of that black is baked on and perfectly smooth. I don’t want to go at it with a wire wheel snd risk getting particles thrown all over the engine. I carefully scraped while following the blade with the vacuum head.
Here’s where I am right now. Gonna give it another scrape in a while.
No where near clean enough. 3M makes these little wizzer discs that work really well. Sorry I don't have a part number handy.
otherwise go in the kitchen and see if the Mrs has some of those green scotch bright cleaning pads. They work really well just a bit more effort.
How clean is clean?
That cast iron should look as new. Nothing short of that.
So I went digging for a photo of my engine the last time I had my intake off. Feels like yesterday. But it isn't. Took some digging. So here's my engine. Just ready for final clean up then glue intake manifold gaskets in place.
Zoom in on the gasket surfaces , keep in mind they will still get a final wipe down. Now you know what level your looking for.
Yes, scraping gaskets suck! But it's got to be clean, and straight and flat!
2025 c3 ('68-'73) of the Year Finalist - Unmodified
2024 C3 of the Year Finalist - Unmodified
Originally Posted by 4-vettes
No where near clean enough. 3M makes these little wizzer discs that work really well. Sorry I don't have a part number handy.
otherwise go in the kitchen and see if the Mrs has some of those green scotch bright cleaning pads. They work really well just a bit more effort.
How clean is clean?
That cast iron should look as new. Nothing short of that.
Thanks. Yeah that’s what I figured. I haven’t built an engine in 30 years. Ive continued to work on it and letting it now soak overnight. It looks alot better than the pictures now. I did use green scotch brite and hopefully that with a fresh pack of razors should do it.
I use a high speed air tool with a wire brush. Works like a dream and a bit better than a drill. Ensure you wear eye protection, preferable a full face shield AND safety glasses AND have a shop vac running in the engine valley AND cover up anywhere that the little wire brush remnants since they might fly everywhere. ..... but yeah, it'll be bright and shiny.
If you install a new quality gasket on a clean, flat surface it should last a while. Where I have had issues is with the China walls leaking. The RTV they used when the manifold was put on slowly loosened up and started leaking oil and affecting the vacuum from the engine. I use RTV on both side of the rubber gaskets they give you for the China walls and put them in and right away I torque everything down to specs.
The Mr. Clean white cleaning pads do work as I used them for the final cleaning of the surface after using a 3M (Wizzer) pad to clean the surfaces but only 95% of the way. The rest is done by hand to prevent damaging the mating surfaces. Alcohol is good for cleaning the old gasket material off the heads and the intake.
2025 c3 ('68-'73) of the Year Finalist - Unmodified
2024 C3 of the Year Finalist - Unmodified
Originally Posted by ctmccloskey
If you install a new quality gasket on a clean, flat surface it should last a while. Where I have had issues is with the China walls leaking. The RTV they used when the manifold was put on slowly loosened up and started leaking oil and affecting the vacuum from the engine. I use RTV on both side of the rubber gaskets they give you for the China walls and put them in and right away I torque everything down to specs.
The Mr. Clean white cleaning pads do work as I used them for the final cleaning of the surface after using a 3M (Wizzer) pad to clean the surfaces but only 95% of the way. The rest is done by hand to prevent damaging the mating surfaces. Alcohol is good for cleaning the old gasket material off the heads and the intake.
Thanks for the advice. Years ago I only used a bead of rtv for the end seals and discarded the rubbers. Wondering what people feel about this considering the really good permatex options available.
Thanks for the advice. Years ago I only used a bead of rtv for the end seals and discarded the rubbers. Wondering what people feel about this considering the really good permatex options available.
This is what I do.. discard th end gaskets and lay a good bead of permatex.
I'm certain that intake manifold installation has been discussed on this forum many times. But perhaps your fairly new here.
And I know, the search function on this forum is useless. Absolutely, totally useless. However, if you go outside the forum, and do a Google search. Most of hits will bring you right back here. With excellent results. Just start your search question with, C3 Corvette .........
Anyway. They make different types of silicone sealants for different purposes. "The right stuff" isn't what you want to seal engine coolant for instance.
However it will seal engine oil like your locking up fort Knox. It's made to fill that gap and hold on tight.
Yes I have actually used just regular standard silicone sealer on the china walls and never had a problem. But then I learned about the right stuff. It is actually even better.
in the spirit of let's do this right the first time,
The Right Stuff on the china walls!
Oh, sorry, you asked if there was a preference. Yes they sell it in a pressurised aerosol dispenser or in a standard tube. Same stuff, that's just packaging.
Here in Australia I find the standard tube to be more cost effective.
2025 c3 ('68-'73) of the Year Finalist - Unmodified
2024 C3 of the Year Finalist - Unmodified
4-vettes. Thanks again. Not so new, 19 years and I’ve read a variety of different opinions on rtv, that’s where I got the copper idea. Just trying to understand from the good experiences. appreciate your feedback!
Well then, sorry about my silly assumption.
But, at the end of the day, when you ask 10 guys what to use on the gaskets to the heads you'll likely get 10 different answers.
But when you ask what to put on the china walls. Approximately 8 out of 10 will say, use the Right Stuff.
Intake manifold gasket replacement
