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Engine Specific Info and Questions => IDI Engine => Topic started by: saurkraut on March 03, 2007, 09:48:31 am

Title: Removing swirl chamber covers.
Post by: saurkraut on March 03, 2007, 09:48:31 am: Any body ever remove the swirl chamber covers from a new head? I have to remove them befor ceramic coating.

I tried tapping them out with a hammer and brass punch and it only move a little. i don't want to dork up a new head.

Would putting it a 150 F oven for an hour help?
Title: Removing swirl chamber covers.
Post by: 935racer on March 03, 2007, 06:40:08 pm: Heating up definately helps, I heat them to 200 degres farenheit, use a blunt object through the injector port and and a hammer to punch them out. Don't ceramic coat those chambers eithers, leave them in, I havent had good luck with CC'ing them.
Title: Removing swirl chamber covers.
Post by: saurkraut on March 04, 2007, 06:24:53 am: Are you recomending that i don't coat the pre-chambers, covers, or what?

I've talked to Swain Tech about it and they seem confident:

http://www.vwdiesel.net/phpBB/viewtopic.php?p=45888&highlight=#45888

If so, what have you tried, and what failed?
Title: Removing swirl chamber covers.
Post by: tylernt on March 04, 2007, 09:21:03 am: Quote
Don't ceramic coat those chambers eithers, leave them in, I havent had good luck with CC'ing them.
I know that somebody saw no benefit to coating only the prechamber inserts, but I thought that coating the entire chamber would result in less heat loss to the coolant, and therefore easier cold starts and more efficiency. Is there a bad side to coating the prechambers?
Title: Removing swirl chamber covers.
Post by: RabbitJockey on March 04, 2007, 09:42:58 am: i kind of doubt it would help cold starting
Title: Removing swirl chamber covers.
Post by: tylernt on March 04, 2007, 10:33:28 am: Quote
i kind of doubt it would help cold starting
The theory is, it should keep more heat in the chamber as the piston nears TDC, instead of losing it into the aluminum walls of the chamber (aluminum is a good thermal conductor, which is why it is often used for computer CPU heat sinks and automotive radiators).

Not sure how dramatic the effect will be, though. If it's significant, I'm sure lots of folks would love to reduce the C/R of their TD's (so they can run more boost) without making it impossible to start in the winter. Us N/A guys would also love it if we never had to buy new glow plugs. ;)
Title: Removing swirl chamber covers.
Post by: saurkraut on March 04, 2007, 10:37:26 am: The master plan is a ceramic coated 1.9 head on the 1.6 so hopfully I can run a slightly smaller radiator and get A big intercoller in front of it. I have an Isuzu NPR intercooler for the 1.6, but it won't clear the larger radiator. I have a new 1.9 head, just have to figure out what i'm going to run for valves, do some port clean up, and send it out for the cermic coating.
Title: Removing swirl chamber covers.
Post by: 935racer on March 06, 2007, 03:02:57 pm: Ceramic coating the pre cups is not a great idea, it keeps heat out of the actual prechamber which slows down the combustion process.
Title: Removing swirl chamber covers.
Post by: jtanguay on March 06, 2007, 03:11:46 pm: Quote from: "935racer"
Ceramic coating the pre cups is not a great idea, it keeps heat out of the actual prechamber which slows down the combustion process.

hmmm so what if you coated the prechamber??? why would ceramic coating the pre cups keep heat out of the actual prechamber?? very interesting!
Title: Removing swirl chamber covers.
Post by: 935racer on March 06, 2007, 04:57:54 pm: Don't ceramic coat anything in there, trust me I tried all sorts of variations, you need that heat. The only thing I would reccomend ceramic coating in that area would be the intake and exhaust valves, the exhaust ports (only if the particular coater is set up for doing so) and piston tops.

And really I think the only one thats worth the time or money is the piston tops.
Title: Removing swirl chamber covers.
Post by: tylernt on March 06, 2007, 05:06:55 pm: Quote
Don't ceramic coat anything in there, trust me
Have you done the aluminum roof of the prechamber? That's what I want to try.
Title: Removing swirl chamber covers.
Post by: 935racer on March 06, 2007, 07:37:17 pm: Yep, no noticeable gains found. What are you hoping to accomplish?
Title: Removing swirl chamber covers.
Post by: tylernt on March 06, 2007, 07:38:20 pm: Quote
Yep, no noticeable gains found. What are you hoping to accomplish?
I want easier cold starts and better MPG.
Title: Removing swirl chamber covers.
Post by: 935racer on March 06, 2007, 07:41:15 pm: I had the exact opposite results, the lack of heat kept in the combustion area meant a colder less complete combustion= poorer starting and less power per amount of fuel injected = less mpg.
Title: Removing swirl chamber covers.
Post by: tylernt on March 06, 2007, 07:44:32 pm: Well crap. So much for that idea.

Sorry you messed up a head trying it, but at least the rest of us benefited. :(
Title: Removing swirl chamber covers.
Post by: 935racer on March 06, 2007, 07:47:01 pm: Haha I wish it was just one head! I've gone through about 5 heads experimenting with just ceramic coating, you should see the stack of heads I have cut in half and tried all sorts of porting methods on!

The way I see it I benefit too cause now I don't have to stay up all night wondering if it would work or not :? :lol: