Normal amt of rust at drain plugs?

Pete,   Are these the bushings that you recommend?

McMaster-Carr Bushings
Item # 4429k418





3--4921K2 Drain-Handle Brass Stop Cock, Removable Handle, 1/4" NPT Male, Internal Seal $6.85 each     

2--4921K3 Drain-Handle Brass Stop Cock, Removable Handle, 3/8" NPT Male, Internal Seal 7.82 each

2--4429K418 Low-Pressure Brass Threaded Pipe Fitting, 3/4 Male x 3/8 Female Pipe Size, Hex Reducing Bushing 4.33 each     

malcolm2 wrote: I have a business account with them. You are correct, their catalog, retail, prices are way up there. It was maybe 8 years ago, so maybe it was not Grainger. But they are nice brass valves and bushings, I also have an account with McMaster & Carr, could have been them. Clark

Clark,
Not wanting to steer anyone in the wrong direction could you please clarify what type of drain cocks you used. Were they the removable stem or the cheap cocks used typically on radiators? A picture if possible would be fantastic.

8122pbrainard wrote: Riley wrote: Unless you drain often, I don't see the benefit over a plug. Seems like a more complicated mouse trap. So Bruce, you like to get the wrenches and thread compound out every fall and then fumble with getting the plugs back in? What's complicated with using your hand to tighten up a thumb screw? I have to ask, do you have T handle garboard drain plugs or square heads?

Jeepers, if I can't handle a drain plug I've got no business working on the engine. The drain plugs are hex heads, except for the FE which has little tiny plugs with square heads. Doesn't sound like a bad system if you use your boat late into the season and you have to drain after each use, but once a season, seems unnecessarily complicated, but some people like to put all kinds of gadgets on their engines....

DrCC wrote: The reason quite a few people install the fancy brass drains, is when the threads in the block and manifolds start to erode to the point where the hex plugs are bottoming out. The fumbling is about the same with each.

Al,
Thanks for bringing that up. I forgot the corrosion of the tapped holes when I was working Bruce over about wrenches, pipe compound and of course the fumbling! I have to disagree with you on the fumbling being about the same. I'm sure you've tried to thread a fitting into a tapped hole that's on an uneven surface like a block before.

MrMcD wrote: Someone asked earlier in this thread why the new fitting rides higher than the old fitting in the block.

Mark,
I think you had better read up on taper pipe thread tolerances!

So after just pulling the plugs and sticking a screwdriver in the holes at the end of each season for the last 23 years now I have to add drain cocks, bushings, hoses and use teflon tape. I should stop reading threads like these.

8122pbrainard wrote: The manifolds should be 3/4" so you'll need some bushings. I suggest brass and 3/8" drains so you'll need 3/4" x 3/8" bushings.

Pete, does this look like what I need? Looked at some hardware stores this weekend but no luck. Probably just order some.

Yeah, I already have them but Ill check their prices too. Thanks.

Cumby, I've never seen drain cocks on exhaust manifolds, but this system is common on both Correct Crafts and Malibus. Both manifolds are connected to each other by a hose with a union in the middle for easy disconnect and draining. I'd do this rather than put a drain cock in each manifold if you want to eliminate the plugs.

Glen,
For some reason with pipe threads on brass fittings, it's common for them to run over (male) and under (female) sized. I have always found a need to set the pipe threader to cut undersize threads on male pipe because the female threads in the fittings where under. The same is true with purchased male threaded fittings. I've had to run a tap in and open up the females many times which is what you'll need to do. What compounds the problem on the block or any casting is the rough uneven surface which makes it hard to get the male thread started. Chase the threads cutting 1 full extra thread and see if you can get the drain cocks started.

On your exhaust manifolds, I think I know what the problem is but it's too bad you are having picture problems since that sure would help. I remember someone having a problem with swinging the drain cock because it hit the elbow. He installed brass 45 degree elbows solving it and with the 45 was still able to probe the drain with a wire to get to the sediment. How far is the bushing going into the manifold? That may also be a problem requiring some tapping. Rule of thumb when fitting pipe threads together is you should be able to turn them together 2 to 2&1/2 times by hand before needing the wrench.

It's not a bad idea to chase the old threads anyway to clean them up.

Glen,
This is what I believe was used to get the drain cock in.

8122pbrainard wrote: How far is the bushing going into the manifold? That may also be a problem requiring some tapping. Rule of thumb when fitting pipe threads together is you should be able to turn them together 2 to 2&1/2 times by hand before needing the wrench. It's not a bad idea to chase the old threads anyway to clean them up.

Not going in far at all. Probably not even one full turn by hand. I was a little nervous about chasing the threads, because it didn't feel like the tap was going in smoothly and I didnt want to force it and mess the threads up. Sounds like thats what I need to do though,

Here we go.

Gary S wrote: How about taking it apart and installing it in pieces,thread in the reduction bushing first, remove the T from the drain,install it's body,then put the T back in?

Tried that. If you look at the pic the bushing is not flush with the opening...it's tilted down a bit so it would have to go even higher than where I'm holding it. I think the only possibility is to try the angled pieces Pete posted.

With the amount and size of rust and scale I tend to get out of my cast iron manifolds, I would have the same concerns with the massively stepped down drain of Pete's as the quick drains from SkiDIM that he dislikes so much, ha. Both seem to be bad ideas to me. They're probably fine on the block drains though, those seem to get plugged up with much smaller sediment and could be probed effectively through the smaller orifice.