V-Twin Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
973 Posts
Discussion Starter #1
OK so I'm working on a friend's '01 Indian Chief. No manual.

S&S motor, 88"er I believe.

Motor is set up with both top and bottom crankcase breathers. There's a crossover tube at the heads, and a bottom vent out of the crankcase. Top one has a filter on it, bottom runs to atmosphere and someone cut it so short it vents all over the frame rail.

Is it a good/bad idea to run both? Can we plug one or the other up?

Also...the carb is an S&S "E." There are two holes open to atmosphere on the backplate. One has a hose routed to the ground, and one is just open.

It looks to me like someone modded the CA emissions setup but didn't plug the holes like they should have? Is there any reason to have the backplate open to air like that at all?

I took some pics to try to illustrate. Gotta go through em and will upload them as soon as I pick out the ones that show the story best.
 

·
Registered
Joined
·
660 Posts
I don't think there is any need in running both vents. My bike has the 92 and earlier cases with the lower crank vent. I just plugged my head vents(edelbrock) at the recommendation of my case mfg (delkron).
You might want to extend the lower case vent with a hose and elevate it, a mist filter might not hurt either.
I use a puke canister/filter on my lower vent hose that allows me to drain any excess if I need to.

I beleive the two holes in the carb backing plate are where the head vents are supposed to route to(?). if the head vents are not being used or are being filtered through an alternative system, like the small daughtery filters or the like, then I think the backing plate holes should have just been plugged off(?).
 

·
Registered
Joined
·
973 Posts
Discussion Starter #3
Talked to S&S, said no point in both vents, but no harm either. Said if we wanted to go with one only, use crank vent rather than head vent

then he disappeared. I had a few more questions and couldn't get any responses. Heh.

SO...to plug the head vents, just use 1/2-13 bolts? Any sealant? What length?

as for the carb...interestingly enough...one of the holes was simply left open, and the other had a hose routed to the ground.

makes zero sense. I'm pluggin both and runnin the crank vent. Should be just right.

thanks man.
 

·
Registered
Joined
·
660 Posts
I think the bolt length will be determined if or how thick of bracket that is supporting the carb is. I am running dual carbs with about an 8 inch intake manifold so my braket going to each head is fairly thick.
You might try running a bolt in by hand first with anything that is going to be mounted there. Then take about 1/4-3/8 inch off of that length just to be safe, maybe more ifyou need to. I used stainless button socket head screws in mine.
The sealant was to help keep from gaulding the aluminum threads as much as anything else. You want to be able to get them out when you need to...good luck with it.....
 

·
Registered
Joined
·
973 Posts
Discussion Starter #5 (Edited)
I think the bolt length will be determined if or how thick of bracket that is supporting the carb is. I am running dual carbs with about an 8 inch intake manifold so my braket going to each head is fairly thick.
sheesh. good point. mounting bolt length would of course vary.

You might try running a bolt in by hand first with anything that is going to be mounted there. Then take about 1/4-3/8 inch off of that length just to be safe, maybe more ifyou need to. I used stainless button socket head screws in mine.
If I thread a bolt in there to check hole depth...what am I threading into? Sorry for the lack of knowledge here, I've only seen the guts of an evo a couple times and can't remember what might be there for a bolt to come into contact with.


The sealant was to help keep from gaulding the aluminum threads as much as anything else. You want to be able to get them out when you need to...good luck with it.....
I was thinking more of air or oil mist escaping around the bolt threads. Not a concern? I'll put some anti-seize on there to avoid galling.

Lastly...again sorry for the lack of knowledge here, but I'm going to plug the two holes circled in the attached pic. The bottom right...what do I need to seal that up? Top one I've got covered.

Thanks again!
 

·
Registered
Joined
·
660 Posts
Dave, I'm not farmiliar with the design of the s&s heads but generaly the breather passages are just a cross drilled hole that intersects a downward passage that is either cast or drilled in the head. You can take a wire or pick of somekind and "feel" the threads in the whole to get an idea of what your working with. There should be nothing to hit in there but the back of the hole.
The pic of the backing plate shows one fitting (lower right) that looks like it has been screwd into the backing plate. It could be an standard NPT thread (pipe). you probly can take that one out and match the thread type to a threaded plug. The other fitting looks like it may be pressed in(?)...if so you could find a plastic slip on plug cap for it,... or for both of them for that matter. A good high temp petroleum rated thread sealant or anti seaze should work for keeping the oil from moving out the threads.
 

·
Registered
Joined
·
973 Posts
Discussion Starter #7
yeah, it's a pipe fitting, just wasnt sure on size. Pipe fitting sizes confuse me, still.

Hell Ill just take the backplate to farkin McFadden-Dale. Gotta get some other fasteners and I absolutely love goin to that place anyway.

me: "Man, that is one really cool lookin.....bolt"

I thought I was an incurable dork until I went with a bro and caught him doing the same exact thing!

buncha losers! heh.

thanks, grndpndr.
 

·
Registered
Joined
·
298 Posts
Are you having a problem with oil leaking from the heads? If not, I am not sure I would just plug the head breathers off.

I am having this problem. I am in the process of routing my head breathers to a collection canister in an effort to maintain pressure relief of the heads and not create a mess at the same time.

Just my thoughts.
 

·
Registered
Joined
·
973 Posts
Discussion Starter #9
The way they had the head breather system set up it was leaking a little, yes, but...it's not really head pressure that's being bled off but crankcase pressure, and Brent Glick at S&S said this motor vents better through the crank anyway, which makes for a much cleaner look, so that's where we're goin.
 

·
Registered
Joined
·
298 Posts
sounds good

Sounds good.
 
1 - 10 of 10 Posts
Top