Ghostrider

G'day All,

I've bought a set of used CMI Split Tube Elbow Tops with dry tails but the tails are way too long for my BBC - Bravo1 set up. I'm thinking the tails are for a set up with a trans?

I have 12" from the back port to the transom when measured from level with the rear bolt of the exhaust now. My tails are a bit over 27" to the tip with the bend at 15" so they are too long and won't fit.

Can anyone tell me the measurements of the standard CMI dry (through transom) tails?
Alternately, is there a way I can make these work?

I was thinking of having a set of custom tails made up or having this set cut shorter to fit but I don't really want the hassle if the standard CMI tails will fit better.

Any advice would be greatly appreciated!

MILD THUNDER

iTrader: (3)

Those tails look to be for a TRS or SSM setup (with trannies)

Standard Bravo tails should make life easier for you, but only if the exhaust holes in the transom are the standard setup. You could mock up what you need using PVC pipe. Glue it all together, then have the pipes built to fit off the PVC template.

Ghostrider

That sounds like a good idea, I might give that a go...

What's the easiest way to evenly enlarge already existing through transom exhaust holes? They are 4" now but I'll need 4.5".

tcelano

What I have done in this situation is get a 2x6 or glue plywood together, then cut a puck using a 4-1/4 or so holesaw. Then, remove the puck from the holesaw, sand it the rest of the way so it fits in th existing hole. Epoxy it in, and use the pilot hole that's already there to cut the 4-1/2" hole. Use masking tape to keep the gelcoat from cracking, or burn through the gelcoat with the holesaw in reverse.

Young Performance

To enlarge existing holes, I will install a hole saw that is the size of the hole that I want to drill in the transom. Then, I will install a hole saw inside of that one that is the size of the hole that is in the transom. Most mandrels are long enough to hold 2 hole saws at once. The only problem you may run into is that the size difference in the 2 hole saws is so close that the smaller one may not fit into the larger one. Basically, the smaller one acts as a guide to drill the larger hole. It works great.
By the way, great advice on the use of pvc to mock up the tails.
Eddie

Ghostrider

Thanks for the tips lads!

Just looking at the middle pic above then comparing to the actual pipes, is it maybe worth seeing if I can have the center section (the elbow part) of the tails removed and have the straight end welded up to the straight flange? That would give me a 16" - 17" Length overall which should equate to 3" out the back through the transom...

I'm not sure if this would be any easier than simply making up new ones? I'm heading out today to grab some PVC, wish me luck, everything down here seems to be metric! (thanks France...) From what I can see of the standard Bravo set up CMI tails is that they're straight from the flange to the transom. Is that correct?

Thanks again for the advice.

tcelano

Eddie, that's a darn good idea, and I'll remember that for next time. Thanks!

Ghostrider

I suppose I should've seen this coming but the CMI Split tube outlets / exits are about 2-3" taller than the standard riser exit height...

I now have a couple of options:
1) Seal up the current transom holes, glass over, recut new holes in line with the current exits or,

2) Have a set of tails made up (if possible) to fit in the current arrangement with the ~2" drop taken in to account. Hoping to hell that I have enough room.

I've bought the PVC to mock up what needs doing (Thanks MILD THUNDER! ) and I'll knock up a proposed set up to run it through the outlets as is but I just hope I can find someone around here up to the task!

I called a stainless marine place yesterday, as it turns out, there idea of stainless and marine was BBQs and handrails. Who knew?

Thoughts?

I'll keep you posted!

jeff1000man

****, just run with the PVC

Ghostrider

You would!!!

Well, through the magic of photoshop, I've managed to come up with a layout (to scale) with what I think I'll need.

The design is based on the bottom of the new tailpipes needing to be 4" lower than the bottom of the riser exit, taking into account the jacketing.

I don't think the angles look too severe and there should be enough room to maneuver it into place without too much stuffing around.

Now to find someone to make my little photoshop dream a reality. I'm off to get more PVC bits!