Baldie

Well I am a true do-it-yourself type of guy, and have been a car guy all my life, with this past year getting into boats.

The boat right now has twin 350's with some TRS drives, and Merc thru hull exhaust. I am going to be doing these upgrades since the boat will only do about 55 mph on the GPS.


Trick Flow heads
Holley EFI Single plane intakes
24lb/hr injectors
Walbro 255 inline pumps
1000 CFM Throttle blades
Microsquirt FMU with 2 wideband O2 for tuning
Some Lunati flat tappet cams (like 236 @.050)

And some nice dry exhaust. The exhaust will be a tricky part as I just went about bought all the tubing today. I bought, all in stainless -

5 - 3.5" .125 wall 90 bends with about 8 foot of straight
4 3" .065 with about 6 foot of straight
4 3-3.5" transitions
16" of 4"x.25" stainless bar plate for machining flanges
2 O2 bungs
2 - 3/4" NPT bungs.


I guess my question is has anyone ever attempted to make a set of these? Any tips? I will be starting on them this weekend, I was going to MIG the inside with stainless and Tig the outside so it will look nice. I know I will be pressure checking them and all that stuff, but any tips would be nice!

dereknkathy

you might wanna try to pick up some old stainless headers that are leaking beyond repair and whip out the 4 inch makita and do a couple autopsies on them. taking stuff apart is the best way to see how it goes together...

Baldie

I have already looked at a dry Gil tails, and am going to model them off that.

I will be starting on them this weekend, flanges are being machined now. Only have about 340$ in material so far for 2 pairs.

Baldie

Well I guess I will keep this thread updated in the meantime.

I am going to buy more straight tonight to finish off the one motor and then I will finish the next one next week. The flanges are being machined this week as well, and the bungs will come in Monday.

Here are some pictures of what is done thus far, and I will keep this updated if anyone is ever interested in making their own dry tails.

Baldie

Well I will keep this going just for referance incase someone wants to do something like this.

I have one intake wired, distributor locked out, and computer mounted with sensors. New heads are here, injectors, fuel pumps, and have the ignitions boxes ready to go. The exhuast for one side is about done, I will start on the other side this weekend if the weather stays nice.

Powerquest_Baby!!

Your attempting to make 4 double jacketed risers?? I think you are going to have major leakage problems. Its just not worth all the hassle and problems IMO.

Baldie

Why is that? Everything is tig welded and pressure tested?

Update : I have all four almost complete and will be assembling the top end of the motor today if the weather turns.

kreed

iTrader: (2)

Progress?

Baldie

Cylinder heads and intake on Port motor. I am awaiting fittings so plumb in the new fuel pump, have to get a block off plate for the existing one, and awaiting a bluetooth adapter so I can wirelessly tune the motor through my lap, smartphone, or laptop as well as view gauges through that as well.

All risers are 85% complete, have to weld in the 1/2 npt bungs for water and the O2 sensor bungs along with weld on the flanges which should be easy.

I was going to run them all the way out to the tip this year, but instead I am going to hook up at the tip and drain enough water there to cool the tip, with the rest draining out the back of the boat. If this doesn't work, I will be letting all the water go out of the tip, and just extend them next year. The reason for this? I have to drill bigger holes in the transome and I have been getting absolutely no help from friends like they said they were going to.

The wiring for the one motor is almost done, I have oil temp gauges and O2 sensor gauge to put in the helm still.

I will be doing one motor at a time, to get a rough tune on the first one, then change the other motor over to the new set up while flashing in the same tunes for both. I will then fine tune with the O2 sensors using a "Auto Learn" and finish from there.

I should have new pictures this weekend if the weather holds out, we haven't had much of a spring here at all, more like a winter, still winter, then rain rain rain, and maybe spring will come soon so I can work on this!

502ss

iTrader: (3)

Subscribed!

I love true "do it your selfers" that think outside the box and are not afraid to try something new!