Hi-Tek Header Install

I have been restoring most of the worn out parts/components on my 92 Ski Nautique CB with the 351W Pro Boss this year. My exhaust was worn out and even though I was really strapped for cash I went ahead and ordered a set of Hi-Tek headers. They were a little tricky getting the bolts tightened up because you can't get a socket on the middle bolts so you have to use an end wrench. I also changed out my ignition to a DUI Performance HEI style distributor with Live Wires. I got the timing set at 12 degrees and the boat starts awesome and it seems to idle a little smoother.

I took it to the lake and ran it this afternoon. Boat seems a little quicker out of the hole, much stronger mid range, and the top end was WOW! My boat would run 45.9 to 46.0 MPH before the ignition upgrade and the Hi-Tek header install. Today it ran 50.5 on Perfect Pa$$ which was awesome. I tuned my Perfect Pa$$ this summer with a GPS to make sure it was accurate but I may take the GPS out to double check because a 4.5 MPH increase was much more than I expected. I took some pics of the before and after pics of the exhaust swap I may post later. Anyway...I am happy and the boat is running great. The only thing I did notice after the Hi Tek install was the rubber exhaust hose from the header to the muffler seems much hotter to the touch. I am not sure what the exact temp was before the header swap but it seems hotter to the touch. I put a laser temp probe on it and it read around 145 degrees while running and if you run the engine at full speed and slow down the exhaust showed a temp of around 200 degrees. Does this seem too hot to anyone?

I did pick up a ground issue because I installed a new wiring harness from PCM to make the conversion from Pro Tech to a standard distributor. My volt meter read low, oil pressure read high, and the water temp read high so I have got to figure that out.

No please, no numbers, no details, no pictures or that giant sucking sound in the area of my wallet is going to get louder and louder...

JR_VIC,

That is sweet, Looks like you're a stickler with the details. Very Very Cool, nice work.

You should probably think about cleaning up that engine a bit- it's filthy.

Jeff the chrome Jabsco is the final straw,way too cool,i am impressed but what the hell i am from La.....is the distr. cap clear also???? reminds me of my hot rod days 1970,boy that makes me feel good........ boat dr

Good show. There are a LOT of little details on that engine to add up to that look.

JR_VIC wrote: TRBenj...I am running a new three blade acme propeller but it was repitched for a higher horsepower engine and a little more top speed. I don't know much about propellers so I'll have to look at my receipt as I can't remember the pitch.

My guess is that youre running the #470 with some cup added. Did you have Acme do your prop work directly? Id love to hear the exact specs on the prop so I can compare to my setup. RPM's and GPS would be great to hear when you get a chance as well.

I love my DUI too. I picked up 200 RPM just by installing it and setting the timing to ~14 degrees. I think Im closer to 12 now with my GT40p heads.

boat dr...yes, that dist. cap is clear. I remember those clear caps as well back in the day. Sorry everytime you have called I have been way to busy. I'll get caught up and return your call soon.

TRBenj...that is just my stock PCM flame arrestor that my buddy chromed and it came stock with that breather hose that comes off the front of the breather over to the filler neck on the valve covers. Talk to you soon.

JR_VIC wrote: The stock tach was right below and right at 5200 RPM and the PP tach peaked at 5180 RPM's a few times but was mainting 5160 RPM's consistently and the speedo today with the family, gear, and 3/4 tank of fuel was running 50.3 and a few times I saw it hit 50.5 MPH. I'll check again next week with the GPS. It seems like my peak RPM before the Hi Tek headers and ignition was around 4700 RPM's but I'll check my notes.

Jeff, those are great numbers. Still love to hear all the info you have about the prop. You have the GT40 heads and Performer intake, correct? Stock cam?

JR_VIC wrote: I will probably add roller lifters this winter.

Jeff, I a$$ume you mean roller rockers? Sounds like a nice little package youre putting together. Id be interested to hear the specs on the cam you go with.

That 612 is 12.5x15.25. It should have ~.105 cup in stock form, so you could be at .130 or .145. Thats a bit more prop than my stock 470 (12.5x15). The fact that youre able to turn it 100 more RPM (Im at ~5050) is extremely impressive- even more so that youre doing it without a cam.

It sounds like there are 300-500 RPM to be gained from the headers alone. Ive got to get me some.