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-   -   Hi lift cams and silent choice?? (https://www.offshoreonly.com/forums/general-q/27512-hi-lift-cams-silent-choice.html)

stevejohns 06-28-2002 12:03 PM

thanks again for all the help guys

US1 Fountain 06-28-2002 02:55 PM


Originally posted by Budman
US1,

How about getting that digital camera out and posting a close-up of those divertors for us folks on the board!
Thanks for all the help!

You asked for it!!!!!
I did the mods myself. You are also correct, just by cut and turning the center lower section around, it does come up a little short of being a perfect alignment with y-pipe. That is why I bought an al tube and made the lower leg from scratch. The Fountains that I've seen with the modified ones use the hoses to correct the misalignment. Not very professional looking IMO. This is before powdercoated, so not very purty.

US1 Fountain 06-28-2002 02:59 PM

A nutter 1
 
Other side. And no, I did not remove the seals when welded. But I have since replaced them with new ones.

US1 Fountain 06-28-2002 03:08 PM

Should also have noted that I did cut off approx 1 1/2 -2" from both ends to shorten the overall length. Cut off the back side to move the valves as close as possible to the transom, yet long enough to double clamp, and cut off the front side to allow the risers to be as long as possible. Every 1" helps.

Okay, I'm done

Budman 06-28-2002 03:40 PM

I had to cut some off of the front and backsides of mine as well. I had to do this because I had an alignment issue. My boat was originally equipped with a small block, so the exhaust holes in the transom were closer together than they would be for a big block. I made up the differenct with the exhuast hose. This might shoot me in the foot when it comes to running a longer riser, unless I had some custom made with a dogleg in them = $$$$!

No signs of reversion yet, and a fairly mild 226/236/112LSA cam. But I worry about reversion a lot because I don't have the inconel exhaust valves in this motor.

Ever had any problems with the air leaking down in your system? Mine has a slow leak. Pretty sure it is leaking from the pressure relief valve. Might replace it temporarily with a brass plug just to eliminate it as the problem.

Thanks for the pic's!

BAD-HABIT 06-29-2002 07:27 PM

Just wondering.....I had to get my risers built at a custom height. I know that Stainles Marine told me the LENGTH of the risers determines the amount of cam that safely can be used....Im not using Silent-Choice just straight thru-transom. Mine are 6" taller than their normal set for Small blocks. Does this count for the length or does it have to be horizontal length????

"Bad-Habit"

KENNY 06-30-2002 09:30 PM

HERE IS WHAT I IM HAVING A PROBLEM WITH, OVER THE WINTER WE REBUILT MY 502 INTO A 540 WITH A ROLLER HYD. CAM DUR. AT .050 I. 230 EX. 236 BECAUSE OF LACK OF FUNDS I HAD TO PUT THE STOCK MANIFOLDS BACK WITH IMCO M73 RISERS INTO THE STOCK S/ CHOICE. THE PROBLEM WAS WATER GETTING SUCKED BACK IN, BECAUSE I WAS TOLD THE RISER WAS TO SHORT,SO BEFORE I DESTROYED THIS MOTOR I BOUGHT A SET OF IMCO POWER FLOW MANIFOLDS AND HAD CUSTOM RISERS MADE THEY DUMP THE WATER ABOUT 4 INCHES FROM THE TRANSOM
INTO THE EXHAUST,ALSO GOT RID OF THE S/ CHOICE THE RISERS ALSO COME UP ABOUT 2 INCHES HIGHER THEN STOCK,NOW CAN SOME ONE TELL ME HOW I CAN STILL GET WATER IN 2 CYL'S
# 2 AND # 8.

Budman 07-01-2002 11:48 AM

What is the LSA of the cam? Too much overlap can still cause reversion at lower (idle) RPM. There was a thread on this subject sometime in the past where Too Old (I think) was having a reversion issue with his engine. He was able to actually look down the exhaust with the engine running and see the water working its way back up the exhaust.

Since #2 and #8 are on the same bank, it sounds to me like you have a leak somewhere that is allowing water into these cylinders. Is it a lot of water or just a little?

KENNY 07-01-2002 09:11 PM

THERE WAS JUST A VERY SLIGHT AMOUNT OF WATER.THE CAM LOBE SEP. IS 112. WHAT I DONT UNDERSTAND IS STOCK MANIFOLDS STOCK RISERS AND S/CHOISE,HAD VERY LITTLE WATER NOW NEW HI PER. IMCO POWER FLOW MANIFOLDS AND A LONG A RISER AS I COULD FIT AND STILL SIGNS OF WATER.


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