Old Hot Rodder, New Questions

[50sFlash]

Well, I have one motor done. Some mild porting, a little compression. Ran it in the tank for a couple hours. I think it will work.
http://i256.photobucket.com/albums/hh181/50sflash/DSC02766.jpg
One to go, but having a hard time finding a '58 35 horse core.

My question: there is about 1" space between the Cav plate, and the bottom of the boat. I would like to raise the motors up 1/2". Can I get buy with the water intake on the nose by the prop, and block off the intake above the cavitation plate? Or do I have to build some type of remote pick-up?
http://i256.photobucket.com/albums/hh181/50sflash/DSC02811.jpg

http://i256.photobucket.com/albums/hh181/50sflash/DSC02813.jpg

http://i256.photobucket.com/albums/hh181/50sflash/DSC02815.jpg

Thanks
Jerry

[Skoontz]

You should be able to routinely put the cav plates at least an inch above the boat bottom. Remember, the water pick up is the screen behind the propeller and when in gear they will feed from the prop wash.

It's been a while since you last posted and i can't remmeber, are you going to install some type of nose cone? Usually the water pick up is placed up front on those.

That will allow you to jack the motor way up.

[Mark75H]

It will "work" ... the question is will it be worth the effort?

[50sFlash]

I have a friend with 2 35s on his boat, and one motor overheats. The only thing I could think of is that there's no water above the cav plate on the Starboard motor, causing it to suck air. Is it worth it? This is a boat I drove 4,000 miles in a blizzard to pick up (free boat). I'll have over a grand in the motors (free motors) I just don't want to melt them down. I just want to get as much drag out of the water without getting radical.

[Mark75H]

I was referring to the porting, your response seems to reply to the motor height.

We know nothing about your friend's set up. You didn't tell us how much higher his motors are, nor if he has tried switching them left and right to see if there is another problem other than the height.

[JohnsonM50]

You should be able to routinely put the cav plates at least an inch above the boat bottom. Remember, the water pick up is the screen behind the propeller and when in gear they will feed from the prop wash.

It's been a while since you last posted and i can't remmeber, are you going to install some type of nose cone? Usually the water pick up is placed up front on those.

That will allow you to jack the motor way up.

Yes it would allow you to raise the motor but the prop will have limits there. 1" above the bottom will work well, even 1 1/2 might. If you can find an adaptable speed prop would be a different story.
The upper intake is an auxillery for 'in reverse' since the prop wont thrust water in the pickup spinning backwards. You could cover it & avoid backin up. It also could be used as a place to add water from an external pitot...
http://i35.photobucket.com/albums/d151/mes355/019.jpg
The pump system on yours is different, it has a return line. youd need to test with care, good news is the return line is because it pumps more than it needs to. Keep up the :cool: work & Good Luck.

[Skoontz]

There are a number of reasons an old 35 could be running hot other than too high or not enough water. They had an overheating issue during that era, i beleive it was related to head gasket/thermostats, but it has been 30 some years since I worked on one that got hot.

[50sFlash]

Thanks for the picture Mike. I like that setup. There is no return. My 4 cyls have a return, but just 1 tube in the 35s. Stats started in '58, but I run the older head without a stat. I'm not planning in trolling backwards, so my guess is I won't overheat backing away from the dock, so I'll give blocking it off a shot. I don't want to get into surface props, or any trick stuff, although if I could find a couple 2 blade brassies cheap. With two motors getting on plane isn't a problem. It's all about looking cool. LOL

Thanks guys
What a great bunch!!
Jerry

[Powerabout]

We used to race 6 and 25 hp ( 1980) with that style of gearcase and we could go as high as 1 " below ( propshaft that is) and the prop would deliver the water to the pick up no probs

[JohnsonM50]

We used to race 6 and 25 hp ( 1980) with that style of gearcase and we could go as high as 1 " below ( propshaft that is) and the prop would deliver the water to the pick up no probs
Ive experimented with my Airborn & a SS performance prop stock to the OMC 25 [not a surface prop]. It had a limit of the anticav-plate being about 1 3/4 above the bottom [flat]. Any higher it would cavitate hopelessly. Anywhere below where it would run was fine cooling with many miles on at 39-41mph.