Ducknutt Build 500 Caddy

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DuckNutt
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Ducknutt Build 500 Caddy

Postby DuckNutt » Mon May 08, 2017 8:37 am

Fella's,
The part pile is huge and I need the last few pieces; what radiator do I use? Glenn (engine builder) recommended a Summit racing universal for my 500 Caddy. I went to their site and there's crossflow, downflow, scirocco and left, right or center? Any discussion/advice appreciated.

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Deano
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Re: Ducknutt Build 500 Caddy

Postby Deano » Mon May 08, 2017 9:05 am

I would recommend getting a purpose built one from Diamondback, Panther, Alumitec, etc. . . . whoever is closer to you. The last Summit universal I bought was crooked (as if the jig was way twisted?) and looked like it came from Stevie Wonder's weld shop. Naturally, they can't all be that bad, but it cured me of taking that route.

A properly built airboat radiator will cost more, but be braced for the rigors of what we do to them. You already have a measurable expenditure in your engine, your radiator is no place to save a couple bucks.

Standard Cadillac cooling note applies: If not running a Caddy thermostat, you have to block the bypass in the block with a 1" freeze plug under where the thermostat would have sit. I'm not familiar with Glenn's preference in that regard, either way will work. As a new Caddy owner you just need to be aware that you can not omit both. This has been expanded on elsewhere, a quick search will yield volumes if you want/need more clarification.

On a different note, if you do order from an automotive type supplier, you want a Ford or Mopar type plumbing arrangement. With the rad behind vs. in front of the engine this becomes backwards. In any case, it will be preferable to go in the top on the port side, and come out the bottom on the starboard side.

Welcome to the Caddy Club. :thumbleft:
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Re: Ducknutt Build 500 Caddy

Postby DuckNutt » Mon May 08, 2017 10:42 am

Thanx Deano. I'll give Alumitech a call so what they have.

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pontoon outlaw
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Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Mon May 08, 2017 11:00 am

I got mine from Summit and I run the hill like a raped ape and it keeps my 507 cool never above ,170 even in the summer time just use lots of rubber bushings at the contact spot where it's bolted on and don't over tighten it to your rigging so it has some play in it when ya hammer her through the hill

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Re: Ducknutt Build 500 Caddy

Postby DuckNutt » Mon May 08, 2017 11:31 am

Outlaw, do you remember which one specifically you use?

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pontoon outlaw
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Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Mon May 08, 2017 4:49 pm

it's the summit universal fit part number 380331 there are a few different types in that category... mine is 31 wide 19 tall 2.25 thick and the cap is on the right side with the hole at the bottom on the same side as the cap and the other hole is at the top opposite of the cap it doesn't have a drain tube neither... been on 5 plus years...cools perfect....507 with a box...spinning a 2 blade 76 WW stump puller mounted right to the engine stand hope this helps price range is 150 to 200 dollars..the only thing I've had to do to it in 5 years is replace the Cap once :) when I mention the above spots .. it's looking through the Engine at the Radiator...

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kwanjangnihm
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Re: Ducknutt Build 500 Caddy

Postby kwanjangnihm » Mon May 08, 2017 7:13 pm

toon I grabbed 2 pics of your ride to show radiator setup :thumbleft:

Image
Image
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Re: Ducknutt Build 500 Caddy

Postby SWAMPHUNTER45 » Mon May 08, 2017 8:03 pm

Call Floral City Airboat would be my advice get the radiator and mount kit

I love Alumitec but their heavy duty unit had in and out on the same side, didn't work for me.

As Deano so gingerly advised, you best make sure about that plug or run a thermostat because it cost another fellow on here a bunch of money.

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Deano
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Re: Ducknutt Build 500 Caddy

Postby Deano » Mon May 08, 2017 8:43 pm

Quite obviously that works in that particular instance. :salute:

The 31x19x2+ dimensions and that being a well tuned Branch motor on a comparatively small hull, are to be credited for those results in spite of the plumbing not being in what is generally perceived to be the preferred configuration of the coolant entering the top and exiting the bottom.

The fact is that I've run many direct drives (including the current one) using the stock radiator that came out of the same car as the engine, which results in the same backwards configuration. This presents no problems for a Cadillac given the 3k rpm limit, but when adding a gear box and faced with the necessity of buying one, I have always (as do most others) avoided running into the bottom as it is simply not optimal.
How much difference it makes could probably be debated, but top-->down is more thermally efficient.

Given that the objective is to reduce the temp of the coolant, why not have the system designed to work as well as possible? How many OEM applications do you see where the coolant enters the bottom of the radiator?

Yes, Swamphunter is correct. Floral City Airboats has what you need as well. Sounds like he's researched that more recently than I have.
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pontoon outlaw
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Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Mon May 08, 2017 8:54 pm

MMMM?? why do you think my plumbing is wrong??? it's just as you described it in your post?? and I turn that beast upwards to 4200 rpm's....in the itchy grass LOL!! :scratch: Deano
Last edited by pontoon outlaw on Mon May 08, 2017 9:00 pm, edited 1 time in total.

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pontoon outlaw
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Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Mon May 08, 2017 8:59 pm

it comes out of the water pump then goes to the top of the radiator then comes out the bottom!!!!!!!!!!!!!!!!! up to the thermostat>>>>

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Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Mon May 08, 2017 9:16 pm

:cheers:
IM000929.jpg
see from the pump to the TOP of the Radiator :thumbleft:

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Deano
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Re: Ducknutt Build 500 Caddy

Postby Deano » Mon May 08, 2017 9:26 pm

pontoon outlaw wrote:MMMM?? why do you think my plumbing is wrong??? it's just as you described it in your post?? and I turn that beast upwards to 4200 rpm's....in the itchy grass LOL!! :scratch: Deano
No, no, no. Never said that your plumbing was wrong. Image
The way your boat runs without getting hot is proof that. 8)
Quite the contrary, I don't know of anything wrong with your boat. How it runs is legendary.

Was only meaning to convey to Ducknutt that in a perfect thermal-dynamic world, it was not optimal.

pontoon outlaw wrote:it comes out of the water pump then goes to the top of the radiator then comes out the bottom!!!!!!!!!!!!!!!!! up to the thermostat>>>>
I think you'll find that the flow is such that the coolant exits the engine at the thermostat after having entered at the water pump. :wink:


:thumbleft: Very cool idler pulley. Image
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Re: Ducknutt Build 500 Caddy

Postby DuckNutt » Tue May 09, 2017 6:20 am

Thanx fella's, LOL I noticed that pulley also!! Ok one more question. My plan is to mount the radiator just forward of the engine approximately the same level but just forward of the engine rather than closer to the prop. My intent is to clean up airflow to my prop with less restriction. IF I do that should I reverse the intake to the radiator?

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Re: Ducknutt Build 500 Caddy

Postby SWAMPHUNTER45 » Tue May 09, 2017 7:40 am

Duck forget about the air stream to the prop brother and put that radiator where it will get the best airflow. A 4-5 inch difference on a big inch engine equates to an easy 10 to 15 degree heat increase, maybe more on some boats. I have done the testing this is not just talk. The Cadillac platform does not like heat like a LS or other engines. On a hot day with the need to run dry that 10 or 15 degrees can be a big concern. The 145f to 185f temp range running seems to be where they like to live with anything after 190f my eyes are riveted to the mechanical gauge. Naturally it will shoot up on shut down as the engine heat soaks my references are running temperatures.

The radiator and mounting supplies that Floral City Airboat offers are priced fair and appear adequate, both Blu and I have run them for about a year now.

The idler pulley was a Branch feature on some of his gear drive builds back years ago. It is not something currently used but Mr Branch really liked them on his high rpm builds. The part supplier discontinued it and a suitable and reasonable cost replacement has not been found. If my memory is correct it came off a Ford vehicle and was a easy fit.

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Re: Ducknutt Build 500 Caddy

Postby DuckNutt » Tue May 09, 2017 8:26 am

Thanx Swamp, if it's one thing I always do is listen to experience, "advice taken and followed". I definitely don't want to screw up a new build and a new Treadwell build! Once I have these last few parts I'll post a build thread of the progress. Expect to see more questions. Thanx again,

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Deano
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Re: Ducknutt Build 500 Caddy

Postby Deano » Tue May 09, 2017 8:52 am

I will just chime in, and resoundingly second what Swamphunter said about rad placement.

When weighing thrust vs. cooling, the thrust to be gained would be miniscule compared
to the dramatic temperature increase and potential for undo headaches and complications.

You can always easily get it run it to run warmer if need be. The other way, not so much.
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pontoon outlaw
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Re: RE: Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Tue May 09, 2017 10:09 am

Deano wrote:
pontoon outlaw wrote:MMMM?? why do you think my plumbing is wrong??? it's just as you described it in your post?? and I turn that beast upwards to 4200 rpm's....in the itchy grass LOL!! :scratch: Deano
No, no, no. Never said that your plumbing was wrong. Image
The way your boat runs without getting hot is proof that. 8)
Quite the contrary, I don't know of anything wrong with your boat. How it runs is legendary.

Was only meaning to convey to Ducknutt that in a perfect thermal-dynamic world, it was not optimal.

pontoon outlaw wrote:it comes out of the water pump then goes to the top of the radiator then comes out the bottom!!!!!!!!!!!!!!!!! up to the thermostat>>>>
I think you'll find that the flow is such that the coolant exits the engine at the thermostat after having entered at the water pump. :wink:


:thumbleft: Very cool idler pulley. Image
I fought with that damn belt for longer than I care to admit before I won.

Haha I hear ya it works great have that same belt on for years with no wear on it

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pontoon outlaw
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Re: RE: Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Tue May 09, 2017 10:09 am

Deano wrote:
pontoon outlaw wrote:MMMM?? why do you think my plumbing is wrong??? it's just as you described it in your post?? and I turn that beast upwards to 4200 rpm's....in the itchy grass LOL!! :scratch: Deano
No, no, no. Never said that your plumbing was wrong. Image
The way your boat runs without getting hot is proof that. 8)
Quite the contrary, I don't know of anything wrong with your boat. How it runs is legendary.

Was only meaning to convey to Ducknutt that in a perfect thermal-dynamic world, it was not optimal.

pontoon outlaw wrote:it comes out of the water pump then goes to the top of the radiator then comes out the bottom!!!!!!!!!!!!!!!!! up to the thermostat>>>>
I think you'll find that the flow is such that the coolant exits the engine at the thermostat after having entered at the water pump. :wink:


:thumbleft: Very cool idler pulley. Image
I fought with that damn belt for longer than I care to admit before I won.



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pontoon outlaw
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Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Tue May 09, 2017 10:12 am

That pulley is off Ford courier or ranger either way I just got new bearings pressed in when it went out a couple years ago

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pontoon outlaw
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Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Tue May 09, 2017 10:14 am

Cuz it is too hard to find a pulley I got bearings from Miller bearing matched up perfectly and had had it pressed at the Machine Shop

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Re: Ducknutt Build 500 Caddy

Postby SWAMPHUNTER45 » Wed May 10, 2017 7:20 am

How the idler came to pass was Mr Branch had a "sleeper" street race car years back that he would on occasion call out the show off or loud mouth. The engine was built to spin up over 6,000 rpm and after every pass he would find the belt thrown off. He checked alignment of the pulleys and they were true so it became apparent the long radius was the cause. If you watch the belt at higher rpm on a Caddy you sometimes can see it bounce on the lower side which is the long run.

On the topic of the belt for a Cadillac airboat the recommendation is to purchase a Gates belt, their quality is very high. Both myself and Blu have thrown a belt in the swamp so this is a serious matter. The Branch recommendation is install the Gates belt with a moderate tension. Run the boat a few hours keeping an eye on belt stretch. After running a few hours re-tighten the belt to a snug and firm feel but not 6 ft pry bar or muscle head tight. The belt if over tightened applies pressure to the crank snout and front main bearing.

You don't want to keep re-applying tension to these belts either as the re-occurring stretch breaks down the fibers. Spend the $20 don't risk a fail.

Use a Gates and carry a spare! Often the better NAPA belt is a Gates fyi.

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Re: Ducknutt Build 500 Caddy

Postby DuckNutt » Wed May 10, 2017 8:46 am

Good advice Swamp!

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Re: Ducknutt Build 500 Caddy

Postby Rick McC. » Wed May 10, 2017 10:37 pm

Deano wrote:
pontoon outlaw wrote:MMMM?? why do you think my plumbing is wrong??? it's just as you described it in your post?? and I turn that beast upwards to 4200 rpm's....in the itchy grass LOL!! :scratch: Deano
No, no, no. Never said that your plumbing was wrong. Image
The way your boat runs without getting hot is proof that. 8)
Quite the contrary, I don't know of anything wrong with your boat. How it runs is legendary.

Was only meaning to convey to Ducknutt that in a perfect thermal-dynamic world, it was not optimal.

pontoon outlaw wrote:it comes out of the water pump then goes to the top of the radiator then comes out the bottom!!!!!!!!!!!!!!!!! up to the thermostat>>>>
I think you'll find that the flow is such that the coolant exits the engine at the thermostat after having entered at the water pump. :wink:


:thumbleft: Very cool idler pulley. Image
I fought with that damn belt for longer than I care to admit before I won.


That's the way mine is plumbed; out from the thermostat to the top of the radiator, the out from the bottom of the radiator to the water pump.
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pontoon outlaw
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Re: Ducknutt Build 500 Caddy

Postby pontoon outlaw » Thu May 11, 2017 6:59 am

Right on buddy as long as that fluid is cool coming through the motor either way mine works just fine and I use a 50-50 mixture

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