500 caddy tweeking tips?

Automotive powered airboat discussion.
Post Reply
divecaptchris1
Southern Airboat Member
Posts: 91
Joined: Sun Apr 28, 2013 6:08 pm
Location: Ozello, Florida

500 caddy tweeking tips?

Post by divecaptchris1 »

Running a 500 caddy on a 15' panther hull with polly, 72 l x l 44 stick prop. only getting 2500 rpms WOT, running the q-jet carb, motor runs like a top, no missing or hesitation, but ifeel I should be getting 3-500 more outa her. Anyone got any tips for getting the last few hundred outa her without a rebuild or other Large $$ undertakings :)
User avatar
John Fenner
Southern Airboat Member
Posts: 2910
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: 500 caddy tweeking tips?

Post by John Fenner »

http://www.southernairboat.com/phpBB3/v ... y+upgrades
Plenty to read in the search forum under 500 Caddy.
I never finish anyth,,,.
User avatar
John Fenner
Southern Airboat Member
Posts: 2910
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: 500 caddy tweeking tips?

Post by John Fenner »

There are many simple tricks as well to gain power on low bucks.
I never finish anyth,,,.
User avatar
:)
Site Supporter - I
Site Supporter - I
Posts: 2110
Joined: Thu Jul 08, 2010 8:07 pm
Location: Baker County, Florida
Contact:

Re: 500 caddy tweeking tips?

Post by :) »

A good dd caddy Cam to start and get a prop that it will turn 2900 or so.
14 ft Combee. 4 seater, BPE 383 sb chevy, 2.09 stinger, 3 blade ww stump puller.
"When the people fear their government, there is tyranny; when the government fears the people, there is liberty." Thomas Jefferson
User avatar
Deano
Site Supporter - V
Site Supporter - V
Posts: 4597
Joined: Thu Jan 06, 2005 11:16 am
Location: Inverness, FL

Re: 500 caddy tweeking tips?

Post by Deano »

What have you already done to it, or is it 100% stock?

Is that the prop CowboyRock had ? If so, I thought it was a paddle.
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan
divecaptchris1
Southern Airboat Member
Posts: 91
Joined: Sun Apr 28, 2013 6:08 pm
Location: Ozello, Florida

Re: 500 caddy tweeking tips?

Post by divecaptchris1 »

Deano wrote:What have you already done to it, or is it 100% stock?

Is that the prop CowboyRock had ? If so, I thought it was a paddle.
deano, it is stock as far as I know, yes it is the prop from cowboy, however all that have looked at it say it is a stick. as you well know I don't have a clue :). I think timing is issue from reading posts on here. But really haven't learned enough to know where to set it! Im a welder and not much of a mechanic! The Motor sat for a long time, and has seamed to run better each time out, of course that is two times out for about 1 hour each :)
User avatar
Deano
Site Supporter - V
Site Supporter - V
Posts: 4597
Joined: Thu Jan 06, 2005 11:16 am
Location: Inverness, FL

Re: 500 caddy tweeking tips?

Post by Deano »

Glad to hear that it's really a stick. That will work. A 44" paddle would be a problem to spin much more.

You really need to put a timing chain in it right on the front side if that hasn't been done.
The one you want is Cloyes #9-1139, iirc. This is not something to put off now that you are running it.
A hundred bucks now, or a rebuild later (maybe sooner than later).

When you do that, confirm that your timing marks for TDC are correct on the balancer and marker. Motors this old could have been Frankensteined along the way and there were 4 or 5 different ones used over the years. You can put a spring kit in the distributor or lock the timing. As far as your timing goes 32 degrees total is good to start, after you have done the above.

If you can spend the $300 for a DD#1 cam and lifters from MTS, that is likely your single biggest bang for the buck.
A 1" spacer between the factory intake and the carburator will help as well.

Do a search, and read away, there's probably more here than you even want to read.
I believe you have my number, feel free to call if you have any questions.
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan
User avatar
Cowboy Rock
Site Supporter - VI
Site Supporter - VI
Posts: 1705
Joined: Sat Feb 26, 2011 5:04 pm
Location: Dry Branch, Ga
Contact:

Re: 500 caddy tweeking tips?

Post by Cowboy Rock »

Chris,,, I thought it was a Paddle,,, I was told if the blade was wider than the hub it was a Paddle,,, Either way I hope it is what you need for your boat,,, Good luck,,,

:drunken: :rebel: :old_glory:
Wet Dreams Too,,,

14 ft. Panther,,, 370ci SBC, 72 in Whirlwind Whispertip, Line-X-350 X bottom,,,

"Full bloodied Dog hunting man"

Dry Branch, Ga.

Thats how I roll,,,
Thunder200
Southern Airboat Member
Posts: 588
Joined: Mon Feb 01, 2010 5:25 pm
Location: Canaveral Groves

Re: 500 caddy tweeking tips?

Post by Thunder200 »

PM SideJobs on here. He has got one bad to the bone Direct Drive Caddy for sure. He may have some Ideas for you?
One Eyed Gator
Southern Airboat Member
Posts: 1359
Joined: Wed May 30, 2007 11:33 am
Location: Ocala,Fl

Re: 500 caddy tweeking tips?

Post by One Eyed Gator »

Like Deano said Timing chain it a must. Cloyes.

Cam and lifters for DD MTS DD1 or better yet DD2 cam have to cut down valve guides.

Good Valve seal is important. So good 3 angle valve and with a spring kit for DD2 cam. I put a reworked set on my motor made a noticeable difference.

There several different Pulley's 1 is stamped pully with harmonic balancer( light) 1 is a cast pully that is balanced, has no balancer Very heavy. Water pump pulleys are the same way there is a stamped steel and cast. Any rotation weight is good the get rid of.

I put the Aluminum set from MTS with there alternator bracket setup. Alternate is for the small body alt I believe SI10.

Running a wood prop a longer prop adapter 3-6" to get prop away from motor.

Good HEI Dist and Coil. There was one year the stock HEI would only add 8 degree of advance I think it was 74'.

Weld exhaust crossout shut on intake manifold.

Definite verify top dead center and pulley mark many different combonations. Also polish oil pump bypass plunge they tend to stick, may even want to shim spring. Get the good copper exhust gaskets from MTS, the other crap does not last.

Just a few quick thoughts.
boobidges
Southern Airboat Member
Posts: 495
Joined: Sat Sep 29, 2007 5:06 pm

Re: 500 caddy tweeking tips?

Post by boobidges »

Is thatgood advice for a 472 also?
boobidges
Southern Airboat Member
Posts: 495
Joined: Sat Sep 29, 2007 5:06 pm

Re: 500 caddy tweeking tips?

Post by boobidges »

Is thatgood advice for a 472 also?
User avatar
sidejobs
Southern Airboat Member
Posts: 1042
Joined: Fri Oct 01, 2010 7:41 pm
Location: chocolate city, fl

Re: 500 caddy tweeking tips?

Post by sidejobs »

All great advice ...however nothing you do will benefit you as much as switching from a wood to a composite prop. I promise no one will argue that on a dd !
________________
IDIOT !
caddy
Site Supporter - II
Site Supporter - II
Posts: 54
Joined: Fri Mar 04, 2011 9:51 am

Re: 500 caddy tweeking tips?

Post by caddy »

sidejobs wrote:All great advice ...however nothing you do will benefit you as much as switching from a wood to a composite prop. I promise no one will argue that on a dd !


X2
One Eyed Gator
Southern Airboat Member
Posts: 1359
Joined: Wed May 30, 2007 11:33 am
Location: Ocala,Fl

Re: 500 caddy tweeking tips?

Post by One Eyed Gator »

oops
Last edited by One Eyed Gator on Fri Jun 21, 2013 2:11 pm, edited 1 time in total.
One Eyed Gator
Southern Airboat Member
Posts: 1359
Joined: Wed May 30, 2007 11:33 am
Location: Ocala,Fl

Re: 500 caddy tweeking tips?

Post by One Eyed Gator »

From what I have learned from the few dedicated Caddy guys on here, dd power is in the little detail. You not making huge hp so all the little details add up. Also the set-up of the hull and rigging make a big difference as well. I can drive my boat thru and over some crazy stuff, put someone in the seat the is used to all kinds of power they cant make it move, oops sometime I cant either Darn DD.

I would also agree that the Carbon prop is the single best change you can make. My motor doesn't run like some but it has been run hard from over 10 ten years. Finally having to replace the crank. Hope to be back on the water so. With the heat I been hearing Juniper and silver glenn call my name.

Faster than some slower than most but sliding and catching fish.

Setup is alumitec, 3/8 poly with 72 472 and a 72" 3 bld H (hurts my ears just saying it, but one on the better all round props. Really want to try 3 bld NGH.
User avatar
John Fenner
Southern Airboat Member
Posts: 2910
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: 500 caddy tweeking tips?

Post by John Fenner »

Look for the tip on using a spacer plate along with filling the void in the plenum that gains about 2/400 rpm.
I never finish anyth,,,.
One Eyed Gator
Southern Airboat Member
Posts: 1359
Joined: Wed May 30, 2007 11:33 am
Location: Ocala,Fl

Re: 500 caddy tweeking tips?

Post by One Eyed Gator »

John is right, Crowhater has always talked about the 1" carb spacer that is divided down the middle yielding a few hundred RPM gain.
User avatar
Deano
Site Supporter - V
Site Supporter - V
Posts: 4597
Joined: Thu Jan 06, 2005 11:16 am
Location: Inverness, FL

Re: 500 caddy tweeking tips?

Post by Deano »

While I think the specifics of the divider could likely be debated, it is pretty well universally agreed that the factory intake lacks sufficient volume due to it's design (to fit under the hood). Adding a spacer helps rectify this lacking volume. On that note, as John eluded to, there is some to be gained by blocking the exhaust bypass. This was done to aid in fast warm up under a hood with a ducted intake, but is not worth the trade off of having a perpetually heated intake charge in our application. Cooler air is denser, and will yeild better results. It seems as though Edelbrock would have thought of this. :roll:
"The suppression of uncomfortable ideas may be common in religion and politics,
but it is not the path to knowledge; it has no place in the endeavor of science."
- Carl Sagan
One Eyed Gator
Southern Airboat Member
Posts: 1359
Joined: Wed May 30, 2007 11:33 am
Location: Ocala,Fl

Re: 500 caddy tweeking tips?

Post by One Eyed Gator »

I did have the exhaust passages welded up on my Edelbrock intake. But I cannot compare as I never had the intake on before the passages were welded. I did not have plenum divider weld-up. I have also run 5 different carb set-ups 500 2 brl, 750 edelbrock, 650 holley vaccum, 750 summit and a 850 holley dp. Each ran 1/2 ass until I spent a great deal of time tuning it. Once tuned with AF ratio meter they were about the same. Edelbrock like to lean out on top though, try a few things and could never get it right. also the Summit 750 have a lean surge just before the secondaries kicked in, chased that for a while finally went back to the 2 brl, best alround.
User avatar
John Fenner
Southern Airboat Member
Posts: 2910
Joined: Tue Feb 14, 2012 12:26 pm
Location: Miami(Cuba) Fl.

Re: 500 caddy tweeking tips?

Post by John Fenner »

Try a 450 Holley with the rear metering block kit, use 68 jets in the primaries, and 73 jets in the secondaries, it will have alot of snap to it plus the cruise will save fuel.
I never finish anyth,,,.
User avatar
crowhater
Site Supporter - III
Site Supporter - III
Posts: 3490
Joined: Thu Feb 01, 2007 8:47 pm
Location: Conroe Texas

Re: 500 caddy tweeking tips?

Post by crowhater »

I ran the same set up for years! I had the same hull, same engine and it was 100% stock except for a cloytes timing chain. The prop I used was a 72x44 Florida airboats paddle prop and I turned it to 3000-3100 rpm. It took a bunch of tweaking to get to that point but I did it and I did not have to spend a bunch of money on go fast parts. The power is there it is just a matter of getting the combo dialed in. My boat could stop and go on wet sand with just me in it and could run standard dry ground loaded. I built the engine myself in the garage with a standard Cadillac master rebuild kit. The engine was .30 over and had 10.1 compression. The intake was factory and the carb was a factory quad. The headers were those cheap chrome block hugger short tubes off eBay and they cost like $200.00. I wish I still had the boat, it was one of the best airboats I ever owned. It would make 8mpg, never broke down, and run 50+mph easy.
18x8 Alum, 496 BBC, 2.6 CH4, 4B 82" S-blades
divecaptchris1
Southern Airboat Member
Posts: 91
Joined: Sun Apr 28, 2013 6:08 pm
Location: Ozello, Florida

Re: 500 caddy tweeking tips?

Post by divecaptchris1 »

Cowboy Rock wrote:Chris,,, I thought it was a Paddle,,, I was told if the blade was wider than the hub it was a Paddle,,, Either way I hope it is what you need for your boat,,, Good luck,,,

:drunken: :rebel: :old_glory:
No issue with the prop! I was hoping it was a stick! my issues are with the motor now! lol!
Post Reply

Return to “Automotive Power Only”