Crow needs some 500 Caddy help

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crowhater
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Crow needs some 500 Caddy help

Post by crowhater »

Ok guys I am missing something and I need some other opions. A friend of mine is building a 500DD boat and I got the new engine fired up for him but something is not right.

500 caddy 30 over
902 heads
10.1 compression
MTS dd flat tappet cam, the biggest before roller
Alum Edlbrock intake, plentum divider welded to the top, exhaust cross over welded shut
HEI dist, welded solid
Timing set at 34*
Quad carb built by Allen at S&S
646 plugs gaped at .45
Long tube caddy airboat headers 2 3/4 collectors
Electric fuel pump Holley blue 6 psi
3 blade 78" narrow blade 78H
1/2" open carb spacer
Brad penn oil and external oil cooler

With the prop set on #1 the engine spins the prop 2500rpm on the trailer.

I know for a fact that the carb is getting full pull on the linkage. The long block was assembled at a local shop and they do good work. This engine should be making way more power than this. A stock 10.1 caddy should spin this prop to 3000rpm so what am I missing? The timing chain is set strait up dot to dot. The air cleaner is a marine steel filter open all the way around.

What am I not seeing?
18x8 Alum, 496 BBC, 2.6 CH4, 4B 82" S-blades

Bdriller
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Re: Crow needs some 500 Caddy help

Post by Bdriller »

What does prop mfg say the required hp to spin this prop up to desired rpm? 78 3 blade looks overly opptimistic also in my opinion id say 2500 is about what id expect

One Eyed Gator
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Re: Crow needs some 500 Caddy help

Post by One Eyed Gator »

Is it the DD2 cam?

Few things that comes to mind:
Cam degree set properly
springs old or binding - valve guides not cut down.
Is timing set correct for the cam

I know you are aware of all the above.

My 472 .040 over similar build turned a 72" 3 bdl H set at 2.5 to 3 2900. For my boat the sweet spot was 2800 on the tralier.

Striker543
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Re: Crow needs some 500 Caddy help

Post by Striker543 »

Simple, but worth mentioning: have you verified all cylinders are firing? These engines are smooth enough you could be missing one and not notice.

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crowhater
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Re: Crow needs some 500 Caddy help

Post by crowhater »

Thanks guys I knew I could count on you.

The cylinder heads are rebuilt, new springs, and the guides are cut down. The cam is the DD2.

Timing is correct and she is firing on all 8. The engine sounds good, its running good.


I just got off the phone with Don at sensenich and he said that motor should be able to spin 2900rpm with that prop set on #2.
18x8 Alum, 496 BBC, 2.6 CH4, 4B 82" S-blades

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jimmyflfr
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Re: Crow needs some 500 Caddy help

Post by jimmyflfr »

I had similar issue and the secondaries weren't opening on the carb . Fixed problem and engine woke up!

Afflicted
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Re: Crow needs some 500 Caddy help

Post by Afflicted »

u know the tach is right?

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crowhater
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Re: Crow needs some 500 Caddy help

Post by crowhater »

the carb is right and you can see the secondary's open. The teach is also right, it was double checked with the timing light.

I talked with Charles and I think he is right. I have never used the MTS dd2 camshaft and I did not assemble this engine. They installed the cam and set the cam dot to dot zero based off the chain, they did not degree the camshaft. Charles said he has seen these cams off as much as 6* and should always be checked with a degree wheel. I believe the cam sheet said it should be 3* advance, so if its 6* retard from the factory he could be a total of 9* retarded on his cam timing and that would sure hurt the power.
18x8 Alum, 496 BBC, 2.6 CH4, 4B 82" S-blades

flying fish
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Re: Crow needs some 500 Caddy help

Post by flying fish »

Marshall

Are you sure TDC is marked correctly (dead stop) to know what your timing is?
Is she detonating? Detonation can be as suttle as RPM loss.
What do your spark plugs tell you for burn?

I would doubt the the ICA on cam + or - 6 compared to manufacturers suggestion being your issue. - JME

Can you post Duration @ .050" tappet lift I&E on DD2 camshaft used. Just curious.

On a gauge, what is your static cranking cylinder pressure??
15' DB - 6.2 LSA - 4 blade 82" R - 2.52 CH-4

never enuff
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Re: Crow needs some 500 Caddy help

Post by never enuff »

Have you tried it with the air breather off, I had the same breather u described and it would not pull enuff air
to feed the engine, this was on a boat with a gear tho.

One Eyed Gator
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Re: Crow needs some 500 Caddy help

Post by One Eyed Gator »

You checked the TDC and dist. yourself, right? not a tooth off. I did that when I changed dist. motor felt dead no power at all.

And I agree with Charles.

Scarecrow
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Re: Crow needs some 500 Caddy help

Post by Scarecrow »

Crow, ask Huntinbigun he could fix your problem. :stirpot: :rebel:

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crowhater
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Re: Crow needs some 500 Caddy help

Post by crowhater »

I checked the dist with engine on TDC #1.



The cam is V8 VT90-DD2 from MTS. Marty is out sick and I want the truth!! What is everyone setting this camshaft at when they degree the cam? The guy covering the phone said to install the cam at zero but the cam paperwork says 3* advance.


Fish this engine has maybe 20m run time on the trailer, not really a good base line for plug reading but no sign of Det that I have seen yet. I could be wrong and it would not be the first time but all the signs point me to incorrect piston / valve timing.

Chris the engine acts lazy when you hit the gas even if the prop is off. With the timing locked and set at 34* the engine should snap up like a light switch.

The problem is that I have let this get in my head and now I am over thinking everything. Its very annoying to me because I have done to many of these engines to not be able to figure this out. The good news is that I am not to proud to ask for help and admit I am stumped.
18x8 Alum, 496 BBC, 2.6 CH4, 4B 82" S-blades

flying fish
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Re: Crow needs some 500 Caddy help

Post by flying fish »

Marshall
You will figure it out.

One thing that has me curious is the static cranking pressure on that piece.

You looking for 100 ft. lbs.

Are you a tooth off on crankshaft and camshaft sprocket dots lining up?
15' DB - 6.2 LSA - 4 blade 82" R - 2.52 CH-4

rac1boat
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Re: Crow needs some 500 Caddy help

Post by rac1boat »

Check the prop, sometimes those stickers are off

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Re: Crow needs some 500 Caddy help

Post by One Eyed Gator »

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flying fish
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Re: Crow needs some 500 Caddy help

Post by flying fish »

cranking cylinder pressure. What is it with butterflies open on (1) cylinder? :)
15' DB - 6.2 LSA - 4 blade 82" R - 2.52 CH-4

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Re: Crow needs some 500 Caddy help

Post by One Eyed Gator »

I just looked at the instruction for the cloyes set. I have always had to rethink it when I installed one.

Instruction show the crank Key at say 2 oclock for GM but I seem to remember it being at about 8 oclock.

And remember bondsman says something about timing on the exhaust stroke. Been a little while since I messed with a caddy.

Ring any bell. You know a lot more them most and you and Charles help me quit a bit, just trying to jog your memory.

Bdriller
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Re: Crow needs some 500 Caddy help

Post by Bdriller »

Pretty sure those blades would fit a fairly strong small block with belt drive say 2-1 do you think that motor is that strong?

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crowhater
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Re: Crow needs some 500 Caddy help

Post by crowhater »

I have no doubt the motor is strong enough it's just acting like it has the work cam shaft. I personally did not install the cam or the timing set, I am trying to help a friend. I have been stuck in Louisiana for the last 3 weeks and came back one weekend to see the family and spent a whole day helping him get the boat ready. 14 hours strait working on his boat on other issues like exhaust, rigging, battery box location, wiring, oil cooler, etc. When I finally got a chance to start his ENINE for the first time it was 9:30, around 11:00 I called it a night. I know how it feels to have your boat right there and want to use it so I really want to help him get it finished. I wish I would have done the engine assembly myself so I would know that everything was correct. After years of paying others to turn wrenches for me I have learned it is better to do it yourself, there are very few people I trust to do my work any more.

If you ever want to do a really fun job you should try replacing the turbo on a Duramax diesel engine. If you go in through the pass fender well you are looking at 10-14 hours of knuckle busting good time and that is the easy way. I thought the horror stories were all hype but trust me it is a true PIA.

The airboat in question is my fathers old Rivermaster 16x8 that I was saving for a rainy day. It had a 472 on it and my friend got to use it for several months before the oil pump bypass stick and he ate up a rod bearing. I warned him about the Cadillac oil pumps and that he needed to install an oil cooler. For some reason idling around all day bowfishing drive up those oil temps and leads to sticking that bypass. He was also using standard 10w-40 motor oil.
18x8 Alum, 496 BBC, 2.6 CH4, 4B 82" S-blades

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HuntingBigun
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Re: Crow needs some 500 Caddy help

Post by HuntingBigun »

Scarecrow wrote:Crow, ask Huntinbigun he could fix your problem. :stirpot: :rebel:


:D :D :D :D :D I would do it but do not know nothing about Caddy but Crow be expert in month after you guys post so I learn more from him :stirpot: :stirpot: :stirpot: :stirpot:
Bigun

http://www.krvsa.com


Click for pics = http://www.flickr.com/photos/huntingbigun/

Killin Time 15.6 Diamondback Deckover Mast 808 Hp SC LS 7 /KRVSA /NRA

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Deano
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Re: Crow needs some 500 Caddy help

Post by Deano »

O.E.G. - When installing the Cloyes set, both dots at 12:00 (up, up) will
put the crank keyway right at 7:00 and will be firing the number one cylinder.

Following the less than clear instructions with the cam@6 and crank@12,
will have you firing on cylinder #4, not one. Fine if you stab the distributor that way.
The keyway placement in the instruction's drawings are wrong for a Caddy in either case.

Bdriller - A fresh, healthy 507 will spin a 3-blade H almost like a warp drive.

Crowhater - You didn't read past Mike mentioning the valve guides needing to be cut down for that cam did you? The lift of that cam does require it to attain full lift. If that was done, it does sound like your valve timing may be off. If it was assembled with a Cloyes timing set and they inadvertently used the wrong keyway, it could be 4 degrees retarded instead of the 4 degrees advanced that they liking intended. If that were the case, it would be 8 degrees retarded and . . . well. . . you know.

I've not had good luck with Holly Blue pumps; could it maybe be suspect? Is the tank pick-up clean and clear?
Barring those seemingly unlikely options, it sounds like you may have to take a look behind that timing cover. If so, you do realize that you can press the locating pins in and pull the cover without dropping the pan, right?
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Bdriller
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Re: Crow needs some 500 Caddy help

Post by Bdriller »

Deano wrote:O.E.G. - When installing the Cloyes set, both dots at 12:00 (up, up) will
put the crank keyway right at 7:00 and will be firing the number one cylinder.

Following the less than clear instructions with the cam@6 and crank@12,
will have you firing on cylinder #4, not one. Fine if you stab the distributor that way.
The keyway placement in the instruction's drawings are wrong for a Caddy in either case.

Bdriller - A fresh, healthy 507 will spin a 3-blade H almost like a warp drive.

Crowhater - You didn't read past Mike mentioning the valve guides needing to be cut down for that cam did you? The lift of that cam does require it to attain full lift. If that was done, it does sound like your valve timing may be off. If it was assembled with a Cloyes timing set and they inadvertently used the wrong keyway, it could be 4 degrees retarded instead of the 4 degrees advanced that they liking intended. If that were the case, it would be 8 degrees retarded and . . . well. . . you know.

I've not had good luck with Holly Blue pumps; could it maybe be suspect? Is the tank pick-up clean and clear?
Barring those seemingly unlikely options, it sounds like you may have to take a look behind that timing cover. If so, you do realize that you can press the locating pins in and pull the cover without dropping the pan, right?
He probably has som issues, however Ill by him a case of the best beer if after he gets all motor issues worked out and spins that 78" 3 blade h at 3k in a sweet spot for prop DD . i will stand corrected when its proven!

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Re: Crow needs some 500 Caddy help

Post by clamped »

Change out the autoclave indicator and it will swing it 4 grand

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crowhater
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Re: Crow needs some 500 Caddy help

Post by crowhater »

I was not there for the cam installation or timing chain set up. He purchased a single key way timing set.

He talked with Marty at MTS today and Marty is sending him a six position timing set and told him he would replace the cam for free if it is way out. By the way Marty is out sick and from what I was told he might have had a stroke.

My old 514 caddy direct drive spun a 72x44 Florida airboat paddle prop to 3000 and change with a factory camshaft set 3* with a Cloytes chain. It took a great deal of fine tuning on everything to finally achieve that performance.
18x8 Alum, 496 BBC, 2.6 CH4, 4B 82" S-blades

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