Comp Cams

[Donziweasel]

If any of you remember, at the end of the boating season last year I had taken a 1997 350 in a 16C and replaced the heads with Vortec, cam with a 264 Comp xtreme marine, Edelbrock intake and Edelbrock 600 CFM Marine carb. It was bogging between 2000 and 3500 rpms. I took the boat to storage about 90 miles away for the winter and when I was down there yesterday, I noticed the boat was outside, not stored warm inside. When I dropped it off, I asked them to look at the engine and see if they could figure out what was wrong with it back in October.
When I called this morning pissed off that my boat was outside at -30, Jay said they had actually been working on it. He said that try as they could, they could not get the bog out. He was beginning to blame it on the cam. Anyone think this could be the problem? This cam is not that aggressive and I thought it would be a nice match for that setup. Any help? I would like to get it fixed before spring so I am not fighting this problem all summer. Rootsy, you helped me with this setup some and I trust your judgement a hell of alot more than my mechanic. Any ideas?

[Rootsy]

it's DEFINITELY NOT the camshaft profile...

[BUIZILLA]

what happened with the jetting ritual again?

[Donziweasel]

I played with the jets and springs some, but did not seem to matter

[mrfixxall]

If any of you remember, at the end of the boating season last year I had taken a 1997 350 in a 16C and replaced the heads with Vortec, cam with a 264 Comp xtreme marine, Edelbrock intake and Edelbrock 600 CFM Marine carb. It was bogging between 2000 and 3500 rpms. I took the boat to storage about 90 miles away for the winter and when I was down there yesterday, I noticed the boat was outside, not stored warm inside. When I dropped it off, I asked them to look at the engine and see if they could figure out what was wrong with it back in October.
When I called this morning pissed off that my boat was outside at -30, Jay said they had actually been working on it. He said that try as they could, they could not get the bog out. He was beginning to blame it on the cam. Anyone think this could be the problem? This cam is not that aggressive and I thought it would be a nice match for that setup. Any help? I would like to get it fixed before spring so I am not fighting this problem all summer. Rootsy, you helped me with this setup some and I trust your judgement a hell of alot more than my mechanic. Any ideas?

WHEN IT GETS WARM,FLY ME OUT THERE AND WE WILL FIGURE IT OUT BUT ITS NOT THE CAM FOR SURE,,,VALVE ADJUSTMENT MABE BUT NOT THE CAM..

[Guy B]

Just had the same deal with my new motor this weekend. Turned out to be water in the fuel. Purchased some fuel from a place I don't think sell's much 93 o. Won't do that again. Good luck

[Donziweasel]

I did use the Comp dual valve springs. Could the valve train be the problem? The fuel should be good and if it had water in it I do not think it would run nice WOT, which it does. This problem pissed me off for the last three weeks of the boating season. I spent a lot of money on these MODS and it would be nice if I could get it running right. :mad: :mad: :mad:

[Rootsy]

what ignition system do you have and what carburetor did you go with... my memory has failed me...

[Donziweasel]

Ignition is a Thunderbolt V I believe and carb is an Edelbrock 600 cfm marine.

[Donziweasel]

Also, valve springs are dual and here are the specs-

Seat Load- 132 lbs @1.750
Open- 293@ 1.250
Spring rate- 322 lbs/in
Coil Bind- 1.150

[RickSE]

Vacuum secondaries or mechanical?

[Rootsy]

Also, valve springs are dual and here are the specs-
Seat Load- 132 lbs @1.750
Open- 293@ 1.250
Spring rate- 322 lbs/in
Coil Bind- 1.150

986 springs...

[LKSD]

Edelbrock perf carb :(

In the other shops defense the Edelbrock is not the best carb to be able to tune out a bog IMO.... I personally would have gone holley & mechanical secondaries... The holley also allows to upgrade to a 50cc accelerator pump if ya need more juice..

You need to figure out if it is a fuel or spark issue causing the majority of the bog.. it also may be a small combo of both.. How much timing advance are you running?? Jamie

[BRIAN73]

Hi,

Here is my two cents because I ran a edelbrock 600 at one point and would never choose that carb, if I could afford a holley.

1. Pump out all the fuel.
2. Change the fuel filter
3. Sell the q-jet and buy a holley 650, tunning a q-jet is like getting blood from a stone.
4. Check the resistance of all of the plug wires

Brian
Soon to have a donzi for sale

[BUIZILLA]

get a REAL carb.............

[Donziweasel]

Will the Holley bolt to the Edelbrock intake? I would be willing to try a Holley. How about CFM with this setup, 600 cfm or 650cfm?

[Rootsy]

get a REAL carb.............


Yeah... That... and it ain't no Holley...

DW, what intake...

[BUIZILLA]

Barry Grant Marine Demon

part # 1282010EM

it comes with 72 / 80 jets, I would go 68 / 74 jets at your altitude, for starters, and see what happens...

make sure your throttle linkage / arm isn't hitting the bottom of the air cleaner / silencer / arrestor, no matter what...

the Performer should be drilled for all applications of fuel mixers...

JH

[Donziweasel]

Edelbrock Performer Vortec dual plane.

[98shovel]

go holley 600 or 650 will work mech. or vac sec. with vacuum the motor only pulls the sec open as far as needed for the amount of fuel req. so fuel cons. should be better ,mech will give u a bit better performance.for square bore holleys edlebrocke makes a thin steel plate for an adapter u can get away without but the carb wont have much bite on the gasket at the sec.
if u go vac by the quick change spring kit and a set of springs
c

[Cuda]

Hi,

3. Sell the q-jet and buy a holley 650, tunning a q-jet is like getting blood from a stone.

It's not a Q jet.

[RickSE]

I used a Holley 4150 650cfm mech. secondary #0-80599 carb when I did my 2-barrel to 4-barrel conversion. The carb worked great with no mods other then jetting down like Zilla says for 3,700ft.

[98shovel]

dont forget the fuel line adapter

[Donziweasel]

I guess if I am going to try a Holley Carb, I might as well try a Holley intake. Any suggestions for the intake?

[BUIZILLA]

leave the intake alone.......

[Donziweasel]

Buizilla, you think the Holley carb and Edelbrock intake are a good match? It would save me a little work and some money, just want to make sure it is a good setup. How about mechanical vs. vacuum secondaries? Not worried about performance as the boat runs pretty damn nice at WOT. More worried about getting rid of my "bog".

[98shovel]

we use elebrock intakes and hollet carbs all the time they work well together
for tuning the vac carb is easyer no jets to worry about on the sec. just springs to time the opening

[BUIZILLA]

I'm starting to prefer the BG over the Holley, but if that's more convenient to get be sure it's a marine version

[Donziweasel]

Rick,
What is elevation for Powell? May re-jet before summer trip.
JP

[BigGrizzly]

I was going to stay out of this but I just can't. Go with the Holley or BG ditch the Eld carb keep the intake it will do well. The eld carb is as hard to work on as the one it was copied from.

[Rootsy]

FWIW, i prefer a BG over a Holley.... comes with all of the bells and whistle right out of the box and the metering blocks don't "leak"...

[Donziweasel]

I looked at the BG website and the Sea Demon seems pretty straight foward to me. Where is a good place to order one from? Will I need any kind of adapter plate to mate it to the Edelbrock intake? How easy are they to tune and jet? I know most people on the boards do not seem to like the Edelbrocks, but personally, I found them pretty user freindly. You could re-jet in 10 minutes, change springs in 2 minutes. I never really worked on another brand of carb, but obviously the Edelbrock is not working right. Just need a place to order from and a price on a 650 CFM Sea Demon. Still undecided about mec vs vacuum secondaries. Any help?

[BUIZILLA]

Barry Grant Marine Demon
part # 1282010EM
it comes with 72 / 80 jets, I would go 68 / 74 jets at your altitude, for starters, and see what happens...
make sure your throttle linkage / arm isn't hitting the bottom of the air cleaner / silencer / arrestor, no matter what...
the Performer should be drilled for all applications of fuel mixers...
JHahemmmmmmm

[RickSE]

Powell is 3,600' elevation now, 3,700' @ full pool.

[Donziweasel]

Buizilla, Where do I order one? All the sites I looked at only have the auto carbs, not marine. Seems hard to find.

[farmer tx]

I went to the Barry Grant website found the carb I wanted then contacted richdesbiens on ebay and told him what I was looking for, he then sent me an email with the item # and a buy it now price. He has 6672 sales with 100% feedback.

http://cgi.ebay.com/ebaymotors/MIGHTY-DEMON-800-ANN-BARRY-GRANT-BLOW-THRU-BLOWER-CARB_W0QQcmdZViewItemQQcategoryZ33550QQihZ001QQite mZ110078903519QQrdZ1QQsspagenameZWDVW

[BUIZILLA]

Farmer's source is excellent...

you will also need a BG fuel line kit....

now pick up the phone and dial_dial_dial :yes:

Fuzzy's Demon is the best responding one i've seen yet, the engine is completely different sounding and VERY crisply responsive with it

[farmer tx]

The fuel line kit was included on the carb I got from him also included a install and tuning DVD.

[Donziweasel]

Just got off the phone with my Mercruiser Mechanic and he said that they think they figured out the problem. Basically, what they told me was that the bog between 2500 and 3000 rpm's is from a lean spot. He said that they were going to modify the accelerator pump (I think he said accelerator pump) to try and get the lean spot out. This sound right?