Everything done but low rpm at WOT. Distributor spring?

[VancouverBoat]

An Edelbrock Marine 750 from Summit or Jegs should do the job.
Summit’s #. EDL1410. @ $575.95.
Have you checked inside the exhaust system for any blockage such as any exhaust shutters or even a rag could cause this kind of problem.
Will the engine free rev in neutral? If so then that would rule out any blockage. I have seen autos with a internal exhaust blockage that would only rev to 1500.

Kenny, thanks. Yes, the exhaust is clear and and it will free rev in neutral.

 

[VancouverBoat]

So a new carb is $600 plus the setup. Would that investment in a 750 vs a 600 give me that much more help out of the hole?

 

[jimmbo]

Carb Throats would be larger, likely hurting Holeshot

 

[flashback]

Yep, atomization suffers...

 

[Scott Danforth]

I'm going to disagree here.

When I drag raced my 3.8, I ran a 650 double pumper for the holeshot

My BBC in the boat could use a bigger carb and I am running an 830 with annular discharge. Going to get a 1050 main body and throttle plate next

Good buddy of mine was married to his 650cfm Edelbrock on his BBC because everyone (including Edelbrock)kept telling him that's all he needed, however kept complaining about lack of power on take off, top end, etc. Could only get 4500 RPM. After I told him if the 850 street demon didn't solve his problems I would buy it for twice what he paid.

10 minutes after bolting it on and adjusting the idle mix, he did a 200 foot long burnout without trying, hit 8000 RPM in first 5 gears and can pull 5500 in 6th

That BBF needs 800-850 cfm

 

[kenny nunez]

The 454 BBC that was in my 21‘ Taylor SC jet boat had a 750 Marine Edelbrock with the “A” cut stock impeller would hit 5k @60 with no problem from a standstill with no bogging.
It was a bone stock 330 hp Indmar conversion.

 

[VancouverBoat]

I appreciate the love you guys have for the technical side, but I am just hoping to get my old engine working better without losing my shirt. I would rather not spend the money if there is some doubt that it would really make a difference for me....

 

[VancouverBoat]

How much more power will I get by going from a 600 cfm to 750 cfm carb? Will I really notice this difference?

 

[jimmbo]

Likely none

 

[VancouverBoat]

I'm going to disagree here.

When I drag raced my 3.8, I ran a 650 double pumper for the holeshot

My BBC in the boat could use a bigger carb and I am running an 830 with annular discharge. Going to get a 1050 main body and throttle plate next

Good buddy of mine was married to his 650cfm Edelbrock on his BBC because everyone (including Edelbrock)kept telling him that's all he needed, however kept complaining about lack of power on take off, top end, etc. Could only get 4500 RPM. After I told him if the 850 street demon didn't solve his problems I would buy it for twice what he paid.

10 minutes after bolting it on and adjusting the idle mix, he did a 200 foot long burnout without trying, hit 8000 RPM in first 5 gears and can pull 5500 in 6th

That BBF needs 800-850 cfm

What is a BBF?

 

[jimmbo]

What is a BBF?

BBF: Big Block Ford, I would guess.

 

[VancouverBoat]

BBF: Big Block Ford, I would guess.

Thanks. I guess I am back to still trying to figure out why I cannot get on a plane. I thought the spark arrestor might be plugged with soot but cleaned that and still cannot get there...

 

[jimmbo]

When you have the Distributor Cap off, grab hold of the rotor, and see if it can be rotated a bit, then spring back. I don't know which direction on a Ford so try both ways. If it moves then springs back, then the Advance should be working, either or not is advancing at the correct rate isn't known as you were bending some parts. If there is no movement, or it moves but doesn't spring back, there is a Problem

 

[Scott Danforth]

What is a BBF?

Big Block Ford. Specifically your 460 cubic inch FE motor

 

[Scott Danforth]

Factory carb from OMC was 715 CFM. OMC part number 0986079 (Holley 9029) The motors responded better with 850cfm. With only a 600 CFM carb, pull the spark arrestor and drop the prop down in pitch to get you out of the hole.

 

[VancouverBoat]

When you have the Distributor Cap off, grab hold of the rotor, and see if it can be rotated a bit, then spring back. I don't know which direction on a Ford so try both ways. If it moves then springs back, then the Advance should be working, either or not is advancing at the correct rate isn't known as you were bending some parts. If there is no movement, or it moves but doesn't spring back, there is a Problem

I just put in a new distributor thinking that was the issue and it did not solve it. Yes, I get the bounce on the rotor.

 

[VancouverBoat]

An Edelbrock Marine 750 from Summit or Jegs should do the job.
Summit’s #. EDL1410. @ $575.95.
Have you checked inside the exhaust system for any blockage such as any exhaust shutters or even a rag could cause this kind of problem.
Will the engine free rev in neutral? If so then that would rule out any blockage. I have seen autos with a internal exhaust blockage that would only rev to 1500.

I want to redefine my answer on the free rev. It seems like it takes time to get up to the higher revs and I hesitate to run it for too long at high revs in neutral. My previous boat would get the high revs almost instantly. This one takes like 5 secs. Is that an issue?

 

[VancouverBoat]

Factory carb from OMC was 715 CFM. OMC part number 0986079 (Holley 9029) The motors responded better with 850cfm. With only a 600 CFM carb, pull the spark arrestor and drop the prop down in pitch to get you out of the hole.

Ok, I am going to look for another prop to try. I hesitate as it seems my prop 15 x 17P was the prop sold with this boat and engine when new.

 

[Scott Danforth]

Ok, I am going to look for another prop to try. I hesitate as it seems my prop 15 x 17P was the prop sold with this boat and engine when new.

But when your boat was new, it has a bigger carb

 

[VancouverBoat]

But when your boat was new, it has a bigger carb

Good point. So should I read that as: smaller carb equals smaller prop pitch?