Another 2bbl to 4bbl question

[JasonB]

Ok, as I get the boat ready each spring, I get the upgrade bug. This year I'm looking at the carb again. I'va asked a variation of this before, but thought I'd throw it out again with better info.<br /><br />The engine is a '76 Ford 302 that was completely rebuilt 2 years ago with items like Clevite bearings, Speed-pro flat top Hyper. pistons, and a crane cam 266H10, lifters, springs with .469 lift, 266 duration. Ignition provided by a pertronix Ignitor 2 with a 35k volt Flamethrower coil. The exhaust is standard Merc log style thru prop. The existing carb is a 2bbl Rochester 2GC that has 1 3/8" venturi, which according to my Hanes manual is 435 CFM. The engine bay is somewhat restrictive to air flow as removing the cover gains 100-200rpm at wot.<br /><br />I am considering an Edelbrock 600 and an aluminimum performer non egr manifold (freshwater only, raw water cooling)<br /><br />The boat is a 19' Deep V Glastron weighing 2400lbs dry. Currently turn a 19 pitch hustler and a 21 pitch MI weheel to about 4050rpm and about 47mph. Holeshot is excellent and the engine does not seem to strain at wot. It really seems as if there is more there.<br /><br />How do you think the described upgrade work on this boat?

 

[rodbolt]

Re: Another 2bbl to 4bbl question

hello<br /> if you do that carb mod be prepared to replace the old log type manifolds, they are very restrictive when compared to modern centerise manifolds.<br /> good luck and let us know how it turns out

 

[f_inscreenname]

Re: Another 2bbl to 4bbl question

Hay <br />You and I could be best friends on this board. I to get the spring bug for upgrades (mine start about a week after putting it away for the year). It is a shame you didn't get a 351W to do all that bottom end work to. After smoking 4 302’s in 3 years I built a 351w for my last boat and was never happier. Love that longer stroke and except for the intake it is a direct swap.<br /> First thing I would do was any way possible get more aair to the motor. You can spend $500.00 plus trying to get a extra 200 rpm out of a motor. Then I would go to the local boat junk yard or e-bay and get a pair of through hull exhaust tips and the proper rubber elbows. That way I could get rid of that restrictive exhaust flow through the outdrive. Then .....I would do the intake and 600 carb. Three of the easiest and least expensive things you can do to build the most HP for the buck. After that it starts into real money for a very few HP. That's where I am at. This year one of my big upgrades is SS roller rockers, about $300.00 for maybe 6 to 10 HP over all. With doing what I said for about (if you hunt ...e-bay in Dec is the best ......sorry) $500.00 you will see about 35 HP easy. After you get that done you could probably go with a bigger cam and roller rockers and, and, and ............................

 

[LubeDude]

Re: Another 2bbl to 4bbl question

f_screenname beat me to it, I was going to tell you to get different exhaust and more air to the engine, Oh well, you got good advice. Put vents in the sides or op top where ever you can put them to get more air to the motor. Your four barrel wont do you any good if you dont.

 

[JasonB]

Re: Another 2bbl to 4bbl question

Good points. I'm not a fan of letting go of the cash necessary to do the upgrade, and upgrading the exhaust isn't a option at the moment either. Looks like some inexpensive vents would be a better use of time/money right now. I have the Rochester disassembled for cleaning rebuild. It performs ok, but maybe freshening it up will help, it's just frustrating to rebuild it as the one I have isn't quite like the one in the instructions.<br /><br />F_in, many of the parts in this motor are from your recommendations a couple years ago. I thought about teh 351, but decided to stay with what I had and save the few extra pounds of weight. The 302 does ok, just seems like there's untapped horsepower that is just barely being held back.

 

[f_inscreenname]

Re: Another 2bbl to 4bbl question

The HP is there any time you have the money or time or both it will be easy to get it out with a couple of cheep upgrades. Takes time (and money). 4th season for me and I will be pulling the motor again for upgrades I wish I could have done the first time (not enough money at the time) so I know how you feel but for me that is half of the fun. <br /> Did I tell you about Northern auto????

 

[JasonB]

Re: Another 2bbl to 4bbl question

Yup, they have lots of my cash. How's that Supernova doing these days? I'm thinking about driving up to your neighborhood to pick up a new trailer for my 19' 'Tron. Not sure about it yet though.

 

[f_inscreenname]

Re: Another 2bbl to 4bbl question

Still in hibernation. Have to go to S.C. this coming weekend for a family event the I am free to get started. I also gave Northern some money over the winter. Changing the lifters ratio (1.6 instead of 1.5, like having a bigger cam) and I have to install a special pilot bearing in the back side of the motors crank so while the motor is out I thought its a perfect time do a refreshing of the bottom end with slight upgrades (parts from Northern) and also see how the last two seasons have been to it. Cant wait. Have had some of these parts since before Christmas. All winter I did home improvements. Dry wall sucks! It almost spring time when a (not so) young married mans fancy turns to the smell of gas and seawater and the roar of a pumping V-8. To me it is almost like heaven.