canajun

I restored a 21' 1974 Nova last year. It turned out sweet, but it wasn't quite fast enough for me. I had it up to 48 on a perfectly flat river at my parents house, but I barely break 40 out on the lake.

It has a 302. When I hit 48, it was basically stock, with a 500 cfm Rochester 2 bbl, running a 15 inch Stiletto. I have a 17 inch, but I only run about 35 with it.

Since then, I put a Prestolite electronic distributor, MSD Blaster II coil and 8.5mm wires, an Edelbrock manifold and a 600 cfm Carter carb.

This thing rockets out of the hole. 50-100 feet and I'm solidly on plane (I have a hydrofoil on the back), no kidding. But, I didn't pick up anything on the top-end over the stock 2 bbl. (Running the same RPM) When I completely open the throttle, it is evident that it is too much for the current setup, as it makes a lot of intake noise, and may even drop RPMs.

So I guess I have two choices. Obviously I need more air to run through the motor in order to make more power.

I have read that the standard thru-prop exhaust is very restrictive, and will essentially thwart any performance improvements that you do. So, I could get a set of center rise manifolds and dump the exhaust out the back, and that may solve my problem.

On the other hand, a simple cam change might be sufficient to wake this motor up.

Any suggestions?

FOUNTAINATLAST

They would both be helpful but do the exhaust first. Even when adding a cam the thru-prop exhaust will hurt your performance and need to be done... Do it in stages to see what & were you increase power/speed, hope this helps.

Turbojack

I second this.

Dangerous Dave

third

Dangerous Dave

What kind of manifolds do you have on there now. Are they the "log" type

canajun

Yes, they are the old "log style."

GoCiggie31

I'm with others and Dave, think about some tuned exhaust manifolds at the same time your putting on the thru hull, if you continue with your upgrades, you will eventually be needing some better flowing manifolds. There are some very reasonable tuneds units on the market: revolutions or maybe even imco thumpers. Depending on your state regs, don't forget to factor in some mufflers after you go thru hull.

If you really want some major gain, think about more engine displacement. Pencil out what your wish list is on the current set up and compare to maybe moving up to a marine 350.
my .02
Good luck and have fun.

Edward R. Cozzi

A 302 Ford with a 2 barrel and cast-iron log exhaust manifolds?
This is a no brainer!

I pulled two 351 Ford engines out of a 33' Bertram and replaced them with new 350/260 packages. The boat raised 3 inches higher out of the water and I had to add 3.5 inches of pitch to get the RPMs out of the stratosphere. Mercruiser did the smartest thing by getting out of bed with Ford.

canajun

Ahhh, the Chevy vs. Ford debate pops up....

I have to admit, this is the first thing I have ever owned with a Ford engine, but....

I met a guy at my marina with a 78 21' Nova with a 350 4 bbl in it today, and my boat just smokes his! Not even close! I even had full tanks of gas. He says the fastest he's ever had his is 35, "with the wind at his back." The lower hulls of our boats are identicle.

Sorry, so much for that theory.

I do think that the exhuast is holding back my engine, though. Nobody really makes custom exhaust for a small block ford. It looks like I will have to swap to a set of center risers for a Pleasurecraft and go through the hull off of them.

Anyone know where I can get a set of block-offs for the y pipe? I know that there is a plate to replace them down under the bellousing, but that would require pulling the motor. I figure somebody has come up with something to just cap the pipes.