Logo
FULL SITE MENU

Speed up my boat

W

wizard

Regular Contributor
"I or I should say my son woul

"I or I should say my son would like to speed up the boat a bit. I am running a 13.25 x 17. I have a 1985 17'Sea Sprite with a 3.0 wee 4 cyl. chevy engine.

And Bob ...... Well I know there is something you will say.
happy.gif

Bob send me a e-mail to [email protected] My son just got a cottage near Port Severen so some Saturday I will get you that Tims I owe you."
 
"Get rid of all the excess wei

"Get rid of all the excess weight including, water in the hull, and any fat people.

Tell him not to have only a half tank of gas or less.

Dump all the beer overboard.

Better yet, leave the beer at home.

Yank all the seats out."
 
"[b]Dump all the beer overboar

"Dump all the beer overboard.

But Chief...then Frank wouldn't go up
334561.gif



But seriously Frank...what does he want, faster hole shot or faster top end because they are mutually exclusive (can only have one or the other) unless he wants to compromise somewhere in the middle. What kind of top end speed and RPM's are you pulling now? What's your current prop made out of Aluminum or SS?


Actually Frank...I sold my boat last weekend, the guy gave me a $10k deposit so I think he's serious, just need to take him for a sea trial in the spring."
 
"I don't care about hole s

"I don't care about hole shot I never nail it nor he had better be seen mailing it. It is aluminum prop. And Chief only two seats Don't drink as for 1/2 tank of gas
question.gif


If the guy gave you $10k I would say it's gone. Good for you."
 
"say 30 gallon tank say 7 poun

"say 30 gallon tank say 7 pounds per gallon, say 10 gallons on board 140 pounds for 20 gallons gas.

All estimated. Got to give you a little more speed less weight = faster boat.

Really kidding with you, if you don't have water in the hull and it's tuned well, and your running wot at proper rpms, there is nothing your gonna do to that 4 banger to hop it up.

I got that 4 banger 140 hp motor in my boat."
 
We do alot of long runs. That&

We do alot of long runs. That's why a bit more speed would be nice. But the boat is ok the way it is. If a new prop will not help.
 
"The hole shot could be import

"The hole shot could be important if you are going to do any water skiing especially slalom, but you still haven't told us what the WOT rpm's are now to see if you have any room left at the top end. You want to keep it in that 4200-4600 range."
 
"Stainless prop can increase s

"Stainless prop can increase speed...
usually 1 or 2 mph over aluminum, but can be expensive doing a trial and error on pitch, cupping etc.
and you have to weigh the gains against the increased risk to the drive.
if you have a hydrofoil - taking it off can give more top end"
 
"This is like a Mustang with a

"This is like a Mustang with a 4-banger!
It does not help changing wheels to get it run like a Mach 1 or Shelby!
4-banger in general, max 25 knots.
If 'need for speed', V6 or V8!"
 
"Nobodys mentioned Tabs, have

"Nobodys mentioned Tabs, have they? Smart Tabs will set you back 150 some odd for that boat. All you have to do then, is estimate what tension of Dampers you need. Most models have the option of 2 different, 80 & 120 lb, if I remember correctly.
Simple Driveway installation, that would take about 1.5 hrs, I'd say. Then, that could depend on how many "well intended" buddies are around at the time of installation , and how much Beer is readily available...."
 
"No tabs will increase top spe

"No tabs will increase top speed.
They may be effective in the planning area, but not on top end providing the boat plans out properly without."
 
"I agree with Morten re; the t

"I agree with Morten re; the tabs.
You won't often see real hydraulic TT's on boats of this size, but if you were to add them, the Smart Tabs offer no at-the-helm control as do real hydraulic TT's. If you are going to add TT's, bit the bullet and go for Bennett or one of the others.
This gives you at-the-helm controlf of your TT's!

Your WOT RPM should be the determing factor in your prop selection. That and which one offers the better performance. But the correct WOT RPM range is going to save your engine in the long run!

I have no idea as to how you are loading this boat. Most of us tend to over-load our boats at times because we want to share the experience with others. When we do this in smaller boats, the effect is exaggerated.
Stern heavy boats offer the largest obsticle to over-come. Move what weight you can, forward. Take only an appropriate amount of people and gear with you.
You may find that this alone gives an improvement to your boat's planing ability.

Other than that, you will need more engine power, and that comes at a cost!

Food for thought and just my two cents!

."
 
"<< No tabs will incre

"<< No tabs will increase top speed.
They may be effective in the planning area, but not on top end providing the boat plans out properly without.>>

The Planing idea is what I was referring to. The boat will get up on plane easier with tabs."
 
I just read through this threa

I just read through this thread and was wondering if you are still wanting to increase the performance of your 3.0L. I know a couple of tricks with that engine that seems to wake them up a little bit. they require the removal of the engine and the services of a machine shop. I only do this when I am replaceing the engine. If interested let me know and I'll share a couple of my secrets with you. Just remember the saying speed cost how fast can you afford to go.
 
"Michael or Frank, I think it

"Michael or Frank, I think it would benefit the forum if this trick was posted in this thread. Everyone enjoys performance enhancement, and especially for a smaller engine performance increase.
Others with same engine may be curious, and others may point out some inherant risks as well.
Please post it for us!
It is always good to learn a new performance trick!
happy.gif


."
 
these are two of the tricks I

these are two of the tricks I found with this engine. 1st one is the flywheeel on the 3.0L is heavier than is needed I had about 20 pounds shaved off of one with no problems. the less weight the engine has to spend equals more power thatcan be delievered to the prop. 2nd trick is in the head remove the 5/16 studs for the rocker arms and replace them with 3/8 studs this will allow you to use big block rocker arms which will increase rocker arm ratio to 1.7 this gives a little more lift on the valves. of corse when I had the head off I cleaned the ports up and gasket matched the ports and manifolds. After I installed the motor in the boat and took her out for a test run I found that I needed to go up 2 degrees in pitch. Higher pitch = faster top end speed. plus with those upgrades the engine accellerates faster and I have a better hole shot. the next time I build a 3.0L I am going to have the block decked. I am trying to break 200 hp without looseing to much fuel economy. when i build the engine I will have it dynoed and post the results. But as of now I don't plan on building it for at least another year.
 
I have a spare 3.0 how much do

I have a spare 3.0 how much do you think you can cut off the top. And where would you get longer push rods?
 
I would need to set down with

I would need to set down with an engine do some thinking and measureing to come up with a max ammount that I would have shaved off of the block deck. But I think I would start with 5 thousands pop up that always seamed to be the right ammount of pop up in the race engines that I have built. As for the push rods they do not need to be changed. the rocker arm ratio is the amount of mechanical advantage that you get out of the rocker arm. just changing the rocker arm will give you about 30 thousands more lift at the valve. If you want to get creative think about longer conecting rods and a piston with an offset wrist pin. I havent looked for a set yet but I'm sure some company out there makes one for the 3.0L
 
Back
Top