502 suggestions

[thom]

ok i have a 28 cheetah deck with a 502 that needs some more ponies..
what do you suggest i do to it to get it to run in the 80's or i am better off just buying a new engine.. i ve been thinking about a either a blower or something of that nature
reading about how fast no diggs is makes me want to upgrade

[jackpunx]

ok i have a 28 cheetah deck with a 502 that needs some more ponies..
what do you suggest i do to it to get it to run in the 80's or i am better off just buying a new engine.. i ve been thinking about a either a blower or something of that nature
there are lots of options.. you can run a blower with low boost.. or you can bump up to a 540 with a quad rotor.. :rollside:

[mbrown2]

The 502 is a good engine to start with....If I were on a budget, I would do a Whipple, and maybe exhaust just to help it breath...the Whipple will be a significant change, the exhaust will not..
If I had a little money to spend...10-12K, I would have it punched to a 540, new heads, etc, and the Whipple and Exhaust...
First option gets you 690ish, the second can get you to near 800 if you are going with the 3.3ltr and some really nice flowing heads...
Also, set aside another 3K to beef the drive with either option...Also, if you don't have external steering, you will need to factor that in as well.

[thom]

what prop do you guys think i should use the way it is now.. stock 502

[78Eliminator]

The first thing you need is an objective and a plan. Bolting shit on is not a good approach. You need to think the whole thing out before you start bolting things on. People are suggesting blowers to you and not even asking you about your bottom end components is a good way to start ruining things....

[mbrown2]

The first thing you need is an objective and a plan. Bolting shit on is not a good approach. You need to think the whole thing out before you start bolting things on. People are suggesting blowers to you and not even asking you about your bottom end components is a good way to start ruining things....
Don't get me wrong, I am assuming he has a 502 Magnum EFI, which has pretty good internals. I ran the same motor with Whipple 2.3, boost at 5, and stock exhaust, and it ran very stout without issue...idle was great as well.

[thom]

Don't get me wrong, I am assuming he has a 502 Magnum EFI, which has pretty good internals. I ran the same motor with Whipple 2.3, boost at 5, and stock exhaust, and it ran very stout without issue...idle was great as well.
that is what i have.. i have heard its a strong motor to upgrade..
i just went to your link looks like i need to upgrade my stereo also.. im in simi quite often.. i will stop by after turkey day and see what you suggest for the stereo

[mbrown2]

what prop do you guys think i should use the way it is now.. stock 502
With a 28ft deck and a stock 502, I would try a 26....that is a pretty heavy boat and the 26 will get you decent acceleration and top end not compromised too much.
With a 26ft cat and a whippled 502, I ran a 30" with 1.5 gear, and it would do 90 at 5100....running very light.

[mbrown2]

that is what i have.. i have heard its a strong motor to upgrade..
i just went to your link looks like i need to upgrade my stereo also.. im in simi quite often.. i will stop by after turkey day and see what you suggest for the stereo
That link is a buddy of mine...he has done a couple boats and cars for me...I recommend them highly....you can see some of their work in my gallery on the Malibu.

[thom]

my objective is to have a strong running boat that is turn key..i dont have the time to be working on it all the time.. It does not need to be the fastest thing on the water but something strong enough i can be proud of it.. but it must be dependable

[mbrown2]

my objective is to have a strong running boat that is turn key..i dont have the time to be working on it all the time.. It does not need to be the fastest thing on the water but something strong enough i can be proud of it.. but it must be dependable
Based on those requirements, I would say give GT, Pfaff, DNE, or Brummet a call and let them know those requirements and give them a speed or acceleration number you are trying to reach along with what type boating you do or weight you carry and then they can give you options....on how to build the current engine or build from scratch...EFI, Blowers, and Whipples I would only trust to a select number of builders locally..

[Krumbsnatcher]

my objective is to have a strong running boat that is turn key..i dont have the time to be working on it all the time.. It does not need to be the fastest thing on the water but something strong enough i can be proud of it.. but it must be dependable
Tom you need to have a plan on what horsepower you want to finally have as well as what type of performance you expect. By placing a blower on you instantly have two issues heat and fuel delivery. Not to even mention the compression issue. I had your similiar problem and here is how i handled it.
Your motor being NA has a compression of 9:1 so you should only be running about 3 to 4lbs of boost. Since, you have time in the winter pull the motor and do right. Stud your block with ARP to tighen up your lower end, and while your at it you might as well put in new bearings and a new oil pump, they are both fairly inexpesive.
If you are going to increase the power you are going to have to get a beefier cam, but that will be decided on the amount of Horsepower you desire. Now off to your heads you all ready have roller lifters so that should save you some cash, however you will need to get some comp-cam rollers.
For you blower check out the Blower shop i picked my entire system up for $3000 from CP, by far the best little blower 250ci solid billet. You will also have to decide on how you plan on feeding the monster, will you be using single or dual carbs.
I found out the hard way on my 540ci i ran her with a single dominator 1050 and ran the stock fuel pickup out of my tank and she ran lean and i pulled two valves on #8.
Also you will need to run a cross over system as well as a thermostatically controlled cooler.
If you have specifics PM me, here is a pic of her finished.
http://www.***boat.com/image_center/data/520/1821IMG_6.jpg
http://www.***boat.com/image_center/data/520/1821IMG_5.jpg

[OGShocker]

ok i have a 28 cheetah deck with a 502 that needs some more ponies..
what do you suggest i do to it to get it to run in the 80's or i am better off just buying a new engine.. i ve been thinking about a either a blower or something of that nature
reading about how fast no diggs is makes me want to upgrade
Call Brian@
B&D Marine
10699 Hickson Street, #19
El Monte, CA 91731
Phone: (626) 443-3721 Fax: (626) 443-1441