PDA

View Full Version : 300hp 7.4 needs more muscle



DeltaDog
07-10-2015, 12:30 AM
Ok, it's a 1996 22' Classic, Bravo 1, 300 hp 7.4 that runs nice but needs more power to make it an exciting ride. Don't have the budget to re-power it but thought some mods to the motor might be worthwhile. Has anyone had success with bolt-on items that made a difference? How about cam, heads, exhaust, or intake? Is it a waste of $$ to try to muscle up this motor or should I just start saving $$ to re-power it?
thanks

MOP
07-10-2015, 04:50 AM
If the engine is still in decent shape a pro charger would do the job.

Greg Guimond
07-10-2015, 08:18 AM
Is that the 2 bolt main 454 (300hp at the prop & 4600rpm) as opposed to the more stout Magnum? Will it hold up to a blower ok?

Ed Donnelly
07-10-2015, 08:21 AM
Weiand supercharger easier install..Ed

Pat McPherson
07-10-2015, 10:10 AM
1996 should be a Gen VI big block. The block has 4 bolt mains but a cast crank and 3/8 bolt rods. The short block is a bit more stout than the older Gen V 330s but not by much.

It has flat top pistons so you could use a set of the GM L-29 105cc heads or go with Edelbrock 110cc aluminum heads to raise the CR and increase flow. You'll also need a bit more cam and a better intake to build more HP. A 1996 Gen VI engine is a roller cam and there are lots of options.

I built up a 1999 L-29 454 with cam upgrade and Stainless Marine exhust. It probably went from 340 to 400HP.

I would not run a supercharger on an engine with cast pistions. It won't last vary long.

fysis
07-10-2015, 02:38 PM
Thatīs the spirit The 22 classic loves muscle. How much power are you looking for . And how much do you want to spend. There are so many options.

BUIZILLA
07-10-2015, 02:56 PM
that is the 310hp peanut oval port version, I had one, a 1995

you'll be starting with a shortblock up build for sure, cam, heads and all

it now has non adjustable rockers as well

the options are many, but the pistons and rods are the weak link for serious power

I know Lil Grizz put a Procharger (?) on his a long time back in a 22ZX and it ran pretty well

MOP
07-10-2015, 08:32 PM
Roots style blowers produce a lot of low end torques hard on drives, the pro chargers make there torque higher up one the boat is on plane much easier on drives.

Greg Guimond
07-12-2015, 08:22 AM
Ok, it's a 1996 22' Classic, Bravo 1, 300 hp 7.4 that runs nice but needs more power to make it an exciting ride. Don't have the budget to re-power it but thought some mods to the motor might be worthwhile. Has anyone had success with bolt-on items that made a difference? How about cam, heads, exhaust, or intake? Is it a waste of $$ to try to muscle up this motor or should I just start saving $$ to re-power it?
thanks


What prop make and size are you running and what top speed are you getting on GPS with the boat?

boatnut
07-12-2015, 10:47 AM
What prop make and size are you running and what top speed are you getting on GPS with the boat?

I have the same engine in a 1997 22 (7.4 liter, carb, 300hp, Bravo One) and I get about 63 gps with a Turbo prop. I got a little more top end with the Bravo prop but I liked the overall handling with the Turbo. I can provide the pitch etc. if useful -- don't have it with me. However when I want to go faster I just use the water speedo in the boat and I jump right up to 67mph! Ed

Greg Guimond
07-12-2015, 12:16 PM
I have the same engine in a 1997 22 (7.4 liter, carb, 300hp, Bravo One) and I get about 63 gps with a Turbo prop. I got a little more top end with the Bravo prop but I liked the overall handling with the Turbo. I can provide the pitch etc. if useful -- don't have it with me. However when I want to go faster I just use the water speedo in the boat and I jump right up to 67mph! Ed

Good info. Which model Turbo? When Precision Propeller was independent they (aka Turbo) had several different models. To start, 3 blade or 4 blade? Thanks

fysis
07-12-2015, 01:26 PM
I have the same engine in a 1997 22 (7.4 liter, carb, 300hp, Bravo One) and I get about 63 gps with a Turbo prop. I got a little more top end with the Bravo prop but I liked the overall handling with the Turbo. I can provide the pitch etc. if useful -- don't have it with me. However when I want to go faster I just use the water speedo in the boat and I jump right up to 67mph! Ed

:) Bulls eye. Just wonder how many old speed records we have with the old reliable water speedo :confused: :sweden:

boatnut
07-12-2015, 07:48 PM
Good info. Which model Turbo? When Precision Propeller was independent they (aka Turbo) had several different models. To start, 3 blade or 4 blade? Thanks

Turbo 1 3 blade 23 pitch. The boat had a Bravo 1 4 blade when I bought it but I did not like mid-range operation with the Bravo 1 prop. The Bravo 1 is like new and available if anyone is interested. Ed

joseph m. hahnl
07-12-2015, 09:05 PM
1996 should be a Gen VI big block. The block has 4 bolt mains but a cast crank and 3/8 bolt rods. The short block is a bit more stout than the older Gen V 330s but not by much.

It has flat top pistons so you could use a set of the GM L-29 105cc heads or go with Edelbrock 110cc aluminum heads to raise the CR and increase flow. You'll also need a bit more cam and a better intake to build more HP. A 1996 Gen VI engine is a roller cam and there are lots of options.

I built up a 1999 L-29 454 with cam upgrade and Stainless Marine exhust. It probably went from 340 to 400HP.

I would not run a supercharger on an engine with cast pistions. It won't last vary long.


Pat Knows :yes: