2 barrell to 4 barrell in 5.7L

[dvandsm64]

putting 4 barrell on 2 barrell 1997 5.7 liter. will this give us huge difference in top speed and hole shot? can i use same intake manifold? i'm pretty sure it is a vortec engine. i think this will push me from 210 hp to 260 hp. any help will be useful.

 

[John_S]

Re: 2 barrell to 4 barrell in 5.7L

First step then is to id heads. Count the intake manifold to head mounting bolts. Six per side (12) is standard heads, 4 per side (8) is vortec heads. In either case about 30-40hp. Huge? No, but a noticeable change.

I suspect it is standard heads. The 5.7L 2brl vortec (250hp) was a '98 model.

 

[Bondo]

Re: 2 barrell to 4 barrell in 5.7L

can i use same intake manifold?

Nope,... Get the Right 1, or yer just wasting yer time...

 

[dvandsm64]

Re: 2 barrell to 4 barrell in 5.7L

o.k.

i'm going to count manifold bolts rite now. i was told it was a vortec 350.
don't know the yr. of motor. i bought the boat in may. was told motor had been replaced (10 hours on it) , because of bad winterization. boat had a total of 160hrs. and was female owned. has so far worked great ,but we love to go fast.

 

[wca_tim]

Re: 2 barrell to 4 barrell in 5.7L

...but we love to go fast.

be careful, it's an addiction not easily shaken...

 

[dvandsm64]

Re: 2 barrell to 4 barrell in 5.7L

wca tim,
do u mean speed as an addiction? we knew that we also have '95 mustang gt with added goodies, and her edge is 265hp. she loves the speed and power more than i do.

 

[dvandsm64]

Re: 2 barrell to 4 barrell in 5.7L

ok, back to the 4 barrell.

i counted 6 bolts/ side intake to head, unless i did it wrong.
other info:

eng.# ok154729
trans.# ok206609
drive#ok058461
firing order 18436572


thanks for any help , infos., yrs., etc...

 

[John_S]

Re: 2 barrell to 4 barrell in 5.7L

i counted 6 bolts/ side intake to head, unless i did it wrong.
other info:

thanks for any help , infos., yrs., etc...

It is a standard head then. But the additional info of engine replacement may mean more verification. I assume the engine serial numbers came off the flame arrester which was the original, not replacement, motor. Someone will be able to do a check on them.

Next decission: (4brl and intake) or (vortec heads, 4brl, and intake). New vortec heads and gaskets will add approx $600 in parts cost (but worth it).

But, you might want to verify your current is still in good shape, with a compression test.

 

[dvandsm64]

Re: 2 barrell to 4 barrell in 5.7L

would new heads , 4bl and new intake be worth $ for the gain?
this boat goes pretty well now.

 

[John_S]

Re: 2 barrell to 4 barrell in 5.7L

would new heads , 4bl and new intake be worth $ for the gain?
this boat goes pretty well now.

In general, boating does not have a positive ROI.

If you buy all the parts new (vs used) around $1300 - 1500. Your labor is free, and you will net another 70hp. Depending on hull, you should get 6-10mph more @ wot, which will mean a new prop. All the old parts can be sold, and would recoup about $400-500 (intake, carb, heads, flame arrester, etc)

If you go carb and intake and decide to do heads latter, you need a whole new vortec intake.

Of course, you have to look at the rest of the boat to decide if this is worth doing.