On Sat, 03 Nov 2007 17:43:13 -0700, Tim wrote:

On Nov 3, 4:02?pm, Short Wave Sportfishing wrote:
On Sat, 03 Nov 2007 18:08:14 -0000, Tim wrote:

wrote:
I have a 32' Luhrs Sportfisher. Currently with Chrysler 318 engines.
I have 2 Chevrolet 350 4 bolt marine engines, one standard, one
reverse rotation. I would like to find out what spec. and what parts
I need to build these engines to 280 to 300 hp on carburators. The
boat weights 17000 lbs. It is my understanding I need foot lbs. of
torque more than rpm. Anyone know if there is a guide or book? Anyone
with information. Thanks in advance.

I'm not really sure, but one thing I'd like to know, is why would you
want to replace teh Chryslers with the chevys?

Not saying one brand is superior to the other, but your mounting and
manifolds and trans bolt patterns are completely different,a nd I
would think that it would take a lot more work to change over the
engines instead of rebuild the 318's.

Are the 318's the old "Big Blocks"? if so, they are vertually the
same blocks as the the 383's, 413,s qand 440's, which would be easier
to overhaul and get the horsepower/torque you're looking for.

If the 318's are the later "small block" versions, they are the same a
block as the 360 and late 60's 274, and you might be strained on
getting the results you desire.

Interesting - not that I don't believe you, but as far as I knew,
MOPAR never built a big block 318.

Then again, I'm not all that up on MOPAR stuff unless it involves the
440.- Hide quoted text -

- Show quoted text -

http://www.sweptline.com/tech/engines.html

Tom, Richard and everybody else. I DO STAND CORRECTED! The early 318
"A" was NOT clasified as a "Big Block" but rather a Polysphere (or
Wideblock) 318. Obviously not the same as the 318 "LA" which was
classed as a true "small block" but not the large 383-440 Big Block
either, even though it did have heavier castings and big block
"characteristics". But I'm still not sure if the 413 is in between
the 383-440's or if it was an over punched wide block 318.

Again I Humbly apologize.

You learn something everyday.

No reason to apologize - all those different engines of the day were
simply amazing.

There aren't very many "classic" engines, but certainly the 318 stands
alone as the best engine ever developed. I might rank the 220 slant
six as one and the 220 Silver Diamond International six as another.

Also considered - 327, 350 and the great 564 International/Ford truck
engine along with the 7.3 liter diesel.

"Short Wave Sportfishing" wrote in message
...


There aren't very many "classic" engines, but certainly the 318 stands
alone as the best engine ever developed. I might rank the 220 slant
six as one and the 220 Silver Diamond International six as another.

Also considered - 327, 350 and the great 564 International/Ford truck
engine along with the 7.3 liter diesel.


I'd thrown in Ford's 260/289/302 as well. The 289 powered many cars,
large and small.

Eisboch

On Sat, 03 Nov 2007 10:57:15 -0700, wrote:

I have a 32' Luhrs Sportfisher. Currently with Chrysler 318 engines.
I have 2 Chevrolet 350 4 bolt marine engines, one standard, one
reverse rotation. I would like to find out what spec. and what parts
I need to build these engines to 280 to 300 hp on carburators. The
boat weights 17000 lbs. It is my understanding I need foot lbs. of
torque more than rpm. Anyone know if there is a guide or book? Anyone
with information. Thanks in advance.

The most I've seen from a carburated 350 is 260 hp. You can get 300
to 320 with multi-port fuel injection, maybe more. With 17,000 lbs of
weight you'll be a lot better off with 454s or even bigger. My old
Bertram 33 weighed 21,000 and it was only a marginal performer with
350 hp 454s.

On Nov 3, 1:27 pm, Wayne.B wrote:
On Sat, 03 Nov 2007 10:57:15 -0700, wrote:
I have a 32' Luhrs Sportfisher. Currently with Chrysler 318 engines.
I have 2 Chevrolet 350 4 bolt marine engines, one standard, one
reverse rotation. I would like to find out what spec. and what parts
I need to build these engines to 280 to 300 hp on carburators. The
boat weights 17000 lbs. It is my understanding I need foot lbs. of
torque more than rpm. Anyone know if there is a guide or book? Anyone
with information. Thanks in advance.

The most I've seen from a carburated 350 is 260 hp. You can get 300
to 320 with multi-port fuel injection, maybe more. With 17,000 lbs of
weight you'll be a lot better off with 454s or even bigger. My old
Bertram 33 weighed 21,000 and it was only a marginal performer with
350 hp 454s.

I had 350's with carbs and 300 hp, it's not difficult. A better choice
is to make those 350's into 383's, plenty of torque at low RPM's and
still light weight. Even better, if you can find them, small block
400's. But to do any of this you need a good engine shop that knows
marine engines. Their's so many choices of heads, valve sizes, cam
shafts.

About five years ago I had a shop I've been dealing with for years
build me 300 hp 350's, completely remachined, new sheet metal, pistons
rings cams, bearings timing gears and chain, oil pumps, ect. Bottom
line, $2500 each, I'd probably bet their about $3000 each now. The
best thing about 350's are the parts are cheap!!!

On Mon, 05 Nov 2007 09:26:15 -0800, Capt John
wrote:

About five years ago I had a shop I've been dealing with for years
build me 300 hp 350's, completely remachined, new sheet metal, pistons
rings cams, bearings timing gears and chain, oil pumps, ect.

I'm sure there are people who can get that kind of power but it can't
be easy or durability/operability is compromised in some way. If it
was easy Mercruiser would be doing it and they're not.
One of the challenges is maintaining low end torque while you hop up
the high end. Another issue is what happens to durability if you have
to run at 5000 RPM to get the 300 hp.

I have a 6.2L MPI (about 373 cid) that Mercruiser rates at 320 hp, so
300 hp out of a carburated 350 is a bit of a stretch.

"Wayne.B" wrote in message
...
On Mon, 05 Nov 2007 09:26:15 -0800, Capt John
wrote:

About five years ago I had a shop I've been dealing with for years
build me 300 hp 350's, completely remachined, new sheet metal, pistons
rings cams, bearings timing gears and chain, oil pumps, ect.

I'm sure there are people who can get that kind of power but it can't
be easy or durability/operability is compromised in some way. If it
was easy Mercruiser would be doing it and they're not.
One of the challenges is maintaining low end torque while you hop up
the high end. Another issue is what happens to durability if you have
to run at 5000 RPM to get the 300 hp.

I have a 6.2L MPI (about 373 cid) that Mercruiser rates at 320 hp, so
300 hp out of a carburated 350 is a bit of a stretch.

Not really. My 350 MPI engine is rated 330 hp.
http://www.michiganmotorz.com/Marine...07+replacement)
315 hp. But they are Vortec base engines.

Notice the MPI? That measn multiport injected. Not carburated. He said
carburated.

"Calif Bill" wrote in message
...

"Wayne.B" wrote in message
...
On Mon, 05 Nov 2007 09:26:15 -0800, Capt John
wrote:

About five years ago I had a shop I've been dealing with for years
build me 300 hp 350's, completely remachined, new sheet metal, pistons
rings cams, bearings timing gears and chain, oil pumps, ect.

I'm sure there are people who can get that kind of power but it can't
be easy or durability/operability is compromised in some way. If it
was easy Mercruiser would be doing it and they're not.
One of the challenges is maintaining low end torque while you hop up
the high end. Another issue is what happens to durability if you have
to run at 5000 RPM to get the 300 hp.

I have a 6.2L MPI (about 373 cid) that Mercruiser rates at 320 hp, so
300 hp out of a carburated 350 is a bit of a stretch.

Not really. My 350 MPI engine is rated 330 hp.
http://www.michiganmotorz.com/Marine...07+replacement)
315 hp. But they are Vortec base engines.

The 400's have siamesed cylinders so they are not very popular in the marine
world. They have cooling problems right where the cylinders meet which is
also right where head gaskets tend to blow out on small blocks.

The stroked 383 is a pretty good configuration but don't expect miracles.
It is just a slightly longer stroke and 33 more cubic inches.

The basic problem is still that the small blocks really like to make hp with
rpm's and there is a limit to what you can do to get hp at low rpm with
them. It's an unavoidable problem when combined with a big heavy boat.
That's why higher displacement is really the way to go in a big boat.

I think the op is gone anyway.

"Capt John" wrote in message
ups.com...
On Nov 3, 1:27 pm, Wayne.B wrote:
On Sat, 03 Nov 2007 10:57:15 -0700, wrote:
I have a 32' Luhrs Sportfisher. Currently with Chrysler 318 engines.
I have 2 Chevrolet 350 4 bolt marine engines, one standard, one
reverse rotation. I would like to find out what spec. and what parts
I need to build these engines to 280 to 300 hp on carburators. The
boat weights 17000 lbs. It is my understanding I need foot lbs. of
torque more than rpm. Anyone know if there is a guide or book? Anyone
with information. Thanks in advance.

The most I've seen from a carburated 350 is 260 hp. You can get 300
to 320 with multi-port fuel injection, maybe more. With 17,000 lbs of
weight you'll be a lot better off with 454s or even bigger. My old
Bertram 33 weighed 21,000 and it was only a marginal performer with
350 hp 454s.

I had 350's with carbs and 300 hp, it's not difficult. A better choice
is to make those 350's into 383's, plenty of torque at low RPM's and
still light weight. Even better, if you can find them, small block
400's. But to do any of this you need a good engine shop that knows
marine engines. Their's so many choices of heads, valve sizes, cam
shafts.

About five years ago I had a shop I've been dealing with for years
build me 300 hp 350's, completely remachined, new sheet metal, pistons
rings cams, bearings timing gears and chain, oil pumps, ect. Bottom
line, $2500 each, I'd probably bet their about $3000 each now. The
best thing about 350's are the parts are cheap!!!

Who's marine chevys are they? Are they late model with roller lifters?
Can't tell you what's in them with out knowing which ones they are. Gm
makes them all but there are a number of variations depending on what year
they are and who they were being sold to.

When you say "build" do you mean hop up or do you mean complete rebuild?
Cause a long block core is only worth a couple hundred bucks so I would
consider other choices. Big blocks or a diesels would be a better fit.

The factory small block marine cam is a decent cam. Not sure you could do
much better. Add an aluminum manifold and a holley 700 and you might get it
near your 280hp. You could bump up the compression a tad but not much given
today's octane. Also if you underprop it a bit that might help. Hard to
get a lot of torque out of small block anything.

Here's my mouse motor but I'm probably only getting 280 or so hp out of it.
I started with a 4 bolt truck core. Aftermarket pistons, pink rods,
edlebrock intake and heads, holley, crane roller rockers, stainless
exhaust. It has the factory marine roller cam but the rockers are 1.6
instead of 1.5. I had a aftermarket cam but it cost me low end. Went back
to the factory cam.

http://home.earthlink.net/~jamesgangnc/ebay/boateng.jpg

wrote in message
ups.com...
I have a 32' Luhrs Sportfisher. Currently with Chrysler 318 engines.
I have 2 Chevrolet 350 4 bolt marine engines, one standard, one
reverse rotation. I would like to find out what spec. and what parts
I need to build these engines to 280 to 300 hp on carburators. The
boat weights 17000 lbs. It is my understanding I need foot lbs. of
torque more than rpm. Anyone know if there is a guide or book? Anyone
with information. Thanks in advance.