vortec headed 383

[crussell85]

So I'm set on building a 383 for my 2001 Glastron GX205 this winter/spring. This is what I'm thinking.

Scat rotating assembly 3.75" stroke, 5.7 rods, 18cc kb d shaped pistons.
GM Iron 062 Iron Vortec Heads, may step up to the GMPP Small Port Bowtie Vortecs (not sure yet)
Crane Cam 2032 2032 Hydraulic Roller Camshaft for Chevrolet 1987-1992 V-8, 305-350
Possible Crane Cam HR-284-2S-12 IG Hydraulic Roller Camshaft for Chevrolet 1987-1999 V-8, 305-350
GMPP Vortec TBI Intake Manifold

Was originally thinking the second cam but would like to be able to run this on a GM tbi system and not sure how the efi will like the second cam.

I will be running thru hull exhaust as I 99% of the time boat on the Grand Traverse Bay, traverse city, MI so there shouldn't be an issue with noise complaints. May eventually install a captains call system depending on how loud it actually is.

Outdrive is a Volvo Penta SX 1.5:1 ratio.

I'm not really putting a budget on this build but it has to be realistic (you know what i mean)

Just looking for opinions or suggestions on my parts list.

 

[Bondo]

Re: vortec headed 383

Ayuh,.... Welcome Aboard,.... I saw yer posts on the other threads,...

Are ya gonna deck the block to tighten the quench,..?? 'course the head gasket will determine where ya want it decked,...

I hear the 062 heads are somewhat prone to crackin',... steppin' up there might be a Good idea,...

I think both of yer cam choices are abit on the Hot rod side,...
An RV/ Truck cam, idle to 5000 rpms is better suited to a boat motor,...

'n, I donno's yer Efi is gonna need a 'puter re-flash or not,...
I'd think the fuel map, 'n ignition advance will be way off,...

Check out the links left by billbayliner in those other threads for more insight into buildin' yer motor,....

Oh,... Even goin' with thru-hull exhaust, yer motor's gonna be kinda Choked up, at the manifolds,...
Stock manifolds are a common plenum design which really, Really chokes the flow,...
Yet another reason to go with a mild cam,...
Air in don't work if it can't get Out,...

 

[crussell85]

Re: vortec headed 383

yes the block will be zero decked while running a .041 head gasket.

The fuel system is an aftermarket setup from Affordable Fuel Injection, so they will take care of all the tuning. They say they can make it run right.

Can you elaborate a little more on the cam? I've read in a few threads where guys are running the GMPP 7395 cam which I believe is the oem vortec roller cam. I looked at the specs of this cam and it seems smaller than what I want but maybe I am wrong......that's why I came here.

This is not my first engine build just my first boat engine build.

 

[crussell85]

Re: vortec headed 383

"This is not my first engine build just my first boat engine build"

Didn't want that to sound like a "know it all" I was just saying for engine assembly, quench, compression ratio's, and so forth I am pretty familiar with that stuff. I guess my biggest hurdle right now is the camshaft. I don't want to buy anything until I find the camshaft I want in case I need to move the compression ratio around.

 

[Bondo]

Re: vortec headed 383

"This is not my first engine build just my first boat engine build"

Didn't want that to sound like a "know it all" I was just saying for engine assembly, quench, compression ratio's, and so forth I am pretty familiar with that stuff. I guess my biggest hurdle right now is the camshaft. I don't want to buy anything until I find the camshaft I want in case I need to move the compression ratio around.

Ayuh,.... I understand,... yer name looks familiar,... hotrodders forum maybe,..??

The Cam thing is all 'bout reversion from to much overlap, suckin' water into the cylinders,...
If ya wanta run a Bigger cam, the exhaust needs to be looked at,...
Either go with true Headers, or possibly longer risers/ elbows to move the water mixin' action further down the tubes,...

Also,....
The Bigger the cam, the Worse the hole shot is,...
Too biga cam, 'n the motor can't get over the hump of puttin' the hull on plane,...
Ya only got 1 gear, 'n hopefully, limited prop slip to get it outa the hole,...

A note on the Head gasket, the Marine composite gaskets use SSteel fire rings, over an automotive steel fire ring,...
The exhaust, head to manifold gaskets are 1 piece, so you can hold 'em in-place, rather than the multi-piece automotive types,...
'n as ya no doubt already know, Fel-pro can't be beat,....

 

[Silly Seville]

Re: vortec headed 383

Can you elaborate a little more on the cam? I've read in a few threads where guys are running the GMPP 7395 cam which I believe is the oem vortec roller cam.

I have the GM 395 cam in my mild Vortec 350. It is NOT stock in the '96-'99 truck engines. It has taller lobes.
With an Edelbrock Performer intake and stock Q-jet and timing, my engine idles at 650 rpm...smooth as silk. That 395 cam is spec for the 350 Mag's and 383HT's that come from Merc's stable. I love the cam profile. It is NOT aggressive, which is the point in a boat. It is steady and builds power in a more linear fashion.

Now, I would like to make a suggestion. If you're going to spend the money on a stroker...why are you limiting yourself to 5.7 rods? Go with a 6! Use up all the room you have to create torque. That way, you don't need a onery camshaft profile. Let the swinging hammers do their job.

 

[crussell85]

Re: vortec headed 383

I have the GM 395 cam in my mild Vortec 350. It is NOT stock in the '96-'99 truck engines. It has taller lobes.
With an Edelbrock Performer intake and stock Q-jet and timing, my engine idles at 650 rpm...smooth as silk. That 395 cam is spec for the 350 Mag's and 383HT's that come from Merc's stable. I love the cam profile. It is NOT aggressive, which is the point in a boat. It is steady and builds power in a more linear fashion.

Now, I would like to make a suggestion. If you're going to spend the money on a stroker...why are you limiting yourself to 5.7 rods? Go with a 6! Use up all the room you have to create torque. That way, you don't need a onery camshaft profile. Let the swinging hammers do their job.

ummm......a six inch rod will not make any more hp/tq than a 5.7 rod. The pin height in the piston changes along with the rods. A six inch rod will cause a very little amount less of piston rock but that's it. If there is any more power to be made with them it is so small that your not going to notice a difference. Running a six inch rod gets the wrist pin into the oiling ring of the piston and I just don't want to deal with all that crap. If I was going to be reving this engine to eight or ten thousand rpms I would consider six inch rods over the 5.7. But to say that they will make more power is just wrong and bad info. They are just easier on the rotating assembly. The stack height of the rod and piston will be the same with either rod. The first Crane Cam I listed I believe is the cam that is used in Mercruisers 383 Scorpion Engine.

Yes bondo I have spent the last few years on HotRodders. In my opinion it's the best vehicle related forum on the net. Lots of knowledgeable people over there. The only reason I am over here is it was suggested that I post my questions here, (I still got several answers from the guys over there) but figured I would see what the guys over here had to say. I think you (bondo) have suggested that I come over here a few times, gotta say though I don't really like the forum. The worse thing is I don't get updates to my email that someone has posted on my thread or a thread that I am subscribed to. That's why I originally lost interest when I joined a few years ago.

At what duration is it critical to pay attention for water reversion?

 

[Bondo]

Re: vortec headed 383

ummm......a six inch rod will not make any more hp/tq than a 5.7 rod. The pin height in the piston changes along with the rods. A six inch rod will cause a very little amount less of piston rock but that's it. If there is any more power to be made with them it is so small that your not going to notice a difference. Running a six inch rod gets the wrist pin into the oiling ring of the piston and I just don't want to deal with all that crap. If I was going to be reving this engine to eight or ten thousand rpms I would consider six inch rods over the 5.7. But to say that they will make more power is just wrong and bad info. They are just easier on the rotating assembly. The stack height of the rod and piston will be the same with either rod. The first Crane Cam I listed I believe is the cam that is used in Mercruisers 383 Scorpion Engine.

Yes bondo I have spent the last few years on HotRodders. In my opinion it's the best vehicle related forum on the net. Lots of knowledgeable people over there. The only reason I am over here is it was suggested that I post my questions here, (I still got several answers from the guys over there) but figured I would see what the guys over here had to say. I think you (bondo) have suggested that I come over here a few times, gotta say though I don't really like the forum. The worse thing is I don't get updates to my email that someone has posted on my thread or a thread that I am subscribed to. That's why I originally lost interest when I joined a few years ago.

At what duration is it critical to pay attention for water reversion?

Ayuh,... Sorry to hear ya don't like the forum default settin's,...

You can go to the top of the page, starboard-side, 'n click on "My profile",....
In there you should be able to find the option to get yer emails,...

Hopefully some of the other fella's will be along for more cam opinions,...
There is a good bit of Talent here at iboats,...
I hope yer stay works out Better this time,...

 

[crussell85]

Re: vortec headed 383

okay, so i just learned that starboard side is the right side. Yea I changed the settings earlier but they must not have taken effect immediately. I just received an email alert when post #8 was submitted so all is hopefully well there. Yea I'm going to give the site a better fighting chance this time. I still love my hotrodders though!

I have read through the Dennis Moore book "Small Block Chevy Marine Performance" a few times but not quite sure on how to take it. I guess I haven't read to many of his books or heard much about him. Is he like the David Vizard of boating? Why was the book discontinued? Is it because its crap? Or just not the market out there for it?

 

[Bondo]

Re: vortec headed 383

okay, so i just learned that starboard side is the right side. Yea I changed the settings earlier but they must not have taken effect immediately. I just received an email alert when post #8 was submitted so all is hopefully well there. Yea I'm going to give the site a better fighting chance this time. I still love my hotrodders though!

I have read through the Dennis Moore book "Small Block Chevy Marine Performance" a few times but not quite sure on how to take it. I guess I haven't read to many of his books or heard much about him. Is he like the David Vizard of boating? Why was the book discontinued? Is it because its crap? Or just not the market out there for it?

Ayuh,.... I donno why it went outa print, just Glad I bought 1 early,..
It's now 1 of the most valuable books on my book shelf,...

Great book, accurate, Solid Info,...

It's pretty much a Bible for Hot roddin' boat motors, Merc's in particular,...
Lotsa info in it, that ain't found in the factory manuals,...

That Efi is interestin', but awfully Pricy,...
I'm more into 4bbl. AFB Clones, 'n mid-rise manifolds,...

If ya wanta do some Marine motor, 'n drive Learnin,...
Head on up to Don'S Adults Only section at the top of the I/O forums,...
There's months of Great readin' in there,...

I too appreciate the hotrodders,... Lotsa Info cross-over, 'n that forum is the Best in that category,...
Been a member from years,...

 

[crussell85]

Re: vortec headed 383

Dennis Moore recommends the lt4 hot cam in the book that I referenced earlier. I'm pretty sure that the lt4 hot cam is pretty close to the second cam that I listed in my original post.

Did you have any info on the earlier question of at what point to be cautious of water reversion?

The price for the kit from AFI is about $1300 which is fairly reasonable. They incorporate the gm throttle bodies and all of the gm sensors which are all readily available from any parts store in the country. I'm not suggesting this system to anyone as of now because I don't even have it but it's on the list.

I hate carburetors. They're stupid!

 

[Walt T]

Re: vortec headed 383

I'll be interested to know what cam you use and how well it works. My stroker has standard camel humps on it now and its great but I have Vortecs 062 heads for it this winter. Hot Rod experience is hard to shake off here as Bondo says marine is a different animal

 

[billbayliner]

Re: vortec headed 383

Bill is right!

Take a look here at a cut view of a quench or squish area.
V6 to V8 engine swap

See the picture in post #15 showing the Vortec quench surface and a LCQ piston (not a D-dish piston)!
The D-dish piston is better suited for a Non or Pre *Vortec chamber.

As for camshaft profile and concerns for water reversion, your exhaust manifold design may help determine which overlap you can get away with.
Some exhaust elbows introduce the seawater very close to the uppermost portion of the down-turn!
Others might introduce the sea water further away from this area.

 

[Tail_Gunner]

Re: vortec headed 383

Sounds like a fun build, i see your wanting to do tbi is that right..I am by no means killing the thrill here but doing a good a carb will net you the same Hp and tq for a lot less money. With that said what tbi are you using and another thought the eldo airgap with a two inch spacer would be a hot combo on that rig but you are going to need a big tbi...ID take a look at comp cams xm 270 hr ground at 110 or 112 if your using std exhaust....... or the 276...The 276 is just as flat as the 270 but just enough overlap to be questionable on std exhasut. Both cams will require some spring work.

http://www.chevyhiperformance.com/techarticles/148_0208_vortec_heads_valve_lift/


http://www.chevyhiperformance.com/techarticles/76178_chevrolet_ht_383_engine/

Valve Spring Upgrade - Beehive Valvesprings for the Vortec V8 - Car Craft Magazine

GM Performance :: View topic - LT4 Hotcam in L31

Quite simple to mod the heads just pull the press in studs replace them with apr studs...You can use blue ls6 spring or the spendy beehiive's and more seat pressure of course comps keeper's and retainer's.


The Twister, Part I
The Twister, Part II
The Twister, Part III


Read more: http://www.chevyhiperformance.com/t...hevrolet_crate_engine_build_iv/#ixzz2qOdcpOUE

 

[Walt T]

Re: vortec headed 383

That extreme energy HR282 is not for vortec heads unless it's modified like your other link. Its a pretty decent choice once the heads are done. Its intended to run at higher rpms than what marine typically runs and marine needs good strong torque below 2500 rpms. Good idle and good driveability with it.

 

[Scott Danforth]

Re: vortec headed 383

I believe the RPM limit of most outdrives is in the 5000 RPM range. you may want to consider that for your cam choice. As Bondo pointed out. More like a tow truck, less like a hot rod. Boat motors are pushing a boat out of water up a hill so to speak.

your exhaust will determine the amount of overlap and duration you can get away with on a marine motor. too much overlap and you such up water at idle.

 

[Tail_Gunner]

Re: vortec headed 383

That extreme energy HR282 is not for vortec heads unless it's modified like your other link. Its a pretty decent choice once the heads are done. Its intended to run at higher rpms than what marine typically runs and marine needs good strong torque below 2500 rpms. Good idle and good driveability with it.

Agreed that post was a car engine yet aside from the cam profile very little difference i am refering to the xm270 along with the xm276... the latter choice would need thru the hull exhuast..Notice the flat curve on the 276

http://www.compcams.com/Technical/DynoSheets/xr276.JPG


08-417-8 - Xtreme Marine

08-418-8 - Xtreme Marine

 

[Tail_Gunner]

Re: vortec headed 383

Neither of those two cam are hot cam's actually fairly mild for auto a bit agressive for marine.I have the 270 in a 4.3 and the result's are great...Think of a 4.3 two stroke in term's of torque very torky As to power bands and rpm levels the sx drive is very hearty and will survive above 400 hp and 5500 has not effected my drive at all.

Again to rpm and low torque the above pic show 1500 rpm and 6 mph no wake speed's ...the boat does not even begin to work until 1800 that's where she begin's to climb out of the hole and 3500 cruiseing speed it jumps at the touch of the throttle...But again all this talk and tbi..

 

[Walt T]

Re: vortec headed 383

I'm familiar with both those marine cams. They're good and work well at low rpms. Hard pull all the way up to 5000. Of course it's helpful if the rest of the engine is built to actually use them. Sticking these in a stock engine ain't gonna help all you guys reading this stuff thinking "Hey that weird dude Walt likes that cam by golly I'm gonna order one and I'm gonna get my dang boat to actually get on plane with my 290 lb ol' lady sittin in the back by golly I won't need to counterweight her with 3 full beer coolers and the 4 kids"

 

[Bondo]

Re: vortec headed 383

Dennis Moore recommends the lt4 hot cam in the book that I referenced earlier. I'm pretty sure that the lt4 hot cam is pretty close to the second cam that I listed in my original post.

Did you have any info on the earlier question of at what point to be cautious of water reversion?

The price for the kit from AFI is about $1300 which is fairly reasonable. They incorporate the gm throttle bodies and all of the gm sensors which are all readily available from any parts store in the country. I'm not suggesting this system to anyone as of now because I don't even have it but it's on the list.

I hate carburetors. They're stupid!

Ayuh,..... The answer to that question is like "What's the Best 350 Chevy",..??
Lotsa variables contribute one way or another,...

I've mentioned a few in this thread,...
The Exhaust used is a Biggie,...

You can run the Wildest cam you care to, with the right dressin's, 'n right applications,....
Hot Rod Jetboats come to mind,...
The full headers have water valves to turn the water on, or off, at different times,...
A jet won't load as quickly as a prop, 'n the motor is able to spin up to 3500 rpms or so, 'n Come Right Into It, when the cam kicks in,...

With the cams yer lookin' at, I'd think atleast a set of longer risers/ elbows would/ might keep the reversion from loadin' the cylinders with water,...
Lotsa exhaust info, 'n applications talked about over at places like offshore only,...