[gerry rautenbach]

what parts will i need to use to build hi torque 383 stroker marine motor

 

[vinniekq2]

high velocity heads with quick burn chambers,low icl cam,fuel injection,high velocity intake manifold.high velocity exhaust,all parts tuned for the ideal RPM of the application.make sure your fuel requirements match CR

 

[Richiehd]

Why all the torque? 383 will probably peak torque @ 5500. You need to go faster? You need RPM. How heavy a boat? and what are you looking to do?

 

[vinniekq2]

richiehd,what 383 that you know of has peak torque @ 5500 RPM?

I wouldnt want to run a boat engine above 4,000 myself.Thats where I would set my max power unless it was a racing boat or ski boat?

 

[Richiehd]

Thats why I asked what he was running. We run our race skiffs up to 7400rpm with 283 power. The river boats we try and limit to 6400. No transmission, direct drive. More rpm, more speed.

 

[Richiehd]

richiehd,what 383 that you know of has peak torque @ 5500 RPM?

I wouldnt want to run a boat engine above 4,000 myself.Thats where I would set my max power unless it was a racing boat or ski boat?

My bad, I went back to the Dyno sheet 541 Torque @ 5071 Rpm. Dart Block 402 C.I. Small Block. Sorry was thinking old 383.

 

[Richiehd]

How many gallons per mile does the boat get like that.

That sounds like a 600hp engine.

He should be able to turn a pretty fat prop with a 4000/4500 rpm tq peak. Should also not be to bad on gas at part throttle and still move a larger boat.

QUOTE]

Yeah, his skiff will burn through 20 gals of gas on a day river cruise, no problem. 523 HP to be exact. Spins a pretty big 2 blade @ about 80 mph.
Funny thing though, I turn my 283 6500 and run right there about 77 MPH, so big cubes and HP isn't everything. Drag and handling become real important when it comes to going fast on water.

 

[gerry rautenbach]

hi torque 383

i have never built a motor for a boat. i know it is a fairly heavy boat it will be for fun and skiing mainly it originally was a 305 then 350 now upgrade to 383 with carb.i have heard of so many combo's but being in South Africa parts are fairly expensive so i want to do it right first time i would like a complete list of a combo that works if at all possible i presume the max revs will not be higher than 5000 ?

 

[vinniekq2]

Dart SHP 180cc Straight Plug Aluminum Heads,GM Hi-Performance 4 Bolt Block(new), Hydraulic Roller Camshaft,edelbrock performer(air gap),nodular or better internal balanced 3,75 stroke cam,hyper or forged pistons,keep compression around 9-9 1/4 for a boat, the engine like this would cost me about $7,500,not cheap and likely 430-440 hp at 5,200 RPM.
power can be adjusted up or down as required,your choice.Im thinking an engine that will last years and be reliable.
are you planning to use fuel injection or carb? for skiing F.I. would be nicer. what kind of exhaust manifolds are you using? wet or dry?
an engine like this would make around 300 hp as low as 3,000 rpm with peak torque around there depending on camshaft chosen.
When I built my 434 I purchased my parts from eastern states and had them air freighted to Vancouver Canada,it was cheaper to ship than the hood I bought in California and had sent by truck.Look into freight costs and see if you can get a package sent?

 

[ap72]

Dart SHP 180cc Straight Plug Aluminum Heads,GM Hi-Performance 4 Bolt Block(new), Hydraulic Roller Camshaft,edelbrock performer(air gap),nodular or better internal balanced 3,75 stroke cam,hyper or forged pistons,keep compression around 9-9 1/4 for a boat, the engine like this would cost me about $7,500,not cheap and likely 430-440 hp at 5,200 RPM.
power can be adjusted up or down as required,your choice.Im thinking an engine that will last years and be reliable.
are you planning to use fuel injection or carb? for skiing F.I. would be nicer. what kind of exhaust manifolds are you using? wet or dry?
an engine like this would make around 300 hp as low as 3,000 rpm with peak torque around there depending on camshaft chosen.
When I built my 434 I purchased my parts from eastern states and had them air freighted to Vancouver Canada,it was cheaper to ship than the hood I bought in California and had sent by truck.Look into freight costs and see if you can get a package sent?

Although a 180cc runner is about right I wouldn't use the SHP heads, if you're going to spend the money for some nice ones I'd look into some Profilers for an "as cast" head.

SBC 23 Degree Cylinder Heads

If you plan on taking this thing up to 6,000 rpm often you may want to consider the 195cc version.

 

[vinniekq2]

Gerry,you will need to decide what you need and at what RPM you will spend the most time.If you want more power than what I stated,then you will need bigger parts like what AP72 said.

the sky is the limit or wallet?

 

[1Gary]

Here is some of Richard's work with me on 383 torquer:

Custom cam 206/214, 106/113/109.5, 0.420"/0.420, (-3)(29)(40)(-6) installed straight up.
Streetmaster intake manifold (1st design).
http://cgi.ebay.com/ebaymotors/Edelb...Q5fAccessories
RPM HP TQ
1000 88 461
1500 149 521
2000 204 535
2500 247 520
3000 289 506
3500 319 478
4000 346 455
4500 357 417
5000 348 366
5500 319 305
Peak BMEP 210.8 @2000. This is some serious cylinder pressure, so a very tight squish (I would be thinkin' 0.035" to 0.040" with a D-cup piston) would be mandatory to prevent detonation on pump gas.

Do think it would work well in a marine application.

 

[ap72]

no way in hell will you have 535ftlbs at 2,000 RPM on any NA sbc 383 that runs on pump gas.

 

[vinniekq2]

1Gary,what heads were you using?and combustion chambers?
what stroke was the 383?Thats a big spread of HP and torque.The hp looks correct and Ive used that intake a couple times with great success. I was looking for slightly more HP via a slightly bigger cam,perhaps put in 2 degrees early.and wasnt expecting quite that much torque,but that chart looks fantastic.

was it 3.8 stroke ??

 

[gerry rautenbach]

more on 383 stroker

like i said the boat is not for racing but should be able to pull skiers easily and have some fun it look"s like the cam is very important any part numbers that i should look at? exhaust's are wet as i understand (big bulky and don't look like they are in very good condition so for heads can i use EDL e street with performer int and 600 marine carb? (will use 383 stroker kit and ballance the assembly ) hopefully you can make sense of all i write. thanks its allmost midnite here in Kimberley South Africa!!

 

[vinniekq2]

yes you can use e street heads and 600 carb.If you dont own them then I dont see why you would buy them? The 3.8 stroke might be a good idea.

another option to bring the rpm down lower and increase the torque sooner
4.03 bore X 3.875 stroke= 396,with same parts I mentioned before or sub street master intake, small roller hydraulic and 500 pounds torque should happen. In a ski boat I would think pulling 6 one ski skiers as easy.

 

[Richiehd]

like i said the boat is not for racing but should be able to pull skiers easily and have some fun it look"s like the cam is very important any part numbers that i should look at? exhaust's are wet as i understand (big bulky and don't look like they are in very good condition QUOTE]

Jerry,Get yourself a marine performance cam.You should stay under 280 degrees duration. When you call the tech line for help make sure and ask them about water reversion, if the guy says "What?" hang up and move on!! Then contact Jones Cam Design in North Carolina
If you are to take full advantage of all that horsepower you are going to have to step on the exhaust. Glenwood makes an excellent exhaust log and elbows that will not be that of a header but much better than cast iron manifolds. A little pricey but worth the investment and will give you years of service, plus they look great! Glenwood located in California USA

 

[gerry rautenbach]

water reversion

could you explain what water reversion is (never heard of it before)

 

[Richiehd]

If you get too much cam overlap and duration, water will get sucked into the exhaust on the intake stroke. You might also find the motor would start dry but when it is in the water, would not start because the exhaust pipe is filled with water. A good cam grinder understands this if he has done work on marine engines before. Usually under 280 degrees duration. I called one of the big cam manufacturers one time and had to explain this to the guy on the tech line. Thats when some one on this site turned me on to Jones Cam Design who has ground cams for marine engines before. I gave him my specs and he had 2 choices for my engine. I put in a solid lifter cam that pulls well from 3500 right up through 7200 rpm.

 

[gerry rautenbach]

more on 383 stroker

gee thanks a lot sorry that i sounded a bit stupid but as i said boat motors is new to me so i think i will go for a hydraulic roller e street heads performer int that should be a good combo from idle to lets say max of 4500-5000 rpm do you think i am on the right track?