OK, forget SuperCharging, I want to rebuild my SBC

[pipnit]

I was toying with the idea of putting a super charger on but I think I want to stay with an N.A. motor. This is what I have right now, roller rockers, cast iron heads, 9.5:1, cast intake, 750cfm ebrock carb, OEM "logs", trs 280. The motor as of 150 hours ago is a 355.
I am thinking of going with aluminum heads, which should lighten it up a little bit and get me to 10:1 without having to run race gas, an alu intake for weight (will this add power?) and maybe some cam work. I'm not sure what is in there right now for a cam. Should I move to a roller cam? How radical could or should I get with the cam? Anyone have info on different grinds? I don't think I want to throw any money at some custom headers, I'd be more interested in keeping the R's around 5500 and having a higher pitch prop and more speed! Any ideas, thoughts or critics are well appreciated.

[gcarter]

Ther're some folks here that know a lot more than I about getting that last bit out of your engine, but here are some thoughts;
For not a lot, there're a number of reputable rebuilders that'll supply a dependable 383 that'll have a lot more potential. Aluminum heads are pretty expensive compared to any performance gains, especially considering you might have to add closed cooling. I understand good stock Vortec heads perform very well for the investment. A good used set of Stainless Marine exhaust will lose some weight AND gain some performance, plus add a lot of bling, and you might get a bargain on eBay.
An aluminum intake manifold will lose some weight and might gain some performance, some here will suggest which ones to look at, they can also make cam reccomendations.
have fun and good luck.

[BUIZILLA]

keep the r's under 5200

fresh or salt?

head casting #'s now?

since you have a TRS if you use SSM exhaust you MUST have custom risers made... IMCO makes a nice setup and they sell a TRS drop riser, all of this should replace the logs.. measure twice before spending coin though..

budget????????????????

then we'll discuss the details

[mrfixxall]

If it were me i would sell what you have and start over woth a 400 block and go from their. You have a trs and that eats hp to a point,you can easily squeeze 500 pump gas hp out of a 417 cid small block..

[younger]

All in the combo, have a look at the major producers of heads afr, edelbrock. dart, world products, all make great packages to get a 400hp sbc. A decent exhaust will only help, glm has an aluminum kit that works well without spending a bundle. Comp cams has a good line of marine cams both roller and hyd flat tappet. Most of my combos have been 64cc head flat top slug, comp at 10.5 to 1 still pump gas with the aluminum heads. Run a dual plane rpm intake with a cam that has around 230 degrees @.050 and lift in the .500" range on flat tappet cam. Any more and reversion becomes a problem with stock type exhaust.

[pipnit]

Thanks for the input. I've been told from a couple people that you don't really start to see the payoff with the custom exhaust until 5500+ rpm. Not sure if that's true or not but I believe a lot of what that guy says, he's pretty meticulous and has a 127mph NA warlock. What kind of dough would I be looking at for custom exhaust? I'm guessing five grand for nice double walled stainless? Not sure if that's where the money is best spent.
I run in fresh water. When I got the boat, the owner thought that the compression was 10.5:1 I rebuild the motor that winter and found the compression was almost at 12.750:1! Heat was never really an issue but the thing was beat to all he**. I was guessing I'm around 400hp right now, only because that's what the builder was thinking. I don't want to go with another block, want to keep this one, just hop it up. Was looking at some of the plug and play heads from Ebrock. I need to check the clearance I have under the hatch. Since this is a TRS boat, there is a hump on the hatch that I think will buy me some more room.

[pipnit]

budget????????????????

then we'll discuss the details

Don't really have a budget. I'm just exploring ideas. I could go from mild to wild, it's easy to talk me in to things Also need to add a deadman leash on the boat this winter.

[mrfixxall]

I dont think your @ 400 hp now..you may be choking the engine with the log exhaust..you can get a set of emi thunders from 1000.00 to 2300.00.. i run the emi's on mine with the aluminum riser(i got more torque from the dyno) vs the stainless steel risers..all you will nees is a s-pipe to go under the steering..i run the edelbrock 2.02 angle plug rpm series cylinder heads.i have a custom set of srp pistons which gives me 10.2-1 i also have 6.0'' compression,also i run 6.0'' Carrillo h beam rods and a bryant crank our of one of my old stock car engines...heads a re flowed and massaged,intake is a edelbrock air gap and a proform 750 cfm carb and a comp cam canshaft..motor dynoed @ 434 hp which was 10 yrs ago so im sure it lost a little hp over the years..the boat will do 68 mph with a 14x24 labbed ultra prop and tip toe into the 70's with a 14x 26 labbed ultra prop..
click on the 3rd link below and have at the vids.


BTW if thats your sparkplug's your using on your profile pic GET rid of them..chit fires will rob your hp..

[BUIZILLA]

Don't really have a budget. I'm just exploring ideas. I could go from mild to wild, it's easy to talk me in to things Also need to add a deadman leash on the boat this winter.

luv'n the no budget.... post a pic of your transom, I need to see the exh. outlet location

[pipnit]

luv'n the no budget.... post a pic of your transom, I need to see the exh. outlet location

I will tomorrow when I go do a clay test for the intake. Right now I'm leaning towards 383 kit, some heads and will explore some headers.

[MOP]

IMO the Gov has just passed 15% Alky in the gas be sure you do your homework, it is very easy for your dollars to go BANG if you push the envelope! You can keep things under control and still get more boat time and less dock time with a ton less sweat! I built a 383 for my 22 it is very mild by many peoples standards, but on a good day it will push it to 65.5. I have max dependability, great fuel economy and very tractable power throughout all ranges. Stuff a 400hp 383 in a much lighter 18 you would be in the low 70's, the 383 develops significant torque compared the 350.

Agin IMO

Phil

[gero1]

i miss b.g on thread like this

[younger]

If there is no budget stroke a check for a large cube small block motown 454 or the like. 600 hp all day long, these large ci sbc are down right awsome!

[maddad]

Even if there is a budget, my last 406 cost about 4k, makes around 450hp and makes over 400lbs of torque just above idle. It also got 3mpg over this past summer, and I do not baby it. Start with as many ci's as you can.

[Harris Performance]

We have built several 383's with great results. We have one of my 383's in a 22 eliminator daytona naturally aspirated that runs almost 90 on pump gas. Also did a 23 Eurosport with a 383 that ran 74 on GPS, we even have one in a 25 Bennington pontoon that runs 59 lol. There are a few internal tricks that need to be done to ensure the motor will live! I have a new 383 sitting here on the floor, and if you are interested, feel free to get in contact with me. Thanks Jeff Harris