What engine would you put in your boat?

[Michigan boarder]

For me a skier I would have a good look at the Eco boost. Big low end torque should be light.

Hot turbos in a plastic tub? Hmmm.........

I agree, that gets me nervous. Plus that's Ford, right?

[Sixball]

I agree, that gets me nervous. Plus that's Ford, right?

Like any Hot Rod guy just a little something that needs to be visited. But plenty of ways to cool no lack of water. Yeper it's a Ford one of the good points.

[Bozboat]

Like any Hot Rod guy just a little something that needs to be visited. But plenty of ways to cool no lack of water. Yeper it's a Ford one of the good points.

Ecoboost turbos are water cooled that ought to make it easier

[nuttyskier2002]

ZZ4 cam (Pace Performance site):

Camshaft: Steel Hydraulic Roller Tappet

Cam Lift: .474” Intake / .510” exhaust

Cam Duration @ .050”: 208 deg. Intake / 221 deg. Exhaust

Lobe Separation: 112 Degree

Here's a 383, 405hp I just found from Blueprint Engines for $3,295

//blueprintengines.com/index.php/products/bp-gm-crate-engines-landing/gm-383-main/item/gm-383-base-bp3830ct1

Cam Type: Flat Tappet

.487 Intake .503 Exhaust

234 Intake / 244 Exhaust duration

@ .050 - 112 degree lobe separation

You won't like the way this engine idles with 234/244 duration. Not to mention you will lose some holeshot in the lower RPM range.

[nuttyskier2002]

The Hammerhead 383 engine that Indmar used to offer uses a camshaft with 222/230 in/ex duration and 112 on the lobe separation. This is the max I would go on duration. 112 is good for lobe separation and I would not go any smaller on this number. This is one aspect that helps keep water from getting into the cylinders. The 208/221 in/ex looks like it would be a nice camshaft for either the 350 or the 383. As a general rule of thumb you want the exhaust duration to be at least 6 to 8 degrees longer than the intake for marine use. If you hand pick your own camshaft you will want to ensure your valve springs and guides and seals are all set up to handle that much lift.

[Woodski]

Marine Cam (one that is in the engine you are pulling):

Roller tappets

Lift: .431" Intake / .451" Exhaust (w/ 1.5 rockers)

Duration: 196 deg Intake / 205 deg Exh @ .050" lift, I think the separation is 112 on that cam.

You can see the 383 will have quite a bit more cam duration than either what you have or a ZZ4 cam. It will lope at idle and probably lose a bit on the holeshot, but will come on very strong in the midrange. The ZZ4 cam does not lope, loses nothing down low and really pulls from 1800 on up (like a lot).

Edited October 15, 2013 by Woodski

[nuttyskier2002]

Wood......I think MB is much more concerned about reliability and longevity than all out performance. I'm sure his wife is going to have to drive this boat too and may not like the lope of a "long" duration camshaft. MB is going to see more improvement than he can handle with just vortec heads and a ZZ4 camshaft......even if he stays with a 350 over the 383.

[Michigan boarder]

That is exactly the kind of feedback I was looking for. I had a feeling it would be too much. Fun in a car, not fun idling around in a boat. The problem I'm having is trying to find something that will be warrantied. I haven't spoken with any of the sites, but everything that has a ZZ4 cam also has aluminum heads and has the marine use disclaimer. Not sure what they would say if I called up and explained my intentions (marine use fresh water only).

Otherwise, what about this one? This is from their marine engines line, Blueprint Engines. 365hp. Duration is only 6 degrees longer on exhaust, is that enough?

//blueprintengines.com/index.php/products/bp-marine-engines-landing/gm-355-marine-main/item/gm-355-base-mbp3550ct-marine

Cam Type: Roller
.480 Intake .489 Exhaust
218 Intake / 224 Exhaust duration
@ .050 - 112 degree lobe separation

[Michigan boarder]

Marine Cam (one that is in the engine you are pulling):

Roller tappets

Lift: .431" Intake / .451" Exhaust (w/ 1.5 rockers)

Duration: 196 deg Intake / 205 deg Exh @ .050" lift, I think the separation is 112 on that cam.

You can see the 383 will have quite a bit more cam duration than either what you have or a ZZ4 cam. It will lope at idle and probably lose a bit on the holeshot, but will come on very strong in the midrange. The ZZ4 cam does not lope, loses nothing down low and really pulls from 1800 on up (like a lot).

Bearing this in mind, that is likely what I will discuss with the engine guy locally (still trying to connect with him). If my block is OK, and depending on the price of the rebuild, rebuild the rotating assembly, ZZ4 cam and aluminum fast burn heads, and call it a day. Exhaust down the road maybe.

Edit: All the above is dependent on how it all compares to a crate engine we decide on. Still torn between the two solutions.

Edited October 15, 2013 by Michigan boarder

[nuttyskier2002]

That is exactly the kind of feedback I was looking for. I had a feeling it would be too much. Fun in a car, not fun idling around in a boat. The problem I'm having is trying to find something that will be warrantied. I haven't spoken with any of the sites, but everything that has a ZZ4 cam also has aluminum heads and has the marine use disclaimer. Not sure what they would say if I called up and explained my intentions (marine use fresh water only).

Otherwise, what about this one? This is from their marine engines line, Blueprint Engines. 365hp. Duration is only 6 degrees longer on exhaust, is that enough?

//blueprintengines.com/index.php/products/bp-marine-engines-landing/gm-355-marine-main/item/gm-355-base-mbp3550ct-marine

Cam Type: Roller

.480 Intake .489 Exhaust

218 Intake / 224 Exhaust duration

@ .050 - 112 degree lobe separation

This is a 350 bored .030" or .040" to yield 355 cu in. It's definitely plenty of power for what you want to do. 218 is right at the point of having a noticeable idle.......not lopey but you'll know it has a cam in it. As it warms up though it will be a little less noticeable. 6 degrees more on the ex is fine. You want longer duration on the exhaust due to the back pressure increase caused by water.

[Woodski]

@nuttyskier & MB: I agree with NS2002 that the extra duration will probably not be appreciated by the CFO, particularly on cold starts where one might have to finesse the throttle to keep the mill turning on those colder sets for a few minutes. I don't think the reliability would be that much affected but one potential with a bigger or longer duration cam is sucking water back down the exhaust. If you look at the go fast boats, they tend to run a longer elbow that injects the water back in to the exhaust farther downstream to avoid any water reversion (which is catastrophic BTW).

FYI: the combination of the fast burn heads / ZZ4 cam with a good exhaust system is excellent. One additional item on the fast burn heads, the valves are bigger so you get a bit more airflow by default.

@MB: as noted before, if you are going to rebuilt and are the least bit apprehensive about aluminum heads, get a set of universal cast iron Vortec heads, use your cast intake (it is the same as an Edelbrock Performer RPM) and go from there, you will have to verify intake manifold bolt patterns for proper fit. Going the crate engine route NS2002 has an excellent option that is probably the easiest solution. I would prefer a roller cam over a flat tappet one.

Edited October 16, 2013 by Woodski

[nuttyskier2002]

Wood......his intake is a pre-1996 and will not bolt to the Vortec or the Fast Burn heads. I definitely agree that Vortecs or Fast Burns are the way to go but he will have to get a vortec type intake to fit. Not only is the bolt pattern different but the location to the runner opening is shifted up about 1/8". In other words the runners (intake to head will not seal). I wouldn't hesitate at all to use the aluminum Fast Burns on a boat if I were just boating in fresh water.

MB there are several ways to go with cylinder heads. Here's a quick rundown:

Stock vortecs - these came on '96-00 Chevy and GMC trucks. They share the same style combustion chamber as the early 90s LT1 Corvette heads. Difference is they are designed for normal (vs reverse) coolant flow. They have a 64cc combustion chamber size and intake runners are 170cc. They are a light cast iron casting and can crack easily if overheated. If you chose to use a set of these you will want to make sure to have then modified for a higher lift camshaft.

Bowtie Vortecs - These are GM aftermarket heads available from GM, Summit and others. These are cast iron heads with the same style combustion chamber as above. Except the combustion chamber is 66cc. These heads have a 185cc intake runner. They are heavier casted heads and more durable than stock vortecs.

Fast Burn - These are also made by GM and available from mostly the same sources. They have the same style combustion chamber as all above but the size is slightly smaller (62cc). They are aluminum and have a much thicker deck mating surface than stock vortecs. The runner size is quite a bit bigger (215cc). They have "D" shaped exhaust ports which will require some matching work (grinding) to your stock exhaust manifolds.

The Fast Burns and Bowtie will both accommodate higher lift camshafts with no mods. Personally I like the Bowties. Hope this helps some!

Edited October 16, 2013 by nuttyskier2002

[Michigan boarder]

Thanks guys, very good to know. Still trying to connect with the local engine dude. Who knows what he's got laying around. My buddy sells trailers and re-habs the trailers that come in under the go-fast boat that the engine guy repairs. He's run the gammot from 900hp big blocks to older direct drives skiers. He had some good ideas for my buddy as they were discussing his old Mastercraft, and he gets what the demands are of a ski boat, similar to the discussions we've been having here. Hope to talk to him tomorrow and see what he can do. But at least I will understand his language as we go down that path. In the end, I still think I'll end up with a crate engine, I think this guy is going to be pricey.

[Woodski]

@NS2002: correct on the intake manifold, thus my "universal" comment which means you have to shop for the combination that fits. His intake will actually bolt to a set of fast burn heads but not the stock Vortec ones, although I would recommend getting an aluminum one if going the fast burn head route. There are also universal intake manifolds available for a nice price that will accommodate either bolt pattern. Correct on the exhaust port for the fast burn heads, also need to make sure the correct gasket is used. Nice rundown on the cylinder head availability.

[Michigan boarder]

_{OK, engine dude is stopping by tomorrow to see what I've got. Top half is still off, block is in the boat. So far I like his approach - let's see what you've got that we can work with to save as much money as possible. Then put the money into the hp gains. He's built 1700hp engines, 260hp engines, etc. weekly, and suggested something around 400hp for me. But not just hp, something with a flat torque band for consistent pulling, and something reliable so that the wife, kids, anybody can start and operate the boat. He said the goal is for it to function like any other boat, just with more horse than before.}

_{Edit: whassup with da font??}

Edited October 18, 2013 by Michigan boarder

[nuttyskier2002]

You probably posted this earlier in this thread so excuse me for asking.........how many hours are on your current engine? I'm thinking at a minimum you will want to bore the block to.030" and install new pistons. Hypers are fine for 400HP. New bearings (main, rod and cam) and new freeze plugs. Clean everything up and new gaskets and a good true roller type timing chain.. You'll want a good solid foundation to put the upgraded heads on and camshaft in. You will probably be okay re-using the connecting rods and crankshaft but have them checked and replace the rod bolts with ARP ones. With 400HP I would use ARP studs on the main caps as well. I'm pretty sure your engine came with a factory roller cam but if it did not.....getting the hardware and doing this upgrade will be worthwhile and a requirement to use the ZZ4 camshaft. Reason for saying this......some truck engines after 1987 did come with flat tappet cams even though the block was cast and machined to accept the hardware for the factory roller. If this is the case for you.......you can easily obtain all required hardware from a junkyard motor.

[Michigan boarder]

642 hours, or close to that. I'll let you guys know how it goes.

[Michigan boarder]

Well, good news. The block is fine, that spot in between the cylinders is "nothing". So here's what he is thinking:

-Aluminum fast burn heads for sure

-A small cam

-New intake

-He would like to see new exhaust manifolds, but depends on expense.

-He would like to make it into a 383, but thinks we will be at the $10k mark pretty quickly

-Looking at something around 350hp to stay under $5k

-He really would rather I bring the boat down and he do the install, water test, etc. and deliver it back to me ready to go, instead of just delivering the engine to me. I understand that, and I'd probably push for the same if I were him. That's more money...but that also means better reliability and less hours for me. We'll see how expensive that tradeoff is.

He's going to put some stuff on paper and get back with me next week.

Edit: He ran his fingers around that bad cylinder and was surprised to feel no damage at all. So it does not need to be bored out.

Edited October 19, 2013 by Michigan boarder

[Michigan boarder]

You probably posted this earlier in this thread so excuse me for asking.........how many hours are on your current engine? I'm thinking at a minimum you will want to bore the block to.030" and install new pistons. Hypers are fine for 400HP. New bearings (main, rod and cam) and new freeze plugs. Clean everything up and new gaskets and a good true roller type timing chain.. You'll want a good solid foundation to put the upgraded heads on and camshaft in. You will probably be okay re-using the connecting rods and crankshaft but have them checked and replace the rod bolts with ARP ones. With 400HP I would use ARP studs on the main caps as well. I'm pretty sure your engine came with a factory roller cam but if it did not.....getting the hardware and doing this upgrade will be worthwhile and a requirement to use the ZZ4 camshaft. Reason for saying this......some truck engines after 1987 did come with flat tappet cams even though the block was cast and machined to accept the hardware for the factory roller. If this is the case for you.......you can easily obtain all required hardware from a junkyard motor.

Thanks, but that is pretty far outside of my comfort level (expertise and time). I am tempted to dig into it and do the complete rebuild myself, but I am afraid I'm going to get pulled away from it too often and end up missing something...and end up with another summer without a boat. We are embarking on a large business increase soon and I am not going to be able to focus on this much at all. Drop an engine in - no problem. Tear apart and rebuild, and then drop in...that puts me over the edge.

[Woodski]

Happy news on the cylinder bore and block. 642 hours is very low, probably like 30k on a car, I would be willing to wager most of the parts are in pretty good shape (bearings, other pistons, etc), these engines should easily go 1500 hours on bottom end components. An ideal intake manifold is the Performer RPM (but it is a copy of the marine manifold you now have but in aluminum). I would not recommend spending any money on the air gap versions, the warming water will help warm up and the fact that the cooling water hangs in the 150 degree mark means you don't really have a lot of heat in there along with the fact there is not much airflow to actually use the concept. You can go with the cast iron exhaust manifolds, you will probably need to change gaskets a bit more frequently due to different cooling rates of the materials and as noted you will have to port match them. I would either go with a ZZ4 cam or your marine cam (you might consider some 1.6 ratio rockers for it) so you maintain good hole shot performance. As the hardware sounds to be in pretty good shape & budget is a concern, I don't see the benefits of going to a 383 as a strong 350 hp 350 cid engine will perform all your tasks with ease. Good luck on his pricing. By the way, you will want to change your spark arrestor, it won't breathe enough air when you are done.

[JB-FOOT]

Wow. been on vacation for a week and quite a lot had been happening...

[dihrdskir]

This thread has me intrigued. There are some knowledgable people out there, all of whom have some information to share and potentially make it more confusing. What I want to know is; where did the big block go? There is no substitute for KUBI KINCHERS. In a marine application the more torque you have and the lower down in the rev range it appears the happier you will be. Aside from turbo/super charging the best way to get it would be increase capacity. You do know you can get 7.4 litres (454 CI) out of a small block now right? I think the money that costs makes it an unrealistic option however mouthwatering it may seem. My advice is to build what is essentially a truck engine. Go for the largest capacity your budget would allow and match it with a set of aluminium heads with the smallest intake port size that is compatible with whatever engine capacity you select. Air speed and volumetric efficiency is everything when it comes to increasing torque. Think about what happens when you hold your thumb partially over the end of a hose, the speed increase is the same principle that applies inside an intake port. (mental picture anyone?). Aluminium heads to allow higher compression and lower the risk of detonation. Don't worry about the cast/aluminium combination my last boat had a 6.0 litre ilmor which is exactly that, only 380 HP, but real figure and not the figment of a marketers dream, with a juicy flat torque curve that made it a pleasure to use. Bang for buck, I would go for a 383, efi. Roller cam and tube headers (HITEK) are a must.

[DWhynot]

We need a vote button: I choose a 383 (your application may vary)

[tvano]

We need a vote button: I choose a 383 (your application may vary)

we need michigan boarders' credit card number so we can buy the "right" engine for him.

[WakeGirl]

This thread has me intrigued. There are some knowledgable people out there, all of whom have some information to share and potentially make it more confusing. What I want to know is; where did the big block go? There is no substitute for KUBI KINCHERS. In a marine application the more torque you have and the lower down in the rev range it appears the happier you will be. Aside from turbo/super charging the best way to get it would be increase capacity. You do know you can get 7.4 litres (454 CI) out of a small block now right? I think the money that costs makes it an unrealistic option however mouthwatering it may seem. My advice is to build what is essentially a truck engine. Go for the largest capacity your budget would allow and match it with a set of aluminium heads with the smallest intake port size that is compatible with whatever engine capacity you select. Air speed and volumetric efficiency is everything when it comes to increasing torque. Think about what happens when you hold your thumb partially over the end of a hose, the speed increase is the same principle that applies inside an intake port. (mental picture anyone?). Aluminium heads to allow higher compression and lower the risk of detonation. Don't worry about the cast/aluminium combination my last boat had a 6.0 litre ilmor which is exactly that, only 380 HP, but real figure and not the figment of a marketers dream, with a juicy flat torque curve that made it a pleasure to use. Bang for buck, I would go for a 383, efi. Roller cam and tube headers (HITEK) are a must.

You said it in your post, bolded for emphasis. And....if this were a big, heavy vdrive then it would make much more sense. But we're talking about a lightweight ski boat & it just doesn't make much sense for the cost as well as the added weight (which makes a huge difference in the ski wake behind this boat).