SDPC Tech Tips: Marine Engines
Vložit
- čas přidán 23. 07. 2024
- In today's tech tips, Nick goes over some common questions we get regarding street car crate engines and marine use. There are distinct differences that could end with you weighing anchor with that low run-time crate engine and...a voided warranty!
Although we are happy to sell you a crate engine, we caution customers against this route and recommend using the proper tools for the job at hand.
#SDPC #SDPCRaceshop #TechsualHealing #Marine #JustBoatStuff #TechsualHealing - Auta a dopravní prostředky
I guess I screw up and put a L31 crate motor in my boat with fresh water cooling 10 years ago. when is this thing going to blow up? It has been running strong for 10 years.
4.3 vortec 4 years running on a ski boat 🤷🏽♂️
335 hours on an LS1 5.7 Corvette MasterCraft Maristar 22.5. That’s not right!
Got a l31 in mine as well. Runs great. Called mercruiser and gave them the casting and it was the same casting numbers they used. Same motor
Now do salt water.
I am in the process of buying my first boat!!! I have been doing my research in various areas!!! THANK YOU FOR BEING SOOO DAMN SMALL!!! I LOVE THE WAY YOU EDUCATE YOUR VEIWERS!!! I'm a new fan!!! 🙂
Thank you for clearing up the confusion.
Someone help this guy because he is having trouble breathing. He is constantly gasping for air!
Ikr, i was more focused on that
Agree
I thought the same thing. I'm like dude take a break and breathe he's getting winded just by talking. Lmfao
I was getting annoyed AF
10👍's up SDPC thanks again for taking us all along with you
rock solid advice, thanks!!
You are assuming that all marine engines are raw water-cooled. Basically every boat that is in saltwater is not. They use the same coolant trucks do and run at almost the same temperatures.
Was gonna say this... FWC doesn't solve all the problems talked about here, but it solves most. It also keeps all the shit from lake or salt water out of your water jackets and makes it easier to winterize. The way I look at it, engine temp is easier to control and a heat exchanger is a lot easier and cheaper to clean and/or repair or replace than the whole engine. On our Detroits, we have a flush port to run fresh water from our potable tank through the raw water side and when we descale every five years, very little comes out. Been thinking too about adding a thermostat circuit to the raw water side to let the engines get up to temp quicker and stay there at lower RPMs since we mostly cruise at 1000-1100 RPM.
Great presentation..alot of mercruiser engines don't have heat exchangers for engine cooling..I remember a guy down at the marina put aluminum heads and intake on his non heat exchanger engine,it was only a week and that engine was toast...
My Sea Ray will run 3,000 rpm for 3 hours at a time running up Lake Powell from Wahweap to Bullfrog. (The lake is 186 miles long). You are correct on the valves and the bore and everything else you mentioned. If you run street heads and are carb’d and run too lean you’ll drop a valve seat especially in older engines designed for leaded gas. I know. I’ve done it. Bottom line in marine engines even mild performance ones its a pay now or rebuild it later and pay a lot more type of deal.
Amazing information thanks
I have a 400 small block carbureted it was a short block build for a truck used the same cam crank etc swapped marine applications on it from heads up and 4 years later still runs great I would say it loads up with fuel after coming in hot but lil nuts rev and clears up I’m just saying diy it can work vortex is different but old school carb motors easy
I remember back in the 80's you couldn't get a stock small block v8 engine over 200 hp! (unless you bought a Corvett) I remember the 225 hp 305 Chevy in our 1978 Bayliner. That engine would SCREAM! At the same time I was in high school shop class working on a 350 in a Caprice, and honestly my grandfathers fuel injected 3.8 Buick would blow the 350 away! They went for years making v6's that would (easily) outrun most v8's until about 1996 or so. I also remember riding in a police crown vic verses the civilian model. WOW! NOT EVEN THE SAME CAR. Fact: If it says marine or police on it, It has power!
Thankyou for this video you are one of the few people that got this correct i beleive the confusion in general is from years ago in the 1960s and 70s more Specically GMBlocks there weren’t too many differences in the Marine Engines yes the Bronze Freeze Plugs , a different Cam and they used a Forged Crank to handle the Tourque often in those days the GMMotors used in Trucks,Industrial and FarmEquipment also utilized Forged Cranks i think the SmallBlock 283 motors came with Forged cranks in some of the Muscle Cars and Trucks i’m not a GMexpert but i recall Oldtimers saying it was the Corvette Impala and some Trucks that had those Forged Cranks , my Da remembers that a lot of HotRodders would buy up any old Chris Craft Engine they could and use that to build a high Performance motor Chris Craft used GeneralMotor and Ford SmallBlock and Big Block engines in the majority of their Motor Yachts so there were plenty of them out there FYI i lived inFlorida off and on for many years
Good video. Also marine engine run cool water constantly from where your boating instead of a hot radiator. Maybe the next truck I get I will put a marine engine in the truck.
they are the same as the GM crate engines. The local dealers buy them from GM and not Mercruiser or Volvo. Stainless steel water pump impeller? all the same. My machine shop says no difference lift on "marine cam". I'm going on inland freshwater boats. All of the head gaskets I use have stainless steel openings in the head gaskets anyway.
I’m going to try it
Boat runs at 175 degrees. There is not a bit of difference between a vortec 350 short block and a gm truck 350 short block. Bore pistons crank rods are all exactly the same. I just rebuilt two Merc Mag Mpi's using salvaged truck vortec short blocks. They were EXACTLY the same. They just slap marine on it, put brass freeze plugs in and charge you an extra grand.
Yep, and what's with this "running lake/salt water through the block
Everyone (so I hope) uses heat exchanger, rendering all the "mods" useless
The ring gaps are typically larger on the marine builds. The std Chevy truck engine cam is very close to what Volvo Penta uses as a marine cam and should not cause any issues. AFAIK the vortec head is a vortec head and the valves and springs are exactly the same. For sure, the core plugs on the marine engine are brass.
The water pump
( brass impeller with stainlesssteel back) crankshaft is different and the Pistons! The mercruiser Pistons have a very large ring land with thicker rings and the skirts. The crankshaft Bob weights are larger to balance it the rods are the same. The blocks can be either four bolt or two bolt Main. iv put a 💯% Chevrolet L31 in my boat because the old engine was never winterize when I bought it so I know everything. But it works out
@@BB-wl4qz I said short block. That doesn't include cam.
No need to be rude. Short block come in different forms. With or without cams. When you call a local builder you will never get a cam with your short block unless you order a specific grind. Therfore I referred to short block because you can order short block from the internet in any flavor you'd like and install whatever cam you want.
My 1999 chevrolet 3500 van 5.7 L31 with zz4 hot cam upgrade springs and aluminum dual plane intake been great! I rebuilt 2 year's age has been in my 23ft Baja Force 220 shit if I get one more season out of it better than 5-7000 $from mercruiser! I spent 1000$ on everything to rebuilt it .. granted I'm doing this myself but it's 5-7000$
Any LT fuel System upgrade tips/ help info videos .?
We are working on some coverage for the Gen V LT fuel systems including some dyno comparisons. It's been in the works for awhile!
Some of the points are valid, some BS. Mercruiser doesn’t add extra clearance to marine engines, same as car truck engines. The computer will run a truck engine same as a marine engine, cam isn’t radical enough to need recalibrating. Some of this is just marketing bs so you pay a higher price.
FACT: If an engine runs, you can put it in a boat
FACT 2: If an engine does not run, you cannot put it in a boat
FACT 3: I need an engine lol
Actually you can put a non running engine in a boat, just dont expect the boat to run
Ring gap has a little more gap for expansion due to thermodynamics, MLS head gaskets, brass freeze plugs, severe duty stainless steel or inconel exhaust valves, valve springs are whatever the cam needs or requires, the cams typically have less duration (about 224 degrees max at 0.050) and a higher LSA (112 to 114) to avoid reversion (unless you have exhaust above the water line then it doesn't matter)....I personally also run my mains just a few thousands looser for thermal expansion. I would say most boat engines have hypereutectic pistons but forged is always better for strength. Also, boat engines aren't about horsepower, it's about torque! Most boat engines rev less than 5500 rpms. You want power in the low to midrange band. The more torque, the more pitch on your prop, the more speed at a lower rpm and faster times to plane. That's why you see tons of big blocks in the 20' and larger boats. Fresh water cooling is a plus if you have it. There's no crazy science to it besides protection from corrosion, heat and reversion. However, you could just run a regular car engine but longevity might be sacrificed. But I have seen people pull a 350 out of a car and run years on it. I would not recommend it though. However you still need to use the coast guard approved carburetion, charging and starting systems with flame arrestors. Noone wants to go boom!
7 years no problem with 327 with vortec head any cam with a 110 lobe separation put the cam in the same power ban as a marine cam
Hey I was wondering what the price was on the crate motor. 5.7 MerCruiser Max the one I have is supposed to be 300 horsepower? Manifold cracked block Cracked put all other parts of good all new parts 450 hours only looking for a block or a crate motor
Unfortunately we aren't a dealer for marine engines.
makes you wonder if marine engines might be a decent choice for a racecar as well. thats why we use truck engines because they are a little stronger, so if marine engines take truck engines and go a step further strengthening them then i might just have to build/buy 2, one for the boat build and one for the drag car build. lol
All alloy ls and yojr worried about corrosion? Mate it’s alloy. And all the gaskets are stainless now. Everything is built to spec these days. Maybe a 1975 350, this is 2023 now
Finally! Someone explains the difference. Another thing to consider, the water that’s pumping through the blocks, it’s a lot! More than what the average car can handle, that’s why boat blocks are galvanized
You can use a car or truck engine but you need a freshwater cooling system, means the engine runs with normal coolant and the coolant gets trough a heat exchanger with lakewater insteat of a radiator with air.
closed loop cooling fixes alll
go with the stock engineered components
I would think running a engine in cold lake water that never gets hot. Would be better than hot antifreeze any day.
None of this stuff is relevant anymore with a closed-loop fresh water cooling system Ring gap
does not matter either since inboard boat motors have thermostat only difference is cam profile vortec heads in trucks have harden valve seats so let's hear the next new difference between marine and automotive
I’m a marine mechanic. I’m working on a vortex 350 with failed heads currently that has tuliped exhaust valves due to non hardened exhaust seats due to heat.
Nope .....they failed when thermostats stuck and it spiked to 325 died ...... restarted at 300 and flooded w 50°lake water and cracked lol. Unless a 2500# load at 3k on flat lake is harder than 4k 1st gear up a 6%grade polling 11000# behind 6000# truck in 110° heat over 160° asphalt ..... just saying.
A water is added to coolant so no .. b. Marine runs same thermostat as the truck .. it's not free flow and the boat block is hotter as there is no airflow for cooling . So the piston clearance issue is bs . Headgaskets at gm are identical for marine and truck engines .. . Also there's 2 types of cooling . Closed and open .. closed uses coolant and a heat exchanger for water and oil ...... open is lake water ..... I ran a stove bolt 6 for 15 years in my 89 starctaft 22' ran 3500 all day no problem . It was open cooling with car exhaust and flow master lol stern cooling exit so I could read telp at exit too .. and hot water for washing hands while fishing ....
Right on the money truck engine will perform poorly out of the hole
You can install a truck engine and add a radiator and electric fan...and thats it ...a closed system...ypu dont ever have to worry abput winterizing the boat!!!!!!😂😂😂😂😂😂
short answer no
Everything you just said is complete nonsense. Aside some gaskets and freeze plugs they are exactly the same the bolt on's are different to accommodate a marine environment. Salt water is going to corrode any motor. Any mercruiser part is a hyped up version of a gm part
Sounds like need to see doctor
"It's a free country you can buy and do what you want". Sorry, wrong. You can buy an engine, and then be stuck to the dealer because they won't give you the software to work on it.
There's way to much misinformation here😂. Ring gap not piston clearance is the most important aspect. Never Ever run Silicon glass pistons in a marine block. Sodium filled exhaust valves are a thing of the past as stainless or inconel is the norm in modern heads. Most all modern blocks use stainless welch plugs also, no need to replace them with brass. The LSA is the only factor on a camshaft to prevent reversion. Which is also affected by exhaust resonance. Bottom line is a race ready short block will last decades. A stock block made to run in an auto will ring bind and break the ring lands. Hypernuetic pistons "silicone glass" can shatter. Most everything marine specific is geared towards explosion prevention in electrical and fuel related parts and must be certified marine including fuel hoses.
Look you are overlooking things way too much a car engine would be just fine just got to wash it out when you get home we're with freshwater you know the cooling system
Amazing information thanks