bertram31.com

whats the cost on the cummins conversion, from truck engine to marine ap ?
on the 6bta 250hp?
phil

I believe the conversion kit runs about $5000 to $6000 plus the cost of the engine.

Harry Babb

Phil,

There's a company up the coast from you in Angleton Tx that does the conversions. Their website is www.hsmarine.com

I've got a set from them, but my boat is the never ending project so I can't give you much info(still on blocks). They put a set in a Tiara about a year & a half ago that was run last season without much problems. They also just put a set in a Blackfin. All 24v Dodge engines. They've been doing them a couple years and have really put together a good set up, if you're looking to go the 'truck engine' route you might want to give them a look.

DanielM

The expert on this is Captain31. Wait 'til he comes in on this.

Dick, I've tried to send PM's to evrybody with questions about the conversions - wouldn't want to be too strong an advocate. I have a lot of respect for the guys Daniel mentioned - the stuff I've seen they have done was top quality, and they helped me remove and reinstall my injector pumps when I recalibrated them last year to get a little more "go" out of my 12 valve Cummins truck engines. They have the 24 valve conversion down to an art, and are working hard on the new common rail engines - have two in a local charter boat doing testing now. I would look at this route over used marine engines. Even with used truck engines, they have never been around salt water, all the marine equipement - which is the first to fail - is brand new, heat exchangers and aftercoolers are oversized, and they are proven engines - for about the cost of used marine takeouts - less than factory remans. And this is if you go with new truck engines.

It depends on if you want to sell your boat down the road and it has truck engines in it vs marine engines on the resale price. That would be something to think about unless you are going to keep it for a long time.

Conversion of an automotive engine over to marine application can be less expensive initially than purchasing a true marine engine... But there are many other differences between the two engines other than just changing out some external parts & may in the long run be just as costly, or more so, as installing a true marine engine in the first place.

Bruce and I have tried to explain this to so many folks that we're blue in the face & yet the topic just keeps re-igniting... Kinda' like those trick birthday candles that can't be blown out.

Here's a multi page thread from another forum that probably has more verbiage devoted to automotive conversions than any other single source on the Net: Auto engine marinization

In a nut shell (& of course, in our opinion), automotive to marine conversions just aren't the way to go...

Br,

Patrick

I looked over the thread from that other board, seemed to be more a discussion about gas vs diesel. Car motors don't work good in boats. Truck and industrial engines - diesel - are what the majority of marine engines are based on, from the 3208 Cat, the various Detroits to the 6 banger Yanmar (a Toyota truck conversion). The 5.9 Cummins is used as a truck motor for 3/4 pickups up, is used in industrial applications as well as for marine generators. I was told by a Cummins rep once that it started out as a forklift engine and was once used on Allis Chalmers tractors. It is a traditional, low rpm diesel. To my knowledge, it has never been used in Ford trucks, as the author of one post in that thread - a self professed expert - seemed to believe. There are differences between the marine and truck versions, at least in the 12 valve engines, but not so much in operating rpm ranges. Truck engines use the Bosche injector pump, which is in some ways better than the Nippon used on marine engines of the same period. Turbos are different, turbo housings are water cooled, of course. Years ago a Cummins rep told me there was absolutely nothing wrong with marinizing a truck engine, except if you bought the parts from Cummins it would be more expensive than a new marine engine. What HS is doing, and what I did with my boat, is not to suggest their marinzed truck engines as a substitute for new marine versions, but as an economical replacement for gas engines. If you have the money for new marine engines, or prefer a used marine engine which may turn out to be someboy else's problem tranferred to you, go for it. If you plan to pay someone to install the engine, want a turn-key, professional job - call Bruce. For those of us who like to tinker, want to know how the power system works, where everything is, do some or most of the work ourselves, the truck conversion process is very interesting, and can be very satisfying as well. Every time I crank my "junkyard" engines - and they ALWAYS fire right up - I know that I have done something in the conversion not everybody has the patience and desire to do - and it gives me a feeling of pride. I've had "marine" gas engines, - diesel truck engines are far superior. With an HS conversion, you'll get water cooled turbo housing, marine bellhousing, oversized heat exchangers and aftercoolers, etc. - a marine turbo if you want one. Cummins was even describing the marine version of the common rail 5.9 on their website as "basically the same engine as in the Dodge truck".

Sorry to be so long winded.

Well I guess I'll throw in my 2 bits. As far as gas engines are concerned I only wish that I had a nickel for every hour I spent on the water with "Car Motors" and in particular the 350 Chevy engine. Then I could afford to purchase new Cummins rather than rebuilding a pair of used takeouts.

Speaking of Diesel engines I have to admit that my experience is in rebuilding existing "Marine engines" in boats, "Industrial engines" in Trucks and Bull Dozers etc.

I hear comments about "Duty Rating" and we all know that a marine engine is always pushing "Up Hill"............ain't no coasting or down hill in a boat.

A Cummins rep told me that the Truck engines have different pistons to alter compression raito and have been detuned to meet emmisions requirments. Same Block, Same Rods, Same Crank and lets face it these are the 3 high stress parts other than the pistons.

I keep waiting to hear something about the basic parts of marine engines being made with different more druable materials. So far its injection pumps, turbo chargers aftercoolers etc that seems to be the major differences. It seems to me that the basics are the same Truck vs Marine.

I have been the renegade Gas Engine Guy around here for years and I am here to say that I have personally ran the living shit out of 350 Chevy engines, cast crank, cast pistons, $50 junk yard motors. I did, in the name of safety use marine carbs, alternators, starters and fuel pumps and in the name of performance I used RV type cams and the good heads. I cannot count the days of comming in from 25-30 miles out with a boat load of divers and gear running 3500 to 4000 RPM all the way in.

I cannot help but to think about a post that I read earlier tonight, Posted by Bruce, about how he paid $225 for a board that contained just a few dollars worth of value. Bruce recognized the true value of the circuit board and I suspect that there are thousands of people that simply do not see it.

If you can afford a turn key job I say good for you but if you are one of us guys that just like tinkering.........convert the truck engine or rebuild a weak take out, then post pictures of the fish you caught for all of us to enjoy.

Harry Babb

Harry - Feisty - I like it!!

Harry, we are in complete agreement.

Guys, Interesting thread. I talked with a couple of owners who had done the conversion prior to deciding to give it a try. One told me that you have to understand that when you lift the hatch you’ll always be looking at a Dodge engine, that is all it will ever be, & you’ve got to be alright with that. Resale value isn’t a factor I’m worried about, if it is you should certainly take that into account as it will matter if you’re selling the boat. The only thing I really wanted to interject is that if you are of a mind to wander down the conversion path, the guys at H&S have done quite a few, and are good folks.

Later,

DanielM

Daniel, could you post Lee's phone number? I have it somewhere, will have to hunt, and the web site seems to be down right now.

Mike

(979) 849-3088

Thanks. I need to call him today about an intake pipe he's making for me.

Chimmin in....

From a gas engine standpoint the basic differences internally are brass freeze plugs, SS exhaust valves and valve springs that are capable of sustained high RPM service. "Some" of the older marine engines used forged rods vs cast and forged pistons vs cast. The carb needs larger jets to run the engine rich and not lean-out at high RPM. The rest is all external bolt on stuff.

On the diesels it depends on which engines your talking about. Many of the J&T Detroits started life as new industrial units, shipped from Detroit to J&T new in a crate. From a DD standpoint there is very little difference...I guess that's why everyone calls them Bus engines. NOW...turbo vs non-turbo is a big difference, in most cases you can't stick a turbo on a natural without changing out pistons, etc. With the diesel it's a matter of internal heat build up and being able to properly burn the amount of fuel needed to make the required HP for marine applications.

All that is required here is some basic P/N research on whatever engine your looking at. If you start running various PN's you will find out "If" there is any difference in the marine vs the industrial or automotive. In most cases the engines are 85% the same...you just have to figure out what 15% is different.

My $.02

1984 chrysler heavy duty truck engines...dosen't mean i wouldn't like new diesels but the record speaks for itself......and the boat does go 40 and burn 10.5 GPH at 26

Is a "bus engine" the same as a "oil sling dump truck engine" or "oil slinging garbage truck engine"

I just wanted to make sure I had the lingo down.

Ernest, I think the 4 cylinder Yannies are converted riding lawnmower engines.

Bad weather in Freeport right now. Need industrial size bilge pumps.

Yes Ernest, they are all one in the same. Although I think the "oil slinging" comments are a bit out dated. I believe the after market CCV systems have cut way down on the "slinging" Much to the dismay of those wishing to sustain the folk lore, there are a lot of nicely painted "fairly" clean Detroits out there. Most of the oldest DD's slop & sling like crazy.

The local Detroit shop once told me "if it ain't leakin oil somewhere, somethings wrong"

The old Detroits, when purchased brand new, were said to have a puddle of oil in the bottom of the crate, from the factory. Like English cars.

there are a lot of nicely painted "fairly" clean Detroits out there

They are part of the Jackie Mason Jewish fleet.

With the advent of air seps, it cut down on the oil film that blanketed the entire engine room and reduced the leaks to a slow drip.

But oil slinging dump truck engine still applies.

My 2 cents worth.

Blocks are blocks. Marine and otherwise aren't made of different material. The marine market is such a small percentage of engines that it would make the marine engine way to expensive to make to cast the block in different materials by the engine maufacterers.

Most cranks, but not all are forged instead of cast.
Exhaust valves can be made of high temp resistant materials. Pistons can be forged instead of cast.

The biggest difference is load vs rpm.

Cams are the most notable difference.

Car engines do not make good boat engines because of this factor. Even Harry changed cams and heads. So a 350 pull out of a 82 Impala stuck right into a boat won't work for very long.

Diesel truck to marine engine conversions have been there from the begining. The first marine engines were industrial or truck engines at the start. They were refined as they advanced but in the scheme of things, very few engine designs are strickly "marine engines".

The difference being a factory new block with marine parts added by a major amnufacturer or a used truck engine converted by two schlubs in their garage with rigged parts.

Factory conversions can be compact in design while garage conversions can have crap hanging where ever it fits and looks like a salvage yard threw up.

Properly done used "truck" engines can be just fine as long as all the bugs have been worked out that the factory versions have discovered many moons ago.

If reliable, it certainly is a viable alternative to new factory diesels.

If done right, the appearance may be different, but the engine design should be close to the same between a factory new and a small shop used conversion.

Thats the trick of the small shop to do that and make the price attractive enough to be able to sell without cutting corners.

The Jackie Mason Jewish fleet doesn't have engines........

"Engines? Why would I want engines? If I had engines, I would have to buy gas. Why would I want to buy gas? Do I LOOK like an idiot?"

The Jackie Mason Jewish fleet doesn't have engines........

"Engines? Why would I want engines? If I had engines, I would have to buy gas. Why would I want to buy gas? Do I LOOK like an idiot?"

right up there with pie r round....

But Randall.....Pie are round.

no scot....actually .... pi r squared