Swapping Chrysler Crusaders for Diesels possible?

[Rotti]

Hello,

so far, I`ve never posted in this section- normally I`m into outboards.... here`s my problem:

My buddy has got a nice Trojan F28 sedan, built ~1978 which is powered by twin gasoline engines, V8, built by Chrysler and I think they`re called "Crusaders". These engines have never run well, they always spit and sputter, won´t idle correctly and are a true pain in the a... due to their enormous hunger for gasoline! What makes this even worse is that you can hardly get gasoline along our coastlines anymore, only diesel which is cheaper anyway.

My friend was so pissed by the performance of the engines that he has just bought another boat with twin 300hp Volvos on dualprop outdrives- doing 45knots and performing like good marine engines should. Now he´s made a suggestion: If I can install some diesel engines in his old boats, he`ll give me a 50% share on it, which I could normally never afford- and I like the Trojan itself, it`s a very solid boat which might be worth keeping it.

What I`ll need to know now is wether there are some folks in here who have some experience with gas-to-diesel conversion and who are willing to give me some advice?

Here`s what I´ll have right now: Twin Crusaders (225hp) on Velvet Drives to twin shafts and props. The gearboxes are V-types, means although they are mounted on the front side of the engines the shaft goes out to the stern of the boat, UNDER the engines!

I`m willing to look up each and every serial number, year of built or whatever will be needed by the experts, but before this I`d like to know wether there is a chance to do a good job on the conversion or not? If the boat is lateron capable of reaching maybe 12 knots maximum and will give me a cruising speed of roundabout 10knots I`m fine with it, so no need for big engines at all!

The main problem is possibly to find engines that can be connected to the gearboxes....I´d like to install twin VW turbodiesels which can be converted to marine engines very easily, but if there are some US- automotive diesel engines that might fit to the gearboxes I´d like to know as well! I just want to do a good job on it or no job at all, since I want to have a save and seaworthy boat when it`s done!

Any help would be very nice, I don´t know to whom I should turn to with this? Please answer!

Many greetings from Germany,
Wolfgang

 

[DJ]

Re: Swapping Chrysler Crusaders for Diesels possible?

Forget US auto diesels, there aren't any, except for truck engines. Those would be more than you need.

There are plenty of choices out there.

US-MerCruiser-Caterpillar, Cummins.

Japanese-Yanmar

European-Volvo, etc.

I do not believe there are any issues with getting the engines to bolt up. The issue is going to be gear ratios in the transmissions. You need to find out what that ratio is. You may be able to adjust propeller pich around that. But you need to know.

 

[QC]

Re: Swapping Chrysler Crusaders for Diesels possible?

Yeah, some of these packages will lose as much as 2000 RPM, so they will probably require a gear ratio change. I like the VW option, with the connection issues being the question and they are fairly high RPM engines, so they may eliminate the ratio issue. If they are rated around 150 bhp (PS) I think you will be pretty happy. Power should not be an issue with what you have said although 10 knots sounds like a pretty inefficient speed for that planing hull. I think you should shoot for a 15 knot cruise minimum and those VW's will probably get you there.

Also, you need to think about good water separating filters, fuel transfer pumps, you'll need return fuel lines for diesels and you need to make sure that your tanks are compatible with diesel. All stuff you need to think about and budget for.

Also, V-drives are pretty common here, they are not driven from the front though, the engines are mounted backwards . . .

Sounds like a great project, wish I was playing.

 

[Rotti]

Re: Swapping Chrysler Crusaders for Diesels possible?

Thank you for the answers! Some thoughts of mine:

I was thinking of the VW exactly because of their capability of running on higher rpm`s, but my choice would have been 2x 70hp turbo charged, because they`re rated up to 4500rpm and I simply don´t need the speed.

We`ve been out with the Trojan this summer and when we were doing around 2500rpm with both crusaders, the boat was running just fine at approx. 10knots. At that speed the water started to go clear from the transom, it was not planning but still much better than cruising at very low speeds. I think this has to do with the enormous width of the F28 hull, it produces a lot of lifting force already at lower speeds.

Maybe it also might be a good idea to prolongue the hull a little bit (2 -3 feet?) at the transom by creating something like a swimming platform with an underwater part as well, just to increase length in the waterline and also add some buoyancy at the stern?

Right now we`re looking at gasoline prices over here which are very close to $6,-US per gallon, diesel is around $4.50 US per gallon....... So 10 knots with both Crusaders consuming 6 gal/h will cost me $72,- per hour. 10 knots with two small VW- diesels at maybe 3200rpm (changed gear ratio!) consuming 3.5 gal/h would just be $31.50 per hour! This is the calculation which keeps me going on and doing some researches!

The Trojan is, in it`s current state, almost worthless over here, because anybody, who has enough money to afford her gasoline consumption has probably also enough money to buy a better and more economic boat right from the start! Poor guys (like me) could maybe afford the boat itself, but don`t have enough chump change for operating it.... sad story!

Next thing: The small VW diesels are very common over here to be marinized. All the parts for this conversion are widely available at halfway affordable prices. You can find spareparts for those engines on every corner, no problem. Service is very good since VW is perhaps the car company with the closest service net all over Europe!

That´s why I`m opting for these engines, but first I need to know wether I could make them bolt to the V-drives or not. Maybe I could even do it by adding something like a coupler, driveshaft or whatsoever?

Please, keep on posting, thank you!

Wolfgang

 

[ac680]

Re: Swapping Chrysler Crusaders for Diesels possible?

Crusaders are Gm engines, chrysler did not use that name.
Per advice, I have a 36 foot Uniflite here, glass boat, but weighs around 24000 Pounds, more than your Trojan, and it has two crusaders, that I rebuild. If I run 2500 RPM, I get 14 knots.
max is 4400 RPM, with 24 knots.
If you are making 2500 RPM, and 10 Knots, than something really bad is the matter. your engines are very sick, and at 2500 RPM you possibly use 15 to 20 gallons an hour.
This 36 foot uniflite at 10 knots runs 1500 RPM or so, maybe 8 gallons an hour. You might want to consider fixing your engines, instead of replacing, because except for the engines and transmissions, there are fuel issues, wiring issues, and mounting issues, and V drive issues..
Anyhow, I did convert a 40 foot Mathews (wood, 1953), from 2 chrysler engines to 2 mercedes 616 engines, those are 2.4 L 67 HP engines, like a mercedes 240D. I do get 13 knots or so full power. I have a sourse here locally for 2 engines, with transmissions, and ofcourse a marine conversion.
Its done by Nanni, a french company. very nice conversion.

But the fuel you will save is not worth the gross expense for a conversion. Fix the gas motors, and you will get a way faster boat, a way more quiet boat, less smell, and easier starting when cold. The money you save will buy you an awful lot of gas.