One big dog out of the pen.

One big dog out of the pen.

Joined: July 15th, 2005, 8:09 pm

April 8th, 2016, 4:05 am #1

This is an archived thread posted by Jerry Namken, back in 2008, along with postings from several others, as a reference for other people around the world who may be taking on a project like this. Thank you, Jerry, for sharing this info with so many people around the world.

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One big dog out of the pen.
February 23 2008 at 8:29 PM Jerry (Login jerrycnamken)


Yes, I lived to tell about. I pulled one of the 454's this afternoon by myself and will get the other one out Sunday afternoon. Pictures will be forthcoming. It is a rush standing next to one of the bad boys. They are big. I took it out with everything still on it. I have no hope of getting all the wiring and hoses back where they belong. I am giving up now before I get frustrated!!!

Jerry the Wrenchhead

edit comment:

Here are some additional threads showing more photos of Jerry and Nadia's 38' Commander restoration project.

Jerry and Nadia embark on a complete restoration and repower project! ... +38.%C3%BE

New big dogs arrive ... ll+bite%21

Pulled a 454 by yourself ??
February 23 2008 at 9:21 PM Paul (no login)

Response to One big dog out of the pen.


Sheesh, that is a big job for one guy, but I know the drill. I do a lot of things myself too, and the key is to work slow and plan how you can leverage and manuver things around without using your back. I built an addition onto our house not too long ago, including virtually everything from running the backhoe, finishing the concrete, laying the block, virtually all carpentry, drywell, HVAC, electric, lights, finishing, and oh yes the shingles too. It's tough holding a 16' long 2X8 up in place with your left arm, but you only need to do it long enough to tag it with a nail gun and then it holds itself. I imagine you did much the same hauling all that iron out by yourself.

I moved some 427 motors around a while ago, unloading them from a box truck myself and getting them into the shop. I think you will smile when I tell you it was a half inch at a time. You know what I mean!

Anyway, congratulations on the accomplishment. That is a big step, you'll be in that bilge for awhile, and you can trace the wires if you need to. As you disconnect the other motor, you could tag em if you want, but quite honestly, it is not a complicated wiring harness to make a pair of motors run. Basic ignition and wiring for instruments, not too bad.

The photos above are from Dave and Lily Varnadore's project, MISS LILY. It's the photo of the day and I posted it because it is such a parallel with your boat, both are 1964 models too.

This is what his looked like during the haul out, and I suspect yours looks pretty much the same. It's a big job, but you should get some confidence knowing others have done it too. Keep the faith, and enjoy the journey. It's supposed to be fun along the way, and it's darn sure going to be fun when you're done.



What an inspriration!
February 24 2008 at 9:27 AM Jerry (no login)

Response to Pulled a 454 by yourself ??


Your message is just what I needed and the pictures look like they came right out of the Summer Palace! I do have a couple inches of water in mine but they are really similar. Pictures later in the day. I, took did the house thing. From 1700 sq. ft. to 3400. I am still doing little things on it. Whew, what a journey.

Both dogs are loose!
February 24 2008 at 7:14 PM Jerry (Login jerrycnamken)

Response to One big dog out of the pen.


It was beautiful on the Bay and the sun was shining bright today. Both engines are out and we will use a crane to lift them out sometime this week. I have a homebuilt trailer that will handle them and the genset and will pull it home next weekend. Everything went fairly well. one 2X4 broke and I replaced it with 3 others. More worisome is that the afterdeck is sagging where it is supposed to be glassed to the after hull, (I think). I cannot imagine why it would not be glassed together. There is a picture of it. It is an easy fix for later. Right now I can't get into the genset room and see what happened because the plywood is covering the hatches.

I sent Paul some photos of the rig I built. I took out the two sliding glass windows and let the 2X beam run through the helm deck. As soon as I had the engines high enough, I slid 2 sheets of 3/4 plywood underneath and put a piano mover under the engines. I can roll them out now so that the crane can snatch them out. It is a mess down in the engine room. Next will come pressure sprayering, vacumming and spray painting. What fun!

Here are Jerrys motor photos ! ( He's been busy folks ! )
February 24 2008 at 9:08 PM

Photos of Jerry's lifting structure
February 24 2008 at 9:12 PM Paul (no login)

Response to Here are Jerrys motor photos ! ( He's been busy folks ! )

Misc photos from Jerry ( Helm station, aft deck, engine bay )
February 24 2008 at 9:17 PM Paul (no login)

Response to Photos of Jerry's lifting structure

(Login jerrycnamken) Just bought the replacement engines! February 25 2008, 9:14 PM

Tom and all:
Thanks for the encouragement! Yes there was a strain on the 2X4s and one cracked during the first lift attempt. I replaced it with 3 others and the sag was negligible then. I am concerned about the sag in the after deck. Having 4 or 5 people standing back where the motor is now would result in much the same, albeit not quite as focused a weight. I will get that fixed in a hurry. This must just be a one off and not typical of most commanders.

I am not much of an electrician. I have several books and tried to read through them, but they put me right to sleep. Part of the problem will be to determine what is what, but maybe more importantly will be what to keep or discard. There are some items on the end of some of the wires that I have no idea what they do. Solinoids, sensors, senders, who knows, and I recognise that a lot has to be wired to two helm stations. But this is where the fun is! I just wished POs had organized and tagged a little different. I will try to improve on that. There is nothing as telling as well tacked up wiring.

Tom, you are right on with cleaning it up. I will enjoy getting the pressure sprayer down there and the shop vac as well. It will look so much better with a couple of coats of grey sprayed on there. All of this attention also has the effect of forcing me to trace out a lot of what is there. I can already see better ways to route the fuel lines, ground wires, etc.

The other big news tonight is that I took the advice and following a suggestion in the forum to look around for a couple of engines that are working found two Crusader 454s with transmissions and 1300 hrs., that are close enough I can go pick up with my trailer, for $2600 bucks. The owner ran them all of last season, but prefers going to diesel, so we both win. The trans are 2:1 velvet drives instead of 2.5:1. I wonder if that means I will have to change the pitch on the props? Here is another learning curve for me and I am not sure if the hp., prop pitch, and prop size is an art or a science. This gives me the option of taking some time to evaluate the ones coming out of the Summer Palace, and still get the boat running on the water this summer. The interior is not in bad shape. The cushions are getting done now. The only thing slowing me down is my day job! And it is still pretty cold to be down in the bilge pressure spraying. Sure enough too cold to paint. This may be a good time to haul her out and redo all the through hulls, rudders and prop bushings as soon as the fleet starts putting in and there is room for me to come out. That will start in about a month here.
Now I have to plan a trip to Yankee land and learn to speak with Neew Yawk accent and pick up the new hearts!

(no login) Re: Just bought the replacement engines! February 25 2008, 10:11 PM

Hi Jerry

Congrats on the new engines, that is the route I went with my 31. If you look at my thread(Commander for $2500) and pictures you can see the mess of wires from years of adding and removing equipment, I stripped out almost all of them! The only factory wires left are nav lights, wipers, fresh water pump, and 12v cabin lights. All 110v wiring is also gone, everything will be rewired through new breaker panels. let me know if you need any help figuring out how to go about rewiring. As far as the engines go you really need 2.5:1 reduction your best bet is to find someplace that services marine gears and they could probably change the reduction.


(no login) Re: Just bought the replacement engines! February 26 2008, 6:10 AM

Congratulations on the score. You can go over them in the shop a lot easier than you can in the boat. Check all fittings, replace filters, impellers, hoses, belts, whatever needs attention. Paint em up and they'll look new.

As for the transmissions, yes 2.5 is what the engineers thought was optimum. You can get a rough equivalent by downpitching the prop because it is going to be spinning faster with the 2.0. If you contact propellersonline and give them the data, tell them the boat weighs 22,000 pounds, give the power rating of the motors and transmission gear, and let them know the same boat came with a 23x25 (someone check me on this please) prop from the factory, then they should be able to select the replacement that will work without having to touch the transmissions.

On the downside I am wondering if the faster spinning and lower pitched props will have more slippage, meaning less speed and more fuel consumption. That would be a good question to ask the experts at


(no login) Resulting prop calculation for a 2.0 gear reduction set up February 26 2008, 7:35 AM

Interesting motor combination you got there.

I agree with the commenets about the 2x4s by the way!

I always like a math problem because it keeps me sharp. Someone please check me on this.

We have a lot of givens to compare as a baseline here, 40+ years later.

The 38 Commander used a 23x25 prop, 2.5:1 gear reduction, and obtained a speed of 32 mph with a 300 hp motor spinning at a max of 4000 rpm with about 15% slippage factor.

Now with a 2.0 gear reduction and the same max engine speed requirement, what prop will provide the same speed? My guess is a 3-blade 23X21, or perhaps a 23x19 or 20 in a 4-blade, and here is why.

Using the 3-blade as an assumption for the following: If the 2.0 gear reduction is actually spinning the prop at 2000 rpm at max engine speed, that 21 inch prop will cover 42,000 inches in a minute. Since 60 miles per hour is one mile per minute (or 63,360 inches per minute) you can do an equation that functions like 60 is to 63360 as X is to 42000. This is the equivalent of multiplying 42000 x 60 and dividing by 63360. The resulting number is mph without slippage facgtored in, which in this case is 39.72 mph and we all know that is not possible, and it has to be factored with a slippage number.

The original 38 Commander has a slippage factor of 14 to 15%. Its comparable unfactored speed number is 37.88 mph, but when you factor in the 15% slippage, resulting in an 85% efficiency rating, that real speed resultant is 32.19 mph. This has been verified in the water.
So now with the 21 prop pitch and 2.0 gear reduction, the 39.77 theoretical speed number must be reduced by a slippage factor. Since I dont think faster spinning props will match the bigger and slower turning props CC used, I think we need to use a 20% slippage (80% efficiency). This would take the theoretical 39.77 mph down to a realistic 31.81 mile per hour top speed.

So now in reality, the 454 motors are liable to be rated higher in power and rpm than the 427. We can use this for calculations but dont want to be running anything at max rpm. What is most important is how the motors, gears, and props work at mid range and three quarter throttle. Since the motors are basically equal to the 427 in overall power, tilt the table toward the 454 on power but probably not torque, we can call them just about equal. My guess for the day would be to try use a 23x21 prop to match the speed of the original boat. Moving to a 23x21.5 pitch moves the speed to 32.57 mph, in theory, assuming the motor is strong enough to maintain a 4000 rpm under the load, which I think it probably can. As noted, its more important how the rig works at mid and ¾ throttle. See what the guys at say!

All numbers above are for 3-blade props. It may well be possible to gain back the additional slippage of the 2.0:1 and smaller pitched props, by going to a 4-blade, in which case I think you would have to reduce pitch by another two inches. Thats another question for

Regards, Paul

(Login billinstuart) Basically agree February 26 2008, 8:44 AM

I basically agree with your calculations and assumptions,with one exception. A faster spinning prop does not necessarily have MORE fact, the reverse may occur. Here's why.

Let's carry this to the extreme..a prop slips 100% at very low rpms. However, the faster you spin it, the more efficient it becomes. As and example, I went from a 14x12 to a 14x10 with cup on my Blackfin with 1:1 final drive. My cruise/top speed increased, and my slip figures now run 10-15% consistently. The surface finish is VERY important to good prop performance, btw. Another approach is to figure prop tip velocity..anything over 175 mph. is borderline for cavitation inception. wow, 175 mph. I hear you say? Yep. That's why surface condition is important. That's also why many 4 blade props have a lower top speed even if the pitch is the same..blade FRICTION.

The stock marine 454 Chebby big block is not real happy at extended rpms over 3600 rpms. Weak stock valve train, cast pistons, etc. They usually produce peak torque at maybe 3200 rpms.

My feeling is..if you can get 4200-4400 rpms flat out, and cruise at 3000 rpms with the secondaries CLOSED you'll be pretty close to optimum.

so Paul, to help keep you sharp. please calculate pi to 250 places for me, will ya?

(no login) Re: Basically agree February 26 2008, 10:51 AM


Thanks for the note !

I'm going to pass on taking pi to 250 places, ha!

Part of my calculations are pure math, part represents a little history with the 38 hull, and part is my own experience with props and 427 motors. I have a lot of respect for CC engineering, and I would wonder why they chose the 2.5 and the 23x25 if 2.0 (and smaller props) would work better.

Therefore, we must assume they knew what they were doing, and I think that's a very safe assumption. You make some good points and I can't argue or take issue with them. My hunch is, I'll bet you can take a 454 setup with 2.0:1 gear reduction, and with the available selection of props at your disposal (including the 4-blade wild card) end up with a workable boat without too much of a sacrifice in speed or economy. If I were doing this for myself, I would not focus on top speed at all, but would work with someone like to find the best cruising speed for the conditions I anticipated encountering on the water in my boating area. In the end, I think it will work, and I'm real interested in hearing exactly how this turns out. Good data, eh?



(Login billinstuart) Agreed February 26 2008, 2:02 PM

I agree a good, workable solution can be found. Maybe part of the decision was rpm/vibration based. The old nemesis tip speed may be involved. In any case, the prop shops are still beating props into shape on the same dies they used decades ago. What worked then will certainly work now, and may be hard to improve on.

Shaft diameter also enters into the equation, as to torque and thrust limitations. Higher rpms, less torque, same thrust.

I also believe the characteristics between the 427 and the 454 are similar, with the 454 maybe a little bit stronger. Both engines are happy at 3000 rpms. and peak out at 4200 or so. Even with a big ol' square cam they aren't gonna make much high rpm power..the exhaust is simply too restrictive.

Personally, I plan on using a down angle transmission in my 31'. Won't help performance, but the engine oil/carb floats will at least sit level.

Photos of the old engines removed

Side pieces removed from helm station ( patterns )

They look like the V berth panels. I did that job a few years back. Did you remove the port holes? I removed my port holes and rebuilt and painted them. You need to be careful of the thickness of the replacemnt panel because of the way it fits around the port hole. If it is too thick it will prevent the port hole from sealing against the fiberglass. I used 1/8 inch marine ply with several coats of penetrating epoxy (to combat the rot around the port hole. I covered the panels with 1/4 inch foam backed vinyl hull liner.

(no login) I know those pieces! March 3 2008, 9:50 AM
You can see the step in the fiberglass where the panel sits and the 3/4 inch or so inner ring ends up flush with the panel so you can bed the inner ring and that should make a good seal with the frame of the porthole

Acid wash prior to awlgrip primer and fairing

pitting around the fittings

micro balloon fairing compound to make it look like new

Painted and installed

One more Paul, for the Helm shots. This is Elizabeth last summer.

Yes, they are the v-berth panels. March 3 2008, 10:56 AM
You are quite right, they are the V-berth panels. Paul inadvertenly referred to them as helm panels. Your advice to epoxy around the ports is noted and will be done. My ports are in extremly poor shape but not for long.

A question for you all. I noticed when I pulled the panels off that the running lights were there. The starboard side is toast. Have you gone to a newer, brighter set of nav lights or kept the originals and remade them? I would hate to put in all this work and then get run over by an old searay or worse!

(no login) Hit by Searay..... March 3 2008, 1:37 PM

If you are ever hit by a Searay, he will be in a lot more trouble than you will. Our old Chris Craft Commanders are built like tanks, Searays are not.

Nuff said,

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(no login) lights March 3 2008, 2:50 PM


My fixtures are original. The screw holes that hold the two halves together had to be drilled and re-tapped then heli-coil inserts installed. You can also find new plastic bulb holders with new contact leads that fit right into the housing. (Perko black plastic double contact bayonet socket)You should also be able to find new new red and green lenses around. If you need a link to those parts, let me know.



Last edited by FEfinaticP on April 8th, 2016, 4:15 am, edited 1 time in total.