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Need some engine help. 426

J

Jennifer1985

New member
Okay so I believe I have a 426 non-hemi Chrysler inboard. I need some help with identifying information based off the plate I have found on my engine.
Model - 426BWR10
Type - 626
Serial - 109573
Tag is hard to read but there is something that says "(Blank Space/Worn Off Plate) Number 6-21"
The head casting number is 2406516 - So I know that associates with a 361/383/413/426 from 1964-1967 with 2.08" Intake and 1.60" Exhaust

And then there was another set of numbers on the front of the engine and top of the engine:
Top - M 1 26 L
6 21 c

Front - S157M



Any and all help identifying this engine would be appreciated so I can begin to rebuild it. I also would need to know what outboard and transmission I can connect to this. My boat is currently setup as a shaft drive by the previous owner, but I would like to convert i back to a stern drive so I have shallower water capability. Thanks for all your help in advance.
 
Yes it is a 426, built in 1967 The big block Mopar was never offered with a stern drive, contact 510 Mopar on these forums as he modifies Mercruiser bell housings to bolt up to a Bravo drive. I am working on a way to hook one up to a Volvo Aquamatic drive for one of my projects. Also check with http://www.hurrikain.com/ for parts/info on your motor.
 
Better than I could have hoped for as I believed I had a 383 for a little while. I have heard these motors are highly sought after and worth quite a bit even in non-running condition... Is this true? Would it be worth it to just sell it and re-power with twin engines like the boat originally had or keep it, rebuild it and have the modified bravo I with it? How long would the modified Bravo I last? Thanks for the input!!!
 
Good morning everyone.

All the big blocks share the same bolt pattern, however it is different than their most commonly used pattern, the small block. Great thing was the distance from the face of the flywheel to the face of the block is the same as the small block Chrysler and the small and big block Chev. So all you have to do to put a BB Chrysler in a Mercruiser is take an original Mercruiser bellhousing, drill the big block pattern into it and weld the starter section into it. I built a jig many years ago that has the Chrysler drill guides in it. The housing bolts to the jig and then I run a drill bit through the drill guides. I cut the starter section from an old auto trans, bolt it to the jig, weld it up. Done. We even put a 426 HEMI into a 27 ft performance boat but it kept twisting the input shafts off the drives, even the best racing drives. Use a 130 tooth 318 flywheel as it has the same teeth as the auto torque converter. Use the original Chrysler front motor mounts and all the original Mercruiser housing mount hardware. I use my own custom manifolds from stainless steel as shown in the 440 mercruiser picture or the adapters I make and the aluminum Chev center risers as shown on the 383 engine picture.
If you are prepared to do this yourself its not hard, you just need a good shop.
The 440 in the picture is now a 1964 426 Stage 2 wedge. I did that conversion 14 years ago. I have a new HD Bravo in it now. Never have any problems.
 

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murfman said:
I am working on a way to hook one up to a Volvo Aquamatic drive for one of my projects.
Click to expand...



Murfman, if this Mopar Engine can be fitted with a Borg Warner "flywheel cover" ("bellhousing" in the Auto world) as shown here........


images


............. you can mate it to any AQ series stern drive.


The industry standard Borg Warner pattern flywheel cover lends itself to the B/W -slash- Volvo Penta PDS adapter housing, shown here in the standard version..........
images


...... and shown here in the Eaton, Donzi, Glastron, Holman Moody, etc 3-1/8" extended version.
images


This housing allows any Borg Warner capable Engine to mate up to an AQ series stern drive.
 
510mopar said:
Good morning everyone.

All the big blocks share the same bolt pattern, however it is different than their most commonly used pattern, the small block. Great thing was the distance from the face of the flywheel to the face of the block is the same as the small block Chrysler and the small and big block Chev. So all you have to do to put a BB Chrysler in a Mercruiser is take an original Mercruiser bellhousing, drill the big block pattern into it and weld the starter section into it. I built a jig many years ago that has the Chrysler drill guides in it. The housing bolts to the jig and then I run a drill bit through the drill guides. I cut the starter section from an old auto trans, bolt it to the jig, weld it up. Done. We even put a 426 HEMI into a 27 ft performance boat but it kept twisting the input shafts off the drives, even the best racing drives. Use a 130 tooth 318 flywheel as it has the same teeth as the auto torque converter. Use the original Chrysler front motor mounts and all the original Mercruiser housing mount hardware. I use my own custom manifolds from stainless steel as shown in the 440 mercruiser picture or the adapters I make and the aluminum Chev center risers as shown on the 383 engine picture.
If you are prepared to do this yourself its not hard, you just need a good shop.
The 440 in the picture is now a 1964 426 Stage 2 wedge. I did that conversion 14 years ago. I have a new HD Bravo in it now. Never have any problems.
Click to expand...

This is starting to sound like a lot of work and a very costly amount of work. Would you recommend that I just leave it as a Shaft Drive? I plan on beefing up the motor a little bit. I did read somewhere that the 426 had about 425HP in 1967 but only 350 in 1966. Can anyone break down those numbers a little farther for me? Also if I have a 426 that came stock with 350 or 425 HP, why would the valve covers have 290 decals on them indicating they only had 290HP? Is it possible someone just threw those valve covers on there and it was probably a mistake? Thanks for all the input guys.
 
Jennifer, the Marine Gasser Engine is not designed to provide the same type of horse power that the Automotive Engine is capable of producing. These engines are under constant load, and with NO coast time.
The Marine industry has a tendancy to exaggerate horse power numbers, and/or the RPM at which the engine's horse power has been rated.

Example: when the 5.7L Vortec SBC was introduced into the Marine world, the industry gave it a 315 horse power rating.
What many turned a blind eye to, was that the rating was taken @ 5,300 rpm!!!!!!

What you want is TORQUE at a relatively low RPM .......... not necessarily horse power.


FWIW..... if you plan to moor this boat, an I/B (shaft drive) will ward-off the corrosion issues much much better.


.
 
Can anyone break down those Engine Identification Codes for me or tell me where I can find the information? Any suggestions for beefing up the torque in this motor? And no the boat will not be moored. Around here on good old Lake Erie, the docking fees are like $400 - $2000 a month for this size boat. Not like the $200/month back in Florida. So for now, until I return to Florida, the boat will be on a trailer. Thanks again.
 
Let me ask you guys something... so the motor right now is mounted way far forward in the middle of the boat. It's literally next to the helm area. And the shaft drive goes all the way back to the back of the boat. Is there a way I can move the motor back to the back and have the shaft drive come out of the transom or move the engine back and have and shorter shaft drive?
 
Moving the engine would possibly change the ride characteristics of your boat,center of gravity.planing ability, Where's the fuel tank located? What type of boat are you running? Length?weight, width, Deepvee, Semivee. Model # and make?
 
The marine 426 wedge was a 290 HP engine. Honestly you would be better off finding a 440 block to build. It would be cheaper in the long run as there are very few choices for off the shelf Pistons for a 426 wedge engine. The difference in price between the Pistons will cover the purchase of a 440 block
 
RicardoMarine said:
Murfman, if this Mopar Engine can be fitted with a Borg Warner "flywheel cover" ("bellhousing" in the Auto world) as shown here........


images


............. you can mate it to any AQ series stern drive.


The industry standard Borg Warner pattern flywheel cover lends itself to the B/W -slash- Volvo Penta PDS adapter housing, shown here in the standard version..........
images


...... and shown here in the Eaton, Donzi, Glastron, Holman Moody, etc 3-1/8" extended version.
images


This housing allows any Borg Warner capable Engine to mate up to an AQ series stern drive.
Click to expand...


That at is exactly what I'm doing. I have access to a 440 to BW flywheel cover and already have a extended Glastron PDS housing along with a Glastron transom assy. and a 280 outdrive with the 1.61 ratio. This hodge podge of parts will be going in a 18' Donzi 2+3 barrel back hull
 
johnnygjr said:
Moving the engine would possibly change the ride characteristics of your boat,center of gravity.planing ability, Where's the fuel tank located? What type of boat are you running? Length?weight, width, Deepvee, Semivee. Model # and make?
Click to expand...

To answer thelse questions I'll say you may want to read the entire posting. I did put all of this information in there. The original setup was a twin engine stern drive boat. The previous owner converted it to a single engine shaft drive and placed the motor in the almost dead center of the boat from every direction. The 426 parts are not hard to find. They are interchangeable between the 383, 426, 440 and a few others for the most part. And it wasn't a 290 hp engine. According to a document published by chrysler, my engine had either 365hp or 425hp depending on the year. Mine as far as I can tell was a 1966 making it 365hp. That's plenty for my boat.

My boat although was originally a twin engine setup, it was offered in a single engine, but it was stern drive. If I keep the shaft drive in there now, I'd like to relocate the engine back to the rear engine compartment and just shorten the shaft and have it come out of the back of the transom.

Its a 1978 Formula Thunderbird 255 Liberator
Completely gutted as I'm doing a full restoration on it. So I can do whatever I want to here really. My main priority is getting the motor running and steering and water usable while I finish the restoration.
 
..........................

Jennifer1985 said:
To answer thelse questions I'll say you may want to read the entire posting. I did put all of this information in there.
Jennifer, these guys are offering you help and free help to boot. There is no need to develope an attitude with any of them.

In all honestly, the info below is what I believe that Johnny was asking for..... and it appears to be the first time posted.

You'll always get more bees with honey than you will with vinegar! :D

The original setup was a twin engine stern drive boat. The previous owner converted it to a single engine shaft drive and placed the motor in the almost dead center of the boat from every direction. The 426 parts are not hard to find. They are interchangeable between the 383, 426, 440 and a few others for the most part. And it wasn't a 290 hp engine. According to a document published by chrysler, my engine had either 365hp or 425hp depending on the year.
Mine as far as I can tell was a 1966 making it 365hp. That's plenty for my boat.
Are you looking at Chrysler Automotive info...... or Chrysler Marine Corp info?


My boat although was originally a twin engine setup, it was offered in a single engine, but it was stern drive. If I keep the shaft drive in there now, I'd like to relocate the engine back to the rear engine compartment and just shorten the shaft and have it come out of the back of the transom.



Its a 1978 Formula Thunderbird 255 Liberator
Completely gutted as I'm doing a full restoration on it. So I can do whatever I want to here really. My main priority is getting the motor running and steering and water usable while I finish the restoration.
Click to expand...
 
RicardoMarine said:
..........................
Click to expand...

Thanks for the reply and I apologize if I seemed to develop an attitude. I assure you I was not. Sorry again. Now I had posted that information before, but apparently it didn't save so I apologize for that as well. I was looking at chrysler marine information and even contacted someone who used to work for chrysler marine and they were able to verify that information for me. So I know that's accurate. But they only worked on the motors, so they don't know anything really about the dynamics and setup of the boat, especially one that a Chrysler engine was never offered in. So again, the original setup was rear mounted twin engines and I am working with a 100% clean slate. I am just wondering if it can be done or worth it to be done to move the engine back to the rear of the boat where the 2 engines were originally and still keep the shaft drive?
 
Do they make a v-drive that would fit and fill your needs? I have no real experience with any of this but I do have a nephew that has a v-drive transmission in his boat so that the inboard motor is to the rear, not centered. Although, I'm pretty sure you won't be able to have the shaft drive coming out the transom unless you get something like an Arneson Surface Drive.
 
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Jennifer1985 Sorry for the confusion here, I read threads numerous times before responding,and i read this one again before answering back. Ricardomarine Thanks for picking up on that,I was really confused after reading post#15. No blood No Foul, All Good!!
 
The 426 Marine engine with a single 4 barrel in the mid 60s was rated at 290 HP, the later 440s were up to 330 HP The highest rated marine big block chrysler wedge was the 440+6 "Mover" from 71-73 with 375 HP, and this motor had 10.5 to 1 compression requiring 100 octane fuel. the 365 HP was the automotive "Street Wedge" with a single 4 barrel and 10.25 to 1 compression offered from 1964-1965 the 425 HP was the "Max Wedge" Drag race engine with 2 4 bbl carbs on a cross ram intake and 12.5 to 1 compression. The Marine 426 was a 290 HP engine with a single 4 bbl and 8 to 1 compression. You do NOT have the3 365 or 426 HP engine. And while parts are available, off the shelf pistons for the 426 wedge are not available, requiring custom pistons to be spec'd and ordered, it is not difficult to get custom pistons, but it is pricey.


The only way to move the engine back is to either convert it to a stern drive, or V-Drive. there is no way to mount an inboard engine at the rear of the boat with a conventional shaft drive.

I know of your boat, it has been kicking around the Cleveland area for the last 2 or 3 years it was for sale for 500$ 2 years ago. That boat is a BIG project, and underpowered with a single 290 HP motor, the 255 Liberator is a tank and needs 500 HP to get 50-55 MPH out of it with sterndrives set up like it is, id expect 35 maybe 40 MPH if you are lucky, and I'd imagine handling will be sketchy with the weight balanced the way it is
 
Okay so according to that manual posted, the motor has from 290 to 325HP. I have seen videos of this boat on the water before it was stored 5 years ago with this engine doing 55 mph. The original engines were Single 260HP engines or a twin setup of 260HP engines, so I don't see how a single 260HP engine can move a boat at 55mph but a 290HP engine cannot. That doesn't make sense.

Now on the second note, you are correct in that the boat is a major project. But since I traded an Xbox 360 that I don't use anymore for it, I'm not too worried about it. And since I am doing all of the work myself, I am saving a ton of money. So I will probably end up without repowering, dropping $12,000 into the boat, but it'll look like new again and these boats are going for $30,000 in good condition and $45,000 in perfect condition. My plan though is to keep it for a while. Even re-powering it, I am looking at probably like $20,000 total with new engines.

So as of right now, I will probably keep the engine and just convert it back to stern drive. Maybe beef it up. With a head kit and supercharger and I can get easily 550HP out of it. Maybe I'll just take it and drop it into my truck and then put 2 new motors into it. Sounds good to me! I guess if I re-power, what would be the recommendation for re-powering? I would want to do twin engines...
 
Your Tag is 426B, the B meaning it is the 290 HP version. The Liberator with twin 260 HP Mercruiser stern drives would run 55 MPH, with a single 260 HP stern drive would run 35-40 MPH. An inboard with all that weight forward will A: keep more of the Hull in the water, and B: does not have the ability to trim the prop up to help the bat get on plane, out of the water. These will make the boat slower.
 
Then how did the guy I bought it off of get it to 55mph on the water with no issue the current way it is? It has trim tabs on the transom and the motor is in the center of the boat. It's 26' long and the motor is I'd say about 8' from the transom. So it's not even on center and it's not closer to the front than the rear.
 
Trim tabs will not add speed, they just help level the boat, or plant the bow for certain conditions. I'm just sharing what 35 years if boating has taught me. A Liberator 255 weighs about 5500-6000 Lbs, and has a 24 degree deadrise, it is a great rough water hull, but it takes over 500 HP to push it to 55 MPH. And that is with stern drives at the correct X dimension and properly spec'd props. a single 290 HP inboard will not do that, an inboard 330 HP 440 in a 19' Century Ski Fury tops out between 55 and 60 and weighs less than 1/2 of your Liberator.
 
From the above thread


Your boat needs a minimum of 500 horsepower or there abouts to perform adequately with a single engine. The Liberator is a heavy boat with a 24* deadrise deep vee hull that cuts through heavy seas like a hot knife through butter. It will make a good Great Lakes boat but with single engine power you will be miserable with a single small block.

Do you really think 30 more HP, more weight, and a less efficient drive system will move the boat well?I am a big fan of Chrysler engines, and of Formula boats, I have been aboard 3 different 255s over the years and they are wave crushers, but they are Horsepower and fuel hogs. With 800 HP they move along great and handle well with twin stern drives. I'm not trying to rain on your parade, just trying to help you from getting in over your head. Your best bet would be to repower the boat with twin 260-300 HP small blocks with either Mercruiser or Volvo drivesand go from there. Sell the 426 and don't look back.

Your boat will not be worth what you invest in it if you keep the inboard motor that is 11 years older than the hull and modified hull. That is another point, IIRC the last 3 feet or so of the hull has been modified, removing the "V" and adding a pad for the rudder and propshaft. Even if these mods were perfectly done by a competent glass guy, they will hurt resale value. There is a reason the boat sat as long as it did and didn't sell.

The best way to end up with a 50,000$ project boat is to spend 100,000$ on it, unfortunately there is more truth to this statement than any boat owner wants to acknowledge.
 
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Jennifer1985 said:
Then how did the guy I bought it off of get it to 55mph on the water with no issue the current way it is?
Click to expand...
He likely DID NOT!


I owned an older Thunderbird Formula 233 for several years....... 260 horse power w/ single prop I/O, so it was a bit under-powered.
But I agree..... these hulls cut through waves beautifully.

However, and as mentioned...... being a Deep V it does require more Torque to get any speed from them.



BTW..... Never take a PO (previous owner) at his/her word.
Even while trying to be truthful and/or accurate......., mistakes and exaggerations are commonly made!



.
 
Right I get mistakes can be made and lies can be told. But he showed me a video of him on the boat running the motor and then showing the speedo going from 0 to 52 I think was the top it hit. I will probably just Re-power since mercruisers are about $3000 each reconditioned through a website or $2000 a piece through a local guy with a shop that does nothing but rebuild engines. Selling the 426 though, would be difficult. Not many people are going to want to put a shaft drive engine into their boat, and trying to sell it as a car motor would mean it would need a lot of work and money and I don't know of anyone who would be interested in doing all of that. Anyone here interested? LOL. Anyways, I thank you for the advice and I guess I will just have to suck it up and get new engines.

I was thinking Mercruisers, but also Volvo Penta's and Fords. Any reason why I would go with one over the other?

And how much power would I need to get this boat up to the 70mph range?

Also, How hard would it be or how expensive would it be to take 2 5.7L V8 engines from like a Camaro and convert them into marine engines?

I know I can 600 to 700HP out of those pretty easy. Anyone ever thought about doing diesels in these since a boat needs torque and not HP?

Would it be worth my time to rebuild this engine and convert it to stern drive and get a second one to match it?

What do you think the MPG would be on this boat with twin 426's and the twin 5.7LV8's and the Mercruisers?

Thanks again for all your advice from everyone. I was in the Navy and know a lot about boats and I love the deep vee hull like you guys were saying. Almost half the reason I chose it. Also because I like the look and style of it. I know it's a heavy boat, but right now it's completely gutted and weighs like 3000lbs. Once I rebuild it'll be back up to like 5000lbs. And like I said, my plan isn't to sell this boat for many, many years. I listen to my spouse nag about it already, so the last thing I am gonna do is rebuild and sell for a loss or to break even. I would never hear the end of it. Right now though, my main concern is getting it water ready. So the plan is:
1. Get current motor running to enjoy until I can.......
2. Re-power the boat with new engines and stern drives
3. New Flooring
4. New Steering Wheel and Cables
5. New Interior
6. Seating
7. Kitchenette and Bathroom
8. New Covers
 
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To get 70 MPH, you will need at least 800 HP, something like 2 502 MPI Mercruisers with Bravo 1 drives. At 70 MPH, you will also need external hydraulic steering for safety. Even piecing things together, you should budget 20,000 to 30,000$ for engines, drives, props, and steering.

This is a good deal on the outdrives and transom assemblies, not mine, and I don't know the seller. But this would get you the pieces you need besides the motors and steering.

http://www.ebay.com/itm/mercruiser-...ash=item51e8ced91f:g:HfsAAOSwnQhXnmR-&vxp=mtr
 
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