'74 351 to '97 302

I have a 1974 volvo penta aq240 (Ford 351) mated to a 270 outdrive. I found a complete '97 vp 5.0Fi (Ford 302) that was mated to an SX. Compression isn't great on my old 351(some cylinders have 200psi, some have 140psi), and I'd like to put in the newer EFI engine instead. The motor mounts look to be in the same location. I've pulled my 351 twice since I've owned it so I understand how that goes down. Is it as simple as pulling the 351, swapping out the bell housings and drive shaft or will i run into some trouble with flywheels or bolt holes not lining up? Thanks.

Attached is an image of when we pulled the 351 for its rebuild. (Note: Strapping an engine hoist to the tailgate of your F250 is not recommended for engine removal... but sometimes there isn't another option.)




Hoping to use this 302:

Re: '74 351 to '97 302

Isn't a computer necessary to run the EFI?

Re: '74 351 to '97 302

Yep. The EFI engine is complete. I noticed this post: http://forums.iboats.com/showthread.php?378895-1995-Volvo-Penta-Swap-%28302-to-351w%29. From the images in Ricardo's post, I believe I simply remove the SX coupler and install the AQ coupler. I just wanted to double check this. I assume oil pan size with be less or the same on the 302, since I'm going smaller, I shouldn't have any clearance issues I think.

Re: '74 351 to '97 302

Yup just change bellhousing and coupler and throw her in....it will bolt in, but you must use the late 5.0 flywheel thats on it now

Re: '74 351 to '97 302

You may or may not have some fuel system issues, as in pressure or volume of delivery, and you will need a fuel injection fuel filter (tighter filter, smaller holes).

Re: '74 351 to '97 302

The 302 has the same paterns as the 351.
cr2k has a good one.. You must also use an electric high pressure fuel pump with regulator to feed the fuel rails.
Also a return line to the tank must be plummed as the pump would be a by-pass type, set at 40 psi for the 302 efi.
Dont forget to buy marine certified stuff!
Good luck

Re: '74 351 to '97 302

I can't help you with regard to your questions about mating compatibility, but it looks like they have been pretty well answered here for you, so I'd like to ask a favor.

Could you post some more photos of the 302? In particular, the areas around the distributor, throttle body and fuel pump (pumps?).

I'm a programmable EFI freak. Marine EFI Fords are quite rare and I'd like to have a look at how the OEM did things.

Re: '74 351 to '97 302

Sure. I'll get you some pics. And I probably will need your help at some point too. It looks like the computer on this Volvo 5.0Fi may be from an OMC or made by OMC. It's got Cobra listed on the side. I'll try to take some more detail pics, and then you can tell me what i got

Thanks. I'll have some pics up soon.

Re: '74 351 to '97 302

While I agree with all posted so far.
My main concern is that you have 200 lbs compression on the old motor.
I think you need a new gauge.
Also before you go loosing a ton of torque by swapping them, maybe you should look into a ring and valve job. If the motor is mechanicly good then why swap it. Just repair what you have and you will like it alot better.
We have quite a few 302 and 351 based race engines around and the 351 is by far a better one.

Re: '74 351 to '97 302

Yea I thought the gauge thing too. Mine does suck. Its one of the ones with the rubber where you just push it in and hold it. So I assumed guage, but I had it tested by a volvo reliable shop in my area to confirm. I've never seen anything like it, but I'm not too experienced. The disparity between the banks is odd. I tried to associate it with firing order or how I though the action was taking place to figure out a cause, but I'm unsure of a correlation. Plan a is for the 302 to be a good working engine and I just do a one for one swap. Plan b, it needs a little work. Plan C, it is a bad motor and I cannibalize the accessories and closed water cooling(worth it alone).

I am interested about what you are saying with the torque though. I've got a 4bbl 351 from 1974. Its basically just the original block with some jack leg cheap parts stuck in it before I got it. In my infancy to this boating game, I switched out things like those nice mallory valve covers for Edelbrock aluminum ones (which are now turning colors and ugly). It's got a performer intake on it now which I'm afraid will die from salt water before too long. Those exhaust are about 3 salt water seasons old and are "OSCO" brand. Anyways, I want to get this 302 ready as an insurance policy if nothing else. But could you help me determine the delta on HP/Torque. According to my shop manual my volvo should have started with 240hp but torque isn't listed. I'm would think that would degrade with age - but I could be wrong. I thought a 97' 5.0 would probably have around 260hp? Unsure of torque ratings on either. Insight?

Re: '74 351 to '97 302

Well I dont have numbers for the torque. And while the factory numbers may look better, you need to compare at what RPM they are making the power.
Apples to apples the 351 will make more torque and probably at a lower RPM than the 302, but most of that depends on the cam and other factors.
The 302 should do fine for you, if it were me, Id save the money converting the boat to EFI and just get intake and dist. to convert the motor to a carb. Then if you want to switch back it is not so hard. I did my old 35 F250, tool off the EFI and added a carb and non-elec dist. It ran better and got about twice the gas mileage. LOL

Re: '74 351 to '97 302

A few years ago I did a search for the 351 Windsor specs. Jack Chamberlain of J.A. Chamberlain in Longwood Fl. responded with the following numbers from a "Ford Power Products" sheet.

WSG-858M

fuel - 87 octane
gross horsepower - 236
gross torque - 343 lbs-ft @ 2900 rpm
type - V8
displacement - 5.8L (351 cu in)
bore - 101.6 mm (4 in)
stroke - 88.9 mm (3.5 in)
venturi - 4
compression ratio - 8.3:1
oil pan capacity - 5.7 L (6 qts)
weight 259 kg (569 lb)

There is a foot note that says:

"In this high mid-range configuration gross torque exceeds 340 lbs-ft in the 2300 to 3000 rpm range and exceed 320 lbs-ft even below 2000 rpm."

The horsepower curve looks quite linear from about 50 at 1500 rpm to about 210 at about 3200 rpm. Then there is a parabolic curve to maximum of 236 at 4200 rpm.

The torque curve looks like a fairly symmetrical arc from about 300 at 1500 rpm to peak of 343 at what looks like about 2750 rpm to 290 at about 4200 rpm.

I know very little about the marineized EFI Fords, but as I understand it Volvo/Penta and OMC teamed up for a few years to produce them with the 302s and 351Ws. The 351Ws are relatively rare. Perhaps someone else can give more details on this.

In any case you will want to run the ECM that came with the engine. If you don't have the original ECM then you should try and find a direct replacement for it. If this is not possible then programmable EFI is probably your only other option but unless you really know what you are doing I wouldn't recommend it.

Re: '74 351 to '97 302

Update: picked up the 302 tonight. Too dark to get many pictures. Boy is EFI a different beast than I'm used to dealing with. It came with a wiring diagram(thank god). The guy who I got it from pulled it from a boat and repowered with a newer chevy (he's a volvo employee so he gets good discounts I guess). It appears to be in good condition. Turns over freely. I'm going to run a compression test on it, but it looks like I may have to disassemble the headers to get to the spark plug holes to get my tester in there. A lot less room than under them than my 351 exhaust. Cam nut to turn over engine was a different size and spark plugs are a 5/8" instead of 13/16". All in all, i'm excited so far.

I'm suprised the water pump was a little different - in and out are on the back where mine is a straight shot inline. At least this one will be harder to install upside down . It has 2 electric fuel pumps and the 2nd pump is water cooled. The owner said volvo did this to prevent vapor lock. Instead of flexible hoses for fuel it actually has lines - nice.

So afterscompression tests and figuring out how to wire into the 10pin plug with some sort of adapter, is there any EFI things I should do like computer wise before hooking up fuel and water and trying to start it.

Also, i'll have those pics up when it gets light(and i get home from work and it doesn't snow) for you who were interested in the ford EFI.

Re: '74 351 to '97 302

Just post all the information you have. I'll try to help where I can and I expect others will as well.

Re: '74 351 to '97 302

Here is my wiring diagram:

5.0L/302 VP Ford EFI wiring diagram

Also, for those that are interested here are some pics of my boat over the years: boat pics

Re: '74 351 to '97 302

From my tracings, it looks like the number pinouts on the wiring harness go to the following. Need help on 5 and 10.
1 - solid black - ground
2 - grey - tach
3 - tan - water temp guage
4 - tan/black - warning alarms
5 - purple - goes to S side of starter relay - ideas? Is this necessary? Do I need to apply power here from something or can i leave it vacant?
6 - red/purple - power out from battery?
7 - yellow/red - switched ignition
8 - blue - oil pressure guage
9 - vacant - doesn't go anywhere - no pin
10- brown/white - from harness to trim sender - is this necessary? I don't have the SX outdrive in my boat and my AQ trim set up is isolated from the harness. Do I need to hot wire this or leave it vacant?

EDITED: Swapped 7 and 5

Re: '74 351 to '97 302

I would imagine that the 10-pin is the neutral safety switch to keep from starting the engine in gear.

Re: '74 351 to '97 302

So would I then apply no voltage, ground the pin or apply 12v to fake it?

Here are some pics of the 302 the sellers gave me.

VP 5.0Fi

Re: '74 351 to '97 302

updates:
hooked up starter relay and got the thing to turn over. Moved rather slow but I'm thinking my battery was weak... low 12v. Put it on the charger.

plugs out - look lean but nothing serious to find on them.

removed PS and alternator belt. The belt going to the raw water pump is only on the crank and raw water pump. The belt is trapped between the crank and engine water pump. WTF? I believe it should be routed around the crank, engine water pump and raw water pump so you can actually take it off. I'm thinking i'll just cut it. clearance between water pump and crank is less than the belt thickness.

engine water pump would not turn over. I thought it did yesterday, but I may not have noticed. it has no place to attach a socket to turn it over. Is the best plan to take off the water pump and investigate? Is this indicative of something more major other than blowing out the water passages and the fact that the engine may have overheated? I think its just frozen from lack of use and the crummy old belts couldn't get traction, but I don't know how hard it should be to spin by hand (it doesn't move).

Thoughts?

Re: '74 351 to '97 302

Thanks for posting the diagram and photos. Interesting stuff.

It is very difficult to identify the device numbers from the diagram but it looks to me like:
Pin 1 - Black = System ground
Pin 2 - Grey = Tach input
Pin 3 - Tan = Water temp gauge sender
Pin 4 - Tan/Black = OP/WT warning switches. This also goes to pin 24 of the EEC which is normally a power steering pump switch input. I have no idea what it is used for here, if at all.
Pin 5 - Purple = Key on power
Pin 6 - Red/Purple = System + 12v
Pin 7 - Yellow/Red = Starter solonoid
Pin 8 - Blue = Oil pressure gauge sender
Pin 9 - Not used
Pin 10 - Brown/White = ??? This wire just goes to an unidentified device at the bottom centre of the diagram. The Brown/White wire doesn't appear to go anywhere else and the only other wire from the device goes to ground. If it is a trim indicator sender, and I suspect that it is, I'd just leave it disconnected if you don't have it, or don't need it.

The engine water circulating pump should spin easily by hand, belts off. If it doesn't it should be checked out.

Hope this helps.