1996 Four Winns Sundowner with 5.0 Cobra engine and drive

[Lou C]

When you slide down the rubber hoses on the exhaust Y pipe, you can tell if there were flappers originally installed because there will be 2 holes on either side of the upper end of the Y pipe. If these are filled with silicone sealer someone did the V/P service bulletin and removed them. If there are holes but no sealer and just the pins, there was an overheat and they melted off. Or someone could have just removed the whole works. If no holes then it may have been built after they stopped installing them, but I think that was in '99.

 

[Lou C]

I tend to agree, wouldn't expect the RTV to stand up to exhaust gas flow even if the exhaust is water cooled. But I can't be sure that the manifold or riser isn't cracked, I haven't seen a crack but that's hardly a thorough test. Been wondering if I could do a more thorough test by filling either the outer coolant channel or the interior exhaust channel with water and seeing if it leaks through the cast, test the manifold and riser separately.

I already bought a new exhaust manifold, it comes with gaskets, I could fit those gaskets whether I fit the new or old manifold but I think it makes more sense to fit the new one even if I convince myself that the old one isn't cracked. It's 1230 Tuesday morning here, the new manifold should be arriving today but I won't be fitting it today, need to fix the knock and compression issue first.

Will post pics of the mating faces tomorrow.



My big compressor broke years ago, didn't bother to fix it, bought it for spraying then only used it occasionally to run small pneumatic drills etc from. The only other compressors I have are 12V tyre inflators hehe, not sure if they'd put air into the cylinder quickly enough to build pressure if there's even a bit of ring blowby (and we'd expect there to be a bit of blowby) even if the valves are OK so it'd either prove no problem with rings or valves or if there is a problem it wouldn't tell me which was the problem?

Not sure whether I'd prefer a cam issue or a head issue. I'd prefer either rather than a bottom end issue...

Nearly forgot about the borescope pics, couldn't find the memory card reader so just bought another from Amazon that'll arrive today.

Out of interest how much would a known good 302W or 351W cost in the US? I phoned one of my LPG conversion customers today, he likes American vehicles, owns 3 x SRT8 vehicles including a Jeep he's added a supercharger to and a 90's Mustang. He might be able to put me in touch with someone selling a 302W or 351W in the UK.

If you were going to do an engine swap but keep the same drive and marine bits would you go with a 302W or 351W? Volvo Penta / OMC rate this spec 302 as only 190hp, rate the 351 at around 250hp.. I'd like the extra power ;-)

5.8L (351 ci) Ford Marine Engine

Michigan Motorz has the 5.8L (351 ci) Ford Marine Engine in stock. Ford 5.8L (351W) marine engine (one-piece rear main seal). This motor has been professionally remanufactured to meet or exceed OEM marine engine stock specifications. This 5.8L Ford engine

www.michiganmotorz.com

This with a nice Holley 650 CFM carb would wake that boat up.
Not sure what a Four Winns Sundowner weighs but I can tell you that my Four Winns 20' bow rider weighs in at 4200 lbs.
Mine has a 4.3 V6 which is just adequate, it should have had a 5.7.

 

[Lpgc]

Post pictures of these gasket faces,....

OK





The new manifold arrived today, supplied with gaskets. I expect the other side manifold (the other side doesn't seem to be getting water in engine cylinders) also won't have any gaskets fitted so today I ordered the same gasket set that was supplied with the new manifold so I can fit gaskets on the other side of the engine.



And the 'new' prop arrived, I fitted it just to make sure it fits, I forgot to take pictures. It's not really new but a reconditioned stainless 14.5 x 19 pitch 'Ballistic' brand stainless prop.

Didn't even take the cover off the boat today. Had some work to do in the morning. Thought about taking the cover off the boat and running some more tests etc but then I thought... I could remove the inlet manifold, check/remove the cam, remove heads all with the engine still in the boat... But I still might not find anything wrong with those components, the problem could still be rod knock so the engine might still need to come out and I might even find the block is cracked. I spent a lot of time today looking online for a replacement engine and phoning around. I could buy a rebuilt car/truck engine for £3k+ but I'd rather spend half that on a known good engine from a crashed car/truck, just that we don't see many good condition but not newly rebuilt Ford 302's / 351's for sale in the UK. it seems engine builders buy up what they can and rebuild them to sell as reconditioned. I spoke to my former customer today who owns a lot of American vehicles, he has a lot of contacts. He's going to phone some of his contacts for me tomorrow to ask if any of them have a 302 or 351 in good running order but not rebuilt that I could buy. If that doesn't work out I might buy a 1994 roller cam 351W engine that came out of a pickup that was 'written off' (insurance write off so the vehicle scrapped but the seller has the good engine) with 80000 miles for £1400. The 351W doesn't have an inlet manifold, obviously I'd need to buy one. It comes with the truck dizzy and I've learned my boat's dizzy won't fit. I've been told conflicting things about the oil pans 302 vs 351, some say they're interchangeable some say they're not, the 351W seller says the engine has an oil pan that isn't deep so should work in the boat. I've checked Ebay and the internet for a 351 2 barrel inlet manifold (so I could re-use my existing carb) and for a marine spec dizzy for the 351 but haven't found anything in the UK so far. Heh, a bit ironic because I could buy a performance aluminium intake, special carbs, supercharger upgrade, etc today!

Any thoughts about any problems I might run into fitting the truck 351 engine into my boat that currently has the 302? Things I'm wondering about are rear main (crank) seal differences (if there's a difference 2 part / 1 part seal will it matter), oil pan, someone mentioned oil pump drive? Inlet manifold is wider on the 351, dizzy is different (longer?) on 351, will my 2bbl Holley work OK with the 351? Maybe I've forgotten something...

5.8L (351 ci) Ford Marine Engine

Michigan Motorz has the 5.8L (351 ci) Ford Marine Engine in stock. Ford 5.8L (351W) marine engine (one-piece rear main seal). This motor has been professionally remanufactured to meet or exceed OEM marine engine stock specifications. This 5.8L Ford engine

www.michiganmotorz.com

This with a nice Holley 650 CFM carb would wake that boat up.
Not sure what a Four Winns Sundowner weighs but I can tell you that my Four Winns 20' bow rider weighs in at 4200 lbs.
Mine has a 4.3 V6 which is just adequate, it should have had a 5.7.

I'd love to but but the missus wouldn't be impressed hehe, by the time I'd bought the carb and paid import taxes it would be very expensive. I'd expect our boats (same make and close to same length) to be around the same weight. Might even expect my cuddy to weigh more than your bowrider(?) but I thought mine weighed closer to 3500 lbs than 4200 lbs.

I expect my engine in it's current condition makes less power than your 4.3. But I aim to put my engine back to close to what it should be, as said above might even upgrade to a 351 (5.8).

I understand the potential problems associated with the concept of 'reversion', exhaust valve remaining open into the induction stroke and potential for sucking water into cylinders... But I wouldn't expect many modern cams (even mild performance) to have such valve overlap? Surely we could make a few changes and increase the power of these engines without needing to worry about reversion? I wouldn't try to go over the top but surely 250hp from the 302 or 300 hp from the 351 is do-able without causing reversion, lack of torque at low rpms or less than smooth idle problems on these engines? I know someone who fitted a Nissan VQ35 in a boat, 3.5L and 240hp, I know it won't have as much low or midrange torque but it'll pull 6000rpm for long periods.

I'm now thinking a bit more about buying and fitting the £1400 351 engine. I'd change it's freeze plugs before fitting because some of them are impossible or difficult to change if the engine is fitted in the boat, I'd have to swap the water pump in from my marine 302 (in fact I need to ask will that fit the 302?) but I wouldn't rush to fit marine head gaskets (which I've ordered today), I'd use it on fresh water to prove it then fit marine head gaskets before using it on salt water.

 

[Lpgc]

I haven't had much to report until today, spent some time researching my options. I narrowly missed out on buying the 351 (mentioned in posts above) that was removed from a pickup, it was sold while I was still researching potential compatibility issues. Went to view a 302 that was rebuilt 5 years ago, the local owner bought it to put in his hot rod but never fitted it, almost standard spec but with lots of new chromed parts, tubular 4>1 headers, RPM intake, Edelbrock 4bbl, auto transmission. etc etc... none of which would work in the boat but which I could have sold on if bought with the engine, someone else bought the complete package for £3300.

I've decided my next step is going to be to lift the engine out of the boat... I'd need to lift it anyway to fit a different engine but I'll check the condition of this engine with a view to fixing it... I'm beginning to suspect a bent conrod on number 2 cylinder. Found out there's a good local engine builder who's well known for building good 302's and keeps all parts in stock.

Today I've removed the boat's rear seat backrest and wood dividing / battery area wall in prep for lifting the engine.

Removed the Cobra drive leg but made a mistake... I didn't disconnect the shifter cable from the leg before pulling the leg. I realised my mistake after trying to pull the leg back several times, it wouldn't pull off but didn't seem to be stuck on the splines. All the force of me trying to pull the leg back will have been pulling on the shift cable. I've noticed the outer part of the cable is secured to the upper part of the drive (the part that rocks up and down that the bellows attach to) by a clamp that's secured by a small bolt, maybe I've been lucky and the outer part of the cable has just pulled through that clamp(?)... in which case I'll be able to fix it by just slackening that clamp, push the cable forward in the clamp, retighten the clamp.





I watched a couple of Youtube videos of people pulling Cobra legs, on their legs they didn't need to disconnect the shifter cable because the shifting worked by the cable rocking an arm near the exhaust. On my Cobra drive the shift cable connects to the leg directly. Found out the hard way that the shift cable should be disconnected first! I should've removed the plastic cover from the drive (3 bolts), behind that cover the shift cable connects to a shaft similarly to a throttle cable. There's nothing broken on the leg, the shift mechanism seems OK but I don't know if there'll be a problem with the shift cable after pulling on it. Seems my shift cable doesn't attach to a bracket on the engine or in the engine bay, can't see it attached to anything inside the boat so I'm guessing it runs straight to the controls, in which case there's nothing to adjust for the shifter inside unless there's some adjuster right at the controls?

 

[Lou C]

This is one of the differences between the original all OMC Cobra (1986-1993) and the joint venture with Volvo OMC Cobra (1994-1994). The original is placed in Neutral to pull the drive and then it just slides off because the shifter is in the pivot housing. On the joint venture Cobra which is exactly the same as a Volvo SX you must disconnect the shift cable.
Figure on replacing your driveshaft bellows if that is water in there. If it is gear oil then figure on replacing the input shaft seal.
For any engine you put in that boat, make sure that the camshaft used, is appropriate for marine use, you do not want any kind of hot rod cam with a lot of overlap, it will suck water up the exhaust (known as exhaust reversion) and put you back in a world of trouble with hydrolock.
That said your transom mount, trim rams and drive look pretty good with minimal corrosion.

 

[Lpgc]

This is one of the differences between the original all OMC Cobra (1986-1993) and the joint venture with Volvo OMC Cobra (1994-1994). The original is placed in Neutral to pull the drive and then it just slides off because the shifter is in the pivot housing. On the joint venture Cobra which is exactly the same as a Volvo SX you must disconnect the shift cable.
Figure on replacing your driveshaft bellows if that is water in there. If it is gear oil then figure on replacing the input shaft seal.
For any engine you put in that boat, make sure that the camshaft used, is appropriate for marine use, you do not want any kind of hot rod cam with a lot of overlap, it will suck water up the exhaust (known as exhaust reversion) and put you back in a world of trouble with hydrolock.
That said your transom mount, trim rams and drive look pretty good with minimal corrosion.

Thanks Lou.

Do you think I'll have damaged the shift cable? I don't know how far it's supposed to stick out at the back, or if the cable seems stretched? Is there an adjuster at the controls?

The universal joints and splines seem in great condition.

It's oil inside the driveshaft bellow. Thanks, I'll see if I can source an input shaft seal.

Is it worth changing the gimbal bearing while the leg is off? How do I know/check it's condition?

The engine the hotrod guy was selling was supposedly built to just standard spec. I would've known to make sure it didn't have a long duration cam before fitting it in the boat but thanks for the tip all the same... As said before I'd rather be told things I might already know than nothing be said and make expensive mistakes! ;-)

Edit - I don't know if this link will work for you, it's a link to the hot rod engine that's been sold. https://www.ebay.co.uk/itm/Ford-V8-Small-Block-302-Engine-AOD-Automatic-Gearbox-/334918218194?hash=item4dfaae71d2:g:dqwAAOSwSRRkkFbf&amdata=enc:AQAIAAAA0EbdjMonUvxvgsFXbakyoE2xuSmYdaA867qLbw0FnnjZKemkSIU1YRzQhLQLumNcaBi+q3YT+6gmfeqUXgBkWSlu2rLsLHVunLF0HWvmBJ30TlkCe8DWz7VKWNhSryDudWwOxfd9MBf3XqjmsXnJ7d1V2+LTLc/LL5Xw3ZTVIs5qG93Q8wFurB06S8OEmCrn8mO1INaakGUV4SsfNfJDmPolY41aOul3nVgQKOYe4stJWbaUpapA2QE82bRUNYG4WZmdjY/6AYZZo7NfMieWnSU=|tkp:Bk9SR8jM6LegYg&nma=true&si=27o%2BKxgJFewO5zabE0gu3X008%2Fg%3D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557 . The seller had 2 x late 40's or early 50's F100's .

 

[Lpgc]

I measured the length of shift cable protruding from the rear of the pivot mating flange, measured the distance from drive leg internal shift arm to drive leg mating flange to the pivot, the two lengths are equal.. so it seems I haven't damaged the shift cable by pulling on it.

Had an idea about lifting the engine... I've got a fold-up engine crane, it's lifting arm seems long enough to reach from the rear of the boat to central above the engine but it won't be tall enough. I can make it tall enough by cutting it's vertical beam near the bottom (below the point where the 8 ton hydraulic ram attaches) and weld in a metre section of box steel (70mm box to match the existing vertical section). Yesterday I phoned a local steel stockist, they could deliver just about any shape/size/thickness steel I wanted, I've had them deliver 6m lengths of angle and flat bar here before but I didn't need 6m of 70mm box section and they charge for cutting. They suggested I visit them and look around their offcuts area as it would work out cheaper to buy offcuts and collect than to have them process a small order. I visited, they had some 70mm box section offcuts but only light gauge, I didn't know how thick the steel would be in the crane mast so it seemed a good idea to buy relatively heavy gauge. I came away with a 2 metre length of 70mm x 70mm x 6mm angle plus various other pieces of angle and flat bar. Back home I cut the 2 metre length of angle in half and welded the 2 halves together to make a 1 metre length of 70 x 70 x 6 box section. I'll use some of the other steel I bought to increase the strength of the crane's rear mast brace. When I've extended the crane height I'll assess how stable it seems to be and maybe increase the width/length of the legs or add some extra bracing to make sure it doesn't fall over...

 

[Lpgc]

I've been making a few modifications to my portable engine crane so I'll be able to use it (it'll have enough lifting height and stability) to lift the engine from the boat...



Increased the height of the mast using some 70mm x 6mm angle that I welded together to form a box section (found out after cutting that the original 70mm mast was only 3mm thick anyway). Added a second box section 70mm x 3mm mast that extends almost to the top of the lengthened original mast, fitted longer angle steel side braces to replace the shorter flat bar side braces. Welded some box section across the width of the front legs and a section extending forward from the middle of that box section - will enable 'slotting on' some wider and longer box section over those short sections to extend the length and width of the base of support with some wood chocks below the extended box section... In the pic I've only attached some box section at the front, I'll need to buy some extra similar box section to slot on at the sides.

 

[Lpgc]

Got the engine out





The crane height extension and help from one of my long time customers who's become a friend (and has been into boating himself for years) made lifting easy.

The engine is currently on a stand in my garage, haven't even drained it's oil yet, seemed easier to drain the oil with the engine on the stand than in the boat. Didn't need to break into the pas lines as they were routed over the top of the engine, so after disconnecting the pas pump I could just move the pump and pipes out of the way. Did drain the pas pump reservoir just to prevent pas fluid leakage in the boat in case the pump falls on it's side.

 

[Lou C]

Great work!
while you got the engine out, if there is any question about the condition of the power steering actuator, replace it! They are a bear to get at when the engine is in place. I had to remove the rear seats and both exhaust manifolds to do that job.

 

[Lpgc]

Thanks @Lou C .

The PAS seemed to work well and the reservoir remained full over the 4 days I used the boat but there was some play in the steering.. If say I turned the wheel left then turned it right (or vice/versa) I could feel maybe 20 degrees of play in the steering. Not really a problem to use but does the play point to an issue with the actuator? On other boats I've had (outboards with Teleflex steering) the steering was tight (no play).

There was an issue with the leg dropping after I'd lifted it on the hydraulics. The rams look in good condition and I don't see any leaks on them, does this mean there'll be a problem with the hydraulic trim pump?

 

[Lpgc]

Drained the oil.
Unusual dipstick combined with drain plug setup... unless that's normal for a boat inboard?
Around half a pint of water came out first but I think that'll just be due to rainwater entering through a removed rocker cover. I had the boat road cover on but it's not great and water runs down it's inside then drips over the engine (or at least it does when I don't attach the support pole).





Got the engine upside down on the stand and removed the sump (oil pan). So far I've only had a quick look, didn't see any obviously bent rods.
Hand cranked the engine, seems a bit of slap in the thrust directions on a couple of pistons when at BDC. Not sure yet if I've detected some play in a big end (rod) bearing on number 5.
Light scoring on some of the pistons and bores.



Some of the core (freeze) plugs seem to be rusting so are probably not marine spec.



Some yellow writing behind this cylinder head... I'd bet this points to the head being bought from a scrapyard or even the full engine. Where are the casting numbers on Ford heads? I've seen a few numbers in the valve springs areas but forgot to take a pic or write the numbers down.

 

[kenny nunez]

OMC was the first with the dipstick/oil withdraw tube. If the core plugs are plain steel then your assumption is probably right about the engine was in a salvage yard in the past.
Nice job on the engine hoist.

 

[flashback]

Yes the core plugs look to be a little rusty..

 

[Lpgc]

When I last made enquires about buying another engine or having my engine rebuilt lots of people advised me to contact this local firm http://www.engine-data.co.uk/engines.html so I called them, they seemed very knowledgeable and helpful. Their website doesn't seem to be working properly at the moment but the link above will give a good idea of what they're about.

I had another chat with them today, they said it'd probably be cheaper to buy a crate engine than to have them rebuild mine. I said I'd be happy if mine wasn't fully rebuilt but any issues with it fixed. They said they'd give it a basic internal inspection for £60 if I took it through to them in a van or trailer. Then they said that since I'm local they'd save me the bother of taking the engine to them, will come out to me on Monday. I'm pleased at that, I think it's going to be well worth the £60 to have people who really know what they're doing building this specific model of engine take a look and tell me what's wrong with it. They asked me to remove the heads before they come, so that's my next job.

 

[ScottinAZ]

When I last made enquires about buying another engine or having my engine rebuilt lots of people advised me to contact this local firm http://www.engine-data.co.uk/engines.html so I called them, they seemed very knowledgeable and helpful. Their website doesn't seem to be working properly at the moment but the link above will give a good idea of what they're about.

I had another chat with them today, they said it'd probably be cheaper to buy a crate engine than to have them rebuild mine. I said I'd be happy if mine wasn't fully rebuilt but any issues with it fixed. They said they'd give it a basic internal inspection for £60 if I took it through to them in a van or trailer. Then they said that since I'm local they'd save me the bother of taking the engine to them, will come out to me on Monday. I'm pleased at that, I think it's going to be well worth the £60 to have people who really know what they're doing building this specific model of engine take a look and tell me what's wrong with it. They asked me to remove the heads before they come, so that's my next job.

60 pounds to get the engine professionally checked is to me, at least a bargain. At least then you know what you are working with, and arent playing the "what if" game.

 

[Lpgc]

Got the heads off.



I still think there's a problem with number 2 cylinder, scuff marks in the bore and I might have seen a broken top ring unless I've just seen the ring gap.





Block casting number...points to 1991



Underside of heads and head casting numbers pointing to 1993






Not sure if the head casting numbers point to 351 heads(?). I know some of the marine 302 Fords used 351 heads. Read they flow better but I don't know if they lower compression?

Would GT40 heads or standard but gas-flowed heads flow better?

 

[ScottinAZ]

that engine has been around the block at least 2x at this point. Your pistons are .040 oversized, and who knows if the crank has been ground. If it needs a refresh, you may well be better off with another motor. I dont know what max oversize for the 302 is, but i think .060 is about all you can do with them, and that will be dependent on bore condition.

 

[Lpgc]

that engine has been around the block at least 2x at this point. Your pistons are .040 oversized, and who knows if the crank has been ground. If it needs a refresh, you may well be better off with another motor. I dont know what max oversize for the 302 is, but i think .060 is about all you can do with them, and that will be dependent on bore condition.

Thanks, yes I too noticed the +.040 pistons and it still looks to me like there's too much piston to bore clearance, we're thinking along the same lines but it'll still be worth having the engine guy take a look on Monday.

I'll be fixing this engine or buying another but either way there'll be some rebuilding to do, it's unlikely I'll be able to get hold of another marine spec engine at reasonable cost so if I get another I'll need to take the heads off to fit marine head gaskets and fit my carb/inlet/dizzy/wp/cam/etc. Since I'll have it in pieces anyway It'd be just as easy to change the heads for a bit more power or maybe the engine firm could flow my existing heads. Maybe I'll have a go at flowing the heads myself, I don't have a flow bench but I once flowed a head following instructions from a David Vizard book lol.

Can anyone tell me what spec my existing heads are (F3JECA).. 302/351 etc?

 

[Lpgc]

The engine expert has been, he spent some time looking at the engine and talking me through what he was doing but we didn't strip it fully down. His initial thoughts were that the engine has obviously been rebuilt, the builder seems to have known what they were doing and took care building it, it generally seems in great condition and hasn't been run much since being rebuilt.

He checked end float of the crank and big ends which were all fine. At one point he suspected that a conrod little end was loose on the gudgeon pin but that turned out just to be the normal movement of the pin in the piston. The cam and followers looked new. No play in the big end bearings when we turned the crank to the start of downstrokes and tried to press down on the pistons.

I pointed out the scoring on the bore of cylinder2, we removed the piston, the skirt looks worn and heat damaged, he said that could be due to a tight spot on the cylinder wall. He removed the piston rings and demonstrated that they don't spring back into position like they should and that would also be due to heat damage. He said these issues with #2 would be the cause of the knock and low compression. He said he missed the scoring on bore #2 because the piston was in the wrong position (covering the scoring) for him to see it when he was looking at the bores from the head side, which didn't fill me with confidence in him, but he seemed to know what he was doing with the other checks and I believe he's correct about the damaged piston and rings on #2 causing the knock.

If I were to second guess part of what he said I might guess that the problems with #2 were caused by a lack of lubrication due to water (from failed marine manifold) washing the oil film instead of a tight spot in the cylinder but that won't affect what needs to be done to fix it...

Either way cyl2 piston and rings need replacing, I should get him to check the bores and re-hone at least cyl2, should also remove the other pistons and check them (skirts, rings and bearings).

This engine might turn out to be an easier fix than I expected.