302 marine conversion

[harleyman1975]

Re: 351 marine conversion

Re: 351 marine conversion

I have many 351 parts to marinize that truck engine in my shed perhaps I can be of some assistance.

 

[bajaunderground]

Re: 351 marine conversion

Re: 351 marine conversion

Kk,

My $.02

I don't want to smash any dreams or discourage anyone from pursuing their interest...but I must ask, what's your end goal? To have a slightly faster boat? Replace the engine? Or?

The reason I'm asking is looking strictly from a dollar and a brain damage standpoint, it'll be far easier to buy a long block 302 (complete with new intake manifold, heads, oil pan, valve covers, etc...) than to locate a 351w, convert what needs converting and then address new parts in the future. I get the feeling your knowledge base is not currently at par with what it takes to do the swap you're contemplating. I don't say that too be arse, but from a logical standpoint...302's are more common than a 351w (moot point), the swap would be a direct bolt-in, in the end it'll be closer to what came with the boat originally, so resale will be easier to consummate. In the end it'll be substantially more cost effective to replace/upgrade a 302. You could also upgrade cams, intake, carburetor for more performance?!

If you choose to do the swap, you've got the right guys on board, as they'll get you where you want to go. They can help you spend you money wisely or unwisely, whichever way you decide.

I went through the same process mentally and decided (for monetary, mental sanity and expediency) to just replace the 302 in my CC. I was able to re-use all the original marine parts (heads, intake, exhaust, belt, pulleys, pumps, covers, dipstick, etc...). There was very little brain damage (all the existing is still intact) and to the common man (or woman) the motor install is (and looks) factory. I can replace the exact part with one from the original motor.

Good Luck.

~Brett

P.S. the Ford 351/400M were junk...low torque and low HP...what a great combo for a heavy truck!!! Very few mods available...I had a 1978 Bronco with the 400M, ran reliably, but not exactly a stump puller.

 

[Kernallklink]

Re: 351 marine conversion

Re: 351 marine conversion

Kk,

My $.02

I don't want to smash any dreams or discourage anyone from pursuing their interest...but I must ask, what's your end goal? To have a slightly faster boat? Replace the engine? Or?

The reason I'm asking is looking strictly from a dollar and a brain damage standpoint, it'll be far easier to buy a long block 302 (complete with new intake manifold, heads, oil pan, valve covers, etc...) than to locate a 351w, convert what needs converting and then address new parts in the future. I get the feeling your knowledge base is not currently at par with what it takes to do the swap you're contemplating. I don't say that too be arse, but from a logical standpoint...302's are more common than a 351w (moot point), the swap would be a direct bolt-in, in the end it'll be closer to what came with the boat originally, so resale will be easier to consummate. In the end it'll be substantially more cost effective to replace/upgrade a 302. You could also upgrade cams, intake, carburetor for more performance?!

If you choose to do the swap, you've got the right guys on board, as they'll get you where you want to go. They can help you spend you money wisely or unwisely, whichever way you decide.

I went through the same process mentally and decided (for monetary, mental sanity and expediency) to just replace the 302 in my CC. I was able to re-use all the original marine parts (heads, intake, exhaust, belt, pulleys, pumps, covers, dipstick, etc...). There was very little brain damage (all the existing is still intact) and to the common man (or woman) the motor install is (and looks) factory. I can replace the exact part with one from the original motor.

Good Luck.

~Brett

P.S. the Ford 351/400M were junk...low torque and low HP...what a great combo for a heavy truck!!! Very few mods available...I had a 1978 Bronco with the 400M, ran reliably, but not exactly a stump puller.

Thanks for your input, I was actually starting to side with just doing a direct replacement with a 302, rather than the 351w. You can pretty much find a good used 302 around these parts for almost next to nothing, and the swap over should be easy. I've already got the exhaust manifolds on order, now just to find an f-150 to suit.

Btw... End goal is to enjoy time with the family on the lake, and be proud of the work that went into the boat.

 

[bajaunderground]

Re: 351 marine conversion

Re: 351 marine conversion

Thanks for your input, I was actually starting to side with just doing a direct replacement with a 302, rather than the 351w. You can pretty much find a good used 302 around these parts for almost next to nothing, and the swap over should be easy. I've already got the exhaust manifolds on order, now just to find an f-150 to suit.

Btw... End goal is to enjoy time with the family on the lake, and be proud of the work that went into the boat.

Then the 302 is the fastest path to that outcome! That's where I ultimately ended up!

 

[haulnazz15]

Re: 351 marine conversion

Re: 351 marine conversion

P.S. the Ford 351/400M were junk...low torque and low HP...what a great combo for a heavy truck!!! Very few mods available...I had a 1978 Bronco with the 400M, ran reliably, but not exactly a stump puller.

Well, it's not that they can't be stump pullers, but the mid-late 70's weren't kind to any engine. When you've got 454's and 460's putting out less than 200HP due to being forced into emissions controls, it makes for engines that don't perform well in stock form. However, the 351C (with it's 4V heads) and 400M can be made into pretty stout engines. The 351C (Boss 351) and others weren't designed to be "stump pullers", but would scream in the higher-RPM's with the high-compression and high-flow 4V heads.

That being said, I'd rather have a 351w in most applications, compared to a 302/351C(M)/400M. If I needed 400+ cu in output, I'm going to an FE (427/428) or 385-series (429/460) Ford.

 

[bajaunderground]

Re: 351 marine conversion

Re: 351 marine conversion

Well, it's not that they can't be stump pullers, but the mid-late 70's weren't kind to any engine. When you've got 454's and 460's putting out less than 200HP due to being forced into emissions controls, it makes for engines that don't perform well in stock form. However, the 351C (with it's 4V heads) and 400M can be made into pretty stout engines. The 351C (Boss 351) and others weren't designed to be "stump pullers", but would scream in the higher-RPM's with the high-compression and high-flow 4V heads.

That being said, I'd rather have a 351w in most applications, compared to a 302/351C(M)/400M. If I needed 400+ cu in output, I'm going to an FE (427/428) or 385-series (429/460) Ford.

The 70's we're kind to not only HP, but fashion too...Bell bottoms...need I say more? I guess in comparison to what's available for the 302'a, 351's for performance the 4351/400M's we're what they were...and yes the FE was awesome for building! Buddy had one on a replica-Cobra that was 650+HP...OMG what a fun car! 429's and 460's the ubiquitous Ford BB...again awesome!

 

[Kernallklink]

Re: 351 marine conversion

Re: 351 marine conversion

Next thing to ponder, i can get a good 302 out of a 1991 f-150. Apparently the f series trucks that had the 302 were still the flat tappet lifters, so my distributor, fuel pump, starter, exhaust manifolds, pullies, water pump, and oil pan should all swap over.

 

[haulnazz15]

Re: 351 marine conversion

Re: 351 marine conversion

Next thing to ponder, i can get a good 302 out of a 1991 f-150. Apparently the f series trucks that had the 302 were still the flat tappet lifters, so my distributor, fuel pump, starter, exhaust manifolds, pullies, water pump, and oil pan should all swap over.

It might have a different harmonic balancer weight, but that's an easy fix. The only thing to pay attention to is the spark plug firing order, as it probably uses the 351w firing order (better balance). The rear main seal would likely be different as well, but I don't know that it affects anything with the oil pan or not.

 

[bajaunderground]

Re: 351 marine conversion

Re: 351 marine conversion

A '91 truck 302 should be a good from a tappets stand point, but since you're gonna have the intake off, you might as well replace the them? They're like $2-3/each. I replaced all 16 in mine. You should be able to re-use the harmonic balancer off the existing marine 302?! The flywheel (at least on mine?) used the lightweight version, make sure that's the one you have...again, you can re-use your existing flywheel.

If my memory serves me the firing order for the '91 should be the same as yours? As a matter of fact, all the internals that I ordered were of the ~1995 302 vintage (somewhere around 1996 Ford went to the roller rockers?).

The firing order should be...1-3-7-2-6-5-4-8. If it were me and the existing marine cam is good, I'd replace the truck one with it. I know it means pulling the timing cover, oil pan (which needs to be pulled anyway), timing gears, etc..unless you can verify the lift/separation/duration of the new motor...you'll want them all pretty close?

~Brett

P.S. I forgot to ask, what was the original year and make of the marine motor that needs replacing? Model Number? If it's older than 1993 the firing order was 1-5-4-2-6-3-7-8. If it is the original the marine cam will not work with the truck motor crank/cam?

 

[Alwhite00]

Re: 351 marine conversion

Re: 351 marine conversion

Boy, us Chevy guys have it way too easy.


LK

 

[Kernallklink]

Re: 351 marine conversion

Re: 351 marine conversion

To give u guys some info, the mercruiser 888 engine that I have has 0 time on it. It is a fresh engine. The p.o. Decided to test run it in the driveway with muffs, and forgot to drain the block when finished. So the block, heads, intake manifold, and exhaust manifold are shot. Everything else is brand new, including the cam, tappers, pistons, etc. I found a 1991 f150 with a fresh rebuilt 302, but when the owner changed residence to a different province, here in Canada that requires a safety inspection of the vehicle before it can be insured. The truck failed due to a cracked frame, so now the owner wants it gone. $250 for a rebuilt 302 with 20,000kms in chassis. That engine is getting stripped to a long block, then going to change to marine grade gaskets (ebay), cam out of the 888, which is a 351w cam. This can be used, since it has been for the 302ho with 302 stock heads. Swap oil pans, timing covers, distributor, Might as well put in the newer tappets and rods since we are already there, 2 barrel cast iron intake (ebay), and the 2 barrel Rochester from the 888. Top it off with the exhaust manifolds from ebay and other peripherals, and rock and roll. I'll post all the pics I can, and possibly video so u guys can tag along. Should be fun to do!

 

[Kernallklink]

Re: 351 marine conversion

Re: 351 marine conversion

I should have the thread changed to "auto 302 to marine 302 conversion"

 

[Bondo]

Re: 351 marine conversion

Re: 351 marine conversion

I should have the thread changed to "auto 302 to marine 302 conversion"

Ayuh,... I'll take care of it for ya,....

 

[haulnazz15]

Re: 351 marine conversion

Re: 351 marine conversion

I should have the thread changed to "auto 302 to marine 302 conversion"

Sounds like you have it taken care of. I will add that if you need some odds-n-ends (exhaust manifolds, etc) shoot me a PM and I can help you out. I've got a spare Merc 233 (351w) sitting complete in the shop at the moment from a different project.

 

[bajaunderground]

Re: 351 marine conversion

Re: 351 marine conversion

To give u guys some info, the mercruiser 888 engine that I have has 0 time on it. It is a fresh engine. The p.o. Decided to test run it in the driveway with muffs, and forgot to drain the block when finished. So the block, heads, intake manifold, and exhaust manifold are shot. Everything else is brand new, including the cam, tappers, pistons, etc. I found a 1991 f150 with a fresh rebuilt 302, but when the owner changed residence to a different province, here in Canada that requires a safety inspection of the vehicle before it can be insured. The truck failed due to a cracked frame, so now the owner wants it gone. $250 for a rebuilt 302 with 20,000kms in chassis. That engine is getting stripped to a long block, then going to change to marine grade gaskets (ebay), cam out of the 888, which is a 351w cam. This can be used, since it has been for the 302ho with 302 stock heads. Swap oil pans, timing covers, distributor, Might as well put in the newer tappets and rods since we are already there, 2 barrel cast iron intake (ebay), and the 2 barrel Rochester from the 888. Top it off with the exhaust manifolds from ebay and other peripherals, and rock and roll. I'll post all the pics I can, and possibly video so u guys can tag along. Should be fun to do!

Sounds like a plan...looking forward to seeing the boat splashed!

 

[Kernallklink]

Re: 302 marine conversion

Well, got to tearing down the 888 engine today. I'm sure glad I bought a good engine stand. They are well worth the money. Took the engine right down to the core, and found no cracks visable to the naked eye, and no evidence of any water in any of the cylinders. All the domes on the heads look good, and the exhaust manifolds are not leaking internally. What dad and I think is that the intake manifold cracked (easily seen) on the thermostat housing, and that the intake manifold gasket failed, causing water to flow into the engine valley. In light of this, we are going to send the block to be magnafluxed and go from there.



Anyone for a milkshake?

 

[bajaunderground]

Re: 302 marine conversion

Well, got to tearing down the 888 engine today. I'm sure glad I bought a good engine stand. They are well worth the money. Took the engine right down to the core, and found no cracks visable to the naked eye, and no evidence of any water in any of the cylinders. All the domes on the heads look good, and the exhaust manifolds are not leaking internally. What dad and I think is that the intake manifold cracked (easily seen) on the thermostat housing, and that the intake manifold gasket failed, causing water to flow into the engine valley. In light of this, we are going to send the block to be magnafluxed and go from there.

That's good news! I wish you guys the best of luck. Hence why some of these guy are adamant about going through the proper procedures to determine what's wrong, rather than throwing money at things hoping it's what's wrong!!

Sounds like a weekend project now!

~Brett

 

[Kernallklink]

Re: 302 marine conversion

Anyone have any experience with speedpro Hypereutectic pistons?

 

[Bondo]

Re: 302 marine conversion

Anyone have any experience with speedpro Hypereutectic pistons?

Ayuh,... They're nice quality pistons,....

Hyper's are the way to go, over cast,...

No need for forged,...

 

[Kernallklink]

Re: 302 marine conversion

Thanks bondo, they are a helluva lot easier on the wallet than forged.