HELP PLEASE! PCM 5.8 351W GT-40 Short Block

[ColeNautique]

Hey guys,

I'm new to learning about motors but I have been having engine issues with my 2001 Air Nautique with the GT-40 motor.

According to my mechanic I'm going to need to either sleeve or machine one of my cylinders. My question is can anyone point me in the right direction to just buy a short block that will work with all of the PCM bolt ons and GT40 heads? I see 351W marine short blocks on eBay for a reasonable price but I'm wondering if the cam is different and what else is different. Anybody know of a refurbished or take off motor for sale?

The mechanic is recommending disassembly and sending the block to the machine shop but they're backed up so long that it would be all summer until my boat is running again. Anyone have any advice here? Its greatly appreciated if you do.

Just as an FYI below is the situation that has been going on with the boat.

-Bought boat with 300 hrs
-Noticed rough idle
-Found Burnt valve
-Fixed burnt valve and got a nasty ticking noise
-Began losing oil pressure under load
-Oil got black (probably from blow by)
-Took it to the boat mechanic and he thinks its one of pistons slapping the cylinder wall
-Now need help on what to do

[Peter6000]

Where,are you located?
I had mine rebuild some 8 years ago the mashing shop at that time in Miami had 3 of these blocks for sale completely assambbled and ready to go.
I haven't checked lately but I would think complete blocks are available the 351w was a quite common engine.
I would also do a leak down test on yours to prove the point and make sure the piston is really bad.

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[ColeNautique]

I am located in Riverside, California. So are you able to confirm for me that a regular 351W short block is the same as what is in the boat now? If that's the case I see them all over eBay for under $1000. I just need to know that there aren't any differences between the regular internals and whats in the Nautique GT-40's.

[gary s]

Marine engines have a greater piston to cylinder wall clearance and brass core plugs FYI. Jasper has a good reputation- something to look into. Peter are you talking Rapido in Miami?

[Peter6000]

I used Performance Engines Miami (Hialeah), out of curiosity is there a way to tell by the serial no or any other indication if it is a marine block?
Its some time ago but I ask the same question years back and got different answer, from only difference is the brass plugs to actually different (stronger) steal.
I was also told that valve timing and crank and cam are different and that is differently not true.
Do you know why the piston to wall clearance is bigger in marine engines?
Also makes me wounder if that is taken into consideration when drilling them up and how its accomplished (smaller piston / bigger drill)
I actually felt that some of the machine shop where giving me a sales speech that was one of the reasons I rebuild my own block.
Worked out well 500h later still no problems an I barefoot quit a bit.

[gary s]

With Fords there is really no such thing as a "marine" or even marine engines,they were per Ford's designation Industrial. Part number will give an indication -for example the lower intake of a GT40's part number is F2JE-9K461-BA. F is for decade of manufacture in this case the 90's. 2 is the year for 1992. J is Industrial,E is engineering office-in this case engine engineering. 9K461 is the part number and BA is for changes to original design, A being the first issue. Block number F4TE-6015- AA for instance is F again for decade,4 for year,T for light truck and E for engine engineering. A 351 F4TE block is the block that has taller lifter bores and the valley is tapped all to accept roller lifters and the lifter spider. Why they never used roller lifters in the industrial engines when the blocks were ready to accept them no one has been able to answer. As to piston clearance even though there is unlimited cooling water unlike a car or truck the engines are usually in a confined space with very little air circulation so they open the clearance so as when the pistons expand they don't "stick" known as scuffing. A good machine shop will bolt on torque plates which simulate the distortion of the heads being bolted to the block. and bore it just below the size they want. Then they hone it to the finished size and surface they want depending on what type of rings are used.

[ColeNautique]

Where,are you located?
I had mine rebuild some 8 years ago the mashing shop at that time in Miami had 3 of these blocks for sale completely assambbled and ready to go.
I haven't checked lately but I would think complete blocks are available the 351w was a quite common engine.
I would also do a leak down test on yours to prove the point and make sure the piston is really bad.

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Thanks for the info,

The mechanic did a compression test and says that #2 is low on compression. Do you think that I should also do a leakdown? I was thinking there was definitely a problem with the low oil pressure I've been experiencing.

[ColeNautique]

With Fords there is really no such thing as a "marine" or even marine engines,they were per Ford's designation Industrial. Part number will give an indication -for example the lower intake of a GT40's part number is F2JE-9K461-BA. F is for decade of manufacture in this case the 90's. 2 is the year for 1992. J is Industrial,E is engineering office-in this case engine engineering. 9K461 is the part number and BA is for changes to original design, A being the first issue. Block number F4TE-6015- AA for instance is F again for decade,4 for year,T for light truck and E for engine engineering. A 351 F4TE block is the block that has taller lifter bores and the valley is tapped all to accept roller lifters and the lifter spider. Why they never used roller lifters in the industrial engines when the blocks were ready to accept them no one has been able to answer. As to piston clearance even though there is unlimited cooling water unlike a car or truck the engines are usually in a confined space with very little air circulation so they open the clearance so as when the pistons expand they don't "stick" known as scuffing. A good machine shop will bolt on torque plates which simulate the distortion of the heads being bolted to the block. and bore it just below the size they want. Then they hone it to the finished size and surface they want depending on what type of rings are used.

Thanks for the info Gary,

Do you think buying something like this would work for me? https://www.wholesalemarine.com/ford...caAlx8EALw_wcB It says that its a marine engine and I assume that has to do with the tolerances you were talking about. If all else is the same any other questions I should be asking these guys before ordering something like this? Like I said I'm new to this whole motor thing but I am fairly mechanically inclined. Just need to know if there are any other differences to look out for.

[ColeNautique]

Also guys are these motors reverse rotation or standard? I'm seriously considering just getting a rebuilt 351W short block and doing the rest myself with a mechanic friend of mine.

[ColeNautique]

I'm looking into buying this short block as a replacement https://www.ebay.com/itm/MARINE-Ford...cAAOSwSrNZ7RWI. Can someone please verify for me whether or not this would work? The shop is saying that it should but I'd really appreciate if someone could verify for me on here.

[gary s]

I have heard thru the grapevine that ATK's are good. The questions I would have just to confirm are- Brass core plugs, 1 piece rear main seal, do they supply a plug for the dipstick since yours is in the pan. Their castings E4AE, E9AE, F0AE don't match, yours being on of the last F4TE's made- see what they say about that. Should not matter but if someone checks your block numbers in the future they will know it's not the original engine. Check with Summit and Jasper as well

[ColeNautique]

I have heard thru the grapevine that ATK's are good. The questions I would have just to confirm are- Brass core plugs, 1 piece rear main seal, do they supply a plug for the dipstick since yours is in the pan. Their castings E4AE, E9AE, F0AE don't match, yours being on of the last F4TE's made- see what they say about that. Should not matter but if someone checks your block numbers in the future they will know it's not the original engine. Check with Summit and Jasper as well

Thanks a lot gary!

[ColeNautique]

Well guys the saga continues, just got off of the phone with the mechanic and he said that after letting the engine heat up the compression was fine in cyl 2 and he thinks the bottom end might be ok. He said that there was almost no oil in the engine which means it must be burning oil at a very fast rate because I topped it off before running it last. He's trying to hunt down the source of a very noticeable and mechanical ticking noise thinking that is probably related. The engine is also idling very high. I'll be interested to see what he finds.

[Peter6000]

Well guys the saga continues, just got off of the phone with the mechanic and he said that after letting the engine heat up the compression was fine in cyl 2 and he thinks the bottom end might be ok. He said that there was almost no oil in the engine which means it must be burning oil at a very fast rate because I topped it off before running it last. He's trying to hunt down the source of a very noticeable and mechanical ticking noise thinking that is probably related. The engine is also idling very high. I'll be interested to see what he finds.

I would still do a leak down test it would tell you where the compression goes if low, you can tell by listening to intake exhaust and oil pan.
For example if you here the air in the intake you have a bad intake valve...
You could have a bent valve that just loosened up by running the engine.
It's a bit of a mess but you can run the engine without valve covers you can may determine where it's coming from.
Or pull the spark plug wires one by one and see if it makes a difference on a specific cylinder, don't get electrocuted.
The oil consumption is a bit strange if you have a bad piston or ring and oil gets burned that spark plug should be black.
If you buy a block I would send them all you engine numbers and pictures and let them tell that it fits. If something goes wrong you have at least some documentation.

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[gary s]

It is a standard (left hand) rotation engine, +1 on what Pete says a leak down will help. Say for example your rings are bad you would hear air out of say your oil cap,dip stick or pcv valve etc