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twin mercruiser 351 CID (5.7) V drive 1.1 reversing ('82?)--maintenance, handling, docking etc. in Tollycraft

T

ttolly

New member
Hi Folks!

Are these reliable engines? There are about 700 hrs on them currently. How long might I expect them to last? I ran a single screw small diesel in my previous boat, and never a twin engine, so a few Q: are these high maintenance engines? Also, is it possible to motor gently and dock on a single engine to spread out usage hrs.? They are in a '30 Tollycraft Express cruiser, 11.6" beam. Also wondering if anyone knows these boats and how easy it is to remove gas tanks (a survey from 2022 noted some corrosion on tanks). Any tips for docking a twin engine?
 
If they are the Ford 351's, they are usually referred to as 5.8l (vs the chevy 350's which get the 5.7l label)...

Reliable, yes, if they are properly sized to the hull, well maintained, and not abused. Marine gasoline engines typically see a top end life of 1000 hours and the bottom ends should see 2000 hours...a leak-down test will give you detailed insight into the engines' condition.

Docking on one engine to save operating hours is not worth the effort in my opinion...

I'm surprise they don't have reduction gears (1.5:1) in a 30 foot hull...if the props allow rated (wide open throttle) RPM, they may be alright.

As far as docking tips, just use the gears and leave the throttles at idle....practice and you will be doing it well - much easier than docking a single screw. certain slip arrangements may need specialized approaches...

Never tried to pull the fuel tank from a Tollycraft...my suggestion is to give the tank area a thorough inspection and find the path of least effort (minimize what has to be removed/cut).
 
Thx! Yes--survey notes them as 351 CID Ford Mercrisers, so maybe the 5.7 was just the surveyors oversight... So how does the boat maneuver if just using the gears and no throttle to dock? And I guess I'd use one engine for forward movement and the other for reverse? Would be like starboard forward if docking on starboard side and port reverse, if heading in bow first, or VV? I have 0 experience with dual engines. Also I was wondering about cruising on just one engine so long as it is done gently? Props are 4 blade bronze, 14"
 
makomark said:
If they are the Ford 351's, they are usually referred to as 5.8l (vs the chevy 350's which get the 5.7l label)...

Reliable, yes, if they are properly sized to the hull, well maintained, and not abused. Marine gasoline engines typically see a top end life of 1000 hours and the bottom ends should see 2000 hours...a leak-down test will give you detailed insight into the engines' condition.

Docking on one engine to save operating hours is not worth the effort in my opinion...

I'm surprise they don't have reduction gears (1.5:1) in a 30 foot hull...if the props allow rated (wide open throttle) RPM, they may be alright.

As far as docking tips, just use the gears and leave the throttles at idle....practice and you will be doing it well - much easier than docking a single screw. certain slip arrangements may need specialized approaches...

Never tried to pull the fuel tank from a Tollycraft...my suggestion is to give the tank area a thorough inspection and find the path of least effort (minimize what has to be removed/cut).
Click to expand...
Thx! Yes--survey notes them as 351 CID Ford Mercrisers, so maybe the 5.7 was just the surveyors oversight... So how does the boat maneuver if just using the gears and no throttle to dock? And I guess I'd use one engine for forward movement and the other for reverse? Would be like starboard forward if docking on starboard side and port reverse, if heading in bow first, or VV? I have 0 experience with dual engines. Also I was wondering about cruising on just one engine so long as it is done gently? Props are 4 blade bronze, 14"
 
It should move fine....best to take it out away from the piers and other items and try it...every hull is unique in some aspects so there is always something to learn.

One in FWD and the other in REV will make the boat spin...and without the details, it just speculation...

Cruising on one engine...if done slowly, could be done, but the boat may or may not track straight...depends ....

Do you have a copy of Chapman's or the USPS training materials?

One dimension describing a prop only tells half the story...
 
makomark said:
It should move fine....best to take it out away from the piers and other items and try it...every hull is unique in some aspects so there is always something to learn.

One in FWD and the other in REV will make the boat spin...and without the details, it just speculation...

Cruising on one engine...if done slowly, could be done, but the boat may or may not track straight...depends ....

Do you have a copy of Chapman's or the USPS training materials?

One dimension describing a prop only tells half the story...
Click to expand...
K Thx again! I get it RE prop, I think--has to do with the blade shape/orientation? RE spin: I meant not having both in gear simultaneously, but using the starboard engine to maneuver the bow, and port to maneuver the stern, if that makes sense when docking bow in starboard side? the stern engine gear would be in neutral and I would use it to bring in the stern (and I guess would have to shift the starboard back to neutral first), which would be similar to shifting forward to reverse and so on with a single engine? Just trying to fig how to simulate single engine maneuver with twin, or VV. But then if necessary to halt forward or reverse momentum if necessary I'd have to bring in a bit of throttle, so I guess I'd to sift both to same position at that point, dep. on which motion, or at least have one in neutral? The USPS training manual covers handling a twin engine?
 
props are mostly described by pitch and diameter; blade count adds a bit more insight....inboards also need a shaft bore diameter.

As far as details, here's an initial suggestion: https://www.yachtsurvey.com/docking.htm The key takeaway, I think, is to practice (a lot if you want to get good).

When I took the USPS course, online and electronic copies didn't exist...you should be able to find a used copy of Chapmans, if you want it, online...
 
makomark said:
props are mostly described by pitch and diameter; blade count adds a bit more insight....inboards also need a shaft bore diameter.

As far as details, here's an initial suggestion: https://www.yachtsurvey.com/docking.htm The key takeaway, I think, is to practice (a lot if you want to get good).

When I took the USPS course, online and electronic copies didn't exist...you should be able to find a used copy of Chapmans, if you want it, online...
Click to expand...
Thx! That links was helpful. BTW--I'm wondering what additives I should consider for the gas. The boat has not actually left the dock in 3yrs. I believe it has been started, and I know it has been winterized (not sure what that means since it is in salt water and has an enclosed cooling system), but I'm thinking before running something should be added to the gas if that old? Does the fuel need to be polished, or will the right additives (sea foam? Stabil? something more/else) help? I've run old gas in my Honda generator never had a problem...
 
ttolly said:
Thx! That links was helpful. BTW--I'm wondering what additives I should consider for the gas. The boat has not actually left the dock in 3yrs. I believe it has been started, and I know it has been winterized (not sure what that means since it is in salt water and has an enclosed cooling system), but I'm thinking before running something should be added to the gas if that old? Does the fuel need to be polished, or will the right additives (sea foam? Stabil? something more/else) help? I've run old gas in my Honda generator never had a problem...
Click to expand...
Ayuh,..... Sample the gas, if it Smells like gas, it don't need any help,....
If it smells rotten, it is, 'n there's no fixing it,.....
 
If the gas is three years old, even if it was stabilized during the winterization process, its is likely degraded. there is no 'solution in a bottle' that will restore it. Diesel oil can be polished...

What you have for cooling sounds like a closed cooling system (aka fresh water cooling - FWC) and winterizing it usually involves draining the raw water side, at a minimum...the engine is usually 'fogged' and the gasoline treated with Stabil...
 
Just hazarding some guesses based on my experience with the 351/Vdrive scenario in my old Carver (RIP). There should be a Borg Warner Velvet Drive on the engine which has a Walter V drive attached to that. The V drive has its own oil supply and in some cases has a coolant hose that is tied to the engine cooling. The transmission too has its own oil. These guys need to be checked out several times per season. I dislike V drives as that puts the shaft stuffing box under the engine where it's about impossible to reach. If not then under the transmission which ain't much better.
Be sure the stuffing boxes get a good service every season whether you like it or not. If it means lifting the engines out, well, there you are. Run straight SAE 30 heavy duty oil in those and change it twice a year. They'll live almost forever.
Tollys are good boats.
Docking with twins is a fine art. Yes, you use one side ahead and one side astern depending on which way you want to swing. With the V drives you can use them as crash boxes since they're hydraulic drive, but be aware that the rest of the gear may not be so cooperative. My advice is to shift them at idle speed, then increase RPM. Your keyed props will thank you. If you're backing into a slip with both wind and current playing against you, you'll be a busy bee for a few minutes. Two eyes just aren't enough in those cases...
 
PS. If that yot has been at the slip for three years it really must come out and have the barnacles taken off and the running gear serviced. A good time to have a service come drain the tanks (your marina should have a list of providers). Check all the through-hull fittings and the rudder shafts. Sticker shock for bottom paint price incoming...
 
o2batsea said:
PS. If that yot has been at the slip for three years it really must come out and have the barnacles taken off and the running gear serviced. A good time to have a service come drain the tanks (your marina should have a list of providers). Check all the through-hull fittings and the rudder shafts. Sticker shock for bottom paint price incoming...
Click to expand...
Thx. The seller said she'd be sure boat is running/ going to speak to a mechanic who looked over boat later to see what's what... hopefully fuel was treated...draining tanks a pain $ I think. Actually, getting this in Canada--bottom paint reasonable g paying US. If I have it done here, it will cost me $3k.--third less there.
 
o2batsea said:
Just hazarding some guesses based on my experience with the 351/Vdrive scenario in my old Carver (RIP). There should be a Borg Warner Velvet Drive on the engine which has a Walter V drive attached to that. The V drive has its own oil supply and in some cases has a coolant hose that is tied to the engine cooling. The transmission too has its own oil. These guys need to be checked out several times per season. I dislike V drives as that puts the shaft stuffing box under the engine where it's about impossible to reach. If not then under the transmission which ain't much better.
Be sure the stuffing boxes get a good service every season whether you like it or not. If it means lifting the engines out, well, there you are. Run straight SAE 30 heavy duty oil in those and change it twice a year. They'll live almost forever.
Tollys are good boats.
Docking with twins is a fine art. Yes, you use one side ahead and one side astern depending on which way you want to swing. With the V drives you can use them as crash boxes since they're hydraulic drive, but be aware that the rest of the gear may not be so cooperative. My advice is to shift them at idle speed, then increase RPM. Your keyed props will thank you. If you're backing into a slip with both wind and current playing against you, you'll be a busy bee for a few minutes. Two eyes just aren't enough in those cases...
Click to expand...
Thx! Actually I see a pic of the stuff gland--appeared to be accessible. They are dripless...
 
ttolly said:
Thx! Actually I see a pic of the stuff gland--appeared to be accessible. They are dripless...
Click to expand...
o2batsea said:
Just hazarding some guesses based on my experience with the 351/Vdrive scenario in my old Carver (RIP). There should be a Borg Warner Velvet Drive on the engine which has a Walter V drive attached to that. The V drive has its own oil supply and in some cases has a coolant hose that is tied to the engine cooling. The transmission too has its own oil. These guys need to be checked out several times per season. I dislike V drives as that puts the shaft stuffing box under the engine where it's about impossible to reach. If not then under the transmission which ain't much better.
Be sure the stuffing boxes get a good service every season whether you like it or not. If it means lifting the engines out, well, there you are. Run straight SAE 30 heavy duty oil in those and change it twice a year. They'll live almost forever.
Tollys are good boats.
Docking with twins is a fine art. Yes, you use one side ahead and one side astern depending on which way you want to swing. With the V drives you can use them as crash boxes since they're hydraulic drive, but be aware that the rest of the gear may not be so cooperative. My advice is to shift them at idle speed, then increase RPM. Your keyed props will thank you. If you're backing into a slip with both wind and current playing against you, you'll be a busy bee for a few minutes. Two eyes just aren't enough in those cases...
Click to expand...
Any idea where the engine serial #s are on those engines? I need to prove pre-2010 to import...
 
Thx all! Actually, I decided on a Sundowner 30 trawler with a Yanmar 4PHM-TE engine, but a bit worried about parts? Also, the heat exchanger seems to function counter-intuitively (at least based on my previous Universal (Westerbeke), in which raw water flowed through the main body of the exchanger, and fresh through the core. I posted a thread about this elsewhere on the site, but a pics of the exchanger and t-stat here. I was worried for e.g. about being able to find those zincs (parts 8, 15--15 seems to be the raw water, and 8 the fresh--I think the T-stat mounts just after that, hence fresh); also can't tell from this how water enters/leaves the core. The lub oil cooler uses the same zincs--any idea why?
1742064528177.png

1742064762072.png
 
the exchanger appears to have a conventional layout based on my limited experience.

I don't think #8 is an anode where #15 is very likely one...as far as availability, get the part number and check with the local dealers or your favorite mail order house...I would not be surprised to learn of aftermarket sources for most maintenance items.

Part #6 appears to have hose nipples ... parts manuals aren't the best source of 'how things operate' - factory service manuals usually fill that void.
 
The sea water flows through the tubes inside the exchanger. It follows a path that goes in one end, makes a u turn and flows back out the same end it came in but through a different hose. You need zincs in the seawater side. The open system diagram below the upper diagram shows a thermostat in the seawater flow to regulate temp. Ignore this diagram if you have closed cooling, your thermostat is different and in a different location.
This chap explains it all pretty well:
 
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