Ford 302 engine oil dipstick - 1995 OMC Cobra, Ford 302, VolvoSX

[Horigan]

I may put what the manual says and monitor oil pressure to ensure I’m not getting oil aeration. It’s been running fine for years with my current approach.

 

[Lou C]

On the GM engines the automotive location for the dipstick was on the starboard side of the block and when these systems for the tube that connects to the pan are used the hole for the dipstick is filled with a rubber plug. On then it’s possible to add an automotive style dipstick; not sure if you could do that with the Ford engines…..

 

[Lpgc]

On the GM engines the automotive location for the dipstick was on the starboard side of the block and when these systems for the tube that connects to the pan are used the hole for the dipstick is filled with a rubber plug. On then it’s possible to add an automotive style dipstick; not sure if you could do that with the Ford engines…..

Thanks Lou, Since realising the dimples on my stick are where oil level should come to if I put in the quantity that's correct according to the manual I'm happy just filling to the dimples. As you know, the engine is relatively newly rebuilt, it doesn't seem to use or lose any oil between changes anyway.

The thing that got me wondering again about oil levels is when I first used the boat on the sea a month ago, up until then I'd only used it on a river and lake. I launched into calm water in a tidal estuary and let the engine run a few minutes to warm up and check gauges etc before heading out to sea. Heading out to sea there was some chop at the mouth of the estuary, hit a wave at around the same time I was putting power on causing the bow to rise up probably higher than it's risen on the river or lakes. I was watching the oil pressure gauge when the bow came up, pressure dropped to zero then immediately up to way high, bounced like this very quickly just a couple of times... This was a bit alarming in the dangerous stretch of fast flowing choppy water, I very quickly throttled down but I think oil pressure was back to normal even before I'd throttled down. The oil pressure reading stayed around normal the rest of the time, it never bounced like that again but did seem a bit low after first slowing down after half an hour on the plane. All this got me thinking again about how much oil the book says it should take and how I'd put in less than that to not go far above the safe area on the stick. After that trip on the sea I pumped out the straight 4 or 4.5 quarts of straight 30 oil, changed the filter and refilled with 6 quarts of 20/50. Only been on the river since but oil pressure seems a bit higher all the time now, even on returning to idle after being on the plane, and I suspect if I'd had the 6 quarts of 20/50 in it at the time the bow came up in the estuary oil pressure would've remained normal then too. I think the engine didn't get oil for a split second due to the smaller quantity sloshing away from the oil pickup tube when the bow came up.

 

[kd4pbs]

Higher oil pressure is also likely due to the heavier weight oil. I see ~ 15PSI more pressure at idle after a hard run with 10W40 synthetic than I did with SAE30 conventional break in oil.

 

[Lpgc]

Higher oil pressure is also likely due to the heavier weight oil. I see ~ 15PSI more pressure at idle after a hard run with 10W40 synthetic than I did with SAE30 conventional break in oil.

I agree, I ran it with 20/50 last year and oil pressure after a hard run was higher than with the straight 30, even when I only had 4 / 4.5 quarts in it in both cases. But with more of the 20/50 in pressure seems to stay higher after a hard run than it did with the smaller amount of 20/50 last year. No doubt in my mind my oil pressure stays higher after a hard run with 4.5 quarts of 20/50 in it than with 4.5 quarts of straight 30 in it but I think it stays even higher with 6 quarts of 20/50 in it. Maybe the extra oil keeps the oil a bit cooler?

 

[Lpgc]

10W40 synthetic

Is that fully or semi synthetic?

I think I used to see a much wider range of oils than seem to be available now. These days it seems most stuff is 0/30, 5/30 synthetic, even some 10/40 semi is labelled as 'classic', then there's the really old stuff like 20/50 mineral and straight 30 or 40. Think I used to see a wider range including 10/40 synthetic.

 

[Lou C]

Here it’s driven by government mandates for fuel economy but none of the oils that are for fuel economy are adequate for inboard marine engines under constant load. The ones I’d use are 20/50, or the Mercruiser/Quicksilver 25/40 or their best which is the 25/50 syn blend. The 20/50 is much cheaper. If you do an oil analysis you’ll see if it holds up in your use.

 

[kd4pbs]

Is that fully or semi synthetic?

I think I used to see a much wider range of oils than seem to be available now. These days it seems most stuff is 0/30, 5/30 synthetic, even some 10/40 semi is labelled as 'classic', then there's the really old stuff like 20/50 mineral and straight 30 or 40. Think I used to see a wider range including 10/40 synthetic.

10W40 synthetic. Rotella T6. Thankfully the EPA has yet to really ruin diesel engine oil, and while it's more expensive, there's no reason I have found to not use it in a non-catalyst gasoline engine.
Yeah - I imagine the pressure is related to a lower temperature due to more oil. There would be virtually unmeasurable pressure increase due to a higher static level causing the pump to have more head due to not having to pump as high above the reservoir of oil.

 

[Lpgc]

My '96 Ford 302 has hydraulic flat tappets / followers, the 'same' engine in a car or truck would have a roller cam. I've never used a zinc additive but have read modern oils are low in zinc and that's bad for the cam. Even the 'classic' 20/50 mineral oil and straight 30 oil I've used doesn't mention zinc on the tin so I don't know if they have the same zinc content as a truly classic oil... But it seems unlikely a modern oil would have as much zinc as a classic oil? How much should we be concerned about zinc content?

I imagine the pressure is related to a lower temperature due to more oil. There would be virtually unmeasurable pressure increase due to a higher static level causing the pump to have more head due to not having to pump as high above the reservoir of oil.

I agree, I'd expect around a 0.5psi difference per foot of head difference but we're only talking maybe an inch head difference.

I have wondered if the oil gets hotter in the boat after a sustained high throttle run than it would in a car / truck, no oil cooler and no airflow around the sump. How common is it for boaters to fit an oil cooler (oil to raw water)?

 

[kd4pbs]

The oil in a boat engine gets very much hotter than an automobile engine, unless you're going up a 10 mile long grade towing a caravan with the accelerator matted the whole way every trip. Every I/O boat I've ever had shows around half the normal oil pressure after a spirited run, then took 10-20 minutes at idle or no-wake speed to recover. I've often thought that all boat engines should come with an oil cooler. Usually the big blocks get them but not the small blocks. I believe a future project is to fit one onto this 5.7Gi-C in the latest boat just for peace of mind.
Shell publishes the ZDDP amounts in the Rotella oils... at least they used to. I think that it's not as much of an issue having reduced zinc levels on a well broken-in flat tappet cam. The stuff you guys get across the pond would likely have different formulations I imagine, so who knows...

 

[Lpgc]

What would be the usual way of plumbing in an oil to raw water heat exchanger / cooler?

Also along similar lines - of plumbing in a heater matrix on a raw water cooled engine?

I was thinking if the 'main' engine hose (the widest diameter water pump to thermostat housing hose) which carries coolant at engine temperature could be T'd into at 2 different points (imagine 2 x 5/8 pipetails sticking out of that hose), then an electric water pump could be used to push water through a heater matrix and/or oil cooler.

 

[kd4pbs]

Factory included oil coolers that I have seen are directly inline with the incoming water line feed as it enters the boat, just like the (usually included in most outdrives) power steering fluid cooler.
As for a heater, the two boats that I've owned which had onboard hydronic/electric water heaters (a built-in liquid-to-liquid heat exchanger and a line-voltage AC powered resistive heating element for when the engine isn't running) basically had a 3/4" hose from the outlet side of the block (directly before/below the thermostat in the thermostat housing) to the water heater. The outlet from the water heater is fed via another 3/4" hose back into the inlet side of the engine circulating pump via a hose barb. This requires a circulating pump which has a connection to accommodate the hose barb, which most of the ones I've seen have. It could be fed back into a tee which is installed in the circulating pump's large inlet hose just as easily if such a water pump with the required fitting isn't available.
I know you know this, but it should be clearly stated that you don't want to put an oil cooler in this loop though since it's going to be at the outlet water temps. You'd want to use the cold seawater feed like they do from the factory.

 

[Lpgc]

Factory included oil coolers that I have seen are directly inline with the incoming water line feed as it enters the boat, just like the (usually included in most outdrives) power steering fluid cooler.
As for a heater, the two boats that I've owned which had onboard hydronic/electric water heaters (a built-in liquid-to-liquid heat exchanger and a line-voltage AC powered resistive heating element for when the engine isn't running) basically had a 3/4" hose from the outlet side of the block (directly before/below the thermostat in the thermostat housing) to the water heater. The outlet from the water heater is fed via another 3/4" hose back into the inlet side of the engine circulating pump via a hose barb. This requires a circulating pump which has a connection to accommodate the hose barb, which most of the ones I've seen have. It could be fed back into a tee which is installed in the circulating pump's large inlet hose just as easily if such a water pump with the required fitting isn't available.
I know you know this, but it should be clearly stated that you don't want to put an oil cooler in this loop though since it's going to be at the outlet water temps. You'd want to use the cold seawater feed like they do from the factory.

Thanks, I don't know what/if a different circulating water pump is available that has a barb though I would think there would be something available. Still I'd prefer not to have to fit a different water pump, so if I were to fit a heater matrix I'd prefer to go with the 2 barbs method. I didn't know the design of boat factory oil coolers or that they're plumbed to raw water. A lot of vehicles have the oil cooler plumbed to the engine's closed cooling system... I realise the oil cooler could be more effective fed with cold water but even fed with hot water from the engine it should work as well it works on a road vehicle that has it plumbed to the closed cooling system?

 

[kd4pbs]

I figure the likes of Mercruiser and Volvo-Penta had the smart engineering figured out. On an automobile, that's all you got if it's not an air-fluid heat exchanger. It would be more effective than nothing if you put it in the block cooling loop, but since it's easy to plumb into the seawater supply, might as well go there. Just place it next to the power steering heat exchanger. The real booger is the oil side of things. It's easy if you already have a remote oil filter, but adaptors will be needed otherwise.
Most small & big block Chevrolet circulating pumps have the port for a barb, but I don't know what is common for Fords. A cursory glance online shows that marine duty pumps have the ports. As for the supply side, if your thermostat housing does not have the fitting, you'd have to make sure it's fed from before it reaches the thermostat to ensure constant flow. Another source for this would be the water passage crossover at the front of the heads... some intake manifolds have ports there that can be used.