Engine Noise When Warm/Hot

[55 Fargo]

After searching this question on this forum and and on the WWW, have decided to present the ?

My 55 Fargo engine, decent even compression, good oil pressure, 50-55 psi at speed, 40 psi idle cold, 30-35 psi at idle hot engine.

Engine temp usually runs in the 170 range.

After a drive, or after starting a hot engine, I have engine noise like a loose/ticking lifter, it disappears as soon as the engine revs up, it is somewhat intermittent. I have tried to pin point, with the usual diagnostics, pulling a plug wire on each cyl, and listening to the engine.

Does anyone have any ideas, what would cause engine noise at idle, on a warm/hot engine?

I have no noises accelerating , when engine is pulling a load....

[Jerry Roberts]

You probably have a loose / ticking lifter .    To find the offending lifter , slide your feeler gauge into each gap until your hear the noise go away . 

[NiftyFifty]

Just the clearances getting wider between the lifter (tappet)and valve when hot, get some welders sleeves and try adjusting the valves, but I wouldn't be overly concerned

[RobertKB]

Me thinks you worry too much. From everything you have said now and previously about your engine it sounds like it is fine. Just enjoy.

[55 Fargo]

Thanx Guys, what me "worry". RobertKB, do you still run 20w50 oil in your engines? I know 4mula uses 30 weight COOP Oil, wonder if the castrol 10w30 gets a bit too thin when hot with this older engine....

[ggdad1951]

I'm running Amsoil ZROD 10W30

[NiftyFifty]

I know this debate has gone around, but IMO the problem with new oils are they are designed to run newer engines, and IMO they run off the cam and lifters too soon, and have almost nothing for zddp in them as per new emissions laws, and unneeded by new engines. You should at least be running an additive with the newer style oils, I still run the Rislone or STP stuff with my AG 30 weight coop oil, just to be sure. You can also slip into Softys or Super Shop in Winnipeg and get oil designed for older vehicles, but be prepared to pay $12-15/L. You can also run 1/2 bottle of GM assembly lube that they sell at Piston Ring, my old boss has been running it the last few years in his 63 ford and it works well.

[55 Fargo]

This may be a worthwhile read for what it's worth.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1049812

[55 Fargo]

The Pennsylvania Crude Myth -- This myth is based on a misapplication of truth. In 1859, the first commercially successful oil well was drilled in Titusville, Pennsylvania.

A myth got started before World War II claiming that the only good oils were those made from pure Pennsylvania crude oil. At the time, only minimal refining was used to make engine oil from crude oil. Under these refining conditions, Pennsylvania crude oil made better engine oil than Texas crude or California crude. Today, with modern refining methods, almost any crude can be made into good engine oil.

Other engine oil myths are based on the notion that the new and the unfamiliar are somehow "bad."

The Detergent Oil Myth -- The next myth to appear is that modern detergent engine oils are bad for older engines. This one got started after World War II, when the government no longer needed all of the available detergent oil for the war effort, and detergent oil hit the market as “heavy-duty” oil.

Many pre-war cars had been driven way past their normal life, their engines were full of sludge and deposits, and the piston rings were completely worn out. Massive piston deposits were the only thing standing between merely high oil consumption and horrendous oil consumption. After a thorough purge by the new detergent oil, increased oil consumption was a possible consequence.

If detergent oils had been available to the public during the war, preventing the massive deposit buildup from occurring in the first place, this myth never would have started. Amazingly, there are still a few people today, 60 years later, who believe that they need to use non-detergent oil in their older cars. Apparently, it takes many years for an oil myth to die.

The Synthetic Oil Myth -- Then there is the myth that new engine break-in will not occur with synthetic oils. This one was apparently started by an aircraft engine manufacturer who put out a bulletin that said so. The fact is that Mobil 1 synthetic oil has been the factory-fill for many thousands of engines. Clearly, they have broken in quite well, and that should put this one to rest.

The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).

Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability.

ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942.

In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range.

In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests.

A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.

By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range.

However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.

Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.

The facts say otherwise.

Backward compatability was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.

The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.

- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.

- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s.

Those who hold onto the myth are ignoring the fact that the new Starburst oils contain about the same percentage of ZDP as the oils that solved the camshaft scuffing and wear issues back in the 1950s. (True, they do contain less ZDP than the oils that solved the oil thickening issues in the 1960s, but that's because they now contain high levels of ashless antioxidants not commercially available in the 1960s.)

Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.

Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also.

Special thanks to GM's Techlink

- Thanks to Bob Olree – GM Powertrain Fuels and Lubricants Group

[Don Coatney]

The Pennsylvania Crude Myth --

 

Pretty much sums it up. If it makes you feel good spend that money and buy all the expensive oils and additives. You will feel good but your engine could care less.

 

Personally I feel good buying Dollar Store oil and my engine is happy.

[Jeff Balazs]

The truth behind the "myth" is that crude from that region was extremely low in sulfur. Sulfur content was almost zero. And it was not an easy component to remove from the product during the refining process of the day. And when sulfur mixes with any water from condensation in say an engine sump guess what forms? A mild form of sulfuric acid. Not real good stuff for bearings etc...

 

You never seem to hear anything about this these days. I guess this is common knowledge that has been lost in the mists of time. But you can be sure they knew all about it back in the day. These days crude spec's are all over the place and refineries have had to get way more sophisticated in how they process. Sulfur is only one of many many components that need to be removed or treated. And all of the facilities have the ability to remove or strip unwanted stuff like sulfur........but this wasn't the case until the last 20 or 30 years. When you got motor oil back in the 60's that had been made using crude that contained a lot of sulfur a fair amount was still present in the final product.

 

Jeff

[_shel_ny]

To go with the Orlee info:

 

"We at AMI may not be lubrication engineers or tribologists, but we are engineers, and know how to read and interpret test reports. We have nothing but respect for Mr. Olree, indeed he is one of the most experienced engine lubrication engineers we have read, but we feel that his opinions leave some issues important to older classic and high-performance vehicle owners unanswered. To address them point by point:



”Engine Oil Myths -
Over the years there has been an overabundance of engine oil myths. Here are some facts you may want to pass along to customers to help debunk the fiction behind these myths.
The Pennsylvania Crude Myth -- This myth is based on a misapplication of truth. In 1859, the first commercially successful oil well was drilled in Titusville, Pennsylvania.
A myth got started before World War II claiming that the only good oils were those made from pure Pennsylvania crude oil. At the time, only minimal refining was used to make engine oil from crude oil. Under these refining conditions, Pennsylvania crude oil made better engine oil than Texas crude or California crude. Today, with modern refining methods, almost any crude can be made into good engine oil.
Other engine oil myths are based on the notion that the new and the unfamiliar are somehow "bad."”

It is human nature to be unsure about new technology. We agree that the situations vis-à-vis Pennsylvania Crude oil and detergent oil is adequately explained by this aspect of human nature. The working fundamentals of many modern technologies such as engine oils are far beyond the grasp of an average person. When reading Bob Olree’s comments, we also acknowledge that they are applicable to an average vehicle and engine. There are few people who have as much direct experience with the issue of ZDDP and API test Sequences as he has.

However, to describe the current situation where oils are being marketed with lower ZDDP than a vehicle’s original specified requirement as merely another “new or unknown = bad” myth does not do the facts of the situation justice.

There are no test reports we know of which conclude that any low ZDDP oil is compatible with older, high spring pressure flat-tappet high-performance engines.

There is on the other hand, research that concludes that the minimum ZDDP requirement is directly related to the lifter foot pressure. In one SAE paper it is reported that: “at a ZDP level corresponding to 0.02% phosphorus, scuffing occurred at 200 pounds lifter load, while it required 240 and 480 pounds lifter load for oils containing 0.04 and 0.06% phosphorus, respectively, to initiate scuffing. At 0.08% phosphorus concentration, no scuffing occurred up to 600 pounds lifter load, the test hardware limit. Scuffing occurred at 350 pounds lifter load with no ZDP (0% phosphorus).”

The older engines and high-performance engines we are concerned about may have lifter foot pressures several times that of a low-performance engine such as those used in the Sequence III tests, and their wear characteristics are not predicted by common Sequence III testing methodology. An additional factor is the dynamic load at the lifter foot. Sequence III engines run at 3600 RPM maximum during the test. Most high-performance TR engines are regularly run to 6000 RPM. The inertial contribution to the lifter foot pressure increases as the square of the increase in RPM. This means that the inertial load at 6000 RPM is 2.67 times it’s value at 3600 RPM.


“The Synthetic Oil Myth -- Then there is the myth that new engine break-in will not occur with synthetic oils. This one was apparently started by an aircraft engine manufacturer who put out a bulletin that said so. The fact is that Mobil 1 synthetic oil has been the factory-fill for many thousands of engines. Clearly, they have broken in quite well, and that should put this one to rest.“

One of our engineers drives 1996 Chevrolet Impala SS with an LT1 engine which was filled at the factory with Mobil 1, and has never had any other oil in it. One might wonder if the Mobil 1 factory fill is actually the same spec as off the shelf product or if it is initially dosed with a break-in additive. It has indeed broken in well, and at over 200,000 miles it still has very little blow-by, so I would agree with Mr. Olree’s conclusion, for his Impala SS at least. Engine break-in problems are usually caused by improper break-in driving habits, not by the difference between synthetic or fossil based oil.



”The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).
Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability. ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942. In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range. In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests. A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling. By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range. However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.
Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.
The facts say otherwise.

Backward compatability was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.

We have never been able to find the results of these tests on older engines. We would need to study those reports to see exactly which engine types and cam/follower types were involved. The fact is that all API test sequences we have studied use non-performance engines with low spring pressures, indeed in the Sequence IIIG test, the static lifter load is 350 pounds . Many high-performance engines have as much as 500 pounds or more of lifter foot pressure. Referring to the Bennet data, this would indicate that in order to keep from scuffing, a ZDP level giving a .065 % minimum phosphorus level would need to be ensured. If one considers that fact that the ZDDP level constantly drops from the initial level as a vehicle is driven, a safety margin above that is advisable. This means that if one wishes to maintain .065% minimum phosphorus, more than that must be present in the initial fill. Our calculations estimate that if you start with a ZDDP level which gives .14% phosphorus, after 2000-3000 miles, the actual ZDDP remaining active has dropped to the point where there is just enough protection.


"The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.
- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.
- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s.
Those who hold onto the myth are ignoring the fact that the new Starburst oils contain about the same percentage of ZDP as the oils that solved the camshaft scuffing and wear issues back in the 1950s. (True, they do contain less ZDP than the oils that solved the oil thickening issues in the 1960s, but that's because they now contain high levels of ashless antioxidants not commercially available in the 1960s.)"

We wish that it were true that all modern oils contained 0.08% ZDP. Our recent tests of two major name brand oils bearing the SM API grade showed that they contain <0.06% phosphorus, therefore they cannot contain even that much ZDP.
We know that there are technologies other than ZDDP which can function as effective EP anti-wear agents for some engine designs, as proven with newer engines with roller cam followers. The most recent SM formulations in particular have shown a move to Boron based EP additives. We have been testing virgin oils on an ongoing basis, and most quality oils in early 2007 have had a phosphorus level in the 0.05% to 0.08% range, lower on average than that of the SL oils. This certainly shows a downward trend which the classic or high-performance car owner needs to be aware of.


”Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.
Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also.“

I do not believe that anyone who has spent time investigating this situation would say that the new oils had insufficient EP characteristics for ALL flat tappet engines, especially low-performance engines. As a matter of fact, the number of oils with API certification proves that low-performance flat-tappet engines can pass the Sequence III tests with acceptable wear. Our study of the ASTM test sequences IIIE, IIIF, IIIG, IVA and VE required to achieve API certification reveal that NONE were developed using high-performance engines. Indeed, these tests were developed using relatively low-performance engines intended to model average current and emerging vehicle engine wear characteristics. This makes sense considering that the purpose of the ILSAC/API specifications is to provide a standard set of performance criteria for oil to be used in new over-the-road automobiles and trucks. The standards are not intended to infer any degree of backwards compatibility with older or specialty engines. While investigating the amount of ZDDP needed to protect engines Olree stated: “Arguing that modern oils should pass tests developed 25 years ago to protect engines built 30 years ago is a rather useless exercise ”. Since he is studying the situation from the perspective of designing the lubrication for the next generation of motors, we see his perspective for making such a statement. In doing so he is acknowledging that the test is not specifically designed to quantify oil’s performance with older engines. Unfortunately, “those” engines are the ones we enthusiasts run and care about.

At AMI our automotive group has 60 years of experience collectively with GM flat tappet engines. In all of this experience, the recent failures of stock cams and lifters due to severe wear is unprecedented. It is this experience as well as supporting reports from others we spoke to that made us try to find out the nature of the problem first hand. After preliminarily concluding that the low ZDDP levels in SL oils were the culprit for the wear we were seeing, we tried to obtain enough ZDDP for our own vehicles. We soon found out that major oil companies and additive manufacturers do not sell small quantities, and buying a large quantity is expensive! When others people in car clubs asked to buy ZDDP with us as well, we finally were able to put together enough justification to place an order. This is how we first found ourselves in the business of selling a ZDDP supplement.

It is our belief that there is no overt movement in the oil industry to create new oils that are bad for older engines as some conspiracy theorists may speculate. There certainly IS a movement in the oil industry to create new oils which are tailored to the specifications and requirements primarily of newer cars, and secondarily of older vehicles. This does not mean that they are concerned at all with 30 years old muscle cars. To the automotive industry an OLD car is 10 years old. The cars we care about are invisible to the OEM industry. While we have great faith in the engineering behind the new oils, we also notice that backwards compatibility with 100% of old engines is not on the product spec sheet. The oil manufacturers obviously know of the importance of the ZDDP to older flat tappet engines, as many of them are steering owners of these engines toward their ZDDP formulated diesel oil line, showing they acknowledge the possible need for higher levels of ZDDP in these engines. Unfortunately the characteristics and available viscosity ranges of diesel oil may not be suitable for our engines.

As Bob Olree knows better than we do, the amount of investment and research required to define, specify and perfect a set of tests and resulting standards is huge, and off-the-cuff recommendations like one sees in advertisements for oil supplements are poorly thought out and ill-advised. Our position on the right oil and additive package to use is simple: an individual should be using the oil specified at the time of manufacture of the specific vehicle. Period. An automotive engine is a fantastically complex and (sometimes) well thought out machine, and we believe that almost all oil additives are simply get rich schemes, impose unnecessary cost, and are unneeded at best, and like some chlorinated additives, dangerous at worst.

Our conclusion and current recommendation is to augment one of the new and superior base stock modern oils of the correct viscosity with additional ZDDP in order to bring the oil’s EP characteristics to that for which the engine was designed. We know from years of oil industry testing that ZDDP is compatible with all base stocks and other additive packages including the newer Boron EP additives, so there is little risk in adding it to achieve the equivalent of 0.12% phosphorus, a level similar to that formulated into SF or SG oils.

[ggdad1951]

why I use the ZROD Amsoil...it's FOR older engines, snake oil or not.

[55 Fargo]

Thanx all for the replies. I will say this, use any oil, or additives you deem necessary for your engine(s).

Whatever product makes you the most comfortable, is the one you should use.

I do not currently believe these engines require any high level amounts of ZDDP, as per some scientific analysis.

If anyone has emperical data to support the need for added ZDDP for our low rpm, lighter valve spring engines., I would sure be interested.

I firmly believe that clean oil, correct viscosity, and a full crankcase is what is key....

[NiftyFifty]

Thanx all for the replies. I will say this, use any oil, or additives you deem necessary for your engine(s).

Whatever product makes you the most comfortable, is the one you should use.

I do not currently believe these engines require any high level amounts of ZDDP, as per some scientific analysis.

If anyone has emperical data to support the need for added ZDDP for our low rpm, lighter valve spring engines., I would sure be interested.

I firmly believe that clean oil, correct viscosity, and a full crankcase is what is key....

Tell that to your "tick" LOL I've purchased esso oil back when we could get it from 2 different places in the same city and had 2 different colours come out..one from the bulk esso dealer, the other from a discount store (SuperStore), that leads me to believe just because the bottles the same, doesn't mean the product always is. All of the expenses on these trucks, the last thing I'm going to do us scrimp on the oil I buy...there's a reason for price differences and a pretty bottle ain't all of it

[RobertKB]

Thanx Guys, what me "worry". RobertKB, do you still run 20w50 oil in your engines? I know 4mula uses 30 weight COOP Oil, wonder if the castrol 10w30 gets a bit too thin when hot with this older engine....

 

Yes, I still run 20w50 in all my engines, sometimes add STP as well. My '53 is ready to turn 100,000 miles fairly soon and it sitll has the original bearings and great oil pressure so I am happy with what I use. I ringed it and lapped the valves at 72,000 miles and it shows no sign of being tired yet. Bearing shells were in the middle of factory specs so I just re-used them. I know the engine is original as both it and the car are P24's and I have owned it since 1975.

[55 Fargo]

Hey all, a bit of an update.

Tonight went out driving, drove her up to 60-65 mph on the highway, and even had to pass a Guy in an old beater 1 ton.

Okay once I get home shut off engine, temp gauge rise to about 185, engine was running at 170 the entire drive about 20 miles worth, so not hot.

I go to start engine, and that noise either a tick or knock is there, disappears as engine temp cools a bit while running.

I did not hear this noise the entire time driving.

I am using Castrol GTX 10W40 oil, and will be changing it tomorrow. I have no clue what this sound is, but it don't sound like lifter ticking. I never hear this ona cold engine, only on a hot engine after restarting it.....

[Merle Coggins]

Could it be your heat riser flapping a bit from the exhaust pulses? You say it goes away when you rev the engine. With higher exhaust flow it would just be held open and not make noise. My theory is that with a moderate manifold temp the spring is holding the flapper partially closed and the exhaust pulses are causing it to flap and make noise. When Hot it is held open and no noise... when cold it has more tension to hold it closed and again no noise.

 

Merle

[NiftyFifty]

Heat soaking it may have just risen from the heat getting up towards the sending unit, will always run cooler driving then sitting. Could be exactly as Merle has said, heat riser..but that you can easy enough with a work glove and someone to start the truck hot...just hold the valve open and see if you still have a noise when at idle. Being that your engine isn't a rebuild, or nothing recent you could have a slow oil pump at idle and it just making things a little noisy. If holding the riser open doesn't fix it, try the heavier oil and see what its like.

[MBF]

I would think you'd have less valve/lifter clearance when hot as the valve and lifter expand so you'd be less likely to hear valve noise on a hot engine.  That's why they suggest setting them when up to temp and heat soaked.

 

Why not take a piece of heater hose or something similarly sized and use it as a stethoscope to see if you can't locate the source of the noise.  If you've got that type of oil pressure I wouldn't worry too much about it. 

[55 Fargo]

I would think you'd have less valve/lifter clearance when hot as the valve and lifter expand so you'd be less likely to hear valve noise on a hot engine.  That's why they suggest setting them when up to temp and heat soaked.

 

Why not take a piece of heater hose or something similarly sized and use it as a stethoscope to see if you can't locate the source of the noise.  If you've got that type of oil pressure I wouldn't worry too much about it. 

Unless a valve is sticking in a guide, once the engine is hot. Started engine today, went for a very short drive no sounds, just s slight lifter tick tick, that is always present. Could this be hot over atomized fuel condition, allowing a lean condition in cyls 1&2 and 5&6........??????

[NiftyFifty]

Check your plugs after a good hot run, and don't let it idle much after your run, if their looking at all white or really light tan you may have a lean issue. Its a well used engine, I wouldn't expect perfection out of it, but completely not to jinx you but my old engine had "decent" running oil pressure right up till the rod let go...nothing will make it bullet proof without a refresh.

[55 Fargo]

Check your plugs after a good hot run, and don't let it idle much after your run, if their looking at all white or really light tan you may have a lean issue. Its a well used engine, I wouldn't expect perfection out of it, but completely not to jinx you but my old engine had "decent" running oil pressure right up till the rod let go...nothing will make it bullet proof without a refresh.

True, old engine, origin unknown, 1 thing, it does not burn oil, and leaks very little, seems to very peppy too. I will drive it, till something happens, which I hope doesn't for a while.

Then she will get the "flattie race engine"........LOL

[55 Fargo]

There is no reason that 1 of these old trucks can run 65 mph all day long, especially with my 3.23 gears. This of course must be qualified by good engine internals.

I have another 251 engine here, she may end up being my rebuild core. I would of course like a more modern smoother trans.

I still think it would be cool to have an automatic behind a fresh flattie engine, ina truck. How about a 2 spd powerglide.....just jokin, a 727 would fit the bill nicely...

[Don Coatney]

One word. Dynaflow.