I ran the Synthetic oil in my 55 Pontiac and loved it. Of course it had a late model crate motor in. Now I've traded for a 1957 T-bird. It's got the 312 and I have no idea how many miles. No blue smoke or blow-by, but that's about the extent of what I know about it. Think it would be OK to run the Synthetic oil in it, or just stick with the tried and true 10W40? One more thing, I can not find the timing marks on the harmonic balancer. Took a steel brush to it but still have not been able to see it. Any help here? Thanks guys, you have always had logical answers to my dopey questions.
I don't know if this situation still applies or not, but I thought I'd pass it along. It seems that synthetic oil was able to migrate through cork gaskets and if the motor in the T-Bird stll has cork gaskets, you might want to stick with regular dino oil. A co-worker had this occur on a new car of his years ago when he tried synthetic and this is what he was told.
I had a bunch of 15-50 Mobil 1 left over from my race car. To save a few bucks, I used it in my bone stock '51 Ford. I have had zero problems with it and if anything, it leaks less than it used to (typical flathead oil spots). This is a 79,000 actual mileage car; it runs so well, I have to believe it was probably rebuilt before I had it. It runs 35 psi at idle and 55 psi at speed, runs cool. After my "experiment", I'm going to keep using it.
I was a little reluctant to make my post because this did occur many years ago when synthetics first hit the market. From your usage in the flathead it would seem that the formulation has been modified over the years to prevent this seepage.
I switched to synthetic oil in a built 440 Mopar. Suddenly had lifter noise. Talked to the engine builter and he explained to me that the synthetic oil was to slick for the hydraulic lifters to pump up properly, that it was designed for the new roller lifter hydraulic lifters. Switched back to my tried and true regular oil and lifter noise went away. Just my experience , I can't say that yours would be the same but I would expect it to be.
Regarding the timing marks, it's not uncommon for them to hide from their owner. Picture attached. The timing marks for all original 1955/56/57 Thunderbirds can be difficult to locate on un-restored or older restorations. In some cases, the timing marks are either dirty or painted over and cannot be found. The timing marks on the Thunderbird are located on the rear pulley edge. The large mark to the left if you are standing in front of the engine is TDC. The five lighter marks represent approximately two degrees each. The marks can be found by using lacquer thinner or sand paper' to remove excessive paint or crud build up.
About 12 yrs. ago I had a '72 Mustang w/a freshly rebuilt 351C . For the first 2 yrs. it didn't leak a drop . Then I put synthetic oil in at one of my regular changes . I instantly had leaks at the rear main , oil pan , & valve covers . Engine builder said to put conventional 10-30 back in . The leaks stopped instantly . I never used it again , and I never will .
Ford Freak, do you happen to know what the gasket materials that were used especially with the valve covers ?
The valve covers were cork , as was the oil pan . Rear main was neoprene . The builder said that synthetic was so slippery that it got through areas that reg. oil couldn't . I can't afford synthetic oil anyways !
I think that my success may have more to do with the weight of the oil rather than a change in formulation. If I had had a bunch of 10-30 instead, I probably wouldn't have tried it. I guess the jury is still out.
Ebbsspeed - Found the timing marks right where you said. The pulley was so rusty they were covered up. Even after sanding the whole edge, they were still invisible. I finally pulled the #1 plug and turned the engine over with my finger on the hole until the compression stroke came up. Then I was able to find the marks on the pulley. Just for giggles I pulled the distributor cap to see where the rotor was sitting. Not where I thought it should be. Upon examaination I found that the plug wires were one hole off. #1 wire was in the hole just before the hole marked #1 on the cap. All the wires were otherwise in the correct position, just all off by one hole. Don't have my new timing light yet so I haven't change them.
I have always been a hardcore fossil oil purest. Even had guys tell me they had used synthetic with not enough noticeable difference to justify the cost which seemed to back up my thoughts but after inheriting a 96 Geo tracker that had synthetic in it and driving the wheels off it with over 150,000 miles and zero maintenance and no problems, I`m going to synthetic in all my cars. Just my experience.
Modern engines for sure but my last two GMC pickups went over 200,000 miles without any leaks or internal problems. I switched to Mobil 1 5W-30 on the third oil change after rings and valves had time to seat. There are probably good reasons not to use synthetic in older designed engines but all of my new stuff including the lawn mower gets full synthetic.
When synthetics first came out there were definite issues with switching from mineral (petroleum based) oils to the synthetics. That is no longer the case, most oils that say they are synthetic are in fact blends of petroleum and synthetic base stocks. The biggest worry would be the modern add packages in the oils today do not support the anti-wear additives that flat tappet or hydraulic flat tappet valve trains require do to the impact they have on catalytic converter's precious metals. So if you are going to run available off the shelf oils whether it is synthetic or petroleum based you will need to add a good anti wear additive to your oil. You need to have between 900 and 1250 ppm Zinc, Phosphorus and Molybdenum for adequate protection. Also keep in mind that anything over 1250 ppm has no added value.
If moisture and carbon are the ruin of motor oil and synthetics can go for longer intervals. How does a synthetic oil shed this build up ?
ran synthetic in 1983 1100 GOLD WING MOTORBIKE,,,over 600,000 km....did compression test...all four cylinders at 151...new they were at 160....it lubricates and protects...much better than fossil oil...AMSOIL...best on market..
One of the reasons I chose to run the Mobil 1 15-50 in my flathead is that any oil 50 Weight or over has sufficient zinc in it for older engines.
That's how I got hooked on micro-brews. If you do run synthetic, make sure you have enough zinc additive.
After using synthetic and having 3 vehicles leak @ oil senders and rear mains, I switched back after repairs to 1/2 Castrol 10W-40 and 1/2 Castrol 10W-40 synthetic (same 1/2 & 1/2 mix but 10W-30 in winter). Sometimes I add about 1/4 qt. Lucas oil additive in the summer. I like changing @ 3-4k no mater what the synthetic folks claim and my compression ratios are great. I have a 1988' 3.8 Cutlass that I started this on at 65k. It now has 337k hard city miles on it without a rebuild or leaks and holds 59 psi oil pressure at idle with AC on in the Texas heat.
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