My 71 442 with a 73 model 455 that we just picked up over the past weekend is showing about 35 on the oil pressure gauge on the road and drops down to about 25 at idle. Does that sound normal?
The original owner has always ran Castrol GTX 5W-30 but at one time lived in Montana. I am wondering if I should go to a different weight oil and if that would give me a little more pressure.
I live in northeast Texas and will probably drive it 50 miles a week.

Thanks in advance!

 

35 is low for highway driving while the 25 at idle is great. What type of gauge are you using?

 

Danny,
Thats a little low but you really need to know if it is correct. If you are going by the factory gauge I would buy an inexpensive mechanical gauge that you can hook up just for testing. If it really is that low you could try a 10w40 and see if it helps a little.

To be honest with you unless you are really driving it hard it will probably run forever like that. Its not ideal but if the engine has a lot of miles it isn't all that unusual.

 

it is a Sunpro.

 

Get a better gage, Sunpro is low quality

 

Updated info. The following pictures are during and after a 30 mile trip down the interstate at 75-80 mph.
It is real low at idle after coming off the interstate, this is at the stop sign idling.

 

At those temps with 5W30, that is fine. I would step up to a 20W50 oil.

 

What is your idle RPM? If your guages are correct, your voltage is too low also, you idle may be set to low.

 

I do not have a tach on this car. I would like to add one in the factory dash location if possible. Can someone recommend an aftermarket tach that would fit like the factory unit?
Also what would be a quality gauge set?
I have noticed my temp runs between 190 and 230. Does that sound like correct operating temp on a July day in Texas?

Thanks,

Danny

 

You don't need a tach for the car, you need a tach/dwell meter to set your idle speed.
https://www.ebay.com/b/Automotive-Dw...83/bn_71620146

Depending on the thermostat you have in your car the temps are a bit high.

 

That electric fan conversion is likely the reason for the higher coolant temperature.

 

Is that a bad thing?
There is a toggle switch under the dash for the fans that I leave on all the time.
what temp is considered hot?

 

I would say over 220 is too hot. I personally don't like over 200 but we don't see Texas temperatures here very often. There is nothing wrong with electric fans if they move enough air. What kind of shape is the rad in? A good 1"+ 2 core aluminum rad should cool better along with a 160 or 180 Robert Shaw high flow thermostat.

 

For the summer in Texas, I'd use a 20W-50 with enough additive for the flat tappets and a 160 thermostat.

 

Not if the fans can move as much or more air than the factory mechanical fan. Unfortunately, a lot of aftermarket fans don't move enough air and lead to higher operating temperatures. I made the statement above as there have been many posts over the years with folks who installed electric fans with the expectation they would cool better only to find that they did not. I just wanted you to be aware that those fans may be an issue.

 

I would say 220 is a little on the high side, especially if that temp is while driving. If that temp is idling, I wouldn’t get too worried. Is the thermal clutch actually engaging? There should be a noticeable roaring sound when the fan clutch engages.

I would suggest installing a 180 t-stat, and using 10w-40 or maybe 15w-40 Rotella. A little less engine heat, and a little more oil viscosity will probably solve your concerns.

Lastly, do you know what the service history is like? Has the timing chain been replaced? If not, better plan on it. The nylon timing gear is a ridiculous design. I understand the nylon coating was designed to keep chain noise to a minimum, but I have never noticed a increase in noise after a timing chain replacement. How much noise could there actually be? When the nylon flakes off, guess where it collects? In the oil pump pickup tube!! The nylon restricts oil flow, leading to bearing wear, which lowers oil pressure. If you do replace the timing chain, if there is a lot of nylon missing plan on removing the oil pan also. Either clean or replace the pickup tube. Once the timing cover is off, the oil pan install is much easier.

 

See post #11 above. The vehicle has aftermarket electric fans and he says the toggle switch is always in the ON position so I assume the fans run constantly.

 

I missed that one. I hang my head in shame. 😞

 

Hey Matt, I do not know if the timing chain has been replaced since the rebuilt engine was installed. I do not think so since they kept good records and I have all the receipts but don't see anything about the timing chain. That is very interesting information, thanks for sharing.

 

On 5/12/2009 they installed a new engine in your car. Do you know what the mileage was on the car when they installed the new engine and what is the mileage on the car now?
If it was a new engine on that date there was a new timing chain installed on that date because a new engine would have a new timing chain contained in the new engine. I highly suspect the timing chain does NOT contain the nylon and you're in good shape. If you could ascertain the mileage on 5/12/2009 and the current mileage you'd get a better understanding of the mileage on the current timing chain.

 

The odometer showed 3863 at the engine change and it has 13444 now so it looks like 9561 miles which is probably actually less because the spedo reads 10 mph fast at highway speeds.

 

20w50 Valvoline VR1 non synthetic. These old girls don't like that thin oil. Change it and monitor again. If it doesn't hold good pressure with the VR1 you have a mechanical issue. I tried Castrol Syntech 5w30 synthetic back in the 90's when the synthetic craze started. My car did the same thing yours is doing. With VR1 she cold idles at 55psi and hot idles at 40.

 

I'm going by what I see written on the invoice (image) you posted on your other thread: "Pull old engine out reinstall new engine". Additionally, that 455 engine List Price = $4039.33 (Net =$2423.60). In any case, whether it is a new engine (as stated) or a rebuilt engine (e.g. plug & play), if it is a new engine it has a new timing chain, if it is a rebuilt engine I "suspect" it was rebuilt with a new timing chain. I'd find it difficult to swallow someone would rebuild that 455 w/o installing a new timing chain. Since you have no "specific" indication in writing, I guess it might be questionable if they installed a new timing chain. I'm siding it has a new timing chain. In both cases, you have ~9K miles on a new timing chain which would mean you have nothing to worry about regarding the timing chain. Considering the install date (5/12/2009) I suspect any timing chain they installed was not a timing chain w/ the nylon coatings. I'm not certain vendors still sell the nylon coated timing chains.

 

Your oil guage is electric. The sending units are notorious for not reading correctly. I would look for a mechanical guage, or a high quality electric unit from a company like Autometer.or similar

 

Are they electric? My Sunpro and my Equus are mechanical. Pretty sure both electric and mechanical are/were available from Sunpro.

 

The narrow sweep of the needle gives it away as an electric guage.

 

Thanks for the advice. I’ll order a set of Autometer gauges.

 

I need to take a pic of mine, pretty sure my mechanical gauge looks exactly like that one. Either way, for the price difference I would hope Autometer gauges are more accurate. My Sunpro temperature gauge read 10 degrees high. I would double check this gauge the autometer gauge with a temp gun.

 

Actually, after a closer look at the above pictures, I can see the Oil pressure plastic tubing, so it is a mechanical guage.

 

For me switching to a 180 thermostat and 20W50 from a 195 thermostat and 5W30 oil, I gained 8 psi, was 37 to 45 psi at around 2000 rpm.

 

The numbers are a little low but not terrible. Even though it only has 44k miles consider replacing the timing chain/gear set and making sure the oil pump screen is perfectly clear. The nylon on the cam gear is 55 years old it has cracked or is going to soon. An original '68 455 with 44k would be upsetting to lose due to insufficient lubrication.

 

Holy crap, I almost posted too. 😂

 

I realize this is an old thread, but my curiosity doesn't rate an entire new one:

Would any rebuilt engine not incorporate a upgraded timing set with a non-nylon sprocket?