oil and weight for 69 Firebird

[James408]

I own a 69 Pontiac Firebird 400. The motor is a Pontiac 400 bored .040 over with #62 heads, 274 Comp Cam Extreme energy with Edelbrock Performer RPM and 750 Holley with vac/secondaries. Trans is a turbo 400 with shift kit and 2800 stall. The rear is a Chevy 12 bolt posi with 4.10 gears.
This is my baby. I drive it mainly on the street but it is driven hard. I may see some 1/8 mile racing. I live in south/central Texas. My average temp on the motor is around 190. In hot summer it may get to 200 degrees when idling but goes down to around 190-195 degrees.

My question is: I come from the old school that uses 20w50 in old tech engines such as mine. I have run Valvoline Vr1 racing 20w50 and Valvoline All-Climate 20w50. The motor has approximately 4000 miles on it. Recently I switched to Royal Purple 15w40.

What is your opinion of oil brand and weight for my application? Is 20w50 two thick for my application or is 15w40 too thin. My bearing clearences are within stock specs. Any opinions are appreciated.

 

[KW]

I believe 15W40 is the best choice for these engines.

 

[Geoff]

15w-40 HDEO has the additive package you need and is probably the right grade as well. Chevron Delo, Shell Rotella, Mobil Delvac.

 

[sgtgeek]

Well alrighty...another Pontiac Muscle Car Texan.....yup...15-40 is what the doc ordered for your ride man......the later GM (LS/LT) likes a tad thinner 40 ....but for your beast the 15-40 is perfect......

 

[k1xv]

I agree with those before me. 15-40 all the way on these old muscle beasts.

 

[gudmund]

15-40 is a very good choice. Question? Do you still have the stock windage tray in the motor? if so, try to find a dip stick out of a 66/67 Pontiac motor-size does not matter, they were all the same be it was a 326/428. pull out yours and put one of these in and you will find your oil is down 1qt. These motors had a 7qt capasity instead of 6, same pan just more oil. They lowered it back down to 6 in 68 on so as to make for a cheaper oil change. I always ran 7 in my Pontiac motors for years and never had any problems until I put in a smog 73 455 motor. They had cheapened up their motors by than by getting rid of the windage tray in the lower end. Being the dip stick is on the right side of their motors with no tray the oil would get wipped up and at high rpm's get pumped out the tube onto the exhaust and SMOKE-LOT'S OF SMOKE! 65 389 GTO/70 455 GTO the more oil the better!

 

[James408]

Hey Gudmund, my motor has the stock windage tray with a few extra holes drilled in it. My block is actually a 1970 4 bolt main Ram Air III block.
Now here is another queston. The factory specs for a 69 pontiac 400 is 6 quarts of oil with filter. I read in High Performance Pontiac Magizine that if you use the shorter oil filter (which I do, a 1258 Napa Gold)capacity is 5 and 1/2 quarts. It stated the longer oil filter(1 quart capcity)you should use 6 quarts of oil. I have never heard of the 7 quart theory. Any suggestions.

By the way, I am brand new to this forum. I am somewhat of an oil freak. Thanks for all of your replies. I am going to stick with the Royal Purple 15w40.

 

[99]

quote:

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Originally posted by James408:


Valvoline Vr1 racing 20w50
Royal Purple 15w40.

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Either of these oils are excellent choices.

 

[JohnnyO]

Back in the day I had a 68 Firebird 350 which I ran 10w-40 in, but I'm up north. In Texas I'd use 15w-40. You're better off being slightly low on oil than being overfilled. I'd go with the 5.5 quarts with the shorter filter assuming the dipstick is accurate. Too much oil and things can get ugly real quick.

 

[gudmund]

the "to much" oil thought is true with all other stock engines out there that did not have windage trays on them. Pontiac's up until the smog days of the 70's came stock with windage trays from the factory. It was the thing to do when building up one's motor and that was to put on a windage tray to help getting the oil away from the crank at high rpm's(something like a 10hp increase at 6000rpm's on the dyno)It's like chevy's rocker arm stud problem in thesmall blocks-you'd pull out the pressed in one(that or pin them) and have the heads threaded for screw in onesalong with putting guideplates well Pontiac 4bbl motors from 67 on all had screwed in studs with guide plates from the factory. Yes I was a Pontiac die hard at one time, it was one of the easyist motor to work on when comparing them to anyoneelse. Yes they had their problems also (ala timingchains-still easy to fix with a chain out of a 4cyl Pontiac along with the easy to take apart and put back together part of it)but I still love the way they always finished off their cars when comparing them to the other GM divisions.

 

[gudmund]

Another tip. If you are going to pull the motor anytime soon, see if you can get a pan off an newer 70's era Trans Am. They have a baffle in them so as to keep the oil from climbing the pan sides when accelorating and hard cornering. If you ever get a chance to look at you oil pressure gauge when doing some hard cornering to the right(if I remember correctly)it will shock you to see the oil pressure drop like a rock. The TA's really needed it being they could pull some pretty hard G's when cornering. If memorey serve's me right they started putting the baffled pan on almost all their motor's in the later 70's up until the last ones (79).

 

[BlazerLT]

5w40

Quick startup lubrication and 40 weight fuel economy and power.

Your don't need anything heavier.

 

[99]

Even with a crank scraper, windage tray and the highest tech trap door oil pan Moroso makes, you don't want to overfill. That'll defeat the whole purpose of having those items in the first place. Stick with the pans rated capacity and whatever the filter holds and call it a day. Now go racing.

 

[James408]

Hey gundmund, I (hopefully) don't plan on pulling my motor anytime soon. At least not for extra oil capacity. It runs to good! With my 4.10s and BF Goodrich G Force Drag Radial P275/50's I can't even take off without spinning excessively. I may have to put my 3.55's back in. Sorry, I got off the subject. Thanks for yall's input.

 

[James408]

Hey Gundmund, I agree with you on the baffle in the oil pan. My pan does not have it. However, my car is only going to go fast staight. It's not set up for tight cornering (yet).

 

[gudmund]

The pan on 1966/67 Pontiac's were the SAME pans on pre 66 and all 68 and newer Pontiac V8's! They all had the same pan which is my point!!!! the pans was never changed!! So what is the Qt total for their oil pans being the dip sticks were changed to read full when 7qts were used in 66/67 and 6qts before/after66/67?? So I guess if a 66/67 motor is ever put into a 68 or newer Pontiac you can only put 6qts in because it's a say 68 car?? If you put a dip stick from a 66/67 Pontiac in a older/newer Pontiac motor you will find you oil is down 1qt!! and if you put the dip stick from a older/newer in a 66/67 Pontiac it will show 1qt overfilled. The only time you will have a problem with putting a dip stick from a 66/67 Pontiac motor in a newer motor is if you put it in a Pontiac motor that does Not have a windage tray which after 72/73 or so most of them did not have(cheaper to build)

 

[gudmund]

KEEP THE 4.10'S, your tires will be spinning even faster with the 3.55's. 4.10 will be better for drag racing-get some better tires!! like a set of say 10 inch wide slicks around 30inches tall. Now for cruising the 3.55's maybe alright. If you really want a drag racer, keep the 4.10's and exchange the 400 for a 428 or 455!! The 4.10's are perfect for the torque of the 455 and you never have to turn it past 55/6000rpm's. The torque output of the 455 was something else when compared the a 400. You did not have to work them as hard as a 400 to get power out of them.

 

[James408]

Hey G, I agree, the 4.10's are alot more fun. I did have some MT slicks but sold them in a whim. I just got the Drag Radials and still need to play with air pressure. I drove an '83 Camaro with a hi po 350 and 4.10 gears that belonged to a friend of mine. It hooked really well with these type of tires. But again a Pontiac 400 is a totally different beast, lots of low end torque.

My dream motor for this car would be a 428, but funds do not allow it at this time. I am still pleased with this 400. My car will still be more of a weekend car and an occasional drag racer.

I just have to say it is nice to talk to fellow Pontiac people. Where I live, there are not very many of us. Thanks for your opinions.

 

[99]

Did you get the MT Drag Radials? If so, hold on tight because they're pretty much as good as running slicks or even the "old" ET Streets. Any other drag radials cannot even compare to them...they're that good.

 

[James408]

I have the bf goodrich drag radials.