Pontiac 400 needs oil...what brand/weight??

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Mar 19, 2004
Lakewood, WA USA
I am restoring my new toy, a 1977 Pontiac 400 (W-72) 4 speed Trans Am, (no a/c),(more fun again) anyway, motor seems fine but, we'll measure the bearings, pull the heads, etc., this engine runs a Crane/Pontiac "S" (.408 lift) cam and Crane 1.52 rockers and is Rochester Q Jet fueled...My Pontiac "expert" uses Castrol SAE 30 but, y'all taught me better, I plan on 6 mo oil changes and AC
/Delco filter, car will be driven Less than 2K miles annually shows/cruises..

What brand/weight OTC oil? Chevron, Havoline, Castrol, Mobil, etc., ? 10W-30, 10W-40 or even 15W-40? Diesel type oil? Car will always be driven till "hot" w/o short trips, etc...please post and add a "why" you recommend your idea?

The analysis are just toooo much for me to decipher? thanx in advance!
I run chevron 10w40 in my 71 pontiac le mans 350. (250 hp/350 ftlbs torque stock, but now sligtly warmer). The 30 weights work well also, but I used to be in Pittsburgh (grew up there) and a split weight works better for that climate. Not sure about the 400, but the 350 is pretty forgiving as far as oil, as long as it has some. Even ran 20w20 one winter in it, and it ran fine. By the way, do yourself a favor and chuck that rochester q-jet out the nearest window. Go to auto zone and pick youself up a 600 cfm+ holley, you'll be glad you did . Just my opinion....
no way on the Q jet, car comes with 2 and it's all # matching, right down to the AM radio that will be reinstalled...that's why this project is gonna be fun, the car w/ original 15x7 rally wheels, all # matching drivetrain inc the 6x heads, and a TON of GM/Year one spare/original parts (2 shaker hoods, snowflake wheels w/ radials, trim pieces, another q jet, 3 radios, mmanuals, catalogs, receipts, new carpets, etc., on and on), $5K for it all! (car is registered, inspected and passes smog "as is") oh, all new suspension pieces, bushings and NO RUST (originally a Seattle car), I'm "leaning to" Penzoil or Chevron/HaAvoline 10w-30 (aren't they exactly the same???) ?? anybody else? please..
I would run Schaeffer's 15W40, if that's the BB.

Im agree with others on the Q-jet.

If you decide to keep and use the 2 carbs, buy a half-dozen Q-jet rebuild kits, especially parts for the Vacuum operated Power Piston.

Personally, I'd opt for a Holly Spreadbore.

[ June 07, 2004, 03:20 PM: Message edited by: MolaKule ]
I would run Amsoil 15W-40. The cost isn't so bad, it seems perfect for that type of motor and it still cranks great with the cool weather in W.wash (I run it year around in my turbo Volvo).

Delivery is next day in Lynden. Should be faster for you, seeing that the local warehouse is in Portland, OR.
Ha, I was just about to ask the same question.

I've got a 1974 Grand Am with a Pont 400 HO package (dual exhaust, blah blah blah).

Been running 10w-40 mobil1 for about 3 centuries now. Currently have a small rear main seal leak (go figure...**** rope).

Car's never seen synthetic, and had an overhaul in the mid 80's.

I to have a Q-jet, but its currently beefed up to 850 CFM...any particular reason why I'd want to trade it in for a lesser CFM holley?

Unlike Jeff with his ideals or restoration...I'm slowly modding the living crap outta mine. I'm currently stripping it to reduce some of its 4000 lb bloatness. Pretty much every part that comes off sheds off massive amounts of weight. The broken AC components alone weighted about 75 lbs!
10w-30 pennzoil, and keep teh Q - If you know how to work on it (get a book if you don't) it will run circles around a holley. problem is, most people just don't know how to PROPERLY tune them, get disgusted and buy a simpler holley.
Keep 'em coming, yea I can do a Q Jet and have some "local experts" in the Tacoma area, thinking an "over the counter oil", particvularly w/ the car sitting and low mileage expectation..would the high mileage "oils" be any real benefit except to lightening my wallet?
I had a brand new 1975 Trans Am with the 400 motor and ran 10/30 in it for the four years I had it.

I never had any trouble with the QuadraJet although I seem to vaguely recall maybe grinding down some of the metering rods?

I do not recall or did not know that the 1977 400 cid engine had any Crane parts in it. The only difference I can recall is that they put shiny rocker arm covers on the '77 and called it a performance upgrade.

It sickens me to think that if I had bought a year earlier, I could have had a 455 Super Duty instead of the limp wristed 400 cid.
the Crane cam is a " modern regrind" of the Pontiac Ram Air Three cam, ...oh, more than the vc's upgrade the 400 engine from the std L78/400 to the W72 to include: Q jetting at 800cfm vs. 750cfm for base engine, 6x heads resulting in 8:1 compression vs. approx 7.6 for "base 400", .374/.407 camshaft, HO oil pump, slotted bearing caps, special balancer, and distributor curve, another 20' duration and dual exhaust in '78 made the W72 a "220HP" rating vs the '77's "200HP" though much of it was at higher rpm (which is 40HP higher than the std L78 1977400CI), yes, the W72 option can be identified by the brushed (not shiney) valve covers and oil fil cap and cowl tag, head ID, oil suggestion?
checkout www.angelfire.com/wa/ or www.texastransam for more than you ever needed to know!

[ June 07, 2004, 05:52 PM: Message edited by: Jeff in Western WA ]
I think I would run Delvac 1300 15W40 or Delo 400 15W40. No need for an exotic oil with twice a year oil changes and 2000 miles a year worth of driveing. Both of the above oils have a healthy dose of Zink and Calcium. THey will keep the engine clean and hold TBN well. They will also protect your valve train better then a PCMO 10W30 or 10W40 could ever hope to. THe carburator is going to be a lot dirter then most of the PCMO are designed to deal with a HDEO will have no problems.

I am actualy partial to Q-Jets so long as they are set up right. THe way GM had them set up was not ideal. Q-Jets hold their tuning better and are not as affected by temps. as holleys are. THe Q-jet will give you better millage and better throtle responce. Just make sure it has a biger accelerator pump then stock. If you do not like touching the old Q-Jet send then to the Carb Shob for $150 they will rebuild it for you.
Seems like the Diesel oils or Amsoil Marine 15w-40 would have more corrosion inhibitors for a car rarely driven. You might want to spray storage seal (light oil at any marine supply or a lot of auto parts stores) down the carbs for extended lay up like we do with boats to keep the cylinder walls from rust pitting.

Also advise putting some Stabil in your gas to keep the fuel lines and carbs from gumming up.

[ June 07, 2004, 09:06 PM: Message edited by: Geoff ]
keep the Q-jet, the problem with them was no one knew anything about them being they grew up with Holley's. Go get a book on Q-jets and learn about them, they work fine when set up right!(back in my days of the 65GTO/455 70GTO I could not afford the Holley so it was the $5/$10used Q-jets from the wrecking yards and at 750cfm it worked great once I learned how they worked-wouldn't have a Holley!) But one thing you need to do when you have it apart is go find a pre 71/65 or newer 389/400/428/455 and get the windage tray from one with the main bolts that hold it on. It's a longer tray that almost covers the whole crank which the 77 one does not do. Than find a dipstick out of a 66/67 326/389/400/421 and you will have a 7qt capacity instead of a 6 with the same pan. If you try this with the 77tray it will whip oil out the dipstick tube are high rpm's, you need the almost full length tray which does a better job of controling the oil anyway. (ps if you ever come across a set of heads off a 70 455, they would great on your 77. This was the only year they had a high compresstion 455 and on a 400 you get a 9to1 with them which is higher than the less than 8to1 yours came with +they breath better for they are the bigger exhaust valves(1.77instead of 1.66 that 77s have).9to1 is easier to find fuel for today than the 10.75to1 of yesterday that the pre 71 400/455s had.)
I will give you that the holley spreadbore is temperature sensative on the adjustment. Retired the one on the LeMans after 24 years of service and replace it with a non spreadbore model with the help of a 1" spacer on my 68 firebird manifold ( the car came originally with a 2-barrel rochester). This one has not problems with temperature sensitivity. The stock carb setting makes that 350 run like a raped ape. btw: It may be a lack of knowledge thing, but between that 2 barrel and 3 other q-jet 4's I've tried. Thanks, but I'll stick with the simpler holleys. IMO there is a good reason for the old acronym K.I.S.S.

Any and all of the oil suggestions above will work fine. I still would go with a good quality dino 10w30 or 10w40.
Holley's simpler? that's a opinion. Not for me, the Q-jet is simpler and easier to work on along with not as mesy when taking the top off. Holley's waste gas (and prone for leaks) every time you try to rejet(and have to replace blow power valves which is/was common on Holley's). Q-jet's don't even need rejeting once the primary's is set and the secondary's can be reset with out even taking the top off, just a metering rod hanger/or air valve reajustment with one little screw-very easy. I did alot of drag racing years ago and the Q-jet was great for when ajustments were being made between runs(had a "Sucrets" box full of metering rods & things). The only real problem with Q-jets was not enough float bowl fuel reserve which is taken care of with a oversized fuel filter, good fuel pump with a electric fuel pump mounted at the tank so as to keep good pressure going forward when making the 1/4mile runs. With the size of secondarys they have they had a tendancy to run out of gas before you could finish the run(was like flushing the toilet when opening them up-"Quad-ra-toilet").
ya know the original W72 Q jet flowed 800 (!) CFM, this one's in the box as it couldn't pass emmissions so a new Q jet was installed (now I got two), gonna "put 'em together", make it right and #'s matching and have the carb shop in Fife WA, jet, scope, snif and correct, the one on it runs nice, secondaries open a bit quick as lighter springs have been installed, passes smog #'s though now exempt, distibutor has been curved nice, but, I'll pull and scope that too to be sure and use the aftermarket HO coil for street driving along with an opened (and higher) '78 shaker , 3:43's vs. stock 3:23's though the '77 shaker will be painted correct and kept along with the correct coil, even GM wires have been replaced w/ Delco! This is gonna stay as much "OEM equivalent" as possible...my '96 DGGM modifed LT-1 powered Impala SS is much faster anyway and with only 9800~ miles another garage/show/ queen since new...Diesel oil? regular dino? High mileage oil???
Pontiac was calling for 10w40 in this car when they were being made and I would probaly stay with something in that weight area - would probaly be using 15w40Delo today. I used to use 20w40 in my 70455GTO which was ARCO's version of Delo at the time in the early 70's.(Dad had a ARCO station back than-should say "service" station for there was a such thing years of ago! back before this am/pm arco garbage laced with 10percent alcahol mix cheap gas of today. In fact Arco does not even make oil anymore, just some house brand labeled stuff now owned by BP.)
geez, I remember using ARCO "Graphite 10W-40" in my 273 cu in Dodge Coronet, now I feel dated, since I worked in a "full service" station, probably most fun on a job almost ever, minor tune up's, lubes, oil, tires, etc., and lots of pumping .599 CHEVRON gas..
what about oil for my Pontiac 400? Diesel oil/high mileage/brand/weight....needs some suggestions and "facts" why..
.599!! thats after I came home from germany in 76, for me it was buying supreme for .369 and pumping reg for .329 prior to the 73 oil embargo. remember my dad selling reg for .199 in 65/66 during some of the famous gas wars and on top of that, trucking companys got a .02 per gal discount(.179)for buying large quanitys!(turned 50 in feb.)
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