The Stovebolt Site Forums The Shop Area Engine Shop GMC ENGINE HELP!

Does anybody have a 228-302 gmc engine taken apart? I am trying to reassemble mine, and have run into a small problem. The very expensive aftermarket aluminum oil pan I will be using does not have baffels in it like the stock pan.

I need to know how many baffels the stock pan had, where they were, and what the dimensions are. I also need to know the depth of a stock pan to determine weather I need to extend the pickup tube on the oil pump.

This is very important to prevent "cavitation" in the oil. Any help would be appreciated. Pictures and measurements would be awesome.

Thanks
John

Hey John,
I just finished my 228 and the pan is on. But I'll take a look tonight and try to get you some dimensions of where the baffles are, etc.

Neil, I would hate for you to take that pan off. I'm sure someone has a pan already off their engine. Looks like you and I are working on the same truck! I have a 1940 3/4 ton.

I have also posted this on the old gmc trucks site, and have a oil pan wanted add in the swap meet area.

When are you planning to fire that old 228 back up?

If you use the old dipstick and keep the level up, having to drop the pickup shouldn't be an issue. No cavitation if the level is kept above the pickup. A deeper pan would just provide more capacity and better cooling.

MN,

I think you are right. But with more oil, there is more of a chance of that oil moving around in that pain. In a worse case scenario, the crank will run through the oil in the pan causing a rapid loss of rpms. The stock pans had baffels in them, for whatever reasson. It stands to reason that a performance built engine should need them more than a stock engine.

Thanks
John

Oh yeah, baffle yes.

But as far as the pickup goes, it might be better to have it higher up off the bottom of the pan so any of the heavy crud parts have less of a chance to get sucked in. More of a chance for them to stay at the bottom of the pan where they will drain out at the next oil change.

I have had several of these engines apart and have not seen a baffle in any of the pans I have worked with. The only one that was really different is the Mil Spec pan off of my military 302. It has a very deep sump on it.

bigbadswingdaddy, I just sent you an email with a picture of a 270 pan and measurements of the baffles.

For the record-

The front baffle is 3" high and 8¾" from the front. The rear baffle is 3¼" high and 6¼" from the rear. The pan is 6¼" deep at the rear, 6¾" or a little more at the plug and 6" deep about 5" from the front then rises at about a 45º angle to the front.

Thanks everyone for the quick replies.

Cletis, could I have you remeasure the heights of the baffels with respect to the mounting flanges? In other words... How deep are the top of the baffels in relation to the engine block?

The tops of both baffles are about 3½" from the mating surface.

Thanks Cletis.

I am going to take another look at that pan, and take some pics tomorrow. I'm thinking it doesn't need the baffels because it is a rear sump pan. It does look like I will have to extend the pick up tube to the rear sump. I don't think it would be healthy to put the oil level to the stock height... prolly bout 18 courts!

Hey bigbadswingdaddy,
I tried looking at the pan but couldn't see anything from the outside. I was hoping there would be a telltale sign of where the baffles are located. You're right, I don't want to drop the pan unless I have to. But I will if you really can't find the info and have nowhere else to turn. Just let me know. It's on a stand right now so wouldn't be a terrible ordeal. Just for the record, the pan is pretty much the same depth from front to back. I don't know if this is normal or not for the 228. In other words, there isn't a sump area towards the rear like you see on most oil pans.

I'm not sure when I'll get it fired up. I actually rebuilt it last fall. Just haven't gotten it installed and started up yet. Getting close.

Again, let me know if you need me to drop the pan and take pictures of it.

Neil,

Cletis has sent me some dimensions. I don't think I need the baffels because of the rear sump design of the pan I have. My pan will hold more oil, and cool it better than a stock pan.

Thanks for the offer, BUT PLEASE DON'T TAKE THAT ENGINE APART.

If you have any questions on your 1940, don't hesitate to send me a pm. Might not be able to help, but us 1940 GMC guys have to stick together!