Poor man's TC baffle project


On the recomendation of Ranger et al I bought the TC Motorsports baffle for installation prior to the next race. On removal of the oil pan I found that the stock oil pan already has a somewhat serviceable baffle and along with the inexpensive TC baffle and a couple bucks worth of HW can be made to simulate some of the pricier baffles.

The TC baffle is nothing more than plate aluminum with clearance holes for the pump, dipstick, and OP switch. If you’re sufficiently inspired you could duplicate this part on your own for less than $10.


Removing the stock baffle is just a matter of drilling the stud in the front passenger side corner of the oil pan where the stud has been swaged over the mounting hole in the baffle and sliding the baffle off of the stud and out of the rubber isolated holes in the side of the pan. Try not to drill the stud any more than absolutely necessary as you’ll use it later to refasten everything.


Once the stock baffle was out I used bimetal hole drills to add some holes to the lower baffle area where it leads into the sump on the driver’s side of the engine. NOTE: Measure the clearance of the holes laterally to the oil pump pickup with the oil pump in the pan. If the holes are drilled too far towards the rear of the pan, the oil pump pickup WILL INTERFERE with the door. (Ask me how I know.)


Next comes a flap door made from some 0.063 sheet steel I had around from another project. This was kind of flimsy and if I were to do it again, I’d probably opt for something thicker or some aluminum plate. I added a couple of hinges from the local Ace Hardware and connected it all with my favorite fastener for the welding impaired. A 3 or 4 mm buttonhead would have worked a little better but you have to be careful how much thickness you add to the back of the door as this impacts its ability to seal the newly added holes in the factory baffle. If you’re careful, you can dimple the factory baffle where the fasteners are to make this a more flush fit, but I’m too lazy to eliminate the last 1 mm gap. You also need to make sure that the hinge mounting allows for free movement of the door. This may involve either replacing the hinge pins with something thinner, ala the VAC wired hinge, or maybe a thin shim under the hinge body where it attaches to the factory baffle. I just lightly pried up on the hinges to make sure that they moved freely.


Next I attached the TC piece, again with pop rivets.


Finally I drilled and tapped the original mounting stud for a 4 mm large head screw and refastened the newly enhanced factory baffle back in place with threadlocker red to make sure it stays there.


Hopefully this will help limit the oil starvation problem M20’s seem to have and eliminate the need for any more bottom end work for a while.


That was well done. Both the effort and the write-up.

Additional thoughts that might be of use.

  1. Put the swing door as far forward as you can because you don’t want it to extend backwards very far. Fish Bratton figured out the other day that the door’s rear will hit the oil pump pickup if it extends rearward very far. This limits how much the door will open.

  2. When removing material in the oil level baffle plate, the piece that the swing door covers, you might want to remove material nice and low. That will allow more oil to come from behind the oil level baffle thru the open door and get to the oil pump pickup.


Ruh roh, didn’t check the pump clearance. Will have to go back and do that. I did however purposely select the hole location relatively low on the baffle.


Nice write up.


I’m not sure that you can check pump clearance, at least not easily. But I don’t think it’s a crisis. The door will open some no matter how you do it because there is some clearance there between the baffle wall and oil pump pickup. A 1/4" door opening will flow a lot of hot thin oil in a second or two of lat g’s in a fast sweeper.


Nice job on that baffle setup!!! I concur with Scott that the trap door is going to hit the oil pump. Because the oil pump nearly touches the bottom of the pan, your door isn’t going to open more than an 1/8" or so. The concave portion on the OEM baffle is there for oil pump protrusion and you need to be about 1" off where the curve starts. If you alleviate the hole closest to the pump and trim the door to cover the one large forward hole and two smaller holes, your door should function properly.


To check clearances to the trap doors I marked the exact location of the oil pump on the scraper. Then I installed the scraper on the pan and held the pump in place while operating the trap doors.


Well aren’t you a clever one .

Seriously tho, that was good thinking.


Thanks gentlemen, issue confirmed. I’ll mod the door a little tonight and see how much clearance I can actually get. Richard’s estimate of about 1/8" is pretty close. I’m sure I can get to a quarter or even a half. I tried turbo’s trick (which WAS clever BTW) but the TC baffle has a pretty nice cutout matched to a ridge on the pump casting that works almost as well. Writeup edited accordingly.


A little judicious grinding and filing gets about a 1/2" but wish I’d done it Turbo’s way from the get go. Disassembled the oil pump. It’s obviously ingested something largish during its existence and there’s about a 5-7 mil deep scratch about 20 mils wide in the top of the inlet gear just about where the chamfer starts and a corresponding groove in the cover. Whatever it was is now flushed. There are other pieces of #6 bearing in the screen so probably the culprit.