Oil pressure issues, looking for a solution Options

[North Coast Jim]

Locked up my 2L motor when doing some spirited driving on a closed course. Spun the rear main bearing. Trying to track down the underlying culprit of low pressure ONLY during hard Left turns.

A little background. Had the original motor, having sat for years, rebuilt in 2019. Stock build up except for HAM heads and a WEB Cam for carbs. Built engine for running 40 IDF Webers. Oil pump is a modified type I from LN Engineering the Type IV store. Car ran great after sorting except for a flickering engine oil pressure as above. Added a Tangerine Racing remote oil cooler to the car as we had some instances of freeway driving getting oil temps to run a bit high to my liking. All original gauges to the car.

First time I saw the light was getting up to speed for a freeway entrance, a left hand 90 degree turn. Immediate lift and return to the barn. Found oil about a pint or two low. Filled back up and proceeded on my drive. Only occurrence that summer and the third year after rebuilding. Put 7000 miles on the motor over 5 years.

When the engine finally expired it was after running laps at the improvised race course for the PIB races on South Bass Island. Crankcase was filled with an extra half quart of oil. Speeds would force a red line run in third gear at four points on the track. On two specific turns, both hard and long left hand turns, the oil light flickered. I got out of the throttle immediately. Happened on three laps and I turned in. Car ran well for rest of the weekend and I drove it home. Went to start it on Wed following and the engines was locked up.

Tear down found a rear main bearing spun tearing the locating pin out of the case. No other bearings showed evidence of oil starvation. Had the case welded, machining in new locating pin locations for rear and the journal forward of that (who knows how many miles were on the original build and this second journal was a bit sloppy). Case was then line bored. Bought new forged crank.

Reluctant to put this thing back together without a find/fix for the oiling issue. Is there a design issue with the internal oiling of our type IV motors that would be a cause. Am I missing anything. Any ideas from the brain trust. Appreciate any and all inputs. Thanks All

[brant]

Type 4 track use requires better oiling

Accusump
Or dry sump

Tuna can can be adequate for the street
Do you have a tuna can?

[North Coast Jim]

Type 4 track use requires better oiling

Accusump
Or dry sump

Tuna can can be adequate for the street
Do you have a tuna can?

No Tuna Can. Bought the SCAT Deep Sump set up. Wasn't too keen on their oil pickup set up with a hose and screw clamp. After we got past that and filled the engine with oil we found the casting porous leaking oil. I can see from outside to the internals. This set up is now sitting on the bench never to be used.

Where to buy the Tune can ??

[brant]

In classifieds here
I can’t remember.. think Rich sells them
Check out the vender classified if not the regular classifieds

[stownsen914]

I used a tuna can on a tracked 914 years ago. Also ran an extra half quart of oil which helped a bit. I think 914rubber carries a tuna can these days?

[914werke]

I think 914rubber carries a tuna can these days?

No they dont.

Even though I sell the temp senders 2 to 1 over the mini sump I feel these are more critical.
HERE

(IMG:style_emoticons/default/bye1.gif)

[North Coast Jim]

I think 914rubber carries a tuna can these days?

No they dont.

Even though I sell the temp senders 2 to 1 over the mini sump I feel these are more critical.
HERE

(IMG:style_emoticons/default/bye1.gif)

Sending my engine builder your way.

[914Sixer]

Try running the 911/914-6 oil filter. Hangs down lower but gives you a half quart more. Plug and play no modification.

[Superhawk996]

Measure the oil pump carefully - T1 pumps are (IMG:style_emoticons/default/stromberg.gif) most have the pump OD too small by up to 0.002” which is a built in oil pressure loss at the pump outlet and an air leak at the oil pump inlet that can lead to aeration and further pressure loss.

Correct OD is 70mm =2.756” and the T4 pump is a light press fit that needs to be tapped into the case. I have measured T4 pump OD at 2.757” using Mitutoyo digital calipers.

Ya ya I know Raby uses T1 pumps and hates the T4 pump. However Raby takes special care to get pumps that fit properly. At one point I believe he was investigating his own billet pumps with a +/- fit tolerance so he could select fit pumps to cases based on posts he made in this forum.

Beware.

[mgphoto]

Agree with superhawk, T1 pump needs too much to make it work properly, o-ringed body, spacer to line up the ports, position of the drive slot and more.
I decided to use the original pump after doing all that work I saw the big picture, it wasn’t the right solution, just my experience.

[porschetub]

Not sure here but think it was a bearing problem that existed with the old case ,poor bearing fit due to the case needing a line bore to remedy ,appears this would have lot to do with oil pressure loss .
Not really sure why the OP continued running like this ??...oil pressure loss @ RPM is a huge red flag ,cheers.
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