MG Sports Cars

I have a 77 Midget with a stock 1500 engine (read below for the full story). Oil pressure was pretty low once warmed up - about 20 psi at 3000 rpm. So I dropped the pan and replaced the main and rod bearings. I had read about using 77MGB rod bearings in place of the stock bearings so ordered these from Vic Brit after reading up on the modification and checking the sizes of STD crank journal diams on the MGB and 1500 engines. I filed the "tang" so the MGB rod bearings would fit and installed them yesterday. After tightening the rod bolts the crank was very hard to turn by hand. Now remember, I'm doing this from under the car and turning the crank by hand. I can turn it, but its much harder to turn now vs with the old bearings I just replaced. I did use engine assembly lube, and changing the main bearings had no effect on the force I had to use to turn the engine. My next step will be to use plasti-gauge to measure the clearance. But I wanted to seek the wisdom of the group to see if anyone has experience with this modification or any suggestions.

Here is the short -full story on my midget: About 12 yrs ago I got anther 1500 engine with the intention of rebuilding it to get more HP and spent lots of $$s on parts from Triumph Tune in the UK. My timeline back then was to get the engine built before I left the country to go to South Africa for a year. I didn't manage it and all the engine parts are still in boxes today. So I had a "spare" 1500 engine I got from a Spitfire that had been in a fire. Just so I could actually drive the car before leaving the country, I torn down most of that engine to replace the gaskets an seals, thru it in the car and drove it 20 miles to where I stored it while I was in South Africa. It has sat undriven in my garage for the past 10 yrs until a few months ago I decided to get it back on the road. It still had the "spare" 1500 engine in it and thats the engine I just replaced the bearing in.