Western bankers are giving Poland a vote of convidence despite its labor stoppages and its slipping economy.

Although Poland has the second largest economy in the Soviet Bloc -- after the Soviets themselves -- it is by far the heaviest debtor to Western bankers, and its economic performance tailed off badly in 1979. Nevertheless, Western banks, led by the Bank of America, will grant Poland a $325 million loan Friday, coming on the heels of a $677 million loan from West German banks last week.

Poland already owes the West $20 billion out of a $65 billion total debt for Comecon, the East European trade bloc.

"The general view among the bankers who know Poland best is that they will work out their situation by themselves," said a London financial expert who just returned from Warsaw. "Obviously some bankers are concerned, but they do not see the same scenario as was followed in the previous period of unrest."

He referred to strikes in 1970 that the government used armed force to put down.

"This is not the same repressive regime as in 1970," he said. "The situation has changed also because the standard of living in Poland has been riased substantially in the last decade."

The center of major strike activity is the huge Lenin Shipyard in Gdansk, one of the few enterprises that brings Poland the large volume of hard currency income needed to pay its debts.

Polish economists have estimated that the strike at the shipyard alone could cost the country $300,000 perday for each vessel being built. The yard was scheduled to build 19 ships this year. Also because of the strikes, 100 Polish and foreign-flag merchant ships were sitting idle in the ports of Gdansk, Gdynia and Szcecin.

Even more vital for Poland's international economic standing are the huge coal fields in Silesia, the region that forms the political base for Edward Gierek, Poland's Communist Party leader.

Poland is the world's second largest exporter of coal, after the United States, and coal income is essential to keep Poland solvent in the eyes of internatinal bankers.

"If the coal mines go on strike then Gierek will be finished," an analyst commented here today.

Reports from Poland today said there were scattered work stoppages in steel mills near Krakow in the southern part of the country, not far from the Silesian mines.

Granted large incentives to increase production, the Silesian miners last year dug 200 million tons of coal for the first time. About a quarter of the output was exported.

A third of the big new West German loan is earmarked to increase coal production. Warsaw is expected to use most of the money to buy new equipment from West Germany and in increase its coal deliveries there starting in 1985.

For years Poland has been buying technology in the West to Stimulate economic growth. While other East European countries have followed a similar development pattern, the Poles have overextended their buying while failing to increase the exports needed to pay their bills.

With the two new loans, Polish officials said they had secured three-fourths of the hard currency needed to meet their debts this year. They also said that their needs would be lower in the next two years.

But the strikes are likely to reduce any progress the country is making on exports and production.

Poland will pay 1.5 percent over the London lending rate for its loans. It is not Known whether Moscow would help Warsaw make loans payments should a default appear imminent.

Some bankers believe that Moscow has previously loaned the Poles hard currency and that some other surplus Comecon credits were directed to Warsaw. c

To win new loans in the midst of economic problems, Poland has made more financial information available than any Soviet ally ever has. The country has run a trade deficit with the West for 11 consecutive years and paid the difference through its loans.