Even before the Nov. 8 general election in Virginia, Tuesday's primary results assure that there will be sweeping changes in the state House of Delegates when it meets again next January.

The leaders of at least three important House committees will change. At least five of the 19 Northern Virginia incumbents will be replaced by political newcomers. The number of black members in the House is likely to increase from just one to four.

Currently, there are 17 Republicans, three independents and 80 Democrats in the House.

Northern Virginia incumbent Democratic Dels. John L. Melnick and Ira M. Lechner of Arlington and Carrington Williams of Fairfax will not be up for election in November. Melnick and Lechner lost their bids for the Democratic nomination for attorney general and lieutenant governor, respectfully, in Tuesday's primary. Williams has said he plans to run for the U.S. Senate next year.

In addition, Republican Dels. Wyatt B. Burrette and James E. Dillard will not be returning. Durrette recently lost his bid for the Republican nomination for attorney general.

Dillard, who had been elected three times, was defeated in Tuesday's primary by a coalition of three conservatives who had labeled the Fairfax County schoolteacher as too liberal for the Republican Party.

The three-man team of Robert L. Thoburn, Lawrence D. Pratt and John W. Adams targeted Dillard as the man to unseat in the six-man race for the five party nomination in the 19th House District in southern Fairfax County.

A letter sent last weekend to known Republicans in the district urged voters to reject Dillard. The three conservatives said they had nothing to do with the letter, which was signed by Kathy Teague, a Fairfax County Republican committee member.

Adams said yesterday that the victory of the three men will mean that voters in November will have a clear-cut choice. "Our party will be taking one position and the other party will be taking another. There won't be any ducking or dodging of the issues."

Dilalrd, who has been most active on education issues, said his six years in the state legislature have "gone down the tubes." He said his defeat obviously meant that people in the Republican Party "are not in a mind to have me as a standard-bearer."

"Evidently the reactionaries have gone out and brought people into the party he charged.

"I'm very disappointed that Jim lost," said three-term Del. Warren E. Barry, who along with second-term Del. Robert E. Harris, won the two other party nominations in the 19th District. "It defies logic," said Barry, who added that Dillard's incumbency would have been an asset for the GOP in the November election.

Joseph Ragan, chairman of the county Republican Party, said, "I admit that they (Thoburn, Pratt and Adams) may be a little more conservative than the other two (Barry and (Harris)." However, he said he is urging the five candidates to run as a team. But Barry, Ragan and Adams all said they did not know whether the five would run together.

Fifteen-term Democratic Del. Lewis A. McMurran Jr. of Newport News, second-ranking in seniority to House Speaker John Warren Cooke, also lost his bid for renomination in Tuesday's primary.

McMurran, chairman of the House Roads and Internal Navigation Committee, was defeated by Robert C. Scott, a 30-year-old black lawyer from Newport News, and two incumbents in a four-way race for three nominations.

Scott credited his victory to "a lot of hard work." He said his supporters telephoned 10,000 voters the day before the election promoting his candidacy. He said the same 10,000 voters were phoned on election day to remind them to go to the polls. He said he took about 200 people to vote.

In addition to Scott, James Christian and Benjamin Lambert, two black Democratic nominees from Richmond, are expected to join Dr. William P. Robinson of Norfolk, the only black member of the House in the next session. Robinson was unopposed for renomination.

Del. Orby Cantrell of Wise Gunty, second-ranking Democratic member of the Roads Committee and an outspoken advocate of more highway funds for rural roads in Southwest Virginia, said he is likely to succeed McMurran as the committee's chairman.

Cantrell noted, however, that he is chairman of the House Counties, Cities and Towns Committee and said he would have to give up that position if he takes McMurran's post.

In addition to changes in the chairmanships of these two House committees, these will be a new chairman of the influential House Appropriations Committee.

Democratic Del. Edward E. Lane of Richmond, the current appropriations chairman, is his partys nominee for attorney general against Republican state Sen. J. Marshall Coleman of Staunton.

Traditionally the senior ranking member of the committee assumes the chairman's position which in this case would be Del. James M. Thomson of Alexandria, the House majority leader. He faces a reelection challenge in November.

Both parties yesterday said they expect to gain additional seats in the House.

Del. George N. McMath of Accomack, chairman of the state Republican Party, said there are 54 Republicans up for election in the November House races.

Thomson said he expects the Democrats to gain six seats throughout the state, including one seats throughout the state, including one each in Northern Virginia's 18th and 19th Districts.