diff --git a/spec/src/consensus.rs b/spec/src/consensus.rs
index 0f059d1dfb4..1627c483f69 100644
--- a/spec/src/consensus.rs
+++ b/spec/src/consensus.rs
@@ -60,8 +60,10 @@ pub(crate) const GENESIS_EPOCH_LENGTH: u64 = 1_000;
 // o_ideal = 1/40 = 2.5%
 pub(crate) const DEFAULT_ORPHAN_RATE_TARGET: (u32, u32) = (1, 40);
 
-const MAX_BLOCK_INTERVAL: u64 = 48; // 48s
-const MIN_BLOCK_INTERVAL: u64 = 8; // 8s
+/// max block interval, 48 seconds
+pub const MAX_BLOCK_INTERVAL: u64 = 48;
+/// min block interval, 8 seconds
+pub const MIN_BLOCK_INTERVAL: u64 = 8;
 
 /// cycles of a typical two-in-two-out tx.
 pub const TWO_IN_TWO_OUT_CYCLES: Cycle = 3_500_000;
diff --git a/sync/src/types/mod.rs b/sync/src/types/mod.rs
index 04170214883..3171878242a 100644
--- a/sync/src/types/mod.rs
+++ b/sync/src/types/mod.rs
@@ -4,7 +4,7 @@ use crate::utils::is_internal_db_error;
 use crate::{Status, StatusCode, FAST_INDEX, LOW_INDEX, NORMAL_INDEX, TIME_TRACE_SIZE};
 use ckb_app_config::SyncConfig;
 use ckb_chain::chain::ChainController;
-use ckb_chain_spec::consensus::Consensus;
+use ckb_chain_spec::consensus::{Consensus, MAX_BLOCK_INTERVAL, MIN_BLOCK_INTERVAL};
 use ckb_channel::Receiver;
 use ckb_constant::sync::{
     BLOCK_DOWNLOAD_TIMEOUT, HEADERS_DOWNLOAD_HEADERS_PER_SECOND, HEADERS_DOWNLOAD_INSPECT_WINDOW,
@@ -103,8 +103,8 @@ impl ChainSyncState {
 
     fn tip_synced(&mut self) {
         let now = unix_time_as_millis();
-        // use avg block interval: (MAX_BLOCK_INTERVAL + MIN_BLOCK_INTERVAL) / 2 = 28
-        self.headers_sync_state = HeadersSyncState::TipSynced(now + 28000);
+        let avg_interval = (MAX_BLOCK_INTERVAL + MIN_BLOCK_INTERVAL) / 2;
+        self.headers_sync_state = HeadersSyncState::TipSynced(now + avg_interval * 1000);
     }
 
     fn started(&self) -> bool {
diff --git a/tx-pool/src/component/orphan.rs b/tx-pool/src/component/orphan.rs
index c8dc3accc0e..ae045beab9c 100644
--- a/tx-pool/src/component/orphan.rs
+++ b/tx-pool/src/component/orphan.rs
@@ -1,3 +1,4 @@
+use ckb_chain_spec::consensus::MAX_BLOCK_INTERVAL;
 use ckb_logger::{debug, trace};
 use ckb_network::PeerIndex;
 use ckb_types::packed::Byte32;
@@ -9,7 +10,7 @@ use ckb_util::shrink_to_fit;
 use std::collections::HashMap;
 
 const SHRINK_THRESHOLD: usize = 100;
-pub(crate) const ORPHAN_TX_EXPIRE_TIME: u64 = 2 * 48; // double block interval
+pub(crate) const ORPHAN_TX_EXPIRE_TIME: u64 = 2 * MAX_BLOCK_INTERVAL; // double block interval
 pub(crate) const DEFAULT_MAX_ORPHAN_TRANSACTIONS: usize = 100;
 
 #[derive(Debug, Clone)]