diff --git a/iroh-sync/src/sync.rs b/iroh-sync/src/sync.rs
index beff870a45..f6bb0d5f9f 100644
--- a/iroh-sync/src/sync.rs
+++ b/iroh-sync/src/sync.rs
@@ -226,12 +226,15 @@ impl<S: ranger::Store<SignedEntry> + PublicKeyStore + 'static> Replica<S> {
     /// received from in a loop. If not receiving, local and remote inserts will hang waiting for
     /// the receiver to be received from.
     // TODO: Allow to clear a previous subscription?
-    pub fn subscribe(&self) -> Option<flume::Receiver<(InsertOrigin, SignedEntry)>> {
+    pub fn subscribe(
+        &self,
+        channel_cap: usize,
+    ) -> Option<flume::Receiver<(InsertOrigin, SignedEntry)>> {
         let mut on_insert_sender = self.on_insert_sender.write();
         match &*on_insert_sender {
             Some(_sender) => None,
             None => {
-                let (s, r) = flume::bounded(16); // TODO: should this be configurable?
+                let (s, r) = flume::bounded(channel_cap);
                 *on_insert_sender = Some(s);
                 Some(r)
             }
diff --git a/iroh/src/sync_engine.rs b/iroh/src/sync_engine.rs
index 6c9c2f377b..5061679e58 100644
--- a/iroh/src/sync_engine.rs
+++ b/iroh/src/sync_engine.rs
@@ -38,7 +38,7 @@ impl<S: Store> SyncEngine<S> {
     /// engine with [`Self::start_sync`], then new entries inserted locally will be sent to peers
     /// through iroh-gossip.
     ///
-    /// The engine will also register for [`Replica::subscribe`] events to download content for new
+    /// The engine will also subscribe to replica events to download content for new
     /// entries from peers.
     pub fn spawn<B: BaoStore>(
         rt: Handle,
diff --git a/iroh/src/sync_engine/live.rs b/iroh/src/sync_engine/live.rs
index 6a8ab50822..f8b2eb7c7d 100644
--- a/iroh/src/sync_engine/live.rs
+++ b/iroh/src/sync_engine/live.rs
@@ -41,7 +41,10 @@ use tracing::{debug, error, error_span, warn, Instrument};
 
 pub use iroh_sync::ContentStatus;
 
-const CHANNEL_CAP: usize = 8;
+/// Capacity of the channel for the [`ToActor`] messages.
+const ACTOR_CHANNEL_CAP: usize = 8;
+/// Capacity of the subscription channel for replica events.
+const REPLICA_SUBSCRIBE_CHANNEL_CAP: usize = 64;
 
 /// An iroh-sync operation
 ///
@@ -194,7 +197,7 @@ impl<S: store::Store> LiveSync<S> {
         bao_store: B,
         downloader: Downloader,
     ) -> Self {
-        let (to_actor_tx, to_actor_rx) = mpsc::channel(CHANNEL_CAP);
+        let (to_actor_tx, to_actor_rx) = mpsc::channel(ACTOR_CHANNEL_CAP);
         let me = endpoint.peer_id().fmt_short();
         let mut actor = Actor::new(
             endpoint,
@@ -627,7 +630,7 @@ impl<S: store::Store, B: baomap::Store> Actor<S, B> {
 
             // setup event subscription.
             let events = replica
-                .subscribe()
+                .subscribe(REPLICA_SUBSCRIBE_CHANNEL_CAP)
                 .ok_or_else(|| anyhow::anyhow!("trying to subscribe twice to the same replica"))?;
             self.replica_events.push(events.into_stream());
 
diff --git a/iroh/tests/sync.rs b/iroh/tests/sync.rs
index a20d7502d9..0141a81b64 100644
--- a/iroh/tests/sync.rs
+++ b/iroh/tests/sync.rs
@@ -24,7 +24,8 @@ use iroh_sync::{
     AuthorId, ContentStatus, Entry, NamespaceId,
 };
 
-const LIMIT: Duration = Duration::from_secs(15);
+/// Time limit for event collection in sync tests.
+const LIMIT: Duration = Duration::from_secs(30);
 
 /// Pick up the tokio runtime from the thread local and add a
 /// thread per core runtime.
@@ -339,7 +340,7 @@ async fn sync_big() -> Result<()> {
     let rt = test_runtime();
     let n_nodes = std::env::var("NODES")
         .map(|v| v.parse().expect("NODES must be a number"))
-        .unwrap_or(3);
+        .unwrap_or(20);
     let n_entries_init = 1;
     // let n_entries_live = 2;
     // let n_entries_phase2 = 5;