diff --git a/src/pages/Explorer/BlockTable.tsx b/src/pages/Explorer/BlockTable.tsx
index 789fd07..a903560 100644
--- a/src/pages/Explorer/BlockTable.tsx
+++ b/src/pages/Explorer/BlockTable.tsx
@@ -18,8 +18,6 @@ interface PositionedBlock {
   branches: number[]
 }
 
-// 1 hour in polkadot
-export const MAX_LENGTH = 3600 / 6
 const blockTable$ = state(
   combineLatest([blocksByHeight$, best$]).pipe(
     debounceTime(0),
@@ -35,11 +33,7 @@ const blockTable$ = state(
           }
         }
       }
-      for (
-        let height = best.number;
-        blocks[height] && result.length < MAX_LENGTH;
-        height--
-      ) {
+      for (let height = best.number; blocks[height]; height--) {
         const competingBlocks = [...blocks[height].values()]
         if (competingBlocks.length > 1) {
           if (height === best.number) {
diff --git a/src/pages/Explorer/block.state.ts b/src/pages/Explorer/block.state.ts
index bda56d2..9948219 100644
--- a/src/pages/Explorer/block.state.ts
+++ b/src/pages/Explorer/block.state.ts
@@ -36,6 +36,7 @@ import {
   takeUntil,
   takeWhile,
   tap,
+  timer,
   withLatestFrom,
 } from "rxjs"
 
@@ -157,8 +158,14 @@ export const [blockInfo$, recordedBlocks$] = partitionByKey(
             NEVER,
           ),
       ),
-      // Reset when chainHead is changed
-      takeUntil(chainHead$.pipe(skip(1))),
+      takeUntil(
+        merge(
+          // Reset when chainHead is changed
+          chainHead$.pipe(skip(1)),
+          // Or after 1 hour
+          timer(60 * 60 * 1000),
+        ),
+      ),
     ),
 )
 
@@ -232,13 +239,19 @@ export const blocksByHeight$ = state(
   merge(
     recordedBlocks$.pipe(
       mergeMap((change) => {
+        if (change.type === "remove") {
+          return of({
+            type: "remove" as const,
+            keys: change.keys,
+          })
+        }
         const targets$ = forkJoin(
           [...change.keys].map((hash) => blockInfo$(hash).pipe(take(1))),
         )
 
         return targets$.pipe(
           map((targets) => ({
-            type: change.type,
+            type: "add" as const,
             targets,
           })),
         )
@@ -254,23 +267,31 @@ export const blocksByHeight$ = state(
     scan(
       (acc, evt) => {
         if (evt.type === "remove") {
-          for (const { hash, number } of evt.targets) {
-            acc[number]?.delete(hash)
-            if (!acc[number]?.size) {
-              delete acc[number]
+          for (const hash of evt.keys) {
+            const height = acc.heightOfBlock[hash]
+            acc.blocksByHeight[height]?.delete(hash)
+            if (!acc.blocksByHeight[height]?.size) {
+              delete acc.blocksByHeight[height]
             }
+            delete acc.heightOfBlock[hash]
           }
         } else {
           for (const block of evt.targets) {
-            acc[block.number] = acc[block.number] ?? new Map()
-            acc[block.number].set(block.hash, block)
+            acc.heightOfBlock[block.hash] = block.number
+            acc.blocksByHeight[block.number] =
+              acc.blocksByHeight[block.number] ?? new Map()
+            acc.blocksByHeight[block.number].set(block.hash, block)
           }
         }
 
         return acc
       },
-      {} as Record<number, Map<string, BlockInfo>>,
+      {
+        blocksByHeight: {} as Record<number, Map<string, BlockInfo>>,
+        heightOfBlock: {} as Record<string, number>,
+      },
     ),
+    map((v) => v.blocksByHeight),
   ),
 )
 
diff --git a/src/pages/Explorer/events.state.ts b/src/pages/Explorer/events.state.ts
index e54d8f0..440af15 100644
--- a/src/pages/Explorer/events.state.ts
+++ b/src/pages/Explorer/events.state.ts
@@ -4,7 +4,6 @@ import { state } from "@react-rxjs/core"
 import { combineKeys } from "@react-rxjs/utils"
 import { filter, map, takeWhile } from "rxjs"
 import { blockInfo$, BlockState, recordedBlocks$ } from "./block.state"
-import { MAX_LENGTH } from "./BlockTable"
 
 const blackList = new Set([
   "System.*",
@@ -102,8 +101,7 @@ export const recentEvents$ = state(
             }
             return group
           })
-        })
-        .slice(0, MAX_LENGTH),
+        }),
     ),
   ),
   [],