# Honing Alusil Engine blocks? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** 5-series, engines, bmw\ **Created:** [February 15, 2025, 5:23am UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146 "2025-02-15T05:23:19Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [February 15, 2025, 5:23am UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/1 "2025-02-15T05:23:19Z")
Im taking my N62 V8 engine down to the block, im going to drop it off at a local BMW shop once removed. id really love to check the cylinder walls but i heard you cant hone alusil blocks like usual has any mechanic had experience with these blocks? is it even possible to have them honed to inspect for damage? also lets say the engine may have to be bored over, then that would just make this block useless if they cant even be honed? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [February 15, 2025, 5:30am UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/2 "2025-02-15T05:30:27Z")
> [@Dakotawoodsusa\_192743](#): > > is it even possible to have them honed to inspect for damage? You visually inspect and measure the cylinders to determine if they need to be bored. And honing and boring are two different things Tester ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [February 15, 2025, 5:46am UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/3 "2025-02-15T05:46:19Z")
yes. i need to hone the block to check for damage or deep scratches, because im pretty sure piston rings are gone. due to car losing compression. or hopefully not a bent rod…which would be even worse damage. i need to check to see if they will have to be bored before i take it off. but i heard you cant just go to town with honing an alusil block because of the silicone crystals for the piston to ride on. just seeing if anyone has an any experience with these before. this engine hasnt been bored before. its still a stock block ---
**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\ **Post date:** [February 15, 2025, 11:15am UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/4 "2025-02-15T11:15:22Z")
I would hope that the shop sleeved the block if it was mine. ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [February 15, 2025, 12:47pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/5 "2025-02-15T12:47:11Z")
Honing would remove scratches, it’s not a check for them. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [February 15, 2025, 2:16pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/6 "2025-02-15T14:16:49Z")
> [@Dakotawoodsusa\_192743](#): > > yes. i need to hone the block to check for damage or deep scratches You need to check for damage or deep scratches BEFORE honing. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [February 15, 2025, 2:46pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/7 "2025-02-15T14:46:22Z")
Boring the cylinders removes material from the cylinder walls to remove deep scratches and makes the cylinders round and straight. Honing the cylinders puts a cross-hatch pattern on the cylinder walls to so the piston rings seat properly when the engine is put into service. ![image](https://global.discourse-cdn.com/cartalk/original/3X/8/0/801a88e8a07029088c748c8c2931184fb61b597e.jpeg) Tester ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [February 15, 2025, 2:48pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/8 "2025-02-15T14:48:34Z")
Google ‘honing alusil engine blocks’ and you’ll get links to BMW, Mercedes, and Audi forums with lots of information. Looks like you can hone, bore, and sleeve them, depending on condition. But it takes an expert shop to do that. ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [February 15, 2025, 4:55pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/9 "2025-02-15T16:55:54Z")
Look for a machine shop that does those engines, let the experts handle it from there… Why would some oil (ATF, Marvel) and Scotch-Brite or whatever pads and brake cleaner not clean them up enough to check for damage?? Machine shop is still your best option if you want it done right, might have to ship it to and from… Money? you are building a BMW, get over it… 🤪 Or save yourself a lot of money and LS swap it… lol ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [February 15, 2025, 6:43pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/10 "2025-02-15T18:43:12Z")
Based on this and your other post, it seems like you are the type who just wants to throw a lot of money at this project without first doing an analysis of what it really needs. For the brief time that it didn’t have oil pressure, you may have done damage to the valve train and not done any to the block or rings. But removing the heads will reveal this. Don’t teardown the block if you don’t need to. If you do need to replace the rings and the block still shows a good cross hatch pattern from the factory honing, you may be able to get away with a 600 grit diamond hone of the cylinder walls. This just removes the tops of the peaks of the old honing process and will allow the new rings to seat quickly. You will need to consult with a certified BMW mechanic on this. They may also be able to do the acid etch in the shop to expose the silicon crystals if needed. BTW silicone is the rubber sealant, silicon is a hard metal. ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [February 15, 2025, 6:43pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/11 "2025-02-15T18:43:52Z")
I see. Im not doing this myself lol!!! I just needed to know if honing these motors was even possible. I got the $$$. But if you cant hone them or bore these blocks i wasnt gonna worry about. But as long as its possible. ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [February 15, 2025, 6:44pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/12 "2025-02-15T18:44:37Z")
I see. Im not doing this myself lol!!! I just needed to know if honing these motors was even possible.im just tearing it down to inspect damage. I got the $$$. But if you cant hone them or bore these blocks i wasnt gonna worry about. But as long as its possible. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [February 15, 2025, 8:17pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/13 "2025-02-15T20:17:20Z")
Here’s a ton of info > **[What you need to know about boring/honing Alusli/ Nikasil blocks](https://www.bimmerforums.com/forum/showthread.php?2156918-What-you-need-to-know-about-boring-honing-Alusli-Nikasil-blocks)** > > Bimmerforums is the preferred online BMW Forum and community for BMW owners. At Bimmerforums, you will find technical how-to information maintenance specifics audio advice wheel and tire combinations and model specific details not found anywhere... ---
**Author:** ![Dakotawoodsusa\_192743](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dakotawoodsusa\_192743](https://community.cartalk.com/u/Dakotawoodsusa_192743)\ **Post date:** [February 15, 2025, 8:22pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/14 "2025-02-15T20:22:55Z")
Okay. Let me ask would the valve train create a knocking? When it was running there was knocking or a loud tapping? That’s what is leading me to believe it’s is possible it spun a rod quickly. Which I didn’t take the motor out of the car yet. I was asking questions before hand. I have only got the motor down to the intake manifold pulled out, along with fuel rail, Throttle body, sensors are all disconnected on the main wiring harness. Because that’s the only way to even get this intake manifold out. But along the way you have to remove the Valvetronic Motors to have enough room to get the fuel rail out. But I noticed scuffs on the eccentric gear I wish I could post photos because they look kinda bad and also on the valvetronic motor itself. ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [February 16, 2025, 5:28am UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/15 "2025-02-16T05:28:16Z")
There are so many things that can cause a knocking or tapping. I once had a timing gear that got loose and it sounded exactly like a spun rod bearing. Tightened down the gear and all was good. Is this one of those engines where the cam moves up and down to vary valve lift and duration? I would not know where to begin on troubleshooting one of those. I would suspect that your issues are there though rather than in the block. ---
**Author:** ![Darron](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/darron/32/21829_2.png) [@Darron](https://community.cartalk.com/u/Darron)\ **Post date:** [February 16, 2025, 8:50am UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/16 "2025-02-16T08:50:46Z")
If there’s damage the block is basically done for, I’ve seen them sleeved with varying degrees of success. To be honest there a very tough block and rarely show damage if everything else is something like and they haven’t been overheated. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [February 16, 2025, 12:12pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/17 "2025-02-16T12:12:23Z")
> [@Dakotawoodsusa\_192743](#): > > yes. i need to hone the block to check for damage or deep scratches, because im pretty sure piston rings are gone. due to car losing compression How do you know the engine lost compression? Did you run a test? How many cylinders low? Did you run a leak down test? ---
**Author:** ![Cavell](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cavell/32/43396_2.png) [@Cavell](https://community.cartalk.com/u/Cavell)\ **Post date:** [February 16, 2025, 4:17pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/18 "2025-02-16T16:17:30Z")
Sometimes a used motor is better option. Better, not best. ---
**Author:** ![old\_mopar\_guy](https://avatars.discourse-cdn.com/v4/letter/o/6bbea6/32.png) [@old\_mopar\_guy](https://community.cartalk.com/u/old_mopar_guy)\ **Post date:** [February 16, 2025, 4:22pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/19 "2025-02-16T16:22:11Z")
Or get a really big shoehorn and put in a 413 for some real grunt. ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [February 16, 2025, 4:58pm UTC](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146/20 "2025-02-16T16:58:36Z")
Naw, go with a 400 “B” block, takes up a little less room, throw a 4.250" stroker crank in a 0.040" over (4.380") bore for a stump pulling 512ci low deck big block Mopar… hehe But I like where you are going with it… 😉 [Next page](https://community.cartalk.com/t/honing-alusil-engine-blocks/199146.md?page=2)