Inline Pro vs Laskey block?
Banned
Joined: May 2002
Posts: 3,624
Likes: 11
From: Raleigh, NC
FRM is not a coating, it is a material.. like steel or aluminum.
It's an aluminum carbon fiber composite.
The frm is 3mm thick so you in theory could bore it quite a bit, but Mahle will only produce 0.25mm oversize pistons since thats all honda makes and no one has done any testing on anything bigger. I plan on getting a set of 88 and 89mm pistons made soon to actually do some reliability testing at larger bores on the stock sleeves, but that would take a while to complete, so 0.25mm over is what we have now.
FRM is what makes the sleeve strong, it is stronger than the standard iron that honda uses in their other blocks (k-series and b-series). When boring over you dont "hit" frm, you are always in the FRM until you go THROUGH the frm and get to bare aluminum.
It's an aluminum carbon fiber composite.
The frm is 3mm thick so you in theory could bore it quite a bit, but Mahle will only produce 0.25mm oversize pistons since thats all honda makes and no one has done any testing on anything bigger. I plan on getting a set of 88 and 89mm pistons made soon to actually do some reliability testing at larger bores on the stock sleeves, but that would take a while to complete, so 0.25mm over is what we have now.
FRM is what makes the sleeve strong, it is stronger than the standard iron that honda uses in their other blocks (k-series and b-series). When boring over you dont "hit" frm, you are always in the FRM until you go THROUGH the frm and get to bare aluminum.
Registered User
Joined: Jul 2003
Posts: 1,461
Likes: 3
From: Mill Creek
Seems to me that if you're going to go through the trouble of tearing the engine apart to bore it out....that you would just add the sleeves and get rid of the FRM all together...otherwise why bother?
Banned
Joined: May 2002
Posts: 3,624
Likes: 11
From: Raleigh, NC
IMHO unless you want to salvage a trashed block there is no reason to sleeve the block. Honda used FRM because its stronger than the normal steel sleeves they use in the k/b blocks and we all know the steel sleeves in the k blocks are very strong with a number of those guys making 7-800 hp for a very long time on stock sleeves.
Joined: Oct 2000
Posts: 9,033
Likes: 21
From: South of the pier, Huntington Beach, CA
IMHO unless you want to salvage a trashed block there is no reason to sleeve the block. Honda used FRM because its stronger than the normal steel sleeves they use in the k/b blocks and we all know the steel sleeves in the k blocks are very strong with a number of those guys making 7-800 hp for a very long time on stock sleeves.
What is your source for FRM being stronger than steel (or iron)?
Thread Starter
Registered User
Joined: Oct 2009
Posts: 951
Likes: 0
From: Trollywood
Really good info, thought the FRM were thin as coating and that´s why we had to sleeve every time the cylinder wall got damaged.
Good news actually, a cast factory sleeve will always seal better than pressed ones.
Good news actually, a cast factory sleeve will always seal better than pressed ones.
Banned
Joined: May 2002
Posts: 3,624
Likes: 11
From: Raleigh, NC
There have been many articles and such released by honda stating this. Back when H22's were first released and again when f23's and the s2000. They went to FRM so they could increase bore size with out increasing bore spacing. they were not able to do this with normal steel sleeves because they were not strong enough. They went with FRM because it is much stronger and allows for longer life and larger bore sizes.
