Since I get a good amount of questions through email and a need for information regarding Block Sleeving, I hope we can make this a Sticky.
Block sleeving is the process of replacing part of the stock cylinder walls and pressing in a new Iron Ductile Sleeve into the block.
As you can see, the Iron Ductile sleeves are much thicker than the stock Cylinders.
Here are the Sleeves out of the block, before installation.
When to sleeve a block?
There are 2 reasons why racers chose to sleeve a block.
1. To increase displacement with a bigger bore.
2. To Strengthen the block for high boost applications.
Increasing the displacement on a Honda/Acura block is achieved through bigger bore size pistons or stroking the motor through different rods length and modifications on the crank. But in this case, we are focusing on Sleeving the block, so bigger bore sizes usually increase 1.8L B18 blocks all the way to 2.1L and slightly more. Since stock Acura/Honda blocks can only go .5 to 1mm overbore, we would need to SLEEVE the block to be able to do 3mm and even up to 6mm overbore on these B-series motors.
This is a common thing to do in All Motor setups. B18 motors usually go 84mm to become a 2.0L, while a B16 with 84mm bore will be about 1.8L Max bore on All Motor Race setups are 87mm bore while reliable bore for the street maxes out at 84mm. In effect, the bigger displacement usually end up in higher torque numbers in these setups.
For D-series, all motor streetable max bore size is 77/78mm bore and maxes out to 79mm for more aggressive setups.
Bigger bore blocks are also done in Turbo setups. But bore size is kept usually at 84mm max to still have a thick sleeve for strength on these high boost/high pressure applications. I personally don’t feel the need for big bore on Turbo setups. Many racers have been successful in making large amounts of HP with just an 81 or 81.5mm bore.
One racer that we sponsor is Courtney Green from Utah. His 93 Civic HB was pushing out mid 600HP on just a sleeved block bored to an 81.5mm
At this time its best ¼ mile time is 10.21 And it’s a true daily driven car using pump gas when driving around town.
Now the other reason to sleeve a block is to strengthen the block to be able to handle the high pressures during boost. The stock sleeves can actually handle a good amount of pressure, but in very extreme conditions, wouldn’t you want peace of mind knowing the block is prepped with a Thick Sleeve to hold these pressures. At boost, the block experiences more pressure than normal and can cause distortion and movement of the walls due to the heat and pressure. With these sleeves, it prevents that and keeps the block in tact to handle more stress than normal.
Common question we get:
Whats the max boost you can put on a stock sleeved block and compare to a Sleeved block?
On a B-series motor, we have pushed the limits to the high teens. 17-18psi on a stock block and I’m sure some have done even more. It will work ok at the very best tuning conditions. But we do recommend SLEEVING the block when you are reaching 14+ psi. This will ensure you have the block ready for those extreme stress the block will go through at that much boost. A sleeved block can handle over 40psi of boost. But 99% of turbo setups, would not go past the 25-30psi range anyways, so the sleeves are adequate enough for many turbo motors out there. And Max bore we usually go with is 84mm.
On D-series blocks, 10-12psi is usually the max we take it up to. More than 12 psi, we recommend sleeving the block already. For D-series blocks, the most we’d go on a turbo setup is a 77mm bore. We actually prefer keeping the 75 or 75.5mm bore on turbo D-series since piston choices are easier at that bore size. Anything bigger than 75.5mm bore is usually Custom pistons and causes more money. As in my previous comment on big bore turbo blocks, its not necessary to go way bigger bore on the D-series as well since the cost effectiveness of it isn’t going to be that significant. So 75 or 75.5mm bore is good enough.
Here’s a picture of a Sleeved 78mm D-series block.
I can go more and more on this subject later on. We can keep adding more information as you guys ask more questions about Sleeving.
Exospeed Racing Products / Exospeed Race Engines
Custom Race Engines, block sleeving, and hardcore race parts.
Last edited by Exospeed*com; 09-12-2004 at 06:59 AM.