Hi, it is known that the B20 sleeves are weak due to their siamese design, and it's evident seeing how and where they crack. I was wondering if sleeving would solve the problem, but not using the known Darton or GE Sleeves due to availability. I'm very far from the US, so please do not suggest me getting a B18 block (non existant around here), sending my block to GE or buying Darton MIDs - it would be far more expensive. The idea is simple - boring the B20 to 85mm, sleeving it with a ductile iron or chrome-moly cylinder liner, and running 82mm pistons to achieve 1.9L. My concern is that the stress points would remain the same, but the sleeve liners would be independent, thus exerting force only on a couple of points instead of twisting the entire sleeve assembly when torsional or vibrational forces are applied. It may be overkill for my mostly-stock N/A setup (165-180whp, 8200rpm), but it makes sense money-wise and I do want it to be as reliable as the original B16A in the car. Changing a block in case of failure requires all sort of paperwork and some money, so I want this block to last. Does anyone has any experience with this type of "sleeving"? Would it solve the problem from an engineering standpoint?

 

Both Golden Eagle and Darton MID sleeves remove the entire factory sleeve pack and replace it with a different sleeve set. The MID's have the advantage of being able to remove one sleeve vs golden eagle where the whole pack has to be replaced if one is damage beyond boring. Your also referring to a sleeve liner but since the factory aluminum where the sleeve is retained is thin to begin with it can cause issues. I would recommend the MID's due to the ability to replace individual sleeves.

 

What in the literal ****.

You want to take a B20 block, and sleeve it down to a GSR bore so you can make 180whp?

I refuse to believe you are unable to source a B18 block. You can't have one shipped to you?

 

Sleeving a B20 block still does not eliminate the weaker saddle area of the block. Bottom Line: A B20 block with the same modifications as a B18 block will ALWAYS be weaker. The sleeving will reduce the potential sleeve splitting issue, but doesn't guarantee no chance of block failure.
With that said, your HP target doesn't really stress the factory B20 sleeve or saddle area... so as long as you stay NA, and you keep the ignition timing at safe values, it is unlikely that you will have a block related failure. No aftermarket sleeving will be necessary. Spend your money on the internal parts.

 

Yes, that is exactly what I want to do. I absolutely do not want this block to fail as finding a replacement would be very difficult and I would have to go through all the hassle and money to register another block twice. Having a B18 block shipped to me would cost at the very least three times more than what a sleeving work like this would cost, not to mention all the paperwork to import used goods, which is a grey area law-wise. If it was a viable option I wouldn't even have posted this question. Not everyone lives where you can go to a junkyard and buy this stuff for $100 and swap it without any issues.

 

I see, it would reduce the chances but it wouldn't be bulletproof. I may be wrong but the sleeve would probably crack where it does originally, but under the liner. It wouldn't be an instant failure but it would eventually get to the point of breakage where it would either leak coolant or interfere with the outer liner fitment. I see there is another type of sleeving like the Benson and LA sleeves that look similar as the Darton Dry Sleeves, but I'm not sure how it is machined as they apparently do not remove the entire sleeve pack as GE does. I could get a custom sleeve set designed and it would be far cheaper than importing a set of Dartons as it's common practice here to save a variety of blocks. I tried to find any videos of the process so I could understand it and tell the sleeve manufacturer what would be needed. If I could get this block as strong as a stock B16A block I would be happy.