The machine shop was boring my block out to 75.25 mm, but they went too far on one cylinder. Now the plan is to bore the block out to either 75.5 mm or 76 mm. The 75.5 mm would be the honda oversize piston, and the 76 mm option would be a Nippon cast piston that has the same dome/dish/weight characteristics of oem. All other internals are oem. I am not running boost or anything crazy, but the engine will be run hard on the track.

My question is about reliability. Is sleeving the cylinders recommended for either 75.5 mm or 76 mm pistons?

 

If I'm not mistaken, 1mm over is the max but I'd need to verify with the FSM. If you have access to one you can look it up. If not, that info might be in a normal Chilton or Haynes manual.

If you don't have access to an FSM you should get one if plan on doing anything to your car. It's really helpful.

 

The manual says the reboring limit is .5 mm.

I've talked with one guy who says he has built a few d16a6 engines with a 1 mm overbore, without sleeving, and had no reliability problems. I was hoping to get a wider poll if others had similar or different experiences.

 

Anyone?

 

76mm has been done, but like the book says, its not really setup to take 1mm overbore on stock sleeves.
As engine builders, we never suggest that bore size for a stock sleeve. Also, keep in mind that each person's setup differs. That 76mm bore for a daily driven car may work but if its run hard, you have higher chance of failing. Its your call.

 

Confirmed, Honda FSM states .5mm over is the maximum limit.

 

Thank you, I know the FSM says .5 mm is the maximum. I could be way off base, but it seems to me that Honda wouldn't approve of a 1 mm piston when they don't make a 1 mm piston. Honda also doesn't offer a performance intake or exhaust for the crx, but that doesn't mean those parts can't be added without sacrificing reliability. There is 1 answer so far that 1 mm could affect reliability. I'm trying to get a wider poll, or maybe some input from someone with 1st hand experience. Thank you.

 

At this point its on you. thats your decision. 76mm on a stock sleeve has been done, but having 1st hand experience of our company building over 100 D-series engines for several years, I wouldnt recommend it.
Does it work for some people? yes it has. Is it recommended? Personally, I wouldnt do it.
Measure out a head gasket. See how much material is left in between the cylinders after you take out 1mm from each cylinder. 1mm may not be that big, but it can make a difference. The smaller gap you have between those cylinders, the higher chance of blowing head gaskets in that area. Thats your call.

 

Exo, don't get me wrong, I appreciate your advice. At this point I have 2 very credible opinions, but they are opposite opinions. It seems the right thing for me to do is try to gather more information, which is why I reposted asking for others to share their experiences.

 

Personally ive helped build alot of motors and if you bore at all and its your DD i suggest sleeve its a little more money ya but it reasures you of reliability and keeps it running that longer and stronger and gives you room to addon like methane injection and dont have to worry about your walls holdin up

 

WIL is right ,It'll work but for how LONG???I have done this 1mm over bore in my own set ups NO problem as of yet with plenty of DYNO passes @ PROSTREETIMPORT...b16a 82mm d16a6 76mm bore...

Now for a builder I would just go with 75.5 and call it a day if it's gonna be a DAILY but if you have a extra car then go 76mm Like i did since i have extra cars to drive...

 

This is my race car, it's not street legal. I figure on putting 25-30 hours on the engine each year, but they're hard miles. If I can get 2 or 3 years out of it before a rebuild, I'd be happy.