D16a6 Piston Bore 73mm?

[89' Project Civic]

I have a D16a6 and I checked the piston bore, because I am rebuilding it, and it read at 73.0mm. The standard bore indicates it has to be 75.0mm so I am very confused!. Any suggestions will be greatly taken.

 

[phunky.buddha]

All Honda D series engines are 75.0mm bore from the factory.

 

[89' Project Civic]

I think it is the build up residue from the combustion in the cylinders taking 1mm off on each side. Could that possibly be it?.

 

[K2e2vin]

You shouldnt' have 1mm thick of residue.

What tools are you using to measure and how accurate are they?

 

[89' Project Civic]

I'm using a mechanical ruler type measuring unit. I don't know if this is why I am getting a wrong reading or not. Which measuring unit should I use?.

 

[89' Project Civic]

By residue I mean the 4-5mm area that the piston makes the combustion. It's from the deck top down to about 5mm. I am going to take it to my local machine shop and see what they think. They are getting business from me anyway so they shouldn't mind measuring the bore size.

 

[Crx Kid22]

use a dial-caliper

 

[89' Project Civic]

Ok, I will try that I need to buy -or- borrow one anyway for this build so I may as well spend the $40 to pick one up. Also, is there a tool that fits into your cylinder bore that you move up and down, then pull out and take a micrometer to?. I saw one in a rebuild write-up once.

 

[89' Project Civic]

I just got back from the machine shop and the guy tested it with a meter that goes right into the bore and we found out that at the top of the piston (near the deck) the measurement is 73mm and in the middle and towards the bottom the measurement is 75mm. He told me that the Honda blocks tend to go "egg shaped", so I'm going to do a fresh bore to 75.5mm and everything should be just fine to accept my new pistons. I also got a good price on Honda OEM rebuild kit from him so this should really work out good. The price he gave me was $175 CAD for the pistons, rings, and pins (I believe the pins come with it). Thanks for helping me out.

 

[K2e2vin]

use a dial-caliper

You're supposed to use a cylinder bore dial. A vernier caliper won't fit in there as you're supposed to measure in 3 spots.

Glad to hear you got all that sorted out. GL on your rebuild.

 

[89' Project Civic]

Thanks bud, I thought I'd leave it up to the real professionals to check that shit out. I'm very happy that I have it all figured out. What do you think of the rebuild kit costing $175 Canadian Dollars. I think it's pretty good. He said that his warehouse in Toronto makes the pistons like Honda does if not better. He is a mechinist after-all and I'm sure he wouldn't sell me junk.