90 CRX Si cylinder boring disaster

[CivicFerio]

I bored out my D16A6 cylinders today to accept .020 inch factory over size pistons but screwed up on the last hole #2 using those Kwik-way boring bars.

For some odd reason the boring bar didn't want to align and only cut out 3/4 of the diameter of the cylinder.. I tried aligning it over 5 times and I know I did it right, I don't know if the cylinder is shaped like an egg or something.. I ended up boring it out to 2.9770in from my planned 2.9700 to be able to cut all the way around..

Now my problem is should I buy .040in pistons or resleeve the cylinder? I'm also worried about if my boring was off then the piston will be slighly off center from the rest, is this very critical?

I hope you guys can help me.. Thank you

Charleston

[jasonb]

The easiest thing to do would be go .040" over. I would rule out the resleeving. If the .040" doesnt workout, just find another block. They are cheap and easy to find. Just go to a honda forum and find someone who went hybrid on their crx.

[CivicFerio]

Thanks for the reply... Where do you get the .040 over pistons?? JE and Arias only makes up to .020inch over for my application... I searched and I can only find pistons in this site http://www.rivergate5speed.com/honda_performance.html

Is there any other manufacturers that sells .040 over pistons and how much am I looking at here? Thanks

Charleston

[Greg Gauper]

Try OPM Motorsports.

[Greg Gauper]

Oops! I checked their site. They have .040" over pistons listed for 1st Gen Civic/CRX's, carb'd & FI, but they don't list pistons for 2nd gen CRX's. You still might give them a call.

King Motorsports might be able to help you out as well.

[jasonb]

The only place that I know has them for sure is Rivergate. But yes, try King and OPM. If they don't havem them, they surely can get htme or get in contact with someone who sells them.

[B Breon]

Believe it or not, but JC Whitney sells a kit for a D16A6 at .040 made by Topline out of Illinois. The kit is pistons, rings, and pins. They are cast, not forged, if that matters. Stock is cast.

[metalworker]

I'm not a Honda expert, but I hope you are using a boring plate. On that motor, there is nothing supporting the top of the cylinders, so they move around when you are machining.

[CivicFerio]

Hello, Thanks guys for responding.. I made a few phone calls today and this is what I found out.

King Motor Sports do sell 90 CRX .040 over pistons but cost $550 a set which includes rings and pins. It is made to order so it will take them 3-4 weeks to make them.

Rivergate ran out of stock and will not have the .040 piston in 4 weeks but they only cost $160 with rings.

OPM said they can get the over sized pistons for me in a couple of days. They cost $250 with rings.

I contacted a local engine parts supply and they can get me .040 pistons with rings for $210 the next day but I don't know the manufacturer yet..

If I start over a Japanese D15B long block which cost $175 but I'm unsure if the blocks are identical I only know the stroke is different.

Right now I'm leaning towards the OPM pistons since they are a reputable company and I just want to finish my darn engine.

All the piston I inquired are cast aluminum but what is the difference between the King Motor Sports piston and the Rivergate piston besides the huge price gap?

Can an average Joe tell them apart by performance?

And is there a possibility that some shops are getting their pistons from the same manufacturer??

Thanks for your input

Charleston

[CivicFerio]

B Breon,

I tried doing a search on JC Whitney and this is the only piston they have http://www.jcwhitney.com/product.jhtml?CAT...requestid=16962

I can't seem to find any Topline pistons on the web. If you have a link please post it. Thanks

metalworker,

I haven't heard of boring plates but are those the same as torque plates used for the V8s? I know torque plates used in V8 block is to simulate a head on the block. Because the head bolts tend to distort the cylinder walls so in theory everything will be round on the final assembly.

Charleston

[Greg Gauper]

Are they forged vs. cast?

Forged pistons ARE legal in IT.

[Dom Pirinchinci]

1. Always bore or hone with a plate to simulate the effect of the cylinder head and bolts. A nice piece of 1/2" plate with some holes milled /drilled in it works well. If you're really cool, you do it with the engine block warmed up somehow (to best represent operating conditions).

2. Try calling Summit or Jeg's or CV for pistons. They may not list them in their All- Chevy, All-the-Time Drag Race catalogs, but they can get anything that their suppliers make, and places like Silv-O-Lite make replacement Honda pistons in several overbores(My latest Silvo catalog only shows D15 slugs for 4G Civics, but it's an older catalog).

3. The reason why your bore didn't clean up might be because it was egg-shaped (and if that's the case, it's a good thing you cleaned it up), but that much radial out-of-round is ALOT. Like, you could see that with the naked eye. From across the room. Without glasses. Even though you are sure that you lined it up right, check the center-to-center distance of 2 vs 1 and 3 vs. 3 and 4 (big height gage on a surface plate, edge finder in a Bridgeport, whatever). If it is shifted, your next overbore may follow it, and the loads transitted by the piston and rod can side-load your rod bearings, or cause excessive rubbing between the crank and the thrust face of the rod. Better to discover that now, and go junkyard shopping for a new block than at the end of Race #1 next season when the engine starts making one of those expensive knocking sounds on the cool down lap.

4. Sleeving bad. D16's cheap.

[This message has been edited by Dom Pirinchinci (edited October 22, 2002).]