B18C1 Engine build Chuck Johnson

Project Honda Civic EJ:  Building the B18C1 Part III

By Chuck Johnson
Photos by Joe Lu

Last we left off, we had just figured out how to improve the rod ratio of Project Civic's B18C1 through the use of a Nissan QR25DE spec rod from K1 Technologies.  In short, to make this rather unorthodox marriage of Nissan and Honda components work, the factory B18C1 crankshaft's rod journals were modified along with the big end of the QR25DE connecting rod.  To help ensure marital harmony for years to come, a set of factory Honda connecting rod bearings were WPC treated and then installed in between the Honda crank and Nissan rod.  WPC treatment of Honda bearings can improve load bearing capacity by as much as 25% as well as reduce friction. The crank was also WPC treated as well to improve wear, increase fatigue strength and reduce friction.  For more details on how we made this long rod combo work, you can read up on part 2 of our engine build here.


You can read more about project EJ Civic here!


je pistons high compression b18c1

With the crank and rod situation figured out, there remained one missing link to make this exogamic marriage of Honda and Nissan components complete.  Without a piston that is shorter in compression distance, none of this long rod business would actually work.  Compression distance, also known as pin height, is the distance from the center of the piston's pin bore to its deck.  To figure out the new necessary compression distance is simple and can be calculated using the formula below.

(Block Height) – (Rod Length) – (½ Stroke) – (Deck Clearance) = Compression Distance

In our case, the new compression distance for our long rod pistons worked out as follows:

(8.340") – (5.630") – (3.433"/2) – (.005") = .989" Compression Distance

A compression distance of .989" is pretty short for an automotive street application.  Actually, it's about as short as one can go without ditching a compression ring, using pin buttons, or having an unacceptably small wrist pin diameter.  With the .989" compression height we didn't have to go to any of those extremes; however, the pin bore was run into the oil ring groove and it was necessary for us to run a rail support.

A detent as well as tension, locks the rail support in place and keeps it from rotating out of the opening. 

In cases where the pin bore crosses into the plain of the oil ring groove, an additional steel rail called a "rail support" is installed underneath the oil ring assembly.  Appropriately named, a rail support does just that, supports the oil ring rail and assembly across the opening in the ring groove caused by the pin bore.  Absence of a rail support would cause the oil ring assembly to essentially unwind itself and spiral through the opening in the ring groove. Simply put, this would lead to disaster. 


Having figured out conceptually how we were going to run our short .989" compression height, we turned to JE Pistons to design and manufacture a set of forged pistons for our long rod B18C1.  Since our B18C1 had seen over 200,000 miles of service, we decided to bore and hone our block to 81.5 mm before putting Humpty Dumpty back together again.  One of the side benefits of this increase in bore was a small increase in displacement of 22 cubic centimeters. Hey, it's not much but we'll take what we can get since this motor will be sucking instead of getting blown. We also WPC treated the bores after machining for less ring and skirt friction and longer life.  The WPC give longer ring, bore and piston life as the treated surface retains lubrication better and is inherently harder and slippery due to the process characteristics.

At the same time, we had JE pistons increase the compression ratio a point and a half to 11.5:1, which should still be street-able even with California's lousy 91 octane gas.  To round out the piston's features, JE Pistons coated the piston's skirts and machined an accumulator groove into the second ring land.  An accumulator groove is designed to increase the area under the first compression ring and reduce the chances of pressure build up and ring flutter at high RPM.  

A 9310 alloy steel wrist pin is used to join the K1 Technologies connecting rod with the forged JE piston.  Instead of the factory 21 MM diameter pin though, a 20 MM sized pin was selected.  Why?   A 20 MM pin is what the QR25DE uses from the factory.  With a decrease in wrist pin diameter, comes a slight decrease in strength and stiffness.  To compensate, a slightly thicker wall wrist pin was used in tandem with the higher strength 9310 material.

With all of the hardware now sourced for our bottom end, we were almost ready to begin its assembly.  Before beginning the assembly, since we wanted to be cautious that we had removed all of the WPC media from the block, we sent the block out to be ultrasonically cleaned and then gave it a good scrub down using a plastic bristled brush and liquid Tide.  It's important to hit the cylinder walls with WD-40 immediately after to prevent corrosion.  Lastly, we used smaller brushes to clean out the oil galleys of the block and also gave all of bottom end components one last cleaning.

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Monday, October 08, 2012 12:02 AM
Not sure if you guys line honed the main caps and block after using ARP main studs. The article doesn't mention this.
Mike Kojima
Mike Kojimalink
Monday, October 08, 2012 6:45 AM
We checked it, you only hone if you need it.
Dusty Duster
Dusty Dusterlink
Monday, October 08, 2012 1:23 PM
Wow, you can WPC-treat cylinder bores, too?
Chuck Johnson
Chuck Johnsonlink
Monday, October 08, 2012 4:16 PM
Yes. You can also WPC treat crankshafts, camshafts, camshaft journals, transmission gears, connecting rods, pistons, wrist pins, and bearings. I think I'm going to get my boxers WPC'd to reduced chaffing:)
Wes Dumalski
Wes Dumalskilink
Monday, October 08, 2012 4:54 PM
Reduced chafing huh? Do they use different media and micro bombardment techniques for the crotch and anus areas?

Seriously we should do a group buy on the above treatment!

That said great article and awesome pics.! Can't wait to see the final results and what this thing puts down power wise. My guess is 200+ WHP for the next 100,000 track miles! :)
Monday, October 08, 2012 7:44 PM
Chuck- trade secret... all the B series oil pumps are the same- non-VTEC, GSR, ITR. Ssshhh... :)

This is the parts page for a 97 CRV- it came with the non-VTEC B20 (84mm x 89mm) engine.


Quite a few of the old GSR block builders just blocked off the oil squirters. That's what I did- just ran Swain coatings on the pistons to keep everything happy. At large bores (85mm+) and pistons from 10 years ago, the skirts tended to knock the squirters off. Oops.
Chuck Johnson
Chuck Johnsonlink
Monday, October 08, 2012 8:11 PM
@Wes- thanks for the compliments. I'm fortunate enough to have my good buddy Joe Lu doing a lot of the photography. I have to give him credit for the good photos and take proper ownership of the bad ones. (Yes, the bad ones are mine.) If anyone ever needs photography work check out www.joeluphoto.com. [insert shameless plug here] Yes, I did just spam MotoIQ's comment section.

@buddha- Thanks for the clarification on the oil pump. The signal to noise ratio on Honda forums is a bit challenging to say the least especially for a "Nissan guy."

In regards to the oil squirters, it seems that removing them is common practice with a lot of stroker engine builds. I've never been a fan of removing squirters if at all avoidable. We've seen oil squirters reduce piston temperatures significantly, ultimately extending piston life. This is in ALMS and NASCAR applications though. I'm sure for what most of us are doing it will be fine.
Monday, October 08, 2012 11:34 PM
Chuck, no problem. I'd guess that 99.99% of the guys on the H-forums have never even dug around inside their engines, and just go by hear-say for their "facts". Most of the ones that really know their stuff aren't posting on the forums anyway. ;)

I don't know that I would call my old setup a stroker build, but it was an 89mm stroke x 85.5mm bore configuration inside of a GSR block (stock 87.2mm stroke) for 2044cc total. There wasn't much extra room in that crankcase. As far as piston temps, I didn't have any trouble with detonation even running 13:1 on pump gas, so I assume that the piston temps were ok without the squirters.
Tuesday, October 09, 2012 8:28 AM
The 'Type-R' oil pump supersedes the earlier pumps. There WAS an older design, Honda just doesn't sell it any more.
Mike Kojima
Mike Kojimalink
Tuesday, October 09, 2012 8:54 AM
Removing oil squirters is a no no except maybe for drag engines that don't have to run very long.
Tuesday, October 09, 2012 2:10 PM
WPC treating my underware would help tremendously. My lower cheek to thigh does get a bit chaffed. especially riding my bike 75 to 100 miles a week. Great write up Chuck! can't wait to see Annie Sam's civic come alive again!
Tuesday, October 09, 2012 6:37 PM
vehicular- I guess it's been that way for quite some time then... there's still a lot of noise on the forums about the R pump being something special compared to the non-R pump you would get at any dealership.

Kojima- I agree that they should be left in place if at all possible, but disagree that they're necessary for long engine life. My B20 block ran 9k all day long for 45k miles before I killed it on a mechanical overrev, and when it came apart everything inside still looked like new (except for the piston I bombed). No squirters. Ask Khiem- I loved that engine.
Wednesday, October 10, 2012 9:45 PM
I agree with Phunky.buddha, I've put together more than a few high revving B-series motors without squirters that are still running, are regularly abused, and have been for years without issue. I don't however remove them from motors that come with them though.

The oil pumps are different based on the years. OBD 1 pumps have a different part number than OBD2 pumps which is why the B20 is the same as the Type R pump. The difference is due to the casting changes that provide a provision for the TDC sensor that was removed from the distributor and bolted to the oil pump starting in 1996.

There is a lot of nonsense floating around on Honda forums but the info is available if you search the right posters or check the archives.

Mike if you guys want to borrow the degree kit designed for the b-series, contact Teddy @ Mavrik Motorsports and I'll see that you get it. It's what I use for my P2H and P2V.
Wednesday, October 10, 2012 9:57 PM
soulpwr, Thanks for the clarification on the oil pumps. That makes sense.

Kojima, talked with Khiem while hunting for ice cream sammiches for the wife- I wasn't thinking of high stress periodic revving (street driving, twisties playtime) as being equivalent to your drag racing example vs 20-30 minutes constant redline abuse on the road course, more just thinking of your "don't have to run very long" statement in terms of mileage only. Squirters are definitely nice to have and will always contribute to longer engine life, but there's honestly no way to tell if they're absolutely necessary for B block reliability unless I (or you) build a non-squirter Honda engine and really beat on it at the track. That's not going to happen on my end- I'm done with B blocks for my own cars.

Mike Kojima
Mike Kojimalink
Wednesday, October 10, 2012 11:03 PM
I have plenty of experience with piston failure on engines without squirters that were fixed by adding them. If the OEM's could save a penny by deleting a feature, they would do so. Also look at the strength to temp graphs of aluminum and you will know why there are squirters.
Monday, August 12, 2013 9:37 PM
hey guys, love the write up. if i may i have 2 questions...
1. when you clay'd the motor did you install the head right to the block or did you use a head gasket ?

2. what type of clay did you use, and where did you get it. I'm in the process of putting together a b18a myself and am going to have to do this step.

thanks and keep up the excellent work!
Friday, March 11, 2016 4:35 AM
I know this is a older build article. I just need to know something. What was your ARP main stud torque spec? I'm hearing a lot of different numbers... from 56 (Stock), to 65 ft.lb. to 80 ft.lb.(ARP recommendation).
Chuck Johnson
Chuck Johnsonlink
Friday, March 11, 2016 5:04 AM

Ultimately what you're trying to do is achieve a certain level of stretch in the fastener. Since you cant measure both ends like a connecting rod bolt, it's important that you instead use ARP torque specs along with the fastener lube that they supply. With ARP studs being a different material and design, OEM torques specs should have no bearing on what torque specs you install the ARP studs to. Hope that helps.
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