boomslang

Many people put B18c or Z10 girdles on their frankenstein motors, but fail to take a few important steps. Here is my write up of the right way to do it. I more or less took FFgeoff's and sgT's advice and applied it.

The #2, #3, and #4 main caps are too high on an LS/CRV motor to bolt a factory B18c girdle on. All three of these caps have to be milled to the same height. Caps #3 and #4 are shown below. Cap #2 is the same height as #4.



After you measure what you need to take off of the caps, set them in the mill vise on top of two dowel pins. If the caps are allowed to sit on the factory pressed in bushings, they won't necessarily sit level. The pics below show a mockup of the cap on pins and then the cap in the mill vise. All caps need to be milled in a vise on top of dowel pins.





On the #2 and #4 caps, a small amount has to be milled on them to make the girdle sit properly on them. Mill them to the same height as the main bolt contact areas. The milled #2 cap is shown below.



Clearance between the milled #4 cap and girdle is shown below.



Now, you are ready to mill the #3 cap. It's the tallest one of the three. You need to be very precise when doing this. Failure to do so could cause the girdle to not function properly and/or a ruined main cap. Use a sharp cutter and make shallow passes.



Pic of milled caps below.



Now comes the important step many people skip. Reaming the caps to accept the bushings. B18c's use 4 large bushings, and 2 smaller bushings. However, the main caps of LS/CRV motors are not wide enough in the center to utilize the smaller bushings. Instead, I decided to use six large bushings and no small bushings. The six large bushings go in the six main cap bolt holes. Here is a pic of the six bushings needed.



You need a 13mm straight flute chucking reamer to ream the holes in the main caps for the bushings. You must use a dial indicator to center over the existing holes properly.





*Caution*: The reamer will have to be stoned down slightly to the proper size to allow the bushings to snugly slip into the main caps. Using a brand new 13mm reamer will ream the holes too large and there will be excessive play between the hole and bushing. Trial and error on scrap steel is the best way to find the proper size hole for the bushings. You want them to slip in snugly, not so tight that they have to be forced in. Use calipers to measure the depth you need to ream to. The reamed #4 cap holes are shown below.



There is more reaming to do. Remember how the B18c uses only four of the larger bushings? Well, the girdle has to be reamed to accept the two additional bushings that I added. The stock girdle is below. The holes on the lowest row of the outer edges are what need to be reamed.



The 13mm reamer will have to be stoned to an even smaller size than before. The bushings are pressed into the girdle. You need a smaller hole for the press fit, obviously. Trial and error on scrap to find the proper size. A dial indicator must be used to center over the holes properly. Measure ream depths carefully with calipers.

Now that is done, you need to press the six bushings into the girdle. Finished product shown below.



And a close up.



Now you are done. Bolt it to your block with B18c main studs and have a machine shop line bore your mains. Finished.

BROOD

Thank you, I'm so glad someone agrees that this is the correct way and with such nice photos to show too

Speed PHreak

Holy dowel pins batman!

Nice write up.....Guess i'll have to put dowels in mine if/when I tear down for a rebuild. Would have been nice to know this little tid bit 6 months ago when I put my girdle in....

I'd still perfer to mill the girdle, guess i'll have to dowel the #2 and 4 caps instead of all three.

boomslang

They are bushings!



(proper machine shop talk)

Full-Race Geoff

dude change your tag under your screen name from future b20 badass to modern b20 badass.


for real, that is KILLER, great work good pictures. Its wonderful to see other guys doin machine work!!!

boomslang

Thanks for the compliments!

Arturbo

Very true rustin. I love it when people post stuff like this so people like me can learn.

art

cornbread

Nice right up but i went the easy way and just bought the Z10 girdel. I haven’t installed it yet but it's a direct bolt on from what i know.

Speed PHreak

You'll still need to dowel the Z10 girdle, if this is the now accepted way to do it. FFgeoff has some thoughts on that i'm sure......

X2BOARD

Oh Oh... GREAT POST...


OOoo... do my girdle baby ! Yeah !

I don't have access to those kinds of tools... much less a decent work area to do anything !

How would I managed to do this myself ? I do my own engine work for the most part, and have done a bit of head/port work, but no longer have access to the machining/grinding tools.

Where can I get this type of work done PROPERLY like InlineFour did it here ?

What is a line bore on the main cap done ? Would I have to explain all of this to a machinist ?

Hey, InlineFour..... interested in making some money, Heh heh ? I have 2 girdles ready to go !

X2

Arturbo

Who isnt interested in making money..

H23ludedude

I can't wait to see the numbers that thing puts down. Rustin, you can do some incredible things with the cars you work with.

ion_four

Very good write-up. I don't have a B20 (may never?) and I don't have a machine shop, but it's still interesting to see how things are done right

boomslang

Okay, I'm blushing now.

boomslang

Line boring is when they machine the main bearing surfaces. It makes sure the bearing surfaces are flat and square with each other so bearings do their job properly. Without line boring, you could cause a bearing to cook/spin because of improper lubrication.

I'm doing an internship at an automotive R&D place. They've got all kinds of heavy duty machinery I can use. When I get sick of working on stuff for the C6 vette, I just go out to the machine shop and start messing around.

I might be able to machine your girdle/caps. I'll think about it.

Ricky Rojales

Man, I love this place (HT)! Nice post, sir!

Dublocivic

First off I would like to say that the write-up is great.. nice and complete! Thanks for the Doweling for Dummies.. it helps guys like me make the right choices.
Secondly (for anyone) I was curious I am going with a 84.5mm GE setup on my b16 and I was curious as if I would even need to put a girdle on..? I wont be going over 95-9700 rpms, with power output around 500-550 to the wheels. I understand that the mains will distort with high hp/rpm applications but since the b16 has minimal cyl wall side-loading, would the girdle would be a necessity with the stated power output?

ccjb100

I'd like to know about this also....

BTW, great write-up!! Very well done...

Beave0101

I think i emailed z10 a while back about what modifications must be done to the girdle and they said it is strictly bolt-on, UNLIKE the b18c one.........thats why they designed it. My world has yet again been turned upside down.


[Modified by Beave0101, 6:13 AM 8/29/2002]

earl

Great write up! Thanks

Speed PHreak

Don't worry too much, this is the BEST way to do it, but not the only way. I shaved to girdle and installed it with no dowel on mine. I couldn't afford to pull the whole engine out at the time and do it this way. I actually installed my block girdle and some ARP rod bolts while he engine was still in the car.....

CHEETAH

iTrader: (2)

nice writeup ...

the Z10 girdles are bolt-ons however still should check play between girdle and cap.

greg

boomslang

Yes, but it should still have the bushings installed in it.

sgT

The only addition i would make is that i would have bost sides of those dowels
press fit as the factory ones are press fit on both sides. but otherwise an excellent
write up

boomslang

They are press fit on both sides? I contemplated doing that, but the precision it would take to have 12 press fit holes line up, along with the whole assembly actually fitting back on the block properly, would be, uh, amazing. The factory Honda girdle isn't manufactured very precise to begin with.

Honda doesn't press fit the main caps on both sides (obviously), so I saw no reason to press fit the girdle to both sides.

Thoughts from any machinists out there?